Cis, trans isomerism of the eleostearate isomers

Abstract

Summary The cis, trans isomers of the conjugated trienes present a difficult problem for complete determination of structure. Several methods of attack have been outlined, and application of two of them have been made to α and β eleostearic acids, α and β licanic acids, and to pseudoeleostearic acid. These results indicate the following structures: α eleostearic: cis‐9, trans‐11, trans‐13 β eleostearic: trans‐9, trans‐11, trans‐13 pseudoeleostearic: trans‐10, trans‐12, trans‐14 α licanic: 4‐keto, cis‐9, trans‐11, trans‐13 β licanic: 4‐keto, trans‐9, trans‐11, trans‐13

Analysis of oleate and linoleate hydroperoxides in oxidized ester mixtures

“…The four peaks are believed to be caused by cis-trans and positional isomers. When the TMS-ether was treated with iodine, the ultraviolet absorption maximum shifted from 233 to 231 nm as found by Nichols et al (11), the infrared peak at 950 cm 1 disappeared and the peak 982 cm -l shifted to 988 cm t, typical of a shift to trans-trans conjugation (12,13). GLC revealed that iodine treatment caused a marked decrease in the first of the four peaks and an increase in the last.…”

Composition, Physical Properties and Drying Characteristics of Seed Oil of Momordica charantia Cultivated in Sri Lanka

“…1) showed a characteristic doublet at wave numbers 991 and 962 cm -1 . A previous study on isomers of eleosteric acid identified a strong spectral band at 993 cm -1 corresponding to b-eleosteric acid and a doublet having a strong band at 991 cm -1 and a weaker band at 963 cm -1 corresponding to trans:trans and cis:trans conjugated double bonds in the a-eleosteric acid, respectively [15]. Therefore, it could be concluded that the corresponding doublet in Fig.…”

Characterization of White Mahlab (Prunus mahaleb L.) Seed Oil: A Rich Source of α‐Eleostearic Acid

“…Moreover, the IR spectra showed a weak band at 948 cm −1 . Paschke and others () reported that trans:trans conjugated double bands show a single strong band at 988 cm −1 , whereas conjugate cis:trans double bands show a doublet stronger at 982 cm −1 and weaker at 948 cm −1 . The infrared spectrum also exhibited typical absorption bands at 3009 cm −1 (the C‐H stretching vibration of the cis ‐double bond [= CH]), 2926 and 2854 cm −1 (the symmetric and asymmetric stretching vibrations of the aliphatic CH 2 and CH 3 groups), 1745 cm −1 (the ester carbonyl functional group of the triacylglycerols), 1464 cm −1 (the bending vibrations of the CH 2 and CH 3 aliphatic groups), 1377 cm −1 (the bending vibrations of the CH 2 groups), 1163 cm −1 (the stretching vibration of the C‐O ester groups) and 724 cm −1 (the overlap of the CH 2 rocking vibration and the out‐of‐plane vibration of the cis ‐disubstituted olefins).…”