Bioassay-guided fractionation of extractives from Potoxylon Melagangai

Poloxylon melagangai or Eusideroxylon melagangai comes from the same family as Eusideroxylon zwageri, well-known as Belian. It is the most durable and resistant towards plant-destroying insects as it is good fur construction. Sequential solvent extraction using hexane, dichloromethane, ethyl acetate and methanol have yielded 3.2%,0.8%,4,3% and 7.0% crude extracts by mass. respectively. Dichloromethane and methanol crude extracts were subjected to fractionation on silica gel column chromathography by increasing the polarity of the solvent system. The fractions which showed similar spot on thin layer chromathography (TIC) plate were combined. 17 combined ITactions obtained for the dichloromethane crude extract. and 15 combined fractions were obtained for methanol crude extract. Gas ehromathography- mass spectrometry (GC-MS) analysis on dichloromethane crude extract and combined ITactions shows the presence of 2-ethoxycarbonyl-3-metltyl-4-azafluorenone (23.55%), followed by i-propyl-9-tetradecenoate (8.80%), xanthine (5.27%), 9-octadeccnamide (4.40%), and tetrapentacontane (3.91 %) as the major chemical compositions. Hexane and dichloromethane crude extracts showed bioactivity against Artemia Salina with IC values for both crude extracts are 50 ppm. Ethyl acetate and methanol crude extracts showed high toxicity against Coptotermes sp. with LC,o at concentration < 0.1 'Yo (w/v). 2-ethoxycarbonyl-3-methyl4-azafluorenone and 1,2- benzenedicarboxylic acid are two bioactive compounds that may responsible fur bioactivity in dichloromethane crude extract. No bioactivity was observed for antifungal on all crude extracts and fractions.