ABSTRACT
Two new indolo[3,2-a]carbazoles (1, 2) were isolated from a deep-water collection of a sponge of the genus Asteropus. The structures of 1 and 2 were determined through the analysis of spectroscopic data including mass spectrometry and 2D-NMR. Compound 1 showed minimum inhibitory concentrations of 25 µg/mL against the fungal pathogen Candida albicans and 50 µg/mL against methicillin-resistant Staphylococcus aureus (MRSA). Compounds 1 and 2 showed no cytotoxicity against the PANC1 human pancreatic carcinoma and NCI/ADR-RES ovarian adenocarcinoma cell lines at our standard test concentration of 5 µg/mL.
Subject(s)
Anti-Bacterial Agents/isolation & purification , Carbazoles/isolation & purification , Heterocyclic Compounds, 4 or More Rings/isolation & purification , Indoles/isolation & purification , Porifera/chemistry , Animals , Anti-Bacterial Agents/chemistry , Anti-Bacterial Agents/pharmacology , Bahamas , Candida albicans/drug effects , Carbazoles/chemistry , Carbazoles/pharmacology , Drug Screening Assays, Antitumor , Heterocyclic Compounds, 4 or More Rings/chemistry , Heterocyclic Compounds, 4 or More Rings/pharmacology , Humans , Indoles/chemistry , Indoles/pharmacology , Methicillin Resistance/drug effects , Methicillin-Resistant Staphylococcus aureus/drug effects , Microbial Sensitivity Tests , Molecular Structure , Nuclear Magnetic Resonance, Biomolecular , Staphylococcus aureus/drug effectsABSTRACT
A Gram-positive, rod-shaped, non-spore-forming bacterium (strain K362(T)) was isolated from a deep-water marine sponge collected off the coast of Curaçao in the Netherlands Antilles. On the basis of 16S rRNA gene sequence similarities, strain K362(T) was shown to belong to the genus Tsukamurella, being most closely related to Tsukamurella pulmonis (99.2 %), Tsukamurella tyrosinosolvens (98.9 %), Tsukamurella strandjordii (98.8 %), Tsukamurella pseudospumae (98.8 %) and Tsukamurella spumae (98.8 %). A combination of the substrate utilization patterns, the fatty acid and mycolic acid profiles and the DNA-DNA hybridization results supported the affiliation of strain K362(T) to the genus Tsukamurella and enabled the genotypic and phenotypic differentiation of strain K362(T) from the seven recognized Tsukamurella species. Strain K362(T) therefore represents a novel species of the genus Tsukamurella, for which the name Tsukamurella spongiae sp. nov. is proposed. The type strain is K362(T) (=DSM 44990(T)=NRRL B-24467(T)).