Pentacyclic antibiotics from a tidal mud flat-derived actinomycete.
J Nat Prod
; 78(3): 524-9, 2015 Mar 27.
Article
em En
| MEDLINE
| ID: mdl-25495422
ABSTRACT
The combination of investigating a unique source of chemically prolific bacterium with an LC/MS-based bacterial strain selection approach resulted in the discovery of two new secondary metabolites, buanmycin (1) and buanquinone (2), from the culture of a marine Streptomyces strain, which was isolated from a tidal mudflat in Buan, Republic of Korea. The carbon backbone of buanmycin (1), comprising 20 quaternary carbons out of 30 total carbons, was determined via (13)C-(13)C COSY NMR analysis after labeling 1 with (13)C by culturing the bacterium with (13)C-glucose. The complete structure of 1 was confidently elucidated, primarily based on 1D and 2D NMR spectroscopic and X-ray crystallographic analysis, as that of a new pentacyclic xanthone. The absolute configuration of the α-methyl serine unit in 1 was established by applying the advanced Marfey's method. The structure of buanquinone (2) was determined to be a new pentacyclic quinone based on NMR and MS spectroscopic data. Buanmycin exhibited potent cytotoxicity against colorectal carcinoma cells (HCT-116) and gastric carcinoma cells (SNU-638) with submicromolar IC50 values and strongly inhibited the pathogenic Gram-negative bacterium Salmonella enterica (MIC = 0.7 µM). In particular, buanmycin demonstrated inhibition of sortase A, which is a promising target for antibiotic discovery.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Quinonas
/
Streptomyces
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Actinobacteria
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Compostos Heterocíclicos de 4 ou mais Anéis
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Antibacterianos
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Antineoplásicos
País/Região como assunto:
Asia
Idioma:
En
Revista:
J Nat Prod
Ano de publicação:
2015
Tipo de documento:
Article