title: Synthesis and biological evaluation of novel leucomycin analogues modified at the C-3 position. I. Epimerization and methylation of the 3-hydroxyl group.
abstract: The synthesis and biological evaluation of sixteen-membered macrolides modified at the C-3 position are described. 3-Epi-leucomycin A7 (9), 3-O-acyl-3-epi-leucomycin A7 analogues (11a-11e), 3-O-acylleucomycin A7 analogues (13b-13e) and 3-O-methylleucomycin analogues (16a, 16b and 22) were synthesized via fully protected intermediates (7, 5a, 5b and 20). After appropriate modification, subsequent deprotections were performed to furnish a variety of leucomycin analogues. Methylation of the 3-hydroxyl group was found to improve the pharmacoprofile of leucomycin antibiotics. 3-O-Methylrokitamycin (16b) showed enhanced antibacterial activity in vitro and 3,3''-di-O-methyl-4''-O-(3-methylbutyl)leucomycin V (22) exhibited improved metabolic stability in rat plasma in vitro.
authors.affiliation: Pharmaceutical Research Center, Meiji Seika Kaisha, Ltd., 760 Morooka-cho, Kohoku-ku, Yokohama 222-8567, Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Furuuchi
authors.forename: Ken-ichi
authors.initials: K
authors.lastname: Kurihara
authors.forename: Takuji
authors.initials: T
authors.lastname: Yoshida
authors.forename: Keiichi
authors.initials: K
authors.lastname: Ajito
mesh_terms: D000900:Anti-Bacterial Agents / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology*; D006193:Haemophilus influenzae / Q000187:drug effects; D007933:Leucomycins / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology*; D008745:Methylation; D008826:Microbial Sensitivity Tests; D016982:Micrococcus luteus / Q000187:drug effects; D015394:Molecular Structure; D001936:Moraxella catarrhalis / Q000187:drug effects; D013211:Staphylococcus aureus / Q000187:drug effects; D013296:Streptococcus pneumoniae / Q000187:drug effects
chemical_list: D000900:Anti-Bacterial Agents; D007933:Leucomycins