RESUMO
Four undescribed sesquiterpenoids, lemneolemnanes A-D (1-4), have been isolated from the marine soft coral Lemnalia sp. The absolute configurations of the stereogenic carbons of 1-4 were determined by single-crystal X-ray crystallographic analysis. Compounds 1 and 2 are epimers at C-3 and have an unusual skeleton with a formyl group on C-6. Compound 3 possesses an uncommonly rearranged carbon skeleton, while 4 has a 6/5/5 tricyclic system. Compound 1 showed significant anti-Alzheimer's disease (AD) activity in a humanized Caenorhabditis elegans AD pathological model.
Assuntos
Antozoários , Caenorhabditis elegans , Sesquiterpenos , Animais , Antozoários/química , Sesquiterpenos/farmacologia , Sesquiterpenos/química , Sesquiterpenos/isolamento & purificação , Caenorhabditis elegans/efeitos dos fármacos , Cristalografia por Raios X , Doença de Alzheimer/tratamento farmacológico , Modelos Animais de Doenças , Humanos , Estrutura MolecularRESUMO
Four new polyhydroxylated steroids plaksterols A-D (1-4), together with two known related steroids ergost-7,9(11),22-trien-3ß,5α,6α-triol (5) and ergosta-6ß-methoxy-7,22-diene-3ß,5α-diol (6), were isolated from methanol extract of the South China Sea marine sponge Plakortis sp. Their structures were identified by spectroscopic analysis, including NMR, MS, and IR. The cytotoxicity of the polyhydroxylated steroids were evaluated, and compound 6 showed moderate inhibitory activities against K562, HL-60 and BEL-7402 cells.