Natural product and medicinal chemistry

我们建议继续与Arnason集团联合开展成功的生物勘探工作。 (1)特别是，我们计划调查多达七个以前未调查的哥斯达黎加树种与著名的抗癌活性。我们已经收集了两个物种的叶子、木材和树皮，并将开始生物测定指导的分离。 (2)我们已经鉴定出在北方魁北克昂加瓦湾海岸收获的藻类的乙基提取物中发现的非常活性的抗疱疹/抗生素成分，其为由半乳糖、甘油和？亚麻酸我们建议合成和评估一个小家族的代谢更稳定的C-糖苷类似物。(3)我们还将分离和确定一个非常活跃的抗癫痫提取物的结构，该提取物是在与传统治疗师讨论后从伯利兹收集的一种菊科植物中分离出来的。使用GABA-T生物测定，半纯化提取物的活性与加拿大目前使用的抗癫痫药物相当。假设结构不是过于复杂，我们将开始对其合成和类似物合成的研究。(4)我们还将继续我们的研究罕见的哥斯达黎加树Ruptilliocarpon caracolito探测额外的组件，可能揭示了生物合成的非常不寻常的螺CD环三萜类化合物，我们以前已经从这个物种的树皮分离。

We propose to continue our successful bio-prospecting approach jointly with the Arnason group. (1) In particular we plan to investigate up to seven previously uninvestigated Costa Rican tree species with reputed anti-cancer activity. We have already collected leaves, wood and bark of two species and will begin bio-assay guided isolation shortly. (2) We have identified the very active anti-herpes/anti-biotic component found in the ethyl extracts of algae harvested on the shores of Ungava Bay in Northern Quebec as a glycolipid built from galactose, glycerol and ?-linolenic acid. We propose to synthesize and evaluate a small family of the metabolically more stable C-glycoside analogs. (3) We will also isolate and determine the structure of a very active anti-epileptic extract isolated from a Piperaceae species collected in Belize after discussion with traditional healers. The semi-purified extract has activity comparable to that of the currently used anti-epileptic drug in Canada using the GABA-T bio-assay. Assuming that the structure is not overly complex we will initiate studies towards its synthesis and the synthesis of analogs. (4) We will also continue our studies of the rare Costa Rican tree Ruptilliocarpon caracolito to probe for additional components that may shed light on the biosynthesis of the highly unusual spiro CD-ring triterpenoids that we have previously isolated from the bark of this species.