Abstract

This study was conducted to develop more efficient and environmentally sound methods for the control of anthracnose. Twelve Thai medicinal plants were tested as potential anti-fungal agents against Colletotrichum gloeosporioides Penz. Hexane and ethyl acetate extracts from the pericarp of Areca catechu and hexane extract from the flower buds of Etlingera elatior demonstrated high inhibitory activity of C. gloeosporioides mycelial growth with EC <inf>50</inf> values of 796.2, 803.9 and 803.9 μg mL ^-1, respectively. These extracts were fractionated and purified by column chromatography. Consequently, six compounds from the A. catechu high active extracts and two compounds from the E. elatior high active extract were isolated. Based on the results of structural elucidation, the six compounds obtained from the A. catechu high active extracts were fernenol, arundoin, lauric acid, myristic acid, palmitic acid and a mixure of β-sitosterol and stigmasterol. The two compounds obtained from the E. elatior high active extract were lauric acid and a mixture of p-sitosterol and stigmasterol. The effects of these compounds on spore germination, germtube elongation and appressorium formation were investigated; fernenol was found to provide the highest inhibition in all aspects based on EC <inf>50</inf> values of 45.8, 26.7 and 65.6 μg mL ^-1. Lauric acid, myristic acid and palmitic acid with EC <inf>5</inf>0 > 200 μg mL ^-1 had the least inhibitory activity. The results suggest that the compounds isolated from the pericarp of A. catechu and the flower buds of E. elatior may be applicable for the control of anthracnose diseases.