Spectroscopic characterization of unusual conjugated linoleic acid (CLA) isomers

✍ Scribed by Jan Fritsche; M. P. Yurawecz; R. Pawlosky; V. P. Flanagan; H. Steinhart; Y. Ku

• Publisher: John Wiley and Sons
• Year: 2001
• Tongue: English
• Weight: 91 KB
• Volume: 24
• Category: Article
• ISSN: 1615-9306
• DOI: 10.1002/1615-9314(20010101)24:1<59::aid-jssc59>3.0.co;2-z

✦ Synopsis

Conjugated linoleic acid isomers (CLA) have sparked considerable interest due to their reported beneficial physiological properties [1]. Recently, Sehat et al. [2] reported the separation and characterization of 12 CLA isomers in a synthetic reference mixture by means of silver-ion high performance liquid chromatography (Ag + -HPLC), gas chromatography-mass spectrometry (GC-MS), and gas chromatography-direct deposition-Fourier transform-infrared spectroscopy (GC-DD-FTIR). Subsequent improved separation of CLA isomers by coupling up to six Ag + -HPLC columns was achieved, especially with respect to geometrical isomers [3, 4]. In the present study, three previously not reported CLA isomers were spectroscopically characterized in a synthetic CLA mixture, namely 6trans,8trans-18 : 2; 13trans,15trans-18 : 2, and 6,8 cis/ trans-18 : 2. Furthermore, the identities of both geometrical 12,14 cis/trans isomers were confirmed by means of GC-MS (4,4-dimethyloxazoline (DMOX) derivatives) and Ag + -HPLC-DAD.