Estimation of the total antioxidant potential in the meat samples using thin-layer chromatography
-
Paweł Piszcz
Abstract
There is limited literature on the antioxidative properties of food of animal origin. Measurements of antioxidative properties are usually performed using the reaction of reduction of colored 2,2-diphenyl-1-picrylhydrazyl (DPPH) radials. Changes of the DPPH color are tracked photometrically. These measurements are interfered by both, the tested samples and reduced DPPH. This study aims to demonstrate the ability to separate different forms of DPPH (DPPH• and DPPH-H) by thin-layer chromatography (TLC). Further, it has been practically applied in the study of the determination of antioxidative properties of the meat samples. It was found that TLC can be used for the separation of different forms of DPPH as well as for measurement of TAP (total antioxidant potential) values related to the DPPH•. The strongest antioxidant properties were observed for pork neck extracted in buffer pH 2 and for smoked salmon fish extracted in acetone, the lowest for veal and turkey fillet extracted in methanol.
1 Introduction
Free radicals are molecules, ions, atoms or groups of atoms having, on the valence shell (or orbital) one, or more, unpaired electron, giving them paramagnetic properties. Often they are highly reactive, unstable and undergoing oxidation and/or reduction reactions. They impair the structure of cell membranes, lipids, proteins and nucleic acids in the cells. As a result, they can cause damage of the vital functions of cells, tissues of the body and the whole body [1].
Living organisms developed many defense mechanisms to protect themselves against free radicals. The defense system of living organisms against free radicals can be divided into three stages: (i) preventing the generation of free radicals (e.g., chelators of transition metals), (ii) removing radicals (antioxidants or scavengers of the free radicals) or (iii) repairing system of damages [2]. According to [3] antioxidant is “any substance that delays, prevents, or removes oxidative damage to a target molecule”. Maintaining a balance between free radicals and antioxidants is essential to maintaining the health.
In the literature, it is observed that the increased interest in compounds (antioxidants) intended to prevent the harmful effects of free radicals on the human body. The current concern is focused on the vegetables, fruits, herbs, spices and honey [4]. There is very little information available on the antioxidative properties of food of animal origin. It should be noted here that after slaughter, a number of uncontrolled chemical reactions (acidification, oxidation, etc.) run in the meat. Next, during the meat preparation for the human consumption, changes in muscle fibers and connective tissue microstructure cause changes in the meat antioxidative properties [5].
Meat is essential for the proper functioning of the human body. Meat from the slaughtered animals contains healthy proteins and essential amino acids (needed to build tissues that the human body cannot create itself). From a nutritional point of view, meat is also a source of minerals [6]. It contains a lot of antioxidants, such as carotenoids (β-carotene, zeaxanthin, lutein), the unsaturated aliphatic compounds (characterized by orange-pink color) and vitamins A and E [7]. Vitamin E (α-tocopherol) is the most active lipophilic antioxidant in the human body. It is soluble in fats and most of the organic solvents. Carnosine is a basic dipeptide and it is also the major non-protein nitrogen-containing compound in the skeletal muscles of vertebrates [8]. It is soluble in water and can catalyze lipid oxidation by free radicals. Its concentration depends on age, race, gender, and color of meat. Vitamin C (ascorbic acid) is involved in the metabolism and biochemical reactions, like a synthesis of hormones or biosynthesis of collagen. It forms an oxidation-reduction buffer of blood plasma and forms the first line of defense against free radicals in the cytoplasm. Glutathione is a tripeptide consisting of glycine, cysteine, and glutamate. Inside the living organisms, it is available in several forms - reduced (GSH), oxidized (GSSG), S-nitrosoglutathione (GSNO) and the mixture of glutathione disulfide and proteins [9]. It is the most important part of the antioxidant system, maintaining the balance between free radicals and antioxidants. Heat treatment, such as cooking, significantly reduces the concentration of antioxidants [10, 11].
DPPH• is a free radical and a scavenger for other radicals. It can be either reduced or oxidized. Reactions on the surface of the electrode in the first stage lead to the formation of an anion DPPH- or cation DPPH+. In the solution, it can be oxidized by strong oxidants, such as hydroxyl radicals, or reduced by antioxidants. Its reduction is, usually, based on the acceptance of a hydrogen atom. It may be a multi-stage reaction. In such case, the electron will be first accepted into the DPPH• molecule, followed by the proton, or vice versa. These reactions strongly depend on the environment in which they run, as it was discussed in detail in the paper [12].
The DPPH• are used as (i) an external standard of electron paramagnetic resonance (EPR) and (ii) to determine sample cleavage [13]. During reduction they change the color. They are used to the photometric or chromatographic estimation of the total antioxidant potential (TAP). Therefore, they are also used to determine total antioxidant potential (TAP) by photometric method [14, 15]. In our previous paper, we have used the TLC for the determination of the oxidized form of DPPH [16]. In this case, the TAP measure was the change of absorbance of the DPPH• spot which is correlated to the change of the DPPH• concentration after its reaction with antioxidants. It is worth to note that previously DPPH• was used to visualize spots on the TLC plate (yellow spots on a purple background) [17].
Measurements of antioxidative properties are usually based on the reduction of colored DPPH•. Changes of the DPPH• color are observed photometrically. The TAP measure is the decrease of absorption at l = 517 nm, after the reaction between radicals and sample. These measurements are interfered by both, the tested samples and reduced DPPH.
The aim of this study was to (i) develop an assay for determining total antioxidant potential [4, 17, 18] related to the DPPH• and (ii) evaluation of antioxidant properties of different kinds of meat. This includes (i) the separation of different forms of DPPH• using TLC; (ii) examine the possibility of determining the TAP by TLC (the TAP measure was the reduction in the absorption at l = 517 nm after the DPPH• reaction with the sample) and (iii) the use of the developed method for the determination of TAPs of meat products.
The aim of this study was to improve the assay for TAP [4, 16, 18, 19] related to the DPPH•. Conditions for the separation of various forms of DPPH were developed. The effect of mixtures of various solvents and the values of their Hildebrand coefficients on the selectivity of the chromatographic system was investigated. The elaborated method was practically used to evaluate the antioxidant properties of various meat species.
2 Materials and methods
2.1 Instrumentation
Samples were prepared using ultrasonic bath UM-0,5 (Unitra-Unima, Olsztyn, Poland), and centrifuge MPW-251 (MPW Med. Instruments, Warsaw, Poland). Measurements were performed using the DS-II-5x10 or DS-II-20x20 (Chromdes, Lublin, Poland) TLC chambers and Helios Epsilon spectrophotometer (Thermo Spectronic, Rochester, NY, USA). Samples were separated on 5 cm x 10 cm commercial glass plates precoated with 0.25 mm layers of silica gel 60 or silica gel 60 F254 and RP-18W modified silica gel coated with fluorescent indicator F254 plates (Merck, Darmstadt, Germany). The chromatograms were scanned using HP Scanjet G210, with software Scion Image and ImageJ [16].
2.2 Reagents
Gallic acid, 96.6% ethanol, 2-propanol, disodium hydrogen phosphate, dihydrogen sodium phosphate (Chempur, Piekary Śląskie, Poland), HCl, NaOH (POCh, Gliwice, Poland), acetone, n-hexane, methanol, DPPH - 2,2-diphenyl-1-picrylhydrazyl, acetonitrile (Sigma-Aldrich, St. Louis, MO, USA), acetone (StanLab, Lublin, Poland) were of analytical-reagent grade and were used without further purification. Water was three times distilled in a quartz apparatus. Solvents were filtered through a (0.22 μm) membrane filter (Millipore, Bedford, USA).
2.3 Samples
The research material consisted of two types of poultry (turkey and chicken fillets), beef (sirloin, veal) and pork (neck, shoulder) meat sample and smoked salmon meat. The meat was bought from the butcher shop at Siedlce (Poland).
2.4 Raw samples preparation
Extracts of the meat at a concentration of 0.5 g/mL were prepared by dissolving 2 g of thawed, minced meat (60 seconds milling) in 4 mL of solvent (methanol, ethanol, hexane, acetone, acetonitrile, water or 0.01 M HCl, pH 2). The meat extracts were placed in an ultrasonic bath, filtered and centrifuged (3 min; 18000 r/min). Such prepared test material was stored tightly in aluminum foil in the refrigerator at a temperature of +5○C.
2.5 TAP measurements
The sample solution (200 mL) was mixed with 100 mL of 1 mM DPPH• in methanol. The mixture was shaken vigorously and left for 5 min at the room temperature in the dark. It turned out that absorbance decreased for five minutes reaching an asymptote. For chromatographic separation 5 μL volume of the sample solutions were applied to the plates as spots with a syringe (Hamilton, Bonaduz, Switzerland). The normal (NP) and reversed (RP-18W) plates were developed after saturation of the tanks with mobile phase vapor for 0.5 h. A TAP of meat samples was determined by measuring the intensity of the purple spots of DPPH•, which turns to the light yellow of DPPH-H. After separation, the plates were dried at ambient temperature for 0.5 h and the surface of each plate was scanned in 8-bit resolution RGB color mode, in the direction of chromatogram development, by means of an HP Scanjet G2410 scanner equipped with Windows-compatible Scion Image software.
As a preliminary study, a method of separation of reduced and oxidized forms of DPPH was elaborated. The influence of the chromatographic conditions for separation (chamber saturated or unsaturated, normal (NP) or reversed (RP-18W) phase systems, the effect of temperature, mobile phase composition, and multiple development techniques) were investigated [16]. The developed method was used to determine the TAPs of meats. Unless it will be specified otherwise the measurements were performed on the NP or RP-18W plates at 20○C, in a saturated chamber, using the mobile phase hexane/acetone (4:1, v/v). A solution of DPPH• in methanol was used as a control sample. The chromatograms were scanned at a resolution of 300 dpi, 24 million colors mode and stored in TIFF formats.
The results are expressed as gallic acid equivalent (GAE) [mg of gallic acid on g of sample]:
where: αGA and αi denote slopes of the calibration curves of gallic acid or investigated sample, respectively.
2.6 Statistical analysis
The measurements of the antioxidant capacity were repeated three times for each sample and the results were averaged and expressed relative to the average result for the control samples containing no analyte. The significance of differences between means was determined by Student’s t-test at p < 0.05. In all cases, the percent relative standard deviation (RSD) did not exceed 10%.
3 Results and discussion
At the beginning, conditions for the chromatographic separation of various forms of DPPH were developed. The dependence of the inverse of retardation factor, Rf, of DPPH• on the inverse of the acetone concentration is shown in Figure 1 and the dependence of the retardation factor on the Hildenbrand parameter in Figure 2. In the first case, a linear correlation, in the second one the inverse proportionality was found. The dependence of the ratio (as well as the difference) of the retardation factors of DPPH• and DPPH-H on the Hildebrand parameter is presented in Figure 3. In both, normal and reversed phase, no elution of DPPH• was observed in hexane. From the other side, the maximal elution (no retention) (Rf ≈ 1) was observed in the pure polar solvents (methanol, acetonitrile, acetone, dichloromethane or 2-propanol). Water could not be used as the mobile phase due to the insolubility of the DPPH•. An exemplary TLC plate is shown in Figure 4.
Dependence of the inverse of retardation factor of DPPH•, 1/Rf, on the inverse of the concentration of acetone, 1/C. Chromatographic conditions: NP plate, temp. +20○C, saturated chamber.
Dependence of the retardation factor, Rf, on the Hildenbrand parameter, δ. Tested mixtures - methanol/water, acetonitrile/water, acetonitrile/methanol, hexane/acetone, hexane/acetone/ethanol. Chromatographic conditions: RP-18W plate, temp. +20○C, saturated chamber.
Dependence of the ratio (●, black line) and the difference (▲, gray line) of RfDPPH• and RfDPPH-H on the Hildebrand parameter, d. Chromatographic conditions: NP plate (left picture), RP (right), temp. +20○C, saturated chamber.
Separation of DPPH• (lower, purple spot) from DPPH-H (upper, yellow spot). Chromatographic conditions: plate – RP-18W (left), NP (right), temp. +20○C; mobile phase - hexane/acetone (20:80% v/v); chamber – saturated.
The antioxidant properties (TAP) of meat are caused by the presence of various compounds in the sample, i.e., enzymatic antioxidants as well as small-molecule ones, soluble in water or in lipids. Therefore, it is impossible to obtain complete information about the sample antioxidant activity just using one extraction solvent. The TAP value depends on extraction conditions and type of meat. The TAP values of various meats after extraction using different solvents are presented in Figure 5, as a function of the time of extraction are presented in Figure 6.
TAP values (GAE) of various meats (500 mg/mL) after extraction using different solvents (x - methanol, ▲ - water, ■- buffer pH 2, ♦ - hexane, ●- acetone).
The dependence of TAP values on the time of extraction in methanol. Meat samples (500 mg/mL): sirloin of beef (white), chicken fillet (gray), pork shoulder (black).
The retardation factor, Rf, depends on the mobile phase, especially on the used solvent. If, as a mobile phase the mixture of two solvents is used, then Rf depends on their relative concentrations. It was found that there is a linear correlation between 1/Rf of DPPH• and inverse of the concentration of less polar solvent in the mobile phase, as it is presented for the normal phase system in Figure 1. However, concentration as the measure of the mobile phase polarity can be easily used only in binary systems. When the mobile phase consists of more than two components or if we want to compare the different phases then it should be used an universal parameter describing the polarity of the mobile phase. We found that the retention of DPPH• was strongly dependent on the δ - Hildebrand polarity parameter (Figure 2). In the reversed phase system (e.g. using the RP-18W plates) Rf increased with the decrease of the δ parameter. As the mobile phases the mixtures of methanol/water, acetonitrile/water, acetonitrile/methanol, hexane/acetone and hexane/acetone/ethanol were investigated. It turned out that, in this case, the Hildebrand parameter is a good measure of the polarity of the solvent mixtures as well as retardation factor. The best separation was obtained at the average values of the Hildebrand coefficients (Figure 3).
For the binary mixtures, such as methanol/water (5 to 20% of water) a slight decrease of the retardation factor (from 0.9 to 0.67) was observed with the increase of water concentration. It means that the retardation factor decreases with the increase of the concentration of more polar solvent. The addition of water caused a slight separation of the two forms of DPPH from each other. However, the better separation was achieved using a mixture of hexane and acetone. Spots on the plates RP-18W are narrower and less pronounced than on NP ones (Figure 4). In addition, to the spots originating from the oxidized and reduced forms of DPPH there are other spots (pink and brown). Multiple developing does not improve the separation.
The TAP values depend on the type of meat and its preparation (extraction conditions). Among them, the samples extracted in methanol (Figure 5), are characterized by the highest total antioxidant activities. They are in the range of 52.43 GAE for smoked salmon and 2.57 GAE obtained for pork. It was found that the concentration of polyphenols is not correlated with the TAPDPPH values of meat extracted in methanol. The TAP values of water extracts ranged from 31.24 GAE for chicken fillet to 23.52 GAE of turkey fillet.
It turned out that the results obtained with TLC are, on average, 1.8 times higher than those obtained with the classical photometric technique. For example, the TAP [GAE] values for chicken fillet were equal 21,43 and 11,56 using TLC and photometric methods, respectively. The corresponding results for the pork neck were 12.62 and 6.96, respectively. This is due to the fact that TAP is directly proportional to the difference in spot surface area of DPPH• recorded without or with the sample. Smaller disturbances caused by the sample and the reduced form of the radicals increase the TAP values. This proves that the use of TLC is more advantageous than the photometric method.
For various meats (Figure 6A) as well as for various solvents (Figure 6B) it was found that the TAPs go through a maximum in a function of time of extraction. Initially (approx. until 5 min) with the increase of extraction time it was observed an increase of the TAP values (Figure 6). Extraction time increased the amount of leached compounds. However, further prolongation of the extraction decreases TAPs due to the oxidation of antioxidants, for example by oxygen. It turned out that similar dependencies were observed for different types of meat (Figure 6A) and various solvents used for extraction (Figure 6B). At the optimal time of extraction (5 min), the use of methanol as a solvent is preferred. It is worth to note that the antioxidative activity of meat depends also on the chemical reactions during processing and storage of meat, as well as the additives used. They cause the formation of MRPs (Maillard Reaction Products), that is the products of Maillard reaction - the reaction between amino acids and sugars. Approximately in 5 min, there is an increase antioxidant activity of certain proteins due to changes occurring in their second, third and fourth-row structure [20, 21]. Too slow freezing/thawing of meat may cause water leakage, together with the dissolved antioxidants. The antioxidant activity of lean meat (veal or poultry) is relatively weak. Pork is the delicate bright red color meat, the intergrown with fat, forming a soft consistency [22]. It is a good source of selenium. Fat contains approx. 50% of unsaturated fatty acids, polyunsaturated from 7 - 14%, and monounsaturated fatty acids 41 - 52%. The most valuable meat, with an average calorific value, is the beef [23]. Fish is a source of vitamins, minerals, and proteins [24]. The content of antioxidants of extracts of different kinds of meat is depending on the solvent used for extraction (Figure 5). The highest TAP was observed for salmon fish extracted in acetone (57.16 GAE) and buffer pH 2 (49.94 GAE).
The dependence of TAP of chicken fillet (500 mg/mL) on time of extraction in acetone (white), methanol (gray) and hexane (black).
4 Conclusions
It was found that TLC can be used for the separation of different forms of DPPH• as well as for the measurements of TAP values related to the DPPH•. The elaborated method was used to test the antioxidant properties of meat. Although meat is not characterized by the strongest antioxidant properties, it is consumed in much larger quantities by the average person than, for example, herbs. The highest antioxidant activity was observed for smoked salmon fish extracted in acetone (probably this is due to the fact that it contains the liquid smoke [25]) and for pork neck extracted in buffer pH 2, the lowest for veal and turkey fillet extracted in methanol. It turned out that the TAPs obtained with TLC are higher than those obtained using photometric method. This means that the separation of the DPPH• from its derivatives and sample components improves the selectivity of the TAP measurement.
Conflict of interest: Authors declare no conflict of interest.
References
[1] Halliwell B, Gutteridge JM. Free radicals in biology and medicine. Edition no. 2. Oxford, UK: Clarendon Press; 1989.Search in Google Scholar
[2] Głód BK, Czapski GA, Haddad PR. Application of high-performance liquid chromatography to the investigation of free radical reactions in biological systems, TrAC –. Trends Analyt Chem. 2000;19(8):492–7.10.1016/S0165-9936(00)00018-2Search in Google Scholar
[3] Halliwell B, Gutteridge JM. Free radicals in biology and medicine. Oxford, UK: Oxford University Press; 2015. https://doi.org/10.1093/acprof:oso/9780198717478.001.000110.1093/acprof:oso/9780198717478.001.0001Search in Google Scholar
[4] Głód BK, Kiersztyn I, Piszcz P. Total antioxidant potential assay with cyclic voltammetry and/or differential pulse voltammetry measurements. J Electroanal Chem (Lausanne). 2014;719:24–9.10.1016/j.jelechem.2014.02.004Search in Google Scholar
[5] Yu TY, Morton JD, Clerens S, Dyer JM. Cooking-induced protein modifications in meat. Compr Rev Food Sci Food Saf. 2017;16(1):141–59.10.1111/1541-4337.12243Search in Google Scholar
[6] Rojas MC, Brewer MS. Effect of natural antioxidants on oxidative stability of cooked, refrigerated beef and pork. J Food Sci. 2007 May;72(4):S282–8.10.1111/j.1750-3841.2007.00335.xSearch in Google Scholar
[7] Balentine CW, Crandall PG, O’Bryan CA, Duong DQ, Pohlman FW. The pre- and post-grinding application of rosemary and its effects on lipid oxidation and color during storage of ground beef. Meat Sci. 2006 Jul;73(3):413–21.10.1016/j.meatsci.2005.12.003Search in Google Scholar
[8] Aruoma OI, Laughton MJ, Halliwell B. Carnosine, homocarnosine and anserine: could they act as antioxidants in vivo? Biochem J. 1989 Dec;264(3):863–9.10.1042/bj2640863Search in Google Scholar
[9] Anderson ME. Determination of glutathione and glutathione disulfide in biological samples. Methods Enzymol. 1985;113:548–55.10.1016/S0076-6879(85)13073-9Search in Google Scholar
[10] Forman HJ, Zhang H, Rinna A. Glutathione: overview of its protective roles, measurement, and biosynthesis. Mol Aspects Med. 2009 Feb-Apr;30(1-2):1–12.10.1016/j.mam.2008.08.006Search in Google Scholar PubMed PubMed Central
[11] Circu ML, Aw TY. Glutathione and apoptosis. Free Radic Res. 2008 Aug;42(8):689–706.10.1080/10715760802317663Search in Google Scholar PubMed PubMed Central
[12] Foti MC. Use and abuse of the DPPH(•) radical. J Agric Food Chem. 2015 Oct;63(40):8765–76.10.1021/acs.jafc.5b03839Search in Google Scholar PubMed
[13] Sharma OP, Bhat TK. DPPH antioxidant assay revisited. Food Chem. 2009;113(4):1202–5.10.1016/j.foodchem.2008.08.008Search in Google Scholar
[14] Badarinath AV, Rao KM, Chetty CM, Ramkanth S, Rajan TV, Gnanaprakash K. A review on in-vitro antioxidant methods: comparisons, correlations, and considerations. Int J Pharm Tech Res. 2000;2:1276–85.Search in Google Scholar
[15] Brainina KZ, Ivanova AV, Sharafutdinova EN, Lozovskaya EL, Shkarina EI. Potentiometry as a method of antioxidant activity investigation. Talanta. 2007 Jan;71(1):13–8.10.1016/j.talanta.2006.03.018Search in Google Scholar PubMed
[16] Głód BK, Wantusiak PM, Piszcz P, Lewczuk E, Zarzycki PK. Application of micro-TLC to the total antioxidant potential (TAP) measurement. Food Chem. 2015 Apr;173:749–54.10.1016/j.foodchem.2014.10.058Search in Google Scholar PubMed
[17] Cieśla Ł, Kryszeń J, Stochmal A, Oleszek W, Waksmundzka-Hajnos M. Approach to develop a standardized TLC-DPPH• test for assessing free radical scavenging properties of selected phenolic compounds. J Pharm Biomed Anal. 2012 Nov;70:126– 35.10.1016/j.jpba.2012.06.007Search in Google Scholar PubMed
[18] Masek A, Chrzescijańska E, Zaborski M. Antioxidative properties of silymarin, 7-aminoflavone, neohesperidin, dihydrochalcone and trihydroxyethylenorutin studied by the electrochemical methods. Int J Electrochem Sci. 2014;9:7875–89.Search in Google Scholar
[19] Ferreira RD, Greco SJ, Delarmelina M, Weber KC. Electrochemical quantification of the structure/antioxidant activity relationship of flavonoids. Electrochim Acta. 2015;163:161–6.10.1016/j.electacta.2015.02.164Search in Google Scholar
[20] Michalska A, Zieliński H. Produkty reakcji Maillarda w żywności, (Maillard reaction products in food), Food, Sci., Technol. Qual. [in Polish] 2007;2:5–16.Search in Google Scholar
[21] Serpen A, Gökmen V, Fogliano V. Total antioxidant capacities of raw and cooked meats. Meat Sci. 2012 Jan;90(1):60–5.10.1016/j.meatsci.2011.05.027Search in Google Scholar PubMed
[22] Haak L, Raes K, Smet K, Claeys E, Paelinck H, De Smet S. Effect of dietary antioxidant and fatty acid supply on the oxidative stability of fresh and cooked pork. Meat Sci. 2006 Nov;74(3):476–86.10.1016/j.meatsci.2006.04.018Search in Google Scholar PubMed
[23] Descalzo AM, Rossetti L, Grigioni G, Irurueta M, Sancho AM, Carrete J, et al. Antioxidant status and odour profile in fresh beef from pasture or grain-fed cattle. Meat Sci. 2007 Feb;75(2):299–307.10.1016/j.meatsci.2006.07.015Search in Google Scholar PubMed
[24] Łuczyńska J, Tońska E, Borejszo Z. Zawartość makro- i mikroelementów oraz kwasów tłuszczowych w mięśniach łososia (Salmo Salar L.), pstrąga tęczowego (Oncorhynchus Mykiss Walb.) i karpia (CyprinusCarpio L.), (Content of macro-and microelements, and fatty acids in muscles of salmon (Salmo Salar L.), rainbow trout (Oncorhynchus Mykiss Walb.), and carp (Cyprinus Carpio L.)), Food, Sci., Technol. Qual. [in Polish] 2011;3:162–72.Search in Google Scholar
[25] Bölicke SM, Ternes W. Isolation and identification of oxidation products of guaiacol from brines and heated meat matrix. Meat Sci. 2016 Jul;117:18–26.10.1016/j.meatsci.2016.02.031Search in Google Scholar PubMed
© 2020 Paweł Piszcz, Magdalena Tomaszewska, Bronisław K. Głód, published by De Gruyter
This work is licensed under the Creative Commons Attribution 4.0 International License.
Articles in the same Issue
- Regular Articles
- Electrochemical antioxidant screening and evaluation based on guanine and chitosan immobilized MoS2 nanosheet modified glassy carbon electrode (guanine/CS/MoS2/GCE)
- Kinetic models of the extraction of vanillic acid from pumpkin seeds
- On the maximum ABC index of bipartite graphs without pendent vertices
- Estimation of the total antioxidant potential in the meat samples using thin-layer chromatography
- Molecular dynamics simulation of sI methane hydrate under compression and tension
- Spatial distribution and potential ecological risk assessment of some trace elements in sediments and grey mangrove (Avicennia marina) along the Arabian Gulf coast, Saudi Arabia
- Amino-functionalized graphene oxide for Cr(VI), Cu(II), Pb(II) and Cd(II) removal from industrial wastewater
- Chemical composition and in vitro activity of Origanum vulgare L., Satureja hortensis L., Thymus serpyllum L. and Thymus vulgaris L. essential oils towards oral isolates of Candida albicans and Candida glabrata
- Effect of excess Fluoride consumption on Urine-Serum Fluorides, Dental state and Thyroid Hormones among children in “Talab Sarai” Punjab Pakistan
- Design, Synthesis and Characterization of Novel Isoxazole Tagged Indole Hybrid Compounds
- Comparison of kinetic and enzymatic properties of intracellular phosphoserine aminotransferases from alkaliphilic and neutralophilic bacteria
- Green Organic Solvent-Free Oxidation of Alkylarenes with tert-Butyl Hydroperoxide Catalyzed by Water-Soluble Copper Complex
- Ducrosia ismaelis Asch. essential oil: chemical composition profile and anticancer, antimicrobial and antioxidant potential assessment
- DFT calculations as an efficient tool for prediction of Raman and infra-red spectra and activities of newly synthesized cathinones
- Influence of Chemical Osmosis on Solute Transport and Fluid Velocity in Clay Soils
- A New fatty acid and some triterpenoids from propolis of Nkambe (North-West Region, Cameroon) and evaluation of the antiradical scavenging activity of their extracts
- Antiplasmodial Activity of Stigmastane Steroids from Dryobalanops oblongifolia Stem Bark
- Rapid identification of direct-acting pancreatic protectants from Cyclocarya paliurus leaves tea by the method of serum pharmacochemistry combined with target cell extraction
- Immobilization of Pseudomonas aeruginosa static biomass on eggshell powder for on-line preconcentration and determination of Cr (VI)
- Assessment of methyl 2-({[(4,6-dimethoxypyrimidin-2-yl)carbamoyl] sulfamoyl}methyl)benzoate through biotic and abiotic degradation modes
- Stability of natural polyphenol fisetin in eye drops Stability of fisetin in eye drops
- Production of a bioflocculant by using activated sludge and its application in Pb(II) removal from aqueous solution
- Molecular Properties of Carbon Crystal Cubic Structures
- Synthesis and characterization of calcium carbonate whisker from yellow phosphorus slag
- Study on the interaction between catechin and cholesterol by the density functional theory
- Analysis of some pharmaceuticals in the presence of their synthetic impurities by applying hybrid micelle liquid chromatography
- Two mixed-ligand coordination polymers based on 2,5-thiophenedicarboxylic acid and flexible N-donor ligands: the protective effect on periodontitis via reducing the release of IL-1β and TNF-α
- Incorporation of silver stearate nanoparticles in methacrylate polymeric monoliths for hemeprotein isolation
- Development of ultrasound-assisted dispersive solid-phase microextraction based on mesoporous carbon coated with silica@iron oxide nanocomposite for preconcentration of Te and Tl in natural water systems
- N,N′-Bis[2-hydroxynaphthylidene]/[2-methoxybenzylidene]amino]oxamides and their divalent manganese complexes: Isolation, spectral characterization, morphology, antibacterial and cytotoxicity against leukemia cells
- Determination of the content of selected trace elements in Polish commercial fruit juices and health risk assessment
- Diorganotin(iv) benzyldithiocarbamate complexes: synthesis, characterization, and thermal and cytotoxicity study
- Keratin 17 is induced in prurigo nodularis lesions
- Anticancer, antioxidant, and acute toxicity studies of a Saudi polyherbal formulation, PHF5
- LaCoO3 perovskite-type catalysts in syngas conversion
- Comparative studies of two vegetal extracts from Stokesia laevis and Geranium pratense: polyphenol profile, cytotoxic effect and antiproliferative activity
- Fragmentation pattern of certain isatin–indole antiproliferative conjugates with application to identify their in vitro metabolic profiles in rat liver microsomes by liquid chromatography tandem mass spectrometry
- Investigation of polyphenol profile, antioxidant activity and hepatoprotective potential of Aconogonon alpinum (All.) Schur roots
- Lead discovery of a guanidinyl tryptophan derivative on amyloid cascade inhibition
- Physicochemical evaluation of the fruit pulp of Opuntia spp growing in the Mediterranean area under hard climate conditions
- Electronic structural properties of amino/hydroxyl functionalized imidazolium-based bromide ionic liquids
- New Schiff bases of 2-(quinolin-8-yloxy)acetohydrazide and their Cu(ii), and Zn(ii) metal complexes: their in vitro antimicrobial potentials and in silico physicochemical and pharmacokinetics properties
- Treatment of adhesions after Achilles tendon injury using focused ultrasound with targeted bFGF plasmid-loaded cationic microbubbles
- Synthesis of orotic acid derivatives and their effects on stem cell proliferation
- Chirality of β2-agonists. An overview of pharmacological activity, stereoselective analysis, and synthesis
- Fe3O4@urea/HITh-SO3H as an efficient and reusable catalyst for the solvent-free synthesis of 7-aryl-8H-benzo[h]indeno[1,2-b]quinoline-8-one and indeno[2′,1′:5,6]pyrido[2,3-d]pyrimidine derivatives
- Adsorption kinetic characteristics of molybdenum in yellow-brown soil in response to pH and phosphate
- Enhancement of thermal properties of bio-based microcapsules intended for textile applications
- Exploring the effect of khat (Catha edulis) chewing on the pharmacokinetics of the antiplatelet drug clopidogrel in rats using the newly developed LC-MS/MS technique
- A green strategy for obtaining anthraquinones from Rheum tanguticum by subcritical water
- Cadmium (Cd) chloride affects the nutrient uptake and Cd-resistant bacterium reduces the adsorption of Cd in muskmelon plants
- Removal of H2S by vermicompost biofilter and analysis on bacterial community
- Structural cytotoxicity relationship of 2-phenoxy(thiomethyl)pyridotriazolopyrimidines: Quantum chemical calculations and statistical analysis
- A self-breaking supramolecular plugging system as lost circulation material in oilfield
- Synthesis, characterization, and pharmacological evaluation of thiourea derivatives
- Application of drug–metal ion interaction principle in conductometric determination of imatinib, sorafenib, gefitinib and bosutinib
- Synthesis and characterization of a novel chitosan-grafted-polyorthoethylaniline biocomposite and utilization for dye removal from water
- Optimisation of urine sample preparation for shotgun proteomics
- DFT investigations on arylsulphonyl pyrazole derivatives as potential ligands of selected kinases
- Treatment of Parkinson’s disease using focused ultrasound with GDNF retrovirus-loaded microbubbles to open the blood–brain barrier
- New derivatives of a natural nordentatin
- Fluorescence biomarkers of malignant melanoma detectable in urine
- Study of the remediation effects of passivation materials on Pb-contaminated soil
- Saliva proteomic analysis reveals possible biomarkers of renal cell carcinoma
- Withania frutescens: Chemical characterization, analgesic, anti-inflammatory, and healing activities
- Design, synthesis and pharmacological profile of (−)-verbenone hydrazones
- Synthesis of magnesium carbonate hydrate from natural talc
- Stability-indicating HPLC-DAD assay for simultaneous quantification of hydrocortisone 21 acetate, dexamethasone, and fluocinolone acetonide in cosmetics
- A novel lactose biosensor based on electrochemically synthesized 3,4-ethylenedioxythiophene/thiophene (EDOT/Th) copolymer
- Citrullus colocynthis (L.) Schrad: Chemical characterization, scavenging and cytotoxic activities
- Development and validation of a high performance liquid chromatography/diode array detection method for estrogen determination: Application to residual analysis in meat products
- PCSK9 concentrations in different stages of subclinical atherosclerosis and their relationship with inflammation
- Development of trace analysis for alkyl methanesulfonates in the delgocitinib drug substance using GC-FID and liquid–liquid extraction with ionic liquid
- Electrochemical evaluation of the antioxidant capacity of natural compounds on glassy carbon electrode modified with guanine-, polythionine-, and nitrogen-doped graphene
- A Dy(iii)–organic framework as a fluorescent probe for highly selective detection of picric acid and treatment activity on human lung cancer cells
- A Zn(ii)–organic cage with semirigid ligand for solvent-free cyanosilylation and inhibitory effect on ovarian cancer cell migration and invasion ability via regulating mi-RNA16 expression
- Polyphenol content and antioxidant activities of Prunus padus L. and Prunus serotina L. leaves: Electrochemical and spectrophotometric approach and their antimicrobial properties
- The combined use of GC, PDSC and FT-IR techniques to characterize fat extracted from commercial complete dry pet food for adult cats
- MALDI-TOF MS profiling in the discovery and identification of salivary proteomic patterns of temporomandibular joint disorders
- Concentrations of dioxins, furans and dioxin-like PCBs in natural animal feed additives
- Structure and some physicochemical and functional properties of water treated under ammonia with low-temperature low-pressure glow plasma of low frequency
- Mesoscale nanoparticles encapsulated with emodin for targeting antifibrosis in animal models
- Amine-functionalized magnetic activated carbon as an adsorbent for preconcentration and determination of acidic drugs in environmental water samples using HPLC-DAD
- Antioxidant activity as a response to cadmium pollution in three durum wheat genotypes differing in salt-tolerance
- A promising naphthoquinone [8-hydroxy-2-(2-thienylcarbonyl)naphtho[2,3-b]thiophene-4,9-dione] exerts anti-colorectal cancer activity through ferroptosis and inhibition of MAPK signaling pathway based on RNA sequencing
- Synthesis and efficacy of herbicidal ionic liquids with chlorsulfuron as the anion
- Effect of isovalent substitution on the crystal structure and properties of two-slab indates BaLa2−xSmxIn2O7
- Synthesis, spectral and thermo-kinetics explorations of Schiff-base derived metal complexes
- An improved reduction method for phase stability testing in the single-phase region
- Comparative analysis of chemical composition of some commercially important fishes with an emphasis on various Malaysian diets
- Development of a solventless stir bar sorptive extraction/thermal desorption large volume injection capillary gas chromatographic-mass spectrometric method for ultra-trace determination of pyrethroids pesticides in river and tap water samples
- A turbidity sensor development based on NL-PI observers: Experimental application to the control of a Sinaloa’s River Spirulina maxima cultivation
- Deep desulfurization of sintering flue gas in iron and steel works based on low-temperature oxidation
- Investigations of metallic elements and phenolics in Chinese medicinal plants
- Influence of site-classification approach on geochemical background values
- Effects of ageing on the surface characteristics and Cu(ii) adsorption behaviour of rice husk biochar in soil
- Adsorption and sugarcane-bagasse-derived activated carbon-based mitigation of 1-[2-(2-chloroethoxy)phenyl]sulfonyl-3-(4-methoxy-6-methyl-1,3,5-triazin-2-yl) urea-contaminated soils
- Antimicrobial and antifungal activities of bifunctional cooper(ii) complexes with non-steroidal anti-inflammatory drugs, flufenamic, mefenamic and tolfenamic acids and 1,10-phenanthroline
- Application of selenium and silicon to alleviate short-term drought stress in French marigold (Tagetes patula L.) as a model plant species
- Screening and analysis of xanthine oxidase inhibitors in jute leaves and their protective effects against hydrogen peroxide-induced oxidative stress in cells
- Synthesis and physicochemical studies of a series of mixed-ligand transition metal complexes and their molecular docking investigations against Coronavirus main protease
- A study of in vitro metabolism and cytotoxicity of mephedrone and methoxetamine in human and pig liver models using GC/MS and LC/MS analyses
- A new phenyl alkyl ester and a new combretin triterpene derivative from Combretum fragrans F. Hoffm (Combretaceae) and antiproliferative activity
- Erratum
- Erratum to: A one-step incubation ELISA kit for rapid determination of dibutyl phthalate in water, beverage and liquor
- Review Articles
- Sinoporphyrin sodium, a novel sensitizer for photodynamic and sonodynamic therapy
- Natural products isolated from Casimiroa
- Plant description, phytochemical constituents and bioactivities of Syzygium genus: A review
- Evaluation of elastomeric heat shielding materials as insulators for solid propellant rocket motors: A short review
- Special Issue on Applied Biochemistry and Biotechnology 2019
- An overview of Monascus fermentation processes for monacolin K production
- Study on online soft sensor method of total sugar content in chlorotetracycline fermentation tank
- Studies on the Anti-Gouty Arthritis and Anti-hyperuricemia Properties of Astilbin in Animal Models
- Effects of organic fertilizer on water use, photosynthetic characteristics, and fruit quality of pear jujube in northern Shaanxi
- Characteristics of the root exudate release system of typical plants in plateau lakeside wetland under phosphorus stress conditions
- Characterization of soil water by the means of hydrogen and oxygen isotope ratio at dry-wet season under different soil layers in the dry-hot valley of Jinsha River
- Composition and diurnal variation of floral scent emission in Rosa rugosa Thunb. and Tulipa gesneriana L.
- Preparation of a novel ginkgolide B niosomal composite drug
- The degradation, biodegradability and toxicity evaluation of sulfamethazine antibiotics by gamma radiation
- Special issue on Monitoring, Risk Assessment and Sustainable Management for the Exposure to Environmental Toxins
- Insight into the cadmium and zinc binding potential of humic acids derived from composts by EEM spectra combined with PARAFAC analysis
- Source apportionment of soil contamination based on multivariate receptor and robust geostatistics in a typical rural–urban area, Wuhan city, middle China
- Special Issue on 13th JCC 2018
- The Role of H2C2O4 and Na2CO3 as Precipitating Agents on The Physichochemical Properties and Photocatalytic Activity of Bismuth Oxide
- Preparation of magnetite-silica–cetyltrimethylammonium for phenol removal based on adsolubilization
- Topical Issue on Agriculture
- Size-dependent growth kinetics of struvite crystals in wastewater with calcium ions
- The effect of silica-calcite sedimentary rock contained in the chicken broiler diet on the overall quality of chicken muscles
- Physicochemical properties of selected herbicidal products containing nicosulfuron as an active ingredient
- Lycopene in tomatoes and tomato products
- Fluorescence in the assessment of the share of a key component in the mixing of feed
- Sulfur application alleviates chromium stress in maize and wheat
- Effectiveness of removal of sulphur compounds from the air after 3 years of biofiltration with a mixture of compost soil, peat, coconut fibre and oak bark
- Special Issue on the 4th Green Chemistry 2018
- Study and fire test of banana fibre reinforced composites with flame retardance properties
- Special Issue on the International conference CosCI 2018
- Disintegration, In vitro Dissolution, and Drug Release Kinetics Profiles of k-Carrageenan-based Nutraceutical Hard-shell Capsules Containing Salicylamide
- Synthesis of amorphous aluminosilicate from impure Indonesian kaolin
- Special Issue on the International Conf on Science, Applied Science, Teaching and Education 2019
- Functionalization of Congo red dye as a light harvester on solar cell
- The effect of nitrite food preservatives added to se’i meat on the expression of wild-type p53 protein
- Biocompatibility and osteoconductivity of scaffold porous composite collagen–hydroxyapatite based coral for bone regeneration
- Special Issue on the Joint Science Congress of Materials and Polymers (ISCMP 2019)
- Effect of natural boron mineral use on the essential oil ratio and components of Musk Sage (Salvia sclarea L.)
- A theoretical and experimental study of the adsorptive removal of hexavalent chromium ions using graphene oxide as an adsorbent
- A study on the bacterial adhesion of Streptococcus mutans in various dental ceramics: In vitro study
- Corrosion study of copper in aqueous sulfuric acid solution in the presence of (2E,5E)-2,5-dibenzylidenecyclopentanone and (2E,5E)-bis[(4-dimethylamino)benzylidene]cyclopentanone: Experimental and theoretical study
- Special Issue on Chemistry Today for Tomorrow 2019
- Diabetes mellitus type 2: Exploratory data analysis based on clinical reading
- Multivariate analysis for the classification of copper–lead and copper–zinc glasses
- Special Issue on Advances in Chemistry and Polymers
- The spatial and temporal distribution of cationic and anionic radicals in early embryo implantation
- Special Issue on 3rd IC3PE 2020
- Magnetic iron oxide/clay nanocomposites for adsorption and catalytic oxidation in water treatment applications
- Special Issue on IC3PE 2018/2019 Conference
- Exergy analysis of conventional and hydrothermal liquefaction–esterification processes of microalgae for biodiesel production
- Advancing biodiesel production from microalgae Spirulina sp. by a simultaneous extraction–transesterification process using palm oil as a co-solvent of methanol
- Topical Issue on Applications of Mathematics in Chemistry
- Omega and the related counting polynomials of some chemical structures
- M-polynomial and topological indices of zigzag edge coronoid fused by starphene
Articles in the same Issue
- Regular Articles
- Electrochemical antioxidant screening and evaluation based on guanine and chitosan immobilized MoS2 nanosheet modified glassy carbon electrode (guanine/CS/MoS2/GCE)
- Kinetic models of the extraction of vanillic acid from pumpkin seeds
- On the maximum ABC index of bipartite graphs without pendent vertices
- Estimation of the total antioxidant potential in the meat samples using thin-layer chromatography
- Molecular dynamics simulation of sI methane hydrate under compression and tension
- Spatial distribution and potential ecological risk assessment of some trace elements in sediments and grey mangrove (Avicennia marina) along the Arabian Gulf coast, Saudi Arabia
- Amino-functionalized graphene oxide for Cr(VI), Cu(II), Pb(II) and Cd(II) removal from industrial wastewater
- Chemical composition and in vitro activity of Origanum vulgare L., Satureja hortensis L., Thymus serpyllum L. and Thymus vulgaris L. essential oils towards oral isolates of Candida albicans and Candida glabrata
- Effect of excess Fluoride consumption on Urine-Serum Fluorides, Dental state and Thyroid Hormones among children in “Talab Sarai” Punjab Pakistan
- Design, Synthesis and Characterization of Novel Isoxazole Tagged Indole Hybrid Compounds
- Comparison of kinetic and enzymatic properties of intracellular phosphoserine aminotransferases from alkaliphilic and neutralophilic bacteria
- Green Organic Solvent-Free Oxidation of Alkylarenes with tert-Butyl Hydroperoxide Catalyzed by Water-Soluble Copper Complex
- Ducrosia ismaelis Asch. essential oil: chemical composition profile and anticancer, antimicrobial and antioxidant potential assessment
- DFT calculations as an efficient tool for prediction of Raman and infra-red spectra and activities of newly synthesized cathinones
- Influence of Chemical Osmosis on Solute Transport and Fluid Velocity in Clay Soils
- A New fatty acid and some triterpenoids from propolis of Nkambe (North-West Region, Cameroon) and evaluation of the antiradical scavenging activity of their extracts
- Antiplasmodial Activity of Stigmastane Steroids from Dryobalanops oblongifolia Stem Bark
- Rapid identification of direct-acting pancreatic protectants from Cyclocarya paliurus leaves tea by the method of serum pharmacochemistry combined with target cell extraction
- Immobilization of Pseudomonas aeruginosa static biomass on eggshell powder for on-line preconcentration and determination of Cr (VI)
- Assessment of methyl 2-({[(4,6-dimethoxypyrimidin-2-yl)carbamoyl] sulfamoyl}methyl)benzoate through biotic and abiotic degradation modes
- Stability of natural polyphenol fisetin in eye drops Stability of fisetin in eye drops
- Production of a bioflocculant by using activated sludge and its application in Pb(II) removal from aqueous solution
- Molecular Properties of Carbon Crystal Cubic Structures
- Synthesis and characterization of calcium carbonate whisker from yellow phosphorus slag
- Study on the interaction between catechin and cholesterol by the density functional theory
- Analysis of some pharmaceuticals in the presence of their synthetic impurities by applying hybrid micelle liquid chromatography
- Two mixed-ligand coordination polymers based on 2,5-thiophenedicarboxylic acid and flexible N-donor ligands: the protective effect on periodontitis via reducing the release of IL-1β and TNF-α
- Incorporation of silver stearate nanoparticles in methacrylate polymeric monoliths for hemeprotein isolation
- Development of ultrasound-assisted dispersive solid-phase microextraction based on mesoporous carbon coated with silica@iron oxide nanocomposite for preconcentration of Te and Tl in natural water systems
- N,N′-Bis[2-hydroxynaphthylidene]/[2-methoxybenzylidene]amino]oxamides and their divalent manganese complexes: Isolation, spectral characterization, morphology, antibacterial and cytotoxicity against leukemia cells
- Determination of the content of selected trace elements in Polish commercial fruit juices and health risk assessment
- Diorganotin(iv) benzyldithiocarbamate complexes: synthesis, characterization, and thermal and cytotoxicity study
- Keratin 17 is induced in prurigo nodularis lesions
- Anticancer, antioxidant, and acute toxicity studies of a Saudi polyherbal formulation, PHF5
- LaCoO3 perovskite-type catalysts in syngas conversion
- Comparative studies of two vegetal extracts from Stokesia laevis and Geranium pratense: polyphenol profile, cytotoxic effect and antiproliferative activity
- Fragmentation pattern of certain isatin–indole antiproliferative conjugates with application to identify their in vitro metabolic profiles in rat liver microsomes by liquid chromatography tandem mass spectrometry
- Investigation of polyphenol profile, antioxidant activity and hepatoprotective potential of Aconogonon alpinum (All.) Schur roots
- Lead discovery of a guanidinyl tryptophan derivative on amyloid cascade inhibition
- Physicochemical evaluation of the fruit pulp of Opuntia spp growing in the Mediterranean area under hard climate conditions
- Electronic structural properties of amino/hydroxyl functionalized imidazolium-based bromide ionic liquids
- New Schiff bases of 2-(quinolin-8-yloxy)acetohydrazide and their Cu(ii), and Zn(ii) metal complexes: their in vitro antimicrobial potentials and in silico physicochemical and pharmacokinetics properties
- Treatment of adhesions after Achilles tendon injury using focused ultrasound with targeted bFGF plasmid-loaded cationic microbubbles
- Synthesis of orotic acid derivatives and their effects on stem cell proliferation
- Chirality of β2-agonists. An overview of pharmacological activity, stereoselective analysis, and synthesis
- Fe3O4@urea/HITh-SO3H as an efficient and reusable catalyst for the solvent-free synthesis of 7-aryl-8H-benzo[h]indeno[1,2-b]quinoline-8-one and indeno[2′,1′:5,6]pyrido[2,3-d]pyrimidine derivatives
- Adsorption kinetic characteristics of molybdenum in yellow-brown soil in response to pH and phosphate
- Enhancement of thermal properties of bio-based microcapsules intended for textile applications
- Exploring the effect of khat (Catha edulis) chewing on the pharmacokinetics of the antiplatelet drug clopidogrel in rats using the newly developed LC-MS/MS technique
- A green strategy for obtaining anthraquinones from Rheum tanguticum by subcritical water
- Cadmium (Cd) chloride affects the nutrient uptake and Cd-resistant bacterium reduces the adsorption of Cd in muskmelon plants
- Removal of H2S by vermicompost biofilter and analysis on bacterial community
- Structural cytotoxicity relationship of 2-phenoxy(thiomethyl)pyridotriazolopyrimidines: Quantum chemical calculations and statistical analysis
- A self-breaking supramolecular plugging system as lost circulation material in oilfield
- Synthesis, characterization, and pharmacological evaluation of thiourea derivatives
- Application of drug–metal ion interaction principle in conductometric determination of imatinib, sorafenib, gefitinib and bosutinib
- Synthesis and characterization of a novel chitosan-grafted-polyorthoethylaniline biocomposite and utilization for dye removal from water
- Optimisation of urine sample preparation for shotgun proteomics
- DFT investigations on arylsulphonyl pyrazole derivatives as potential ligands of selected kinases
- Treatment of Parkinson’s disease using focused ultrasound with GDNF retrovirus-loaded microbubbles to open the blood–brain barrier
- New derivatives of a natural nordentatin
- Fluorescence biomarkers of malignant melanoma detectable in urine
- Study of the remediation effects of passivation materials on Pb-contaminated soil
- Saliva proteomic analysis reveals possible biomarkers of renal cell carcinoma
- Withania frutescens: Chemical characterization, analgesic, anti-inflammatory, and healing activities
- Design, synthesis and pharmacological profile of (−)-verbenone hydrazones
- Synthesis of magnesium carbonate hydrate from natural talc
- Stability-indicating HPLC-DAD assay for simultaneous quantification of hydrocortisone 21 acetate, dexamethasone, and fluocinolone acetonide in cosmetics
- A novel lactose biosensor based on electrochemically synthesized 3,4-ethylenedioxythiophene/thiophene (EDOT/Th) copolymer
- Citrullus colocynthis (L.) Schrad: Chemical characterization, scavenging and cytotoxic activities
- Development and validation of a high performance liquid chromatography/diode array detection method for estrogen determination: Application to residual analysis in meat products
- PCSK9 concentrations in different stages of subclinical atherosclerosis and their relationship with inflammation
- Development of trace analysis for alkyl methanesulfonates in the delgocitinib drug substance using GC-FID and liquid–liquid extraction with ionic liquid
- Electrochemical evaluation of the antioxidant capacity of natural compounds on glassy carbon electrode modified with guanine-, polythionine-, and nitrogen-doped graphene
- A Dy(iii)–organic framework as a fluorescent probe for highly selective detection of picric acid and treatment activity on human lung cancer cells
- A Zn(ii)–organic cage with semirigid ligand for solvent-free cyanosilylation and inhibitory effect on ovarian cancer cell migration and invasion ability via regulating mi-RNA16 expression
- Polyphenol content and antioxidant activities of Prunus padus L. and Prunus serotina L. leaves: Electrochemical and spectrophotometric approach and their antimicrobial properties
- The combined use of GC, PDSC and FT-IR techniques to characterize fat extracted from commercial complete dry pet food for adult cats
- MALDI-TOF MS profiling in the discovery and identification of salivary proteomic patterns of temporomandibular joint disorders
- Concentrations of dioxins, furans and dioxin-like PCBs in natural animal feed additives
- Structure and some physicochemical and functional properties of water treated under ammonia with low-temperature low-pressure glow plasma of low frequency
- Mesoscale nanoparticles encapsulated with emodin for targeting antifibrosis in animal models
- Amine-functionalized magnetic activated carbon as an adsorbent for preconcentration and determination of acidic drugs in environmental water samples using HPLC-DAD
- Antioxidant activity as a response to cadmium pollution in three durum wheat genotypes differing in salt-tolerance
- A promising naphthoquinone [8-hydroxy-2-(2-thienylcarbonyl)naphtho[2,3-b]thiophene-4,9-dione] exerts anti-colorectal cancer activity through ferroptosis and inhibition of MAPK signaling pathway based on RNA sequencing
- Synthesis and efficacy of herbicidal ionic liquids with chlorsulfuron as the anion
- Effect of isovalent substitution on the crystal structure and properties of two-slab indates BaLa2−xSmxIn2O7
- Synthesis, spectral and thermo-kinetics explorations of Schiff-base derived metal complexes
- An improved reduction method for phase stability testing in the single-phase region
- Comparative analysis of chemical composition of some commercially important fishes with an emphasis on various Malaysian diets
- Development of a solventless stir bar sorptive extraction/thermal desorption large volume injection capillary gas chromatographic-mass spectrometric method for ultra-trace determination of pyrethroids pesticides in river and tap water samples
- A turbidity sensor development based on NL-PI observers: Experimental application to the control of a Sinaloa’s River Spirulina maxima cultivation
- Deep desulfurization of sintering flue gas in iron and steel works based on low-temperature oxidation
- Investigations of metallic elements and phenolics in Chinese medicinal plants
- Influence of site-classification approach on geochemical background values
- Effects of ageing on the surface characteristics and Cu(ii) adsorption behaviour of rice husk biochar in soil
- Adsorption and sugarcane-bagasse-derived activated carbon-based mitigation of 1-[2-(2-chloroethoxy)phenyl]sulfonyl-3-(4-methoxy-6-methyl-1,3,5-triazin-2-yl) urea-contaminated soils
- Antimicrobial and antifungal activities of bifunctional cooper(ii) complexes with non-steroidal anti-inflammatory drugs, flufenamic, mefenamic and tolfenamic acids and 1,10-phenanthroline
- Application of selenium and silicon to alleviate short-term drought stress in French marigold (Tagetes patula L.) as a model plant species
- Screening and analysis of xanthine oxidase inhibitors in jute leaves and their protective effects against hydrogen peroxide-induced oxidative stress in cells
- Synthesis and physicochemical studies of a series of mixed-ligand transition metal complexes and their molecular docking investigations against Coronavirus main protease
- A study of in vitro metabolism and cytotoxicity of mephedrone and methoxetamine in human and pig liver models using GC/MS and LC/MS analyses
- A new phenyl alkyl ester and a new combretin triterpene derivative from Combretum fragrans F. Hoffm (Combretaceae) and antiproliferative activity
- Erratum
- Erratum to: A one-step incubation ELISA kit for rapid determination of dibutyl phthalate in water, beverage and liquor
- Review Articles
- Sinoporphyrin sodium, a novel sensitizer for photodynamic and sonodynamic therapy
- Natural products isolated from Casimiroa
- Plant description, phytochemical constituents and bioactivities of Syzygium genus: A review
- Evaluation of elastomeric heat shielding materials as insulators for solid propellant rocket motors: A short review
- Special Issue on Applied Biochemistry and Biotechnology 2019
- An overview of Monascus fermentation processes for monacolin K production
- Study on online soft sensor method of total sugar content in chlorotetracycline fermentation tank
- Studies on the Anti-Gouty Arthritis and Anti-hyperuricemia Properties of Astilbin in Animal Models
- Effects of organic fertilizer on water use, photosynthetic characteristics, and fruit quality of pear jujube in northern Shaanxi
- Characteristics of the root exudate release system of typical plants in plateau lakeside wetland under phosphorus stress conditions
- Characterization of soil water by the means of hydrogen and oxygen isotope ratio at dry-wet season under different soil layers in the dry-hot valley of Jinsha River
- Composition and diurnal variation of floral scent emission in Rosa rugosa Thunb. and Tulipa gesneriana L.
- Preparation of a novel ginkgolide B niosomal composite drug
- The degradation, biodegradability and toxicity evaluation of sulfamethazine antibiotics by gamma radiation
- Special issue on Monitoring, Risk Assessment and Sustainable Management for the Exposure to Environmental Toxins
- Insight into the cadmium and zinc binding potential of humic acids derived from composts by EEM spectra combined with PARAFAC analysis
- Source apportionment of soil contamination based on multivariate receptor and robust geostatistics in a typical rural–urban area, Wuhan city, middle China
- Special Issue on 13th JCC 2018
- The Role of H2C2O4 and Na2CO3 as Precipitating Agents on The Physichochemical Properties and Photocatalytic Activity of Bismuth Oxide
- Preparation of magnetite-silica–cetyltrimethylammonium for phenol removal based on adsolubilization
- Topical Issue on Agriculture
- Size-dependent growth kinetics of struvite crystals in wastewater with calcium ions
- The effect of silica-calcite sedimentary rock contained in the chicken broiler diet on the overall quality of chicken muscles
- Physicochemical properties of selected herbicidal products containing nicosulfuron as an active ingredient
- Lycopene in tomatoes and tomato products
- Fluorescence in the assessment of the share of a key component in the mixing of feed
- Sulfur application alleviates chromium stress in maize and wheat
- Effectiveness of removal of sulphur compounds from the air after 3 years of biofiltration with a mixture of compost soil, peat, coconut fibre and oak bark
- Special Issue on the 4th Green Chemistry 2018
- Study and fire test of banana fibre reinforced composites with flame retardance properties
- Special Issue on the International conference CosCI 2018
- Disintegration, In vitro Dissolution, and Drug Release Kinetics Profiles of k-Carrageenan-based Nutraceutical Hard-shell Capsules Containing Salicylamide
- Synthesis of amorphous aluminosilicate from impure Indonesian kaolin
- Special Issue on the International Conf on Science, Applied Science, Teaching and Education 2019
- Functionalization of Congo red dye as a light harvester on solar cell
- The effect of nitrite food preservatives added to se’i meat on the expression of wild-type p53 protein
- Biocompatibility and osteoconductivity of scaffold porous composite collagen–hydroxyapatite based coral for bone regeneration
- Special Issue on the Joint Science Congress of Materials and Polymers (ISCMP 2019)
- Effect of natural boron mineral use on the essential oil ratio and components of Musk Sage (Salvia sclarea L.)
- A theoretical and experimental study of the adsorptive removal of hexavalent chromium ions using graphene oxide as an adsorbent
- A study on the bacterial adhesion of Streptococcus mutans in various dental ceramics: In vitro study
- Corrosion study of copper in aqueous sulfuric acid solution in the presence of (2E,5E)-2,5-dibenzylidenecyclopentanone and (2E,5E)-bis[(4-dimethylamino)benzylidene]cyclopentanone: Experimental and theoretical study
- Special Issue on Chemistry Today for Tomorrow 2019
- Diabetes mellitus type 2: Exploratory data analysis based on clinical reading
- Multivariate analysis for the classification of copper–lead and copper–zinc glasses
- Special Issue on Advances in Chemistry and Polymers
- The spatial and temporal distribution of cationic and anionic radicals in early embryo implantation
- Special Issue on 3rd IC3PE 2020
- Magnetic iron oxide/clay nanocomposites for adsorption and catalytic oxidation in water treatment applications
- Special Issue on IC3PE 2018/2019 Conference
- Exergy analysis of conventional and hydrothermal liquefaction–esterification processes of microalgae for biodiesel production
- Advancing biodiesel production from microalgae Spirulina sp. by a simultaneous extraction–transesterification process using palm oil as a co-solvent of methanol
- Topical Issue on Applications of Mathematics in Chemistry
- Omega and the related counting polynomials of some chemical structures
- M-polynomial and topological indices of zigzag edge coronoid fused by starphene
