Andrographis paniculata has been reported to have antiviral, antipyretic and anticancer activities. Andrographolide, an ent-labdane diterpene, is an active constituent in this plant. In this study, andrographolide (1) and its natural derivative 14-deoxy-11,12-didehydroandrographolide (2) and 5 other semisynthetic derivatives were tested for their activity against Grampositive and Gram-negative bacteria and Candida albicans. Only derivatives bearing a 14-acetyl group showed activity, and this activity was only against Gram-positive bacteria. 14-Acetylandrographolide showed the highest potency against Bacillus subtilis; the other 14-acetylandrographolides with additional substitution at the 3- and 19-hydroxyl groups showed lower activity against Gram-positive bacteria. The morphology of B. subtilis after being treated with 14-acetylandrographolide was investigated with TEM. This is the first report on 14-acetylandrographolide’s quantified antibacterial activity, and the crucial functional group of this ent-labdane that plays an important role in perturbing the morphogenesis of B. subtilis leading to cell death.
据报道,穿心莲具有抗病毒、解热和抗癌活性。
穿心莲内酯是一种内唇二萜,是这种植物的活性成分。本研究测试了
穿心莲内酯(1)及其天然衍
生物 14-脱氧-11,12-二脱氢
穿心莲内酯(2)和其他 5 种半合成衍
生物对革兰氏阳性菌、革兰氏阴性菌和白色念珠菌的活性。只有含有 14-乙酰基的衍
生物才具有活性,而且这种活性只针对革兰氏阳性菌。14- 乙酰基
穿心莲内酯对枯草杆菌的活性最高;其他在 3- 和 19- 羟基上有额外取代基的 14- 乙酰基
穿心莲内酯对革兰氏阳性菌的活性较低。用
TEM 研究了经 14-乙酰
穿心莲内酯处理后的枯草杆菌形态。这是首次报道 14-acetylandrographolide 的量化抗菌活性,以及这种ent-labdane 的关键官能团在扰乱枯草杆菌的形态发生导致
细胞死亡方面发挥的重要作用。