Samples from each disc were divided into three zones

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Unformatted text preview: %), alkali soluble (39.24 %) and ash content (2.73 %) were observed in the top portion with positive correlation with height portion. The lignin and holocellulose content were insignificantly affected by the height portion and board properties. In general, chemical properties of oil palm trunk particle do not affect on the particleboard properties. 171 23rd-25th June 2010 3rd ICYC 2010 Universiti Sains Malaysia NAT-P4 EUGENOL: A NATURAL PRODUCT IN CLOVE THAT INHIBITS MYCOTOXIGENIC FUNGI AND MYCOTOXIN BIOSYNTHESIS IN RICE GRAINS K.R.N. Reddy, N.I. Farhana, S.B. Nurdijati, B. Saad and B. Salleh School of Biological and Chemical Sciences, Universiti Sains Malaysia, 11800 Pulau Pinang, Malaysia E-mail: drkrnreddy@gmail.com Rice grains are colonized by mycotoxigenic fungi at or immediately after harvest. The antifungal component of cloves (Syzygium aromaticum = Eugenia aromaticum ) was isolated, characterized and tested for efficacy against mycelial growth of Aspergillus spp. and Penicillium citrinum and their mycotoxin (aflatoxin B1 and citrinin) biosynthesis. The major component, eugenol was extracted from cloves and identified on TLC plate as dark colored spot with R f 0.5 along with standard. This compound was purified by column chromatography. HPLC of this sample showed the eugenol peak at RT 5.03 minutes with 79.3 % purity. Based on the HPLC results, 1 g of powdered cloves contained 40 mg of 13 eugenol. The proton and C NMR confirmed the identity of eugenol. IR spectru m of this sample showed -1 +1 OH functional group at 3462 cm and the molecular weight was estimated at M/z 165 (m peak) by mass spectrometry, which agreed with the eugenol composition C 10H12O2. For bioautography test, TLC plates were spray inoculated with Aspergillus flavus, A. parasiticus, A. niger, A. ochraceus and Penicillium citrinum. Eugenol on TLC inhibited mycelial growth of all fungi tested. In agar diffusion tests, eugenol produced inhibition zones ranging from 30 to 55 mm at 4.8 mg/disc depending on the Aspergillus spp. tested and completely inhibited Penicillium citrinum. On rice grains treated with eugenol at 1.8 mg/g and 2.4 mg/g citrinin and aflatoxin B1 biosynthesis...
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