Volume 238, Issue 7

Heterocyclics particularly those containing oxygen and nitrogen atoms are unique precursors for the synthesis of various agrochemicals and pharmaceuticals. Bis-coumarins are well-known oxygen-containing heterocycles of great significance. The development of methods to prepare bis-coumarins is of great interest in synthetic organic chemistry because of their versatile importance in medicinal chemistry and chemical biology. Bis-coumarins are well known for their antibiotic, antimicrobial, anti-HIV, and antitumor activity. Due to the vast application of bis-coumarins, the synthesis of these heterocycles has attracted huge interest from researchers. In this review, we have summarized the diverse synthetic routes of bis-coumarin synthesis making use of different catalysts and solvents under versatile reaction conditions.

Most coal-fired industrial flue gases contained low concentration CO. How to deal with it effectively was a research hotspot in recent years. Catalytic oxidation was considered as the most promising method in the 21st century for the removement of CO with the high efficiency, environmentally friendly, easy to operate and low cost. In this review, the reaction mechanisms of CO oxidation were described, which could provide ideas for the development of new catalysts. The effects of supports and preparation methods on catalysts activity was also reviewed systematically. In addition, some suggestions and outlooks were provided for future development of CO catalytic oxidation.

The rising concern about the environmental pollution, particularly due to the setup of more industrial sectors has grabbed the attention of scientists and researchers. Many textile businesses emit Malachite Green and Methylene Blue (MG and MB) into the atmosphere, posing serious health risks. In this study, a copper metal-organic framework doped with iron nanoparticles (Cu-MOF@Fe 3 O 4 ) was synthesized utilizing the slow evaporation approach, commencing with cuprous chloride and 2-mercaptobenzimidazole in a 1:2 ratio. Cu-MOF@Fe 3 O 4 was characterized using a variety of techniques, including FTIR, SEM, and DRS analysis. The SEM analysis showed a rough and uneven morphology for the Cu-based MOFs. The XRD analysis confirmed the crystallinity of the products. The average crystallite size for Cu-MOF, Fe 3 O 4 nanoparticles and Cu-MOF@Fe 3 O 4 were found to be 0.22, 1.00, and 1.00 nm. While the surface area of Cu-MOF was found to be 213.192 m 2 g −1 while in Cu-MOF@Fe 3 O 4 it shows an increase, i.e., 218.268 m 2 g −1 as calculated through the iodometric method. A series of experiments were conducted to assess the surface area, chemical oxygen demand (COD), limit of detection (LOD) (0.065559, 0.0136), limit of quantification (LOQ) (0.198662, 0.041312), point of zero charge (PZC) (5.2), pH levels (6, 7), contact times (10, 25 min), photocatalyst dosages (0.3, 0.05 g), dye concentrations (2, 10 µg/mL), and temperature effects (50°, 90°) on the adsorption and photocatalytic degradation of MG and MB, respectively. Photodegradation of both dyes followed pseudo-second order kinetics with R 2 values of 0.9833 (MG) and 0.8875 (MB). The adsorption isotherms (Freundlich and Langmuir) for MG and MB dye were analyzed and the experimental data holds a good correlation with Freundlich isotherm. The sample application of Cu-MOF@Fe 3 O 4 as a photocatalyst, has high efficiency,  % photocatalysis (96.9 % MG, 99.4 % MB) with reusability (95–100 %) upto 10 cycles to photodegrade MG and MB dye in wastewater. To the best of our knowledge, this is the first report on the deployment of copper-based MOFs-doped with magnetite for the photocatalytic degradation of MG and MB dyes.

The treatment of industrial waste water using cyanobacteria in photobioreactor for the removal of sulphide, COD and phenol. The microorganisms were collected from the effluent treatment plant of a petroleum refinery and a biofilm was developed in nutrient medium. The reactor was fed with cyanobacteria. After biofilm formation and acclimatization, the same procedure was followed for 16 days in a rectangular tray type photo bioreactor for the treatment of industrial waste water. From continuous mode of operation, it was found that the phototrophic microorganisms can degrade the pollutants present in industrial waste water. The removal efficiency of hardness 75 %, sulphide 95.8 %, COD 98.7 %, phenol 99.9 % and nitrate 83.7 % was studied. The present works shows that it is feasible to use cyanobacteria in a photo bioreactor for the treatment of industrial waste water.

The present work expands previous studies on the kinetics of the n-C 3 H 7 I unimolecular decomposition and the thermodynamic properties of n-C 3 H 7 I and i-C 3 H 7 I molecules, by providing combined experimental and theoretical data on the rate constant for reaction of n-C 3 H 7 I + Ar ⇌ n-C 3 H 7 + I + Ar, as well as thermodynamic data for iodopropane isomers, calculated based on the density functional theory. The n-C 3 H 7 I dissociation rate constant has been precisely determined in shock-tube experiments by applying atomic resonance absorption spectrometry (ARAS) at the resonance transition wavelength of atomic iodine (183.0 nm) in a temperature range from 830 to 1230 K at a pressure of 3–4 bar. The resulting expression is presented in the Arrhenius form: k 1st  = 1.17 × 10 13 exp(−191.4 kJ mol −1 / RT ) (s −1 ). Theoretical RRKM/ME calculation of the temperature- and pressure-dependent rate constant and channel branching ratio have been based on quantum chemical calculations and were performed over a wide range of thermodynamic conditions ( T  = 300–2000 K, p  = 10 −4 to 10 2  bar). Additionally, the thermochemistry of the reactions of n-C 3 H 7 I dissociation and isomerization has been calculated on B3LYP/cc-pVTZ-PP level of theory. Thermodynamic data, which are provided in NASA polynomial format, are in a better agreement with the available experimental data and previous theoretical estimates.

Silver nanoparticle (AgNPs) is known as a new generation of antibiotics with high bactericidal activity and resistance toward numerous bacteria strains. In the present study, AgNPs were synthesized using propolis extract and microwave heating technique. Results indicated that, the prepared hydroalcoholic propolis extract had brix, turbidity, total phenol content and antioxidant activity of 5.21° Bx, 1.75 % a.u., 82.52 mg/g (gallic acid) and 93.32 %, respectively. FTIR analysis also indicated that the prepared extract had several main functional groups such as hydroxyl, carboxyl, amide I, amin and esters, which those could act as reducing and stabilizing agents in fabrication of stable AgNPs. Furthermore, GC-MS analysis demonstrated that alpha-terpinene, coumaran, p -methoxycinnamic acid, dimethyl caffeic acid and pinostrobin chalcone were the main bioactive compounds of the prepared propolis extract. Results revealed that AgNPs with small particle size (86 nm) and polydespersity index (0.299), and high zeta potential (−23.34) values could be synthesized using 0.1 mL of the extract in combination to 9 mL silver nitrate (1 mM) under microwave heating for 30 s. TEM analysis demonstrated that spherical fabricated AgNPs had uniform particle size distribution with particle size of less than 100 nm. Finally, synthesized AgNps indicated higher bactericidal activity against Listeria monocytogenes and Escherichia coli , with obtained clear zone diameter of 22 and 19 mm, respectively.

There have been significant developments in the use of siRNA in the silencing of cancer-allied target proteins with substantial apoptotic effects. Nevertheless, the challenges regarding siRNA delivery for cancer therapy remain a major concern for taking these therapies successfully from laboratory to in vivo studies. Biomaterials are defined traditionally as any material that is used for either medical or dental applications that contact the host cells in any form, such as a drug carrier a device, or as a prosthesis towards the replacement of damaged tissues. The main issues to be fulfilled by the biomaterial for clinical applications are biocompatibility, bioactivity, ability to carry drug to target site, inflammatory responses and other factors based on its application. The present study focuses on the in vitro inflammatory response to the CS nanoparticles using RAW 264.7 and bone marrow derived macrophage cells. Additionally, the in vitro release kinetics of siRNA with varying concentrations and pH, transfection efficacy and biocompatibility were also investigated. The results of siRNA cumulative release increased at pH 5 and 3, which may be corresponding to the protonation, and a delayed release was seen at 7, which was ascribed to unprotonated amine groups inside the CS. The results of release kinetics confirmed a sustained release of siRNA from CS NPs. Considering that CS is a biocompatible polymer, it typically has little impact/damage on cells, as numerous researchers have observed during in vitro experiments. Inflammatory studies were carried out in vitro with RAW 264.7 and BMC cells derived from mice. The gene and protein expression studies showed that the materials might cause some slight inflammation on exposure with both RAW 264.7 and BMC cells in vitro , which is completely negligible. However, putting together the overall data it can be concluded that CS NPs can be a promising material for in vivo applications, which is in agreement with the results of other researchers, but the only concern being its ability to carry siRNA and protect it from nuclease and other enzymatic attacks.

Rheumatoid Arthritis (RA) is regarded as a long-term autoimmune disorder, which triggers inflammation in joints and distresses the organs in the body. Nanotechnology, a science-based technique is a tremendously growing-field with numerous applications where nanoparticles are used to resolve the complications in the habitual life. While comparing to other metals, iron oxide nanoparticles (Fe 2 O 3 NPs) were synthesized at minimal cost using eco-friendly natured materials and also has ability to deliver drug at a specific targeted site. In the present study, a topical nanoemulgel was formulated using Fe 2 O 3 NPs synthesized from Punica granatum. The results of Fe 2 O 3 NPs characterization divulged that the particles were sphere-shaped in nature and the bioactive compounds from the extract acted as capping and reducing agents. Nanoemulgels (F1 to F5) were formulated using different concentrations of Fe 2 O 3 NPs and characterized. Among the formulations F4 nanoemulgel revealed good stability with a zeta potential charge of −53 mV and a polydispersity index of 0.24. L929 cells were treated with F4 formulation and this confirmed that the formulation was non-toxic to normal cells. F4 treated MG63 cell lines revealed the anti-inflammatory property (IC 50  = 90.77 μg/ml) of the nanoemulgel. Thus, nanoemulgel containing Fe 2 O 3 NPs synthesized from P. granatum can be an effective, eco-friendly and cost-effective approach to treat RA.