tested in vitro on antifungal and antimycobacterial activity. The highest potency was exhibited by derivatives with electron withdrawing groups (EWG) in positions 2 and 4 of the ring B. As halogens also have electron withdrawing properties, novel halogenated derivatives were prepared by Claisen-Schmidt condensation. All compounds were submitted for evaluation of their antifungal and antibacterial activity
查耳酮,即具有1,3-二苯基丙-2-烯-1-酮化学模式的化合物,具有广泛的生物活性,例如抗氧化剂,抗炎剂,抗癌剂,抗感染剂等。该小组一直专注于查耳酮的吡嗪类似物;已经合成了多个系列并在体外测试了其抗真菌和抗分枝杆菌活性。在环B的2和4位带有吸电子基团(EWG)的衍生物表现出最高的效力。由于卤素也具有吸电子性能,因此通过Claisen-Schmidt缩合反应制备了新型卤代衍生物。所有化合物均已提交以评估其抗真菌和抗菌活性,包括其抗分枝杆菌作用。在针对八种选定真菌的抗真菌试验中,带有2-溴或2-氯取代的非烷基化衍生物显示了光滑念珠菌和叉毛癣菌(原指发癣菌)的生长抑制。在选定的细菌中,2-氯衍生物对葡萄球菌具有最高的抑制作用。此外,还针对所有产品筛选了针对结核分枝杆菌H37RV My 331/88,堪萨斯分枝杆菌My 235/80,鸟分枝杆菌152/80和耻垢分枝杆菌CCM 4622的抗分枝杆菌
Chalcones and their pyrazine analogs: synthesis, inhibition of aldose reductase, antioxidant activity, and molecular docking study
analogs synthesized by Claisen–Schmidt condensation were tested for inhibition of aldosereductase, which is the key enzyme in the development of secondary diabetic complications. The most active compounds exerted IC50 values within the micromolar scale, and their interactions with the enzyme were described in a molecular docking study. Antioxidant activity of several representative compounds was explored
The title (E)-(3-nitrophenyl)-1-(pyrazin-2-yl)prop-2-en-1-ones were prepared by the Claisen- Schmidt condensation of acetylpyrazines and 2-nitro-, 3-nitro- and 4-nitrobenzaldehyde in pyridine using diethylamine as the catalyst. The compounds were bioassayed for in vitro antifungal, antimycobacterial and photosynthesis-inhibiting activity. The high potency of (E)-1-(5-tert-butylpyrazin-2-yl)-3-(4-nitrophenyl)prop-2-en-1-one againstMycobacterium tuberculosis(MIC 0.78 μg/ml) and moderate activities of several compounds againstTrichophyton mentagrophytesandCandidaspp. do not support the assumption that phenolic groups are essential for antimycobacterial and antifungal activity of chalcones and their analogues. In fact, the nitro-substituted compounds were superior to the previously described hydroxylated congeners with antimycobacterial activity (MIC ≥ 12.5 μg/ml). The compounds also reduced chlorophyll content in green algaChlorella vulgaris, and some of them inhibited photosynthetic electron transport in spinach chloroplasts as well. The photosynthesis-inhibiting activity of nitro derivatives was lower than that of the corresponding hydroxylated analogues.
Four series of ring substituted (E)-3-phenyl-1-(2-pyrazinyl)-2-propen-1-ones were prepared by means of modified Claisen-Schmidt condensation of acetylpyrazines with aromatic aldehydes. The structures were confirmed by elemental analysis, IR, H-1 NMR and C-13 NMR spectra. The compounds were tested for specific biological properties and some derivatives exhibited photosynthesis-inhibiting, antifungal and antimycobacterial properties. The most pronounced effects were observed with compounds substituted with phenolic groups. Ortho-hydroxyl substituted derivatives were more potent than the corresponding para-hydroxyl substituted analogues. (C) 2002 Editions scientifiques et medicales Elsevier SAS. All rights reserved.
Study of hydrophobic properties of biologically active open analogues of flavonoids
Hydrophobicity can either be determined experimentally or predicted by means of commercially available programs. In the studies concerning biological activities of pyrazine analogues of chalcones, 3-(2-hydroxyphenyl)-1-(pyrazin-2-yl)prop-2-en-1-ones were more potent than the corresponding 3(4-hydroxyphenyl)-1-(pyrazin-2-yl)prop-2-en-1-ones. As the difference in lipophilicity may be a factor responsible for the difference in the potency, R-M values of the compounds were determined by RP-TLC and compared with log P values calculated by various commercially available programs. Important discrepancies were found between experimental and computational lipophilicity data. Therefore, we have tried to find a reliable method for calculating R-M values from in silico derived molecular parameters. The R-M values obtained with the chromatographic system consisting of Silufol UV 254 plates impregnated with silicon oil as the stationary phase and acetone-citrate buffer ( pH = 3)50:50 (v/v) as the mobile phase correlated well with van der Waals volumes (V-W) and hydration energies (Delta G(H2O)) derived of molecular models calculated on RHF/AM1 level. (C) 2012 Elsevier Inc. All rights reserved.