Premium
Antibiotics from Gliding Bacteria, LXXVIII . Ripostatin A, B, and C: Isolation and Structure and Structure Elucidation of Novel Metabolites from Sorangium cellulosum
Author(s) -
Augustiniak Hermann,
Höfle Gerhard,
Irschik Herbert,
Reichenbach Hans
Publication year - 1996
Publication title -
liebigs annalen
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.825
H-Index - 155
eISSN - 1099-0690
pISSN - 0947-3440
DOI - 10.1002/jlac.199619961026
Subject(s) - chemistry , polyketide , phenylacetic acid , stereochemistry , propionate , metabolite , absolute configuration , bacteria , total synthesis , antibiotics , phenylalanine , acetic acid , derivative (finance) , biochemistry , biosynthesis , amino acid , enzyme , biology , financial economics , economics , genetics
Three closely related new metabolites named ripostatins were isolated from the myxobacterium Sorangium cellulosum and their structures elucidated by spectroscopic methods. Two of them, ripostatin A ( 1a, b ) and B ( 2a ), are 14‐membered macrolides with an acetic acid and a phenylalkyl side chain, whereas the third metabolite ripostatin C ( 3a ) is an acyclic derivative of ripostatin A. By application of the method of Helmchen the absolute stereochemistry could be determined as (11 R ,13 R ) for ripostatin A, 11 R ,13 S ,15 R for ripostatin B and 11 S for ripostatin C. The polyketide origin of A was revealed by feeding experiments with 13 C‐labeled precursors demonstrating the incorporation of one molecule of phenylacetic acid derived from phenylalanine, one propionate unit, and ten acetate units.