Cyclopeptide Alkaloids: Stereochemistry and Synthesis of the Precursors of Discarines C and D and Myrianthine A
作者:Marco A. Mostardeiro、Vinicius Ilha、Janice Dahmer、Miguel S. B. Caro、Ionara I. Dalcol、Ubiratan F. da Silva、Ademir F. Morel
DOI:10.1021/np400313w
日期:2013.7.26
The stereochemistry of discarines C (1) and D (2) and myrianthine A (3), three cyclopeptide alkaloids isolated from Discaria febrifuga, was determined by a combination of NMR studies of 1–3, enantioselective gas chromatography, and comparison of NMR data with those of synthetic tripeptides. For the synthesis of peptides, the nonproteinogenic amino acid 3-phenylserine was also obtained in its four diastereoisomeric
discarines的C(立体化学1)和d(2)和myrianthine A(3),从分离的3种肽生物碱Discaria febrifuga,用的NMR研究的组合来确定1 - 3,对映选择性气相色谱和NMR数据的比较与合成三肽的那些。对于肽的合成,还获得了非蛋白质氨基酸3-苯基丝氨酸,它具有四种非对映异构体形式(l和d threo,通过非对映异构三肽的重结晶获得,l和d erythro通过与Mitsunobu反应得到苏-tripeptides)。本文描述的一般合成策略允许在保护或二甲基化游离N末端的情况下获得三肽。该策略还允许合成具有咪唑烷酮环的相应肽。