Dipterocarpus crinitus (Dipterocarpaceae) known as “keruing mempelas” by the local is widely distributed in Johor and
Pahang . The stem bark of Dipterocarpus crinitus which was collected from Jengka, Pahang has been extracted in methanol
by cold immersion method. The extract was fractionated by column chromatography to afford 6 fractions (DC1- DC6). Fraction
DC 3 and 4 were further purified by column chromatography and led to the isolation of 5 oligomer resveratrol: !-Viniferin (1),
"-viniferine (2), Hopeaphenol (3), isohopehenol (4) and laevifonol (5). The structure of the compounds were confirmed by one
and two-dimensional NMR analyses and comparison with previous data . The polyphenolic compounds which are known as
phytoalexin were further investigated for antioxidant and damping off disease agent. The antioxidant indicated lower
scavenging activity (DPPH) compared to BHT and ascorbic acid with percent scavenging activity of between 46.6 % to 15.8 %.
However the compounds revealed strong inhibition zone against four genus of fungal i.e Rhizoctonia solani, Fusarium sp,
Pythium sp. and Phytophthora sp., the pathogens of vegetables. In this work we have proved that the stem bark of this timber
which is rich in phytoalexine (the antifungal substance) and are not used in timber industry has great value in combating
damping off disease. In Malaysia, wood dust have been commercialized as antifungal and fertilizer agent .