Antifungal and antibacterial naphthoquinones from Newbouldia laevis roots.
From a dichloromethane extract of Newbouldia laevis roots, four new (6-hydroxydehydroiso-alpha-lapachone, 7-hydroxydehydroiso-alpha-lapachone, 5,7-dihydroxydehydroiso-alpha-lapachone and 3-hydroxy-5-methoxydehydroiso-alpha-lapachone) and six known naphthoquinones have been isolated. Their structures were established by spectroscopic methods (UV, EI mass spectrometry, 1H and 13C NMR) and that of 7-hydroxydehydroiso-alpha-lapachone was confirmed by X-ray crystallography. All naphthoquinones showed antifungal activity against Cladosporium cucumerinum and Candida albicans, and activity against the bacteria Bacillus subtilis and Escherichia coli.
Gafner
S
S
Institut de Pharmacognosie et Phytochimie, Université de Lausanne, Switzerland.
Wolfender
J L
JL
Nianga
M
M
Stoeckli-Evans
H
H
Hostettmann
K
K
D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000302:isolation & purification*; D000935:Antifungal Agents / Q000737:chemistry / Q000302:isolation & purification*; D018360:Crystallography, X-Ray; D009285:Naphthoquinones / Q000737:chemistry / Q000302:isolation & purification*; D010946:Plants, Medicinal / Q000737:chemistry*; D013057:Spectrum Analysis
D000900:Anti-Bacterial Agents; D000935:Antifungal Agents; D009285:Naphthoquinones