An alternative approach to the synthesis of anticancer molecule spirobrassinin and its 2 '-amino analogues

摘要

A convenient synthesis of the cruciferous phytoalexin (S)-(-)-spirobrassinin and its (+/-)-2 '-amino analogues have been achieved. Our synthetic route towards (S)-(-)-spirobrassinin is based on the CrO3-mediated cyclization of chiral 1-(2 ',3 ',4 ',6 '-tetra-O-acetyl-ss-D-glucopyranosyl)brassinin and subsequent removal of the chiral auxiliary. (+/-)-2 '-Amino analogues of spirobrassinin and 1-methoxyspirobrassinin were obtained from thioureas in one step in an efficient manner with the aid of CrO3. New synthesized compounds were screened in vitro for antiproliferative/cytotoxic activity against six human cancer cell lines by MTT assay. Amino analogues with CF3 functionality displayed good antiproliferative effect. Graphic abstract