Alkaloids--Synthesis

A family of tetrahydroisoquinoline alkaloids, the ecteinascidins, are a group of biologically active secondary metabolites produced by the marine tunicate Ecteinascidia turbinata. Ecteinascidins have shown in vivo anti-tumor activity against P388 lymphoma, B16 melanoma, M5076 ovarian sarcoma, Lewis lung carcinoma, and LX-1 human lung and MX-1 human mammary carcinoma xenografts in laboratory mice. Because ecteinascidins are produced in low yields, 1x10^-4%, supply for clinical development is a significant problem. The ultimate goal of this study is to develop an enzyme-based synthesis of the ecteinascidins. In this regard, the biosynthesis of these alkaloids has been investigated. Optimal conditions for in vitro ecteinascidin biosynthesis were found. The origin of the C22-C1 two-carbon unit was identified as pyruvate and the tyrosine and DOPA diketopiperazines were identified as key intermediates. Methods were developed for an in-the-sea aquaculture of the colonal marine ascidian Ecteinascidia turbinata.