Chemical Study of Alkaloids in Tropical Medicinal Plants as the Lead-Compounds to Develop New Biologically Functional Molecules.

1.在泰国和马来人的传统使用中，光叶被称为鸦片替代品。对马来西亚该植物的生物碱成分进行了重新研究，分离得到4个新的吲哚生物碱，它们的特殊结构通过全合成和/或光谱分析得到确证。研究了一种新的手性全合成三叶草生物碱的合成策略。体外实验明确了三尖杉碱和三尖杉碱伪吲哚的阿片类激动剂的特性。米拉吉宁拟吲哚的激动力是吗啡的20-50倍，作用于Mu-和Delta-阿片受体。2.为了建立新的沙帕碱型亨特利生物碱的合成路线，进行了模型实验，通过自由基环化策略合成了单萜类吲哚生物碱--吉西水仙。从泰国产的侧柏核中分离得到7个非生物碱类化合物和2个糖苷类吲哚类化合物。制备了10-羟基磺胺及其五乙酰衍生物，用于C3立体化学的研究。

1.The leaves of Mitragyna speciosa Korth.have been known as an opium substitute in troditional use by Thai and Malay natives. Reinvestigation of the alkaloidal constituents of the plant in Malaysia resulted in the isolation of four new indole alkaloids, whose unusual structures were elucidated by total synthesis and/or spectroscopic analysis. New synthtic strategy for the chiral total syntheses of minor Mitragyna alkaloids was studied. A potent opioid agonistic property of mitragynine and mitragynine pseudoindoxyl was clarified in vitro experiments. Mitragynine pseudoindoxyl, whose agonistic potency is 20-50 fold greater than that of morphine, acts on mu-and delta-opioid receptors.2.To establish the synthetic route of new Sarpagine-type Hunteria alkaloids, a model experiment was done, through which a monoterpenoid indole alkaloid, geissoschizine, was synthesized via radical cyclization strategy. Inhibitory effects of corymine, an alkaloidal component from Hunteria zeylanica, on glycine receptors was found.3.From Nauclea orientalis in Thailand, seven non-alkaloidal and two glycosidic indole compounds were isolated. 10-Hydroxystrictosamide and its pentaacetyl derivative were prepared to examne the C3 stereochemistry.