Antioxidant and antimicrobial alkaloids isolated from twigs of Uvaria grandiflora Roxb

Abstract

Phytochemical investigation of the MeOH-EtOAc (1:1 v/v) soluble fraction partitioned from the MeOH extract of twigs of Uvaria grandiflora Roxb. led to the isolation of six known compounds including aristolactam AII (1), aristolactam BI (2), velutinam (3), griffithinam (4), isoursuline (5), and sinactine (6). Their structures were determined on the basis of spectroscopic analysis and comparison with the literature data. Described in this work is the first report of isoursuline (5), an azafluorene derivative, and sinactine (6), a tetrahydroepiberberine, being isolated from plants in the Uvaria genus. Antioxidant and antimicrobial activities of some isolated compounds were evaluated. Among screened compounds, velutinam (3) showed antioxidant activity in the DPPH radical scavenging assay.