Studies On The Synthesis Of Antibiotic Tunicamycins

The tunicamycins which were originally isolated from Streptomyces lysosuperficus and S.chartreusis in 1971,is a group of nucleoside antibiotics with fatty acid amide.Tunicamycins inhibit the activity of bacterial translocase I and the eukaryotic Glc NAc-1-P transferase,which synthesize precursors crucial to bacterial cell wall synthesis and the N glycosylation of eukaryotic proteins.Owing to their capability of inhibiting protein N glycosylation,the tunicamycins may become a good medicine in the future.Uridine as an accessible material can give the portion of uracil at the beginning.Then,via the stannic chloride(SnCl4)mediated Mukaiyama aldol reaction and oxidative cyclization reaction,we can get the tunicaminyl uracil with high stereoselectivity,which is the key structure of tunicamycins.Tunicaminyl uracil can be the acceptor and the block of glucose as the donor,we attempt to get the the portion of trisaccharide by gold(I)-catalyzed glycosylation reaction.