title: Hygrocins a and B, naphthoquinone macrolides from Streptomyces hygroscopicus.
abstract: Two new naphthoquinone macrolides, hygrocins A (1) and B (2), were isolated from the fermentation broth of Streptomyces hygroscopicus. Hygrocin A is not stable due to the presence of an active methylene group (C-22), which undergoes intramolecular aldol condensation with the quinone ring to yield a gamma-lactam derivative, 6. Its structural elucidation was achieved by chemical conversion to 3, an unusual diazomethane derivative, and confirmed by its alkaline hydrolysis product 4, hydrogenation derivative 5, and "degradation" product 6. The structure of hygrocin B was determined by combined chemical and spectroscopic methods.
authors.affiliation: Chemical and Pharmaceutical Development, and Chemical and Screening Sciences, Wyeth Research, 401 N. Middletown Road, Pearl River, New York 10965, USA. caip@wyeth.com
authors.forename: Ping
authors.initials: P
authors.lastname: Cai
authors.forename: Fangming
authors.initials: F
authors.lastname: Kong
authors.forename: Mark E
authors.initials: ME
authors.lastname: Ruppen
authors.forename: Greg
authors.initials: G
authors.lastname: Glasier
authors.forename: Guy T
authors.initials: GT
authors.lastname: Carter
mesh_terms: D047029:Lactams, Macrocyclic; D018942:Macrolides / Q000737:chemistry* / Q000302:isolation & purification*; D015394:Molecular Structure; D009285:Naphthoquinones / Q000737:chemistry* / Q000302:isolation & purification*; D019906:Nuclear Magnetic Resonance, Biomolecular; D013302:Streptomyces / Q000737:chemistry*
chemical_list: D047029:Lactams, Macrocyclic; D018942:Macrolides; D009285:Naphthoquinones; C506975:hygrocin A; C506976:hygrocin B