IDENTIFICATION AND QUANTIFICATION OF NONVOLATILE LIPOPHILIC SUBSTANCES IN FRESH SAPWOOD AND HEARTWOOD OF LODGEPOLE PINE (PINUS-CONTORTA DOUGL)

Content and composition of lipophilic extractives from fresh sapwood and heartwood of lodgepole pine (Pinus contorta Dougl.) were investigated by solid-phase extraction, GC and GC-MS technique. The acetone extractive content in sapwood was 1.9-2.2 % of oven dry wood, among which were included 1.1-1.3% triglycerides, 0.02-0.03 % free fatty acids, 0.3-0.4 % free resin acids, 0.15-0.21 % steryl esters and waxes, 0.02 % monoglycerides, and 0.02-0.03 % sterols, fatty alcohols and diglycerides. A Triglycerides considerably higher amount of extractives es was present in heartwood, i.e., 10-12 %, including 0.6-0.7 % triglycerides, 0.8-1.1 % free fatty acids, 4.0-5.6 % free resin acids, 0.25-0.33 % steryl esters and waxes, 0.4-.5 % monoglycerides, and 0.08-0.1 % sterols, fatty alcohols and diglycerides. The most abundant fatty acid residues in the wood triglycerides were oleic (18:1), linoleic (18:), linolenic (18:3) and palmitic (16:0) acids. Together they formed about 85 % and 65 % of the total fatty acid composition in the sapwood and heartwood trigycerides, respectively. Of the steryl esters and waxes, 18:2 was the most dominant residue, followed by 18:3 and 18:1. Twelve major free fatty acids and seven free resin acids were identified and quantified. The abundant free fatty acids in both sapwood and heartwood were 18:2 and 18:1, making up 32-41 % and 24-28 % of the total fatty acid amount, respectively. Palustric acid was the dominant free resin acid, its relative proportion to the total resin acids was 52 % in the outer sapwood and 29 % in the inner heartwood. Other major resin acids detected included abietic, isoabietic, dehydroabietic, neoabietic acids.