title: Studies on mycobacillin derivatives. IV. O-methylation of the antibiotic and identification of the active tyrosine residue.
abstract: Methylation of myocobacillin with dimethyl sulfate and methyl iodide produced respectively mono- and di-methyl derivatives. the products were inactive against fungal spores and erythrocytes. Tyrosine hydroxyl groups only were methylated; in the monomethyl derivative, the hydroxyl of the tyrosine residue in position 6 is methylated, whereas the hydroxyl of the tyrosine in position 4 remains free; both hydroxyl groups are methylated in the dimethyl derivative. The results indicate that the hydroxyl group of the tyrosine residue in position 6 is essential for the biological activity of mycobacillin.
mesh_terms: D000935:Antifungal Agents / Q000494:pharmacology; D001230:Aspergillus / Q000187:drug effects; D055598:Chemical Phenomena; D002621:Chemistry; D004912:Erythrocytes / Q000187:drug effects; D009158:Mycobacillin / Q000031:analogs & derivatives / Q000494:pharmacology; D013172:Spores, Fungal / Q000187:drug effects; D013329:Structure-Activity Relationship
chemical_list: D000935:Antifungal Agents; D009158:Mycobacillin