Antioxidant and antimicrobial activities of Saraca thaipingensis Cantley ex Prain

ABSTRACT

Objective: To investigate antioxidant and antimicrobial activities of Saraca thaipingensis Cantley ex Prain; and isolation of its flower extracts. Methods: The plant species (flowers, leaves, and twigs) were extracted by hexane, dichloromethane, ethyl acetate and methanol; and tested for antioxidant activity (DPPH assay) and antimicrobial activity (agar dilution method) against twenty-seven strains of microorganisms; gram positive and gram negative bacteria, and diploid fungus. Bioactive constituents were isolated by column chromatography. Results: The plant extracts has been firstly reported to display strong antioxidant activity and antimicrobial activity selective against gram positive bacteria (Corynebacterium diphtheriae NCTC 10356 and Streptococcus pyogenes) with MIC of 256 μg/mL. Stigmasterol and a mixture of triterpenoids and phenolic compounds were isolated from the flower extracts. Conclusions: The study revealed that the S. thaipingensis is a new source of natural antioxidants and antimicrobials with potential for medicinal uses.