Guevara A P, Vargas C, Sakurai H, Fujiwara Y, Hashimoto K, Maoka T, Kozuka M, Ito Y, Tokuda H, Nishino H
Institute of Chemistry, College of Science, University of the Philippines, Diliman, Quezon City, Philippines.
Mutat Res. 1999 Apr 6;440(2):181-8. doi: 10.1016/s1383-5718(99)00025-x.
In the course of studies on the isolation of bioactive compounds from Philippine plants, the seeds of Moringa oleifera Lam. were examined and from the ethanol extract were isolated the new O-ethyl-4-(alpha-L-rhamnosyloxy)benzyl carbamate (1) together with seven known compounds, 4(alpha-L-rhamnosyloxy)-benzyl isothiocyanate (2), niazimicin (3), niazirin (4), beta-sitosterol (5), glycerol-1-(9-octadecanoate) (6), 3-O-(6'-O-oleoyl-beta-D-glucopyranosyl)-beta-sitosterol (7), and beta-sitosterol-3-O-beta-D-glucopyranoside (8). Four of the isolates (2, 3, 7, and 8), which were obtained in relatively good yields, were tested for their potential antitumor promoting activity using an in vitro assay which tested their inhibitory effects on Epstein-Barr virus-early antigen (EBV-EA) activation in Raji cells induced by the tumor promoter, 12-O-tetradecanoyl-phorbol-13-acetate (TPA). All the tested compounds showed inhibitory activity against EBV-EA activation, with compounds 2, 3 and 8 having shown very significant activities. Based on the in vitro results, niazimicin (3) was further subjected to in vivo test and found to have potent antitumor promoting activity in the two-stage carcinogenesis in mouse skin using 7,12-dimethylbenz(a)anthracene (DMBA) as initiator and TPA as tumor promoter. From these results, niazimicin (3) is proposed to be a potent chemo-preventive agent in chemical carcinogenesis.
在对从菲律宾植物中分离生物活性化合物的研究过程中，对辣木种子进行了研究，并从乙醇提取物中分离出新型O-乙基-4-(α-L-鼠李糖氧基)苄基氨基甲酸酯(1)以及七种已知化合物，即4(α-L-鼠李糖氧基)-苄基异硫氰酸酯(2)、尼亚齐米辛(3)、尼亚齐林(4)、β-谷甾醇(5)、甘油-1-(9-十八烷酸酯)(6)、3-O-(6'-O-油酰基-β-D-吡喃葡萄糖基)-β-谷甾醇(7)和β-谷甾醇-3-O-β-D-吡喃葡萄糖苷(8)。以相对较高的产率获得的四种分离物(2、3、7和8)，使用体外试验测试了它们对肿瘤促进剂12-O-十四烷酰佛波醇-13-乙酸酯(TPA)诱导的Raji细胞中爱泼斯坦-巴尔病毒早期抗原(EBV-EA)激活的抑制作用，以此来检测它们潜在的抗肿瘤促进活性。所有测试化合物均显示出对EBV-EA激活的抑制活性，其中化合物2、3和8表现出非常显著的活性。基于体外实验结果，尼亚齐米辛(3)进一步进行体内试验，发现在以7,12-二甲基苯并(a)蒽(DMBA)为引发剂、TPA为肿瘤促进剂的小鼠皮肤两阶段致癌过程中具有强大的抗肿瘤促进活性。根据这些结果，尼亚齐米辛(3)被认为是化学致癌过程中一种有效的化学预防剂。
