Sporidesmins. XIV. Modifications to the Opened -S-S- Bridge of Sporidesmin for Coupling to Proteins by Transacylation

Abstract

Alkylation of the opened -S-S- bridge of sporidesmin formed diethyl secosporidesmin-S,S?-diacetate(3), dimethyl secosporidesmin-S,S?- diacetate (4), methyl 3-mercaptosecosporidesmin-11a-S-acetate (5) and methyl 11a-mercaptosecosporidesmin-3-S-acetate (6) which were condensed with ε-amino groups of poly(L-lysine), bovine plasma albumin and rabbit serum albumin. The thiol group in compound (6) could not be demonstrated by conventional tests but its presence was established by its mass spectrum.