Lignans from the fruits of Pandanus kaida Kurz. (Pandanaceae) and theirs a-Glucosidase inhibitory activities

Abstract

Pandanus kaida Kurz is a arbsute, which is combined with others medical plants for treatment of kidney stones, epididymitis and eyes diseases in Vietnamese traditional medicines. However, little scientific publication is available for this plant. The aim of this study is to isolate chemical constituents of the fruits of Pandanus kaida K. (Pandaceae) in order to provide more information to add to the database of medical plants in Vietnam. Results showed five compounds including: epi-pinoresinol (1), (+)-pinoresinol (2), (+)-syringaresinol (3), (+)-medioresinol(4), and (+)-isolariciresinol (5), which have been isolated from the fruits of Pandanus kaida K. (Pandanaceae), collected in Duc Hoa District, Long An Province, Vietnam. Extraction was carried out by heating under reflux and liquid-liquid extraction with organic solvents of increasing polarity to yeild corresponding soluble fractions, then, using chromatography methods such as column chromatography on silica gel, preparative TLC and eluting with organic solvents of different polarity for obtaining five compounds. Their chemical structures were elucidated based on the NMR spectroscopic analysis, HR-ESI-MS, the specific optical rotation and comparison with the literature. Three lignans (+)-pinoresinol (2), (+)-syringaresinol (3), and (+)-medioresinol (4) showed potent a-glucosidase inhibitory activity.