RESUMO
Six undescribed lanostane triterpenoids (1-6), together with three known compounds (7-9) were isolated from Inonotus obliquus. Compounds 3-5 are the rare natural compounds featuring a 4,5-seco-lanostane core with a 5,7,9-trien-21,24-cyclopentane moiety. The structure elucidation of the compounds was conducted by spectroscopic techniques and the ECD method. The absolute configuration of compound 1 was confirmed by single-crystal X-ray diffraction analysis. All isolated compounds were assayed for their neuroprotective activity against H2O2-induced cell injury using human neuroblastoma SH-SY5Y cells. Compound 9 exhibited the most potent neuroprotective activity and the flow cytometry analysis indicated that 9 could protect SH-SY5Y cells from oxidative damage by inhibiting cell apoptosis.
Assuntos
Antineoplásicos/química , Misturas Complexas/química , Inonotus/química , Lanosterol/química , Neuroblastoma/tratamento farmacológico , Fármacos Neuroprotetores/química , Triterpenos/química , Antineoplásicos/farmacologia , Produtos Biológicos/química , Produtos Biológicos/farmacologia , Linhagem Celular Tumoral , Cromatografia Líquida , Misturas Complexas/farmacologia , Avaliação Pré-Clínica de Medicamentos , Humanos , Peróxido de Hidrogênio/metabolismo , Conformação Molecular , Estrutura Molecular , Fármacos Neuroprotetores/farmacologia , Estresse Oxidativo/efeitos dos fármacos , Triterpenos/farmacologiaRESUMO
Four pairs of ß-carboline enantiomers (1A: /1B: -4A: /4B: ), 2 ß-carboline derivatives (5: â-â6: ) with a single enantiomeric configuration, together with 2 known achiral congeners (7: â-â8: ) were isolated from the stems of Picrasma quassioides. Their structures were elucidated on the basis of extensive spectroscopic analyses and quantum mechanical calculations. Compound 5: possesses a 4,5-seco ß-carboline framework and represents the first example of this type of ß-carboline alkaloids from nature. A possible biosynthetic pathway is proposed to generate the racemate 4: and the enantiomerically pure compounds 5: and 6: . All isolates were screened for their cytotoxicity against hepatocellular carcinoma Hep3B and HepG2 cells, which revealed that enantiomeric compounds 4A: and 4B: had distinctive effects in HepG2 cells. Further investigation showed that 4B: could induce apoptosis in HepG2 cells.