Extractives in Acacia mangium and Acacia crassicarpa stemwood and knots

Acacia mangium stemwood contained over 1% of hexane-soluble extractives, whereas A. crassicarpa contained only 0.1-0.2%. The amount of lipophilic extractives was on the same level in heartwood and sapwood, while knots contained smaller amounts. Long-chain saturated fatty acids, hydroxyl fatty acids and alcohols, with 22 to 28 carbon atoms, make up the major part of the extractives in A. mangium. A crassicarpa contains mainly short-chain fatty acids with 16 to 20 carbon atoms. Polyphenols in heartwood, sapwood, and knots of A. mangium and A. crassicarpa were analysed on GC, GC-MS, HPSEC, and NMR. Melacacidin and isomelacacidin dominated in A. crassicarpa and teracacidin and its corresponding flavan-4-one in A. mangium samples. Also bi- and triflavonoids were found in the samples. The amounts of polyphenols were larger in the knots than in the heartwood of both species, while the composition within species was the same.