Abstract
The fatty acid compositions and the positional distributions of fatty acids in triacylglycerols were investigated on the lipids extracted from steer bones (radius, tibia and rib) and pig bones (humerus, femur, scapula, lumber vertebra and rib). Bone marrow lipids tested in this study were largely composed of neutral lipids. The predominant fatty acids of lipids from steers were C16:0, C16:1, C18:0 and C18:1, and it was noticed that the lipids were abundant in C18:1 and that radius and tibia neutral lipids contained a small amount of C18:0. Although the fatty acid compositions of lipids from radius were similar to that of tibia, the lipids from rib contained more C18:0 and total saturated acids and less C18:1 than the lipids from radius or tibia on neutral lipid fractions and also on phospholipid fractions. The predominant fatty acids present in pig bone marrow lipids were C16:0, C18:0, C18:1 and C18:2, and the fatty acid compositions were comparatively resembled among the lipids from bones of different anatomical locations on both the neutral lipids and phospholipids. In general, bone marrow phospholipids contained less C16:1 and C18:1 and more polyunsaturated fatty acids such as C20:3, C20:4, C22:5 and C22:6 than neutral lipids in all bones tested. And, the lipids from steers contained more C16:1, C18:1 and total unsaturated acids and less C16:0 and C18:2 than the lipids from pig marrows. In the case of steer bone marrow triacylglycerols, C16:0 and C18:0 predominated in position 1, C18:1 was preferentially distributed on positions 2 and 3, and C18:2 was mostly present in position 2. Consequently, positions 2 and 3 of triacylglycerols from radius and tibia were occupied nearly 90% by unsaturated acids. In the case of pig bones, C14:0, C16:0 and C16:1 were predominantly esterified to position 2, whereas C18:1 was preferentially esterified to positions 1 and 3, and C18:2 was similar to C18:1, with preference for positions 1 and 3. From these results, contrary to steer bone lipids, position 2 of pig bone marrow triacylglycerols was largely occupied by saturated acids, and position 3 was predominantly occupied by unsaturated acids.
