β-Hydroxy-L-valine and 4-Amino-3, 6-dihydroxy-2-methylhexaiioic Acid, Constitutional Amino Acids of the Antibiotic YA-56

Abstract

From the acid hydrolyzate of the antibiotic YA-56 X (Zorbamycin) and Y belonging to the phleomycin-bleomycin group, 3 unique amino acids were isolated and their structures were determined to be β-hydroxy-L-valine and 2-(3'- amino-tetrahydrofuryl-2'-yl)-propionic acid and an isomer of the latter compound.
Considerations of NMR of the antibiotic YA-56 and of the reaction conditions led us to a view that the latter two new amino acids were not an integral part of the YA-56 molecule but were artifacts derived from 4-amino-3, 6-dihydroxy-2-methylhexanoic acid constituting of YA-56 X and Y.