Abstract：
:Docosahexaenoic acid (DHA) is a semiessential polyunsaturated fatty acid (PUFA) for eukaryotic cells that is found in natural sources such as fish and algal oils and widely used as an ingredient for omega-3 containing foods or supplements. DHA effects are connected to its natural structure with six cis double bonds, but geometrical monotrans isomers can be formed during distillation or deodorization processes, as an unwanted event that alters molecular characteristics and annihilates health benefits. The characterization of the six monotrans DHA regioisomers is an open issue to address for analytical, biological, and nutraceutical applications. Here we report the preparation, separation, and first identification of each isomer by a dual approach consisting of the following: (i) the direct thiyl radical-catalyzed isomerization of cis-DHA methyl ester and (ii) the two-step synthesis from cis-DHA methyl ester via monoepoxides as intermediates, which are separated and identified by nuclear magnetic resonance spectroscopy, followed by elimination for the unequivocal assignment of the double bond position. This monotrans DHA isomer library with NMR and GC analytical characterization was also used to examine the products of thiyl-radical-catalyzed isomerization of a fish oil sample and to evaluate the trans isomer content in omega-3 containing supplements commercially available in Italy and Spain.
journal_name
Chem Res Toxicoljournal_title
Chemical research in toxicologyauthors
Menounou G,Giacometti G,Scanferlato R,Dambruoso P,Sansone A,Tueros I,Amézaga J,Chatgilialoglu C,Ferreri Cdoi
10.1021/acs.chemrestox.8b00021subject
Has Abstractpub_date
2018-03-19 00:00:00pages
191-200issue
3eissn
0893-228Xissn
1520-5010journal_volume
31pub_type
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