Nutritional and metabolic studies of noncyclic dimeric fatty acid methyl esters in the rat

Methyl esters of noncyclic dimeric fatty acids were prepared by fractionation of the crude product ob-tained by heating a mixture of methyl oleate and di-fert-butyl peroxide for 48 hr at 130 C in a high pressure reactor. Rats fed diets containing less than 1% of the noncyclic dimer methyl ester showed no significant difference in growth, feed efficiency, and liver size, from those fed nutritionally adequate diets. The¹⁴C-labeled dimer was also synthesized and administered to rats via gastric intubation. The results indicated that an average of 85% of the radioactivity was recoverable from the gastrointestinal tract and feces within 48 hr of administration and that such an amount was not absorbed by the rat. Within a 48 hr period ca. 5% of the¹⁴C was recovered in the expired CO₂ and about 1% in the urine. Prefeeding rats diets containing dimer did not appear to influence the metabolism of either dimer or methyl oleate.