PDF(Pubmed)
Abstract：
Four polyoxygenated stigmastanes (1-4) alongside known analogues (7-8) and flavonoids (5-6) were isolated from a dichloromethane/methanol (1:1, v/v) extract of the whole plant of Vernonia kotschyana Sch. Bip. ex Walp. (Asteraceae). Their structures were determined by means of spectroscopic and spectrometric analysis. The relative stereochemistry of the new compounds was established and confirmed via biosynthesis evidence and cyclization of 1 under acidic conditions. A plausible biosynthetic pathway to the new compounds and the chemophenetic significance of the isolated constituents were also discussed. The crude extract, fractions, and compounds (1-3) were assessed for their antibacterial activity against five highly prevalent bacterial strains. The fractions and compounds showed low to moderate activity with minimal inhibitory concentrations (MICs) > 125 µg/mL.
摘要：
从VernoniakotschyanaSch的整个植物的二氯甲烷/甲醇（1：1，v/v）提取物中分离出四种多氧化的柱状体（1-4）以及已知的类似物（7-8）和类黄酮（5-6）。Bip.前Walp.（菊科）。它们的结构是通过光谱和光谱分析确定的。通过生物合成证据和1在酸性条件下的环化作用，建立并证实了新化合物的相对立体化学。还讨论了新化合物的合理生物合成途径以及分离成分的化学表型意义。粗提物,分数，和化合物(1-3)被评估它们对五种高度流行的细菌菌株的抗菌活性。级分和化合物显示出低至中等的活性，最小抑制浓度（MIC）>125μg/mL。
