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

1.北米特拉吉那的叶子。在泰国和马来当地人的传统使用中被称为鸦片的替代品。对马来西亚该植物的生物碱成分进行了重新研究，分离出四种新的吲哚类生物碱，通过全合成和/或光谱分析阐明了其不同寻常的结构。研究了一种新的手性全合成方法。体外实验明确了米特拉金和米特拉金假吲哚基的阿片类药物拮抗作用。米特ragynine pseudoindoxyl的激动效价是吗啡的20-50倍，作用于mu-和delta-阿片受体。为建立新型萨帕琴型龙胆生物碱的合成路线，采用自由基环化策略合成了单萜类吲哚类生物碱——龙胆碱的模型实验。2 .研究了黄缕黄菌生物碱成分堇青石碱对甘氨酸受体的抑制作用。从泰国核仁中分离到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strictosamide及其五乙酰衍生物，考察了其C3立体化学性质。

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.