Bioassay-Guided Isolation and Identification of Antifungal Compounds from Polyalthia longifolia Benth. & Hook

Abstract

Antifungal activity of the petroleum ether extract of Polyalthia longifolia leaves was detected by direct bioautography on silica gel TLC plates against Alternaria solani. The active principle was further isolated by bioassay-directed fractionation using column chromatography and followed by GC-MS analysis. Separation of active antifungal principle was done by silica gel column chromatography which produced total ten fractions. Antifungal activity of these fractions was once again checked against Alternaria solani and fraction 1, 2 & 3 were found to be most active. These three active column fractions were further analyzed by gas chromatography-mass spectrometry. The first fraction contain four major compounds are caryophyllene, aromadendrene, viridiflorene and longifolene-(V4) whereas fraction two showed presence of two major compounds are α-guaiene, β-chamigrene.

Keywords:

• Polyalthia longifolia
• petroleum ether extract
• bioautography
• column chromatography
• GC-MS