Effects of a novel medium-long-medium-type structured lipid synthesized using a two-step enzymatic method on lipid metabolism and obesity protection in experimental mice.

We synthesized a novel, structured lipid containing caprylic acid at its -1,3 position and docosahexaenoic acid at its -2 position (1,3C-2D-TAG) by using a two-step enzymatic method and then investigated the relationship between the types of fatty acids in the structured lipid and their physiological functions. Furthermore, we compared the effects of similarly structured lipids on postprandial lipid metabolism and obesity protection. The results revealed that the novel structured lipid synthesized using the enzymatic method not only exhibited better physical properties than traditional oils but also had high oxidation stability and crystallization degree. In terms of physiological function, the low-dose 1,3C-2D-TAG group exhibited higher cholesterol and triglyceride levels, lower kidney weight or body weight, and higher serum aspartate aminotransferase and blood urea nitrogen levels than control group, whereas the high-dose 1,3C-2D-TAG group exhibited higher triglyceride levels. Moreover, the medium-dose 1,3C-2D-TAG group had remarkably higher high-density lipoprotein cholesterol levels and lower low-density lipoprotein cholesterol levels than the high-lipid, control, and 1,2,3C-TAG groups; however, the cholesterol and triglyceride levels and kidney and liver functions did not differ significantly among these groups. The study results suggest that 1,3C-2D-TAG can not only facilitate the effective utilization of the energy supplied by medium-chain fatty acids but also help overcome difficulties in the absorption of long-chain polyunsaturated fatty acids.