RESUMO
Five new naphthalenones, two enantiomers (−)-1 and (+)-1 leptothalenone A, (−)-4,8-dihydroxy-7-(2-hydroxy-ethyl)-6-methoxy-3,4-dihydro-2H-naphthalen-1-one ((−)-2), (4S, 10R, 4’S)-leptotha-lenone B (5), (4R, 10S, 4’S)-leptothalenone B (6), and a new isocoumarine, 6-hydroxy-5,8-dimethoxy-3-methyl-1H-isochromen-1-one (4), along with two known compounds (+)-4,8-dihydroxy-7-(2-hydroxy-ethyl)-6-methoxy-3,4-dihydro-2H-naphthalen-1-one ((+)-2) and (+)-10-norparvulenone (3) were isolated from the marine-derived fungus Leptosphaerulina chartarum 3608. The structures of new compounds were elucidated by HR-ESIMS, NMR, and ECD analysis. All compounds were evaluated for cytotoxicity and anti-inflammatory activity. Compound 6 showed moderate anti-inflammatory activity by inhibiting the production of nitric oxide (NO) in lipopolysaccharide-stimulated RAW264.7 cells, with an IC50 value of 44.5 μM.
Assuntos
Anti-Inflamatórios não Esteroides/isolamento & purificação , Organismos Aquáticos/química , Ascomicetos/química , Descoberta de Drogas , Macrófagos/efeitos dos fármacos , Naftalenos/isolamento & purificação , Animais , Anti-Inflamatórios não Esteroides/química , Anti-Inflamatórios não Esteroides/farmacologia , Organismos Aquáticos/crescimento & desenvolvimento , Organismos Aquáticos/isolamento & purificação , Ascomicetos/crescimento & desenvolvimento , Ascomicetos/isolamento & purificação , Linhagem Celular Tumoral , China , Cromatografia Líquida de Alta Pressão , Equinodermos/crescimento & desenvolvimento , Equinodermos/microbiologia , Humanos , Macrófagos/imunologia , Macrófagos/metabolismo , Espectroscopia de Ressonância Magnética , Camundongos , Estrutura Molecular , Naftalenos/química , Naftalenos/farmacologia , Naftóis/química , Naftóis/isolamento & purificação , Naftóis/farmacologia , Oceano Pacífico , Células RAW 264.7 , Espectrometria de Massas por Ionização por Electrospray , EstereoisomerismoRESUMO
The snow flea Ceratophysella sigillata, a winter-active species of springtail, produces unique polychlorinated octahydroisocoumarins to repel predators. The structure of the major compound, sigillinâ A, was elucidated through isolation, spectroscopic analysis, and X-ray crystallography. Sigillinâ A showed high repellent activity in a bioassay with predatory ants. A promising approach for the total synthesis of members of this new class of natural compounds was also developed.