Abstract
Carotenoids are well-known antioxidants. They have the ability to quench singlet oxygen and scavenge toxic free radicals preventing or reducing damage to living cells. We have found that carotenoids exhibit scavenging ability towards free radicals that increases nearly exponentially with increasing the carotenoid oxidation potential. With the oxidation potential being an important parameter in predicting antioxidant activity, we focus here on the different factors affecting it. This paper examines how the chain length and donor/acceptor substituents of carotenoids affect their oxidation potentials but, most importantly, presents the recent progress on the effect of polarity of the environment and orientation of the carotenoids on the oxidation potential in supramolecular complexes. The oxidation potential of a carotenoid in a nonpolar environment was found to be higher than in a polar environment. Moreover, in order to increase the photostability of the carotenoids in supramolecular complexes, a nonpolar environment is desired and the formation of hydrogen bonds should be avoided.
Highlights
Carotenoids are a group of compounds widely existing in nature
The goal of this paper is to provide guidance for designing novel supramolecular carotenoid complexes, by modifying hosts or searching for new delivery systems for carotenoids, as this is very important in the pharmaceutical, food and cosmetic industries
The antioxidant activities of the complexes are very important from the point of view of their application and storage stability
Summary
Carotenoids are a group of compounds widely existing in nature. They are based on a C40-tetraterpenoid skeleton and are usually classified into two main groups: hydrocarbon carotenoids, known as carotenes (e.g., β-carotene and lycopene), and carotenoids containing oxygen, known as xanthophylls (e.g., canthaxanthin and lutein). Since the ability of scavenging free radicals and shelf lives of carotenoids in delivery systems are both related to the antioxidant activities of the carotenoids, the factors affecting the oxidation potentials of carotenoids need to be examined. The first oxidation potentials (E0) of the selected carotenoids [21,46,47,48,49] shown in Figure 3 are different depending on the conjugation lengths and electron donor/acceptor substituents. Echinenone contains one less electron-withdrawing carbonyl group than canthaxanthin, and the oxidation potential is much lower than that of canthaxanthin (676 vs 775 mV), the conjugation length is slightly shorter than that of canthaxanthin (the NDBs are 12 and 13, respectively). FiFgiugruere3.3.SStrtuructcutureress, ,nnuummbbeerr ooffddoouubblelebobnodnsd(sN(DNBD)Ba)ndanfidrstfiorxstidoaxtiiodnatpioontenptoiatelsn(tviasl.sSC(vEs). oSfCsEel)ecotfed secleacrtoetdencoairdost.eTnhoiedosx. iTdhaetioonxipdoatteinontiaplsowteenrteiamlsewaseurreedmienaCsuHre2Cdl2inbyCtHh2eCml2ebthyodthoef mcyectlhicodvooltfamcymcleictry vo(lCtaVm) mwietthryme(aCsVur)emweintht ermroera±su1r0emmVe.nTt heerrreoferre±n1c0e emlecVtr.odTehueserdefienrethnecemeealseuctrreomdeentus sweads sianturthateed mceaalsoumreeml eelnectstrwodaes (sSaCtuEr)a. tCedalicbarlaotmioenl welietchtrfoerdreoc(eSnCeEg).aCvealtihberaptiootnenwtiaitlhs cfeorrrroeccteendetgoaSvCeEth[e46p,4o8te].n8ti6alms V cowrraesctaedddetod StoCtEhe[4p6o,4te8n].ti8a6lsmreVpowrtaesd ainddReedf. t[o47t]hteo pcoortreencttiafolsr rtehpeoarbtseednicne oRfeffe. r[r4o7c]etnoe ccoarlirbercattfioonr .thTehis abasdendciteioonf fwerarsoscheonwe ncatloibbraetnioene.dTedhiisnatdhdeiteixoanmwpalessshgiovwenn itno Rbeefn. e[4e6d]e.dTihnetchaerbeoxnamatpolmessgairveennuinmRbeefr.ed [46fo].rTβh-ecacraortbeonne.atoms are numbered for β-carotene
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
