Nazumazoles A–C, Cyclic Pentapeptides Dimerized through a Disulfide Bond from the Marine Sponge Theonella swinhoei
摘要:
A mixture of nazumazoles A-C (1-3) was purified from the extract of the marine sponge Theonella swinhoei. The mixture was eluted as an extraordinarily broad peak in the reversed-phase HPLC. The structures of nazumazoles were determined by interpretation of the NMR data and chemical degradations. Nazumazoles contain one residue each of alanine-derived oxazole and alpha-keto-beta-amino acid residue. Nazumazoles exhibited cytotoxicity against P388 cells.
Nazumazoles A–C, Cyclic Pentapeptides Dimerized through a Disulfide Bond from the Marine Sponge Theonella swinhoei
摘要:
A mixture of nazumazoles A-C (1-3) was purified from the extract of the marine sponge Theonella swinhoei. The mixture was eluted as an extraordinarily broad peak in the reversed-phase HPLC. The structures of nazumazoles were determined by interpretation of the NMR data and chemical degradations. Nazumazoles contain one residue each of alanine-derived oxazole and alpha-keto-beta-amino acid residue. Nazumazoles exhibited cytotoxicity against P388 cells.
Concise, Stereoselective Route to the Four Diastereoisomers of 4-Methylproline
作者:Annabel C. Murphy、Maya I. Mitova、John W. Blunt、Murray H. G. Munro
DOI:10.1021/np070673w
日期:2008.5.1
has often been hindered by long reaction sequences or low stereoselectivity in the synthesis leading to reference samples. The preparation of the four diastereoisomers of 4-methylproline by a concise and stereoselective route is presented and features a six-step route with late-stage stereodivergence, good stereoselectivity for both cis- and trans-series (75% and 88% de, respectively), and good overall