Optical activity of lactones from animal and vegetable fats

Abstract

The isolation of optically active lactones from animal and vegetable fats is described. As the optical activity of lactones isolated from butterfat is ascribed to their biological origin, special attention was paid to the optical purity of the lactones. Lactone mixtures from butterfat, goat milk fat and coconut oil were found to be dextrorotatory, those from babassu oil levorotatory. The total lactone mixtures of two out of three samples of palm‐kernel oil were slightly dextro‐, whereas that of the third one was levorotatory. After isolation of the individual lactones from the mixtures, levo‐ and dextrorotatory lactones were demonstrated side by side in palm‐kernel oil and in coconut oil. The δ‐lactones of palmkernel oil were levo‐, the γ‐isomers dextrorotatory. In coconut oil only the δ‐C12 lactone was levorotatory, whereas the other components of the δ‐series were dextrorotatory. The specific rotation [a]d of the chemically pure lactones was considerably lower than that of model lactones, this being an indication of their optical impurity. As it was evident from model experiments that no racemization of the lactones occurred during isolation, it follows that both optical antipodes are formed in the fats in unequal amounts, via different pathways.

Testing Methods of Weathered Specimen

“…IR spectrophotometry 48,83,101,102,[106][107][108][112][113][114][115] is the predominant method for analyzing the changes in weathered specimens. IR has been used to study acrylonitrile-butadiene-styrene copolymer, ABS, low density polyethylene, LDPE, high density polyethylene, HDPE, polypropylene, PP, acrylic/urethane, polyurethane, PU, polystyrene, PS, polycarbonate, PC, polyisobutylene, PIB, polyesters, polyamide, PA, acrylic resins, epoxy resins, EP copolymer, polyoxymethylene, POM, polyvinylchloride, PVC, cotton, coatings of 145-54, 2011.…”

“…Confocal Raman microscopy was also used to demonstrate gradual increase in crystallinity of surface regions of naturally aged polyethylene. 254 13.11 NUCLEAR MAGNETIC RESONANCE 1 H NMR and 13 C NMR spectra 94,95,114,127,131,132,146,150,159,163,179,182,201,208,213,215,217,[255][256][257][258][259][260][261][262][263][264] were used to characterize changes in polysulfones, unsaturated polyester resins, polyurethanes, polyethylene, polyacetal, polystyrene, dyed fibers, and coatings. 252,253 Non-destructive properties of the method are important in these studies.…”