Anti-termitic potential of heartwood and bark extract and chemical compounds isolated from Madhuca utilis Ridl. H. J. Lam and Neobalanocarpus heimii King P. S. Ashton

The effect of wood extracts as antitermitic agents has been investigated in two Malaysian timber species, namely Madhuca utilis (bitis) and Neobalanocarpus heimii (chengal). The samples taken from Perak State Forest Reserve felled trees with the age of 38 and 45 years old, respectively. The composition of the extracts were analysed by GC-MS. In the toluene/EtOH extracts of M. utilis 19 (bark) and 17 (heartwood, hW) chemical constituents have been identified in total. The dominant compounds in bark were (2Z, 6E)-farnesol (44%) and thymol methyl ether (29%) and in hW terpinen-4-ol (38%) and.-terpinene (16%). The N. heimii essential oils contained 16 chemical constituents (8 in bark and 8 in hW) with benzyl carbinol (62%) and benzyl isoamyl ether (34%) for bark and eicosane (C20) (50%) and cyclopentanone (19%) for hW. Higher concentration of extracts from bark and hW of N. heimii, and from bark of M. utilis) gave 100% mortality of 3rd instars of Coptotermes gestroi Wasmann and 99% for M. utilis hW extract. The extracts of both wood species showed promising antitermitic properties against subterranean termites.