ABSTRACT
Sorangicin A, a macrolide polyether antibiotic and the ansamycin antibiotic rifampicin inhibit DNA-dependent RNA polymerase to a similar extent. Resistance to sorangicin A is due to a mutation in the RNA polymerase which renders the enzyme less sensitive. Parallel investigations with rifampicin revealed partial cross-resistance, which was more marked in sorangicin A-resistant mutants than in rifampicin-resistant mutants.
Subject(s)
Aminoglycosides , Anti-Bacterial Agents/pharmacology , Escherichia coli/drug effects , Rifampin/pharmacology , Cross Reactions , DNA-Directed RNA Polymerases/antagonists & inhibitors , Drug Resistance, Microbial , Macrolides , RNA, Bacterial/biosynthesisABSTRACT
Papulacandin B inhibits glucan biosynthesis in cells of Saccharomyces cerevisiae and Candida albicans. Biological studies with a series of papulacandin derivatives showed that the short fatty acid chain and the galactose residue are not required for activity at the target site, but that they can affect penetration. On the other hand, the long fatty acid residue is essential for biological activity.
