Liu Quan, Chen Chao-Jun, Shi Xiang, Zhang Li, Chen Hui-Juan, Gao Kun
Lanzhou University, People’s Republic of China.
Chem Pharm Bull (Tokyo). 2010 Nov;58(11):1431-5. doi: 10.1248/cpb.58.1431.
(23E)-25-Methylcycloart-23-en-3β-ol (1), a cycloartane-type triterpenoid featuring an unusual skeleton of 31 carbon atoms, (17E)-cycloart-17,26-dien-3β-ol (2), a new cycloartane-type triterpenoid, and the other two new compounds 4R-hydroxy-4-(9S-hydroxy-12-methylhexan-6-yl)-3-methylcyclopent-2-enone (6) and 7-hydroxy-5-(2'-hydroxy-4',5'-dimethoxyphenyl)-2-methoxy-6-methyl-1,4-naphthoquinone (7), together with three known cycloart-3β-ol triterpenoids (3-5) were isolated from aerial parts of Aphanamixis grandifolia. Their structures were elucidated by spectroscopic analysis, and that of 1 was confirmed by single-crystal X-ray diffraction. The absolute configuration of two carbon stereocenters of compound 6 was determined to be 4R,9S by means of circular dichroism (CD) and auxiliary chiral α-methoxy-α-(trifluoromethyl)phenylacetic acid (MTPA) derivatives, respectively. The compound 3 exhibited significant cytotoxicities against HL-60, Hep G2 and HeLa, and compounds 1, 2, 5, 6 and 7 exhibited modest cytotoxicities. No activity of compound 4 could be due to the absence of the hydroxyl group at C-24.
(23E)-25-甲基环阿尔廷-23-烯-3β-醇（1），一种具有31个碳原子不寻常骨架的环阿尔廷型三萜类化合物，(17E)-环阿尔廷-17,26-二烯-3β-醇（2），一种新的环阿尔廷型三萜类化合物，以及另外两种新化合物4R-羟基-4-(9S-羟基-12-甲基己烷-6-基)-3-甲基环戊-2-烯酮（6）和7-羟基-5-(2'-羟基-4',5'-二甲氧基苯基)-2-甲氧基-6-甲基-1,4-萘醌（7），与三种已知的环阿尔廷-3β-醇三萜类化合物（3 - 5）一起从大叶山楝的地上部分分离得到。通过光谱分析阐明了它们的结构，化合物1的结构通过单晶X射线衍射得到证实。分别借助圆二色性（CD）和辅助手性α-甲氧基-α-(三氟甲基)苯基乙酸（MTPA）衍生物确定化合物6的两个碳立体中心的绝对构型为4R,9S。化合物3对HL-60、Hep G2和HeLa表现出显著的细胞毒性，化合物1、2、5、6和7表现出适度的细胞毒性。化合物4无活性可能是由于C-24位不存在羟基。
