RESUMO
Dermacoccus abyssi sp. nov. strains MT1.1 and MT1.2 are actinomycetes isolated from a Mariana Trench sediment at a depth of 10 898 m. The fermentation process using complex media led to the production of three new pigmented heteroaromatic (oxidized and reduced) phenazine compounds, dermacozines H-J (1-3). Extensive use was made of 1D and 2D NMR experiments and high-resolution MS to determine the structures of the compounds. The new dermacozines showed radical scavenging activity, and the highest activity was observed for dermacozine H (1), with an IC50 value of 18.8 µM.
Assuntos
Actinomycetales/química , Sequestradores de Radicais Livres/isolamento & purificação , Fenazinas/isolamento & purificação , Compostos de Bifenilo/farmacologia , DNA Bacteriano/genética , Sequestradores de Radicais Livres/química , Sequestradores de Radicais Livres/farmacologia , Sedimentos Geológicos/química , Concentração Inibidora 50 , Estrutura Molecular , Ressonância Magnética Nuclear Biomolecular , Oxirredução , Fenazinas/química , Fenazinas/farmacologia , Filogenia , Picratos/farmacologiaRESUMO
Dermacoccus abyssi sp. nov., strains MT1.1 and MT1.2 are actinomycetes isolated from Mariana Trench sediment at a depth of 10 898 m. Fermentation using ISP2 and 410 media, respectively, lead to production of seven new oxidized and reduced phenazine-type pigments, dermacozines A-G (1-7), together with the known phenazine-1-carboxylic acid (8) and phenazine-1,6-dicarboxylic acid (9). Extensive use was made of 1D and 2D-NMR data, and high resolution MS to determine the structures of the compounds. To confirm the structure of the most complex pentacyclic analogue (5) we made use of electronic structure calculations to compare experimental and theoretical UV-Vis spectra, which confirmed a novel structural class of phenazine derivatives, the dermacozines. The absolute stereochemistry of dermacozine D (4) was determined as S by a combination of CD spectroscopy and electronic structure calculations. Dermacozines F (6) and G (7) exhibited moderate cytotoxic activity against leukaemia cell line K562 with IC(50) values of 9 and 7 microM, respectively, while the highest radical scavenger activity was observed for dermacozine C (3) with an IC(50) value of 8.4 microM.