Phan Minh Giang, Phan Tong Son, Hamada Yumi, Otsuka Hideaki
Faculty of Chemistry, College of Natural Science, Vietnam National University, Hanoi.
Chem Pharm Bull (Tokyo). 2005 Mar;53(3):296-300. doi: 10.1248/cpb.53.296.
Six new ent-kaurane-type diterpenoids were isolated from the leaves of the endemic Vietnamese medicinal plant Croton tonkinensis GAGNEP. (Euphorbiaceae) together with three known ent-11alpha-acetoxy-7beta,14alpha-dihydroxykaur-16-en-15-one (1), ent-kaur-16-en-15-one 18-oic acid (5) and ent-18-hydroxykaur-16-ene (7). Their structures were determined by spectroscopic analyses to be ent-7beta-acetoxy-11alpha-hydroxykaur-16-en-15-one (2), ent-18-acetoxy-11alpha-hydroxykaur-16-en-15-one (3), ent-11alpha-acetoxykaur-16-en-18-oic acid (4), ent-15alpha,18-dihydroxykaur-16-ene (6), ent-11alpha,18-diacetoxy-7beta-hydroxykaur-16-en-15-one (8), and ent-(16S)-1alpha,14alpha-diacetoxy-7beta-hydroxy-17-methoxykauran-15-one (14). ent-Kaurane-type diterpenoids from Croton tonkinensis 2-4, 6, and 9-13, were tested for toxicity in the brine shrimp lethality assay. Compounds 9, 10, and 12 demonstrated significant activity, compounds 2, 3, 6, and 11 showed weak activity, and compounds 4 and 13 were inactive.
从越南特有的药用植物东京巴豆（Croton tonkinensis GAGNEP.，大戟科）的叶子中分离出6种新的对映-贝壳杉烷型二萜类化合物，同时还分离出3种已知化合物，即对映-11α-乙酰氧基-7β,14α-二羟基贝壳杉-16-烯-15-酮（1）、对映-贝壳杉-16-烯-15-酮18-酸（5）和对映-18-羟基贝壳杉-16-烯（7）。通过光谱分析确定它们的结构分别为对映-7β-乙酰氧基-11α-羟基贝壳杉-16-烯-15-酮（2）、对映-18-乙酰氧基-11α-羟基贝壳杉-16-烯-15-酮（3）、对映-11α-乙酰氧基贝壳杉-16-烯-18-酸（4）、对映-15α,18-二羟基贝壳杉-16-烯（6）、对映-11α,18-二乙酰氧基-7β-羟基贝壳杉-16-烯-15-酮（8）和对映-(16S)-1α,14α-二乙酰氧基-7β-羟基-17-甲氧基贝壳杉烷-15-酮（14）。对东京巴豆中分离得到的对映-贝壳杉烷型二萜类化合物2 - 4、6以及9 - 13进行了卤虫致死试验的毒性测试。化合物9、10和12表现出显著活性，化合物2、3、6和11表现出较弱活性，化合物4和13无活性。
