Li Renfeng, Zhao Ximei, Shi Baojun, Wei Shaopeng, Zhang Jiwen, Wu Wenjun, Hu Zhaonong
Nat Prod Commun. 2016 Oct;11(10):1425-1428.
To explore novel lead compounds for botanical pesticides from natural sources, a new pregnane glycoside (periplocoside) P2 as well as its isomer, a known pregnane glycoside P1, were isolated from the root barks of Periploca sepium using a bioactivity-guided method, and their structures were confirmed by ID NMR, 2D NMR, IR, ESI-MSn and HRMS. Their insecticidal activities were evaluated against 3rd instar larvae of M separata, and the results indicated that P2 exhibited excellent insecticidal activity with LC₅₀ values of 2.9 and 2.2 mg/mL after 24 and 48 h, respectively, much lower than those of the positive control celangulin-V (24.7 and 21.0 mg/mL after 24 and 48 h, respectively). This work demonstrated that pregnane glycosides from Periploca sepium could be promising lead compounds for developing botanical pesticides urgently needed in agriculture.
为了从天然来源探索新型植物源农药先导化合物，采用生物活性导向法从杠柳根皮中分离得到一种新的孕甾烷糖苷（杠柳苷）P2及其异构体、一种已知的孕甾烷糖苷P1，并通过一维核磁共振（¹D NMR）、二维核磁共振（²D NMR）、红外光谱（IR）、电喷雾离子化多级质谱（ESI-MSn）和高分辨质谱（HRMS）对其结构进行了确证。测定了它们对粘虫3龄幼虫的杀虫活性，结果表明，P2表现出优异的杀虫活性，在24 h和48 h后的半数致死浓度（LC₅₀）值分别为2.9和2.2 mg/mL，远低于阳性对照苦皮藤素V（24 h和48 h后的LC₅₀值分别为24.7和21.0 mg/mL）。该研究表明，杠柳中的孕甾烷糖苷有望成为开发农业急需的植物源农药的先导化合物。
