Antibacterial diterpenes from Calceolaria pinifolia.
J Nat Prod
; 66(2): 242-6, 2003 Feb.
Article
em En
| MEDLINE
| ID: mdl-12608857
ABSTRACT
Two new isopimaranes, 19-methylmalonyloxy-ent-isopimara-8(9),15-diene (5) and 19-malonyloxy-ent-isopimara-8(9),15-diene (6), were isolated using bioassay-guided fractionation of the CH(2)Cl(2)-MeOH (11) extract of the aerial part of Calceolaria pinifolia along with eight other diterpenes (1-4, 7-10) and two triterpenes (11, 12). All compounds were assayed against Staphylococcus aureus (SA), methicillin-resistant S. aureus (MRSA), Bacillus subtilis (BS), and Escherichia coli (EC). 4-Epi-dehydroabietinol (2) and ent-isopimara-9(11),15-diene-19-ol (8) were found to be active against MRSA with MIC values of 8 and 2 microgram/mL, respectively. Mechanistic studies of 8 in BS suggested rapid and nonspecific inhibition of uptake and incorporation of radiolabeled precursors into DNA, RNA, and protein consistent with membrane-damaging effects in bacteria. Compound 8 did not afford protection against an acute infection with SA in mice.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Plantas Medicinais
/
Scrophulariaceae
/
Diterpenos
/
Antibacterianos
Limite:
Animals
/
Female
/
Humans
País/Região como assunto:
America do sul
/
Argentina
Idioma:
En
Revista:
J Nat Prod
Ano de publicação:
2003
Tipo de documento:
Article
País de afiliação:
Estados Unidos