title: Isolation and spectral characterization of thermally generated multi-Z-isomers of lycopene and the theoretically preferred pathway to di-Z-isomers.
abstract: Lycopene has a large number of geometric isomers caused by E/Z isomerization at arbitrary sites within the 11 conjugated double bonds, offering varying characteristics related to features such as antioxidant capacity and bioavailability. However, the geometric structures of only a few lycopene Z-isomers have been thoroughly identified from natural sources. In this study, seven multi-Z-isomers of lycopene, (9Z,13'Z)-, (5Z,13Z,9'Z)-, (9Z,9'Z)-, (5Z,13'Z)-, (5Z,9'Z)-, (5Z,9Z,5'Z)-, and (5Z,9Z)-lycopene, were obtained from tomato samples by thermal isomerization, and then isolated by elaborate chromatography, and fully assigned using proton nuclear magnetic resonance. Moreover, the theoretically preferred pathway from (all-E)-lycopene to di-Z-isomers was examined with a computational approach using a Gaussian program. Fine-tuning of the HPLC separation conditions led to the discovery of novel multi-Z-isomers, and whose formation was supported by advanced theoretical calculations.
authors.affiliation: a Innovation Division , Kagome Co., Ltd. , Nasushiobara , Japan.
authors.forename: Masaki
authors.initials: M
authors.lastname: Honda
authors.affiliation: b Department of Materials Science , The University of Shiga Prefecture , Hikone , Japan.
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Kudo
authors.affiliation: b Department of Materials Science , The University of Shiga Prefecture , Hikone , Japan.
authors.forename: Takahiro
authors.initials: T
authors.lastname: Kuwa
authors.affiliation: a Innovation Division , Kagome Co., Ltd. , Nasushiobara , Japan.
authors.forename: Takuma
authors.initials: T
authors.lastname: Higashiura
authors.affiliation: a Innovation Division , Kagome Co., Ltd. , Nasushiobara , Japan.
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Fukaya
authors.affiliation: b Department of Materials Science , The University of Shiga Prefecture , Hikone , Japan.
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Inoue
authors.affiliation: b Department of Materials Science , The University of Shiga Prefecture , Hikone , Japan.
authors.forename: Chitoshi
authors.initials: C
authors.lastname: Kitamura
authors.affiliation: b Department of Materials Science , The University of Shiga Prefecture , Hikone , Japan.
authors.forename: Munenori
authors.initials: M
authors.lastname: Takehara
mesh_terms: D002338:Carotenoids / Q000737:chemistry* / Q000302:isolation & purification*; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D000077276:Lycopene; D018551:Solanum lycopersicum / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D011789:Quantum Theory; D013237:Stereoisomerism; D013696:Temperature
chemical_list: D002338:Carotenoids; D000077276:Lycopene
keywords: density functional theory; geometric isomerization; lycopene; purification; spectral analysis