Band 78, Heft 11-12

The exact structure of phloridzin was further confirmed as phloretin 6′- O -glucopyranoside by a single-crystal X-ray diffraction experiment. The distribution changes of phloridzin in flowering, fruitlet, and fruit ripening phases of Malus rockii were quantified by an HPLC with an external standard. The concentrations of phloridzin in leaves, twigs, and bark and xylem of twigs increased at first and then decreased, and reached the highest value in the fruitlet period. The highest concentration of phloridzin was found in leaves, with the percentage contents of 10.92–14.43 %. What is more, the decreased value of the concentration of phloridzin in leaves from fruit ripening period was almost equivalent to the increased value of the concentration of phloretin. This interesting physiological phenomenon should be able to provide the readers, especially plant physiologists, with a new perspective for the development and utilization of phloridzin.

Black rice ( Oryza sativa L.) is a rich source of phenolics and anthocyanins. It was aimed to investigate the effect of different extraction methods such as conventional solvent extraction, ultrasound-assisted extraction (UAE), and microwave-assisted extraction (MAE) on antioxidant activity and phenolic profiling of black rice free, esterified, and bound phenolics fractions. Spectrophotometric methods were used to evaluate antioxidant activity and HPTLC was used for phenolics profiling. The highest content of % yield, total anthocyanin (TAC), total phenolic (TPC), and total flavonoid (TFC) contents were detected in MAE. It was also observed that antioxidant activity based on DPPH, ABTS, superoxide radical-scavenging and ferric reducing antioxidant power (FRAP) assays showed highest activity in MAE. Eight phenolic compounds were identified and quantified by a validated HPTLC method. MAE showed most abundant phenolic compounds. A significant positive correlation was established between % yield, total phenolic content, and total flavonoid content ( p  < 0.05) where a significant negative correlation was established between % yield, TPC, and TFC with IC 50 of antioxidant activity ( p  < 0.05). Diverse phenolic contents and antioxidant activity were studied with different forms of phenolics with the different extraction methods. It designates that the extraction techniques had effects on the bioactive compounds as well biological properties.

Melanogenesis is the process where skin pigment melanin is produced through tyrosinase activity. Overproduction of melanin causes skin disorders such as freckles, spots, and hyperpigmentation. Myricetin 3- O -galactoside (M3G) is a dietary flavonoid with reported bioactivities. M3G was isolated from Limonium tetragonum and its anti-melanogenic properties were investigated in α-melanocyte stimulating hormone-stimulated B16F10 melanoma cells. The in vitro anti-melanogenic capacity of M3G was confirmed by inhibited tyrosinase and melanin production. M3G-mediated suppression of melanogenic proteins, tyrosinase, microphthalmia-associated transcription factor (MITF), and tyrosinase-related proteins (TRP)-1 and TRP-2, were confirmed by mRNA and protein levels, analyzed by RT-qPCR and Western blot, respectively. Furthermore, M3G suppressed Wnt signaling through the inhibition of PKA phosphorylation. M3G also suppressed the consequent phosphorylation of CREB and nuclear levels of MITF. Analysis of MAPK activation further revealed that M3G increased the activation of ERK1/2 while p38 and JNK activation remained unaffected. Results showed that M3G suppressed melanogenesis in B16F10 cells by decreasing tyrosinase production and therefore inhibiting melanin formation. A possible action mechanism was the suppression of CREB activation and upregulation of ERK phosphorylation which might cause the decreased nuclear levels of MITF. In conclusion, M3G was suggested to be a potential nutraceutical with anti-melanogenic properties.

A new isoindole alkaloid, 6-hydroxy-2-(4′′′-hydroxy-3′′′-methoxyphenethyl)-4-(4′-hydroxy-3′-methoxyphenyl)-7-methoxy-1 H -benzo[f]isoindole-1,3(2 H )-dione, named oleraisoindole B was isolated from Portulaca oleracea L., its structure was elucidated using NMR and UHPLC-ESI-Q-TOF/MS spectroscopic methods, and presented anti-inflammatory activity at 5 μM.

Eleven compounds were isolated and identified from ethanolic extracts of Solanum virginianum fruits, including two new compounds ( 1 – 2 ) and nine known compounds ( 3 – 11 ). Their structures were determined to be melongenaterpene C15- O - β -D-glucopyranoside ( 1 ), (9 Z )-3,7,11,15-tetramethyl -hexadeca-1,6,10-triene-3,5,14,15-tetraol-5- O - β -D-glucopyranoside ( 2 ), actini-dioionoside A ( 3 ), byzantionoside B ( 4 ), citroside A ( 5 ), 7Z-roseoside ( 6 ), matenoside A ( 7 ), megastigmane ( 8 ), dihydrophaseic acid 3′- O - β -D-glucopyranoside ( 9 ), taraxerol ( 10 ), and huzhangoside C ( 11 ). In this paper, NMR spectroscopy was used to study the structures of the compounds, comparing their data with those in the literature. In addition, the potential anti-inflammatory activity of the compounds was also evaluated using the RAW264.7 cell inflammation model induced by lipopolysaccharide (LPS). The terpenoids showed no significant anti-inflammatory activity.

Carbonic anhydrase (CA) enzymes are a common catalytic enzyme in many organisms. Vertebrates and invertebrates have different CA isoforms. Sixteen different isozymes of the α-CA isoform found in vertebrates have been identified so far. The main task of this enzyme is to catalyze the reversible conversion of carbon dioxide into bicarbonate and hydrogen ions in the body. It is widely distributed in many organs and tissues. They are involved in important physiological processes such as pH and CO 2 homeostasis, biosynthetic reactions such as gluconeogenesis, lipogenesis, ureagenesis, bone resorption, calcification, tumorigenicity, and electrolyte secretion. As a result of the literature research, it has been determined that the most effective inhibitor of the carbonic anhydrase enzyme is sulfonamides. The R group in the general molecular structure of R-SO 2 –NH 2 generally consists of aromatic or heteroaromatic ring systems. The sulfonamides interact strongly with the Zn 2+ ions in the active site of the enzyme. In this study, 10 sulfonamide derivatives were synthesized. Analyses of the obtained compounds are evaluated by using 1 H NMR, 13 C NMR and HRMS spectroscopic methods. The inhibition effect of the obtained compounds on the carbonic anhydrase enzyme was investigated by means of in vitro kit method. For the selected compounds, docking studies were performed and the enzyme active sites and binding points were determined. It was revealed that the strongest interaction with CA enzymes (CA-I, CA-II, CA-IX, CA-XII) active sites was observed with the compound 2e .

A series of new benzoxazole-hydrazone and benzoxazole-1,3,4-oxadiazole derivatives have been designed, synthesized and evaluated as cytotoxic agents toward human A549 lung cancer cells. Compounds 3d, 3e, 5b, 5c, 5d and 5e were the most potent compounds with IC 50 values of <3.9, 10.33, 11.6, 5.00, <3.9 and 4.5 μg/mL, respectively, which are higher than reference drug cisplatin (IC 50  = 19.00 μg/mL). The flow cytometry-based apoptosis detection assay was performed to determine their effects on apoptosis in A549 cells. All tested compounds induced apoptosis in A549 cell line.