RESUMO
The phytochemical study of Stereocaulon montagneanum harvested in Sumatra (Indonesia) led to the isolation of 11 known compounds including two metabolites not previously described in the genus Stereocaulon, peristictic acid (8) and menegazziaic acid (10). The complete 1H and 13C NMR spectral assignments of stictic acid derivatives are reported with some revisions. Five depsidones belonging to the stictic acid chemosyndrome were superoxide anion scavengers as potent as ascorbic acid and with no toxicity on two human cell lines.
Assuntos
Antioxidantes/farmacologia , Sequestradores de Radicais Livres/farmacologia , Compostos Heterocíclicos de 4 ou mais Anéis/farmacologia , Líquens/química , Oxepinas/farmacologia , Protetores contra Radiação/farmacologia , Superóxidos/metabolismo , Animais , Antioxidantes/química , Antioxidantes/isolamento & purificação , Linhagem Celular , Avaliação Pré-Clínica de Medicamentos , Sequestradores de Radicais Livres/química , Sequestradores de Radicais Livres/isolamento & purificação , Compostos Heterocíclicos de 4 ou mais Anéis/química , Compostos Heterocíclicos de 4 ou mais Anéis/isolamento & purificação , Humanos , Indonésia , Queratinócitos/efeitos dos fármacos , Queratinócitos/efeitos da radiação , Melanoma Experimental , Camundongos , Estrutura Molecular , Ressonância Magnética Nuclear Biomolecular , Oxepinas/química , Oxepinas/isolamento & purificação , Protetores contra Radiação/química , Protetores contra Radiação/isolamento & purificação , Solventes , Raios UltravioletaRESUMO
The diphenyl ether, lobarin (1) (syn. lobariol carboxylic acid) related to lobaric acid was isolated for the first time as a natural product along with five known compounds from Stereocaulon halei, a fruticose lichen collected in Indonesia. The structure of lobarin was elucidated by spectroscopic data analysis and its most stable conformers were determined by molecular mechanic dynamic calculations. A marked superoxide anion scavenging was found for compound 1 while no cytotoxicity on the B16 murine melanoma and HaCaT human keratinocyte cell lines was observed.
Assuntos
Antineoplásicos Fitogênicos/química , Antineoplásicos Fitogênicos/farmacologia , Líquens/química , Éteres Fenílicos/química , Éteres Fenílicos/farmacologia , Animais , Linhagem Celular Tumoral , Humanos , CamundongosRESUMO
The isolation and structural determination of rac-eudesm-7(11)-en-4-ol, C15H26O, from the steam distillate of the flowers of Dipterocarpus cornutus Dyer (Dipterocarpaceae) is described. The structure was determined from spectroscopic data and a single-crystal X-ray study. Two similar independent molecules comprise the asymmetric unit of the structure.