Studies on the Interaction between Plant Secondary Metabolites and Xenobiotics

通过对植物次生代谢物与外源物相互作用的生物学和化学研究，揭示了高等植物保护设施的效力。1. 首先调查了对苯并咪唑类杀菌剂具有抗菌活性的植物次生代谢物，确定了蓼科植物中5个化合物为抗mbc物质（多菌灵，苯甲酰和硫代甲基均为苯并咪唑类杀菌剂），并对其化学结构进行了鉴定：蓼属植物大黄素(1)和α -生育酚(2)；石竹中的5-甲氧基-6,7-亚甲基-二氧基黄酮(3)和3,5-二羟基-4-甲基二苯乙烯(4)；和2,6-二甲氧基-1,4-苯醌(5)。2. 分析了其抗MBC活性与醌类（炭疽醌和萘醌）或黄酮的构效关系。活性最高的化合物是醌类中的拉帕醇（3-羟基-4-戊烯基萘醌）和类黄酮中的未取代黄酮或5-甲氧基黄酮。3. 解毒剂对MBC的作用模式被认为是微管蛋白聚合的抑制剂，从而导致有丝分裂的失败，这是非常感兴趣的。据我们目前所知，上述解毒剂在体外不与MBC竞争β -微管蛋白的结合位点。4. 从豆科植物刺槐（Piscidia erythrina）中分离出具有生理活性的次生代谢产物异黄酮、倍半萜衍生物和低聚二苯乙烯，并分别对其结构进行了鉴定；蔷薇科蔷薇、玉兰、剑兰（玉兰科）和苔属（柏科）。

Biological and chemical studies on the interaction between plant seconda secondary metabolites and xenobiotics were conducted to reveal the potency of protective facilities of higher plants. 1. At first the plant secondary metabolites which exhibited antidoting activity against benzimidazole fungicides were surveyed and the following five compounds all from Polygonaceae were recognized as anti-MBC (=carbendazim, an active principle of benomyl and thiophanate-methyl both benzimidazole type fungicides) substances, and identified their chemical structures: emodin (1) and alpha-tocopherol(2)from Polygonum sachalinense; 5-methoxy-6,7-methylene-dioxyflavone (3) and 3,5-dihydroxy-4-methylstilbene (4) from P. nodosum; and 2,6-dimethoxy-1,4-benzoquinone (5) from P. thunbergii. 2. Structure-activity relationships between the antidoting activity against MBC and quinones (anthra- and naphtho-quinones) or flavones were analyzed. The most active compounds were lapachol (3-hydroxy-4-prenylnaphthoquinone) in quinones and unsubstituted flavone or 5-methoxyflavone in flavonoids. 3. The mode of action of the antidoting agent against MBC which is believed to be an inhibitor of tubulin polymerization and consequently resulting in a failure of mitosis, was very much interested. So far as we know at present is that the antidotes mentioned above do not compete with MBC for the binding site of beta-tubulin in vitro. 4. Some physiologically active secondary metabolites, isoflavonoids, sesquiterpene derivatives and oligostilbenes were isolated and elucidated their structures respectively, from Piscidia erythrina (Leguminosae); Rosa rugosa (Rosaceae) and Chloranthus Japonicus and C. serratus (Chloranthaceae); and Carex spp. (Cypreaceae).