Lycopene, analysis

Olmedilla, B., Granado, F., Southon, S., Wright, A.J. et al., A European multicentre, placebo-controlled supplementation study with alpha-tocopherol, carotene-rich palm oil, lutein or lycopene analysis of serum responses, Clin. Sci. (Land.), 102, 447 56, 2002. 

CUNNINGHAM F X Jr, POGSON B, SUN Z, MCDONALD K A, DELLAPENNA D and GANTT E (1996) Functional analysis of the (3 and e lycopene cyclase enzymes of Arabidopsis reveals a mechanism for control of cyclic carotenoid formation . Plant Cell, 8, 1613-26. 

GANN P H, GIOVANNUCCI E, WILLETT W, SACHS F H, HENNEKENS C H and STAMPFER M I (1999) Lower prostate cancer risk in men with elevated plasma lycopene levels results of a prospective analysis , Cancer Res, 59, 1225-30. 

Etminan, M. et al.. The role of tomato products and lycopene in the prevention of prostate cancer a meta-analysis of observational studies. Cancer Epidemiol. Biomarkers Prev., 13, 340, 2004. 

A similar system, but with a more hindered porphyrin (tetramesitylporphyrin = tetraphenylporphyrin bearing three methyl substituents in ortho and para positions on each phenyl group), was tested for P-carotene oxidation by molecular oxygen. This system was chosen to slow the oxidation process and thus make it possible to identify possible intermediates by HPLC-DAD-MS analysis. The system yielded the same product families as with lycopene, i.e., (Z)-isomers, epoxides, and P-apo-carotenals, together with new products tentatively attributed to diapocarotene-dials and 5,6- and/or 5,8-epoxides of P-apo-carotenals. The oxidation mechanism appeared more complex in this set-up. 

The carotenoid isomerase (CRTISO) was the first isomerase associated with the desaturation steps and named at a time when Z-ISO was unknown to exist ise.ws.ieo.iei (and reviewed in references ). In vitro analysis of substrate conversion " and transcript profiling in planta associated CRTISO with the desaturation steps. Isaacson demonstrated that CRTISO is specific for the 7,9 or 7,9- cis bond configuration and is not involved in the isomerization of the l5-l5-cis double bond to the trans conformation. As recently shown, Z-ISO is required for isomerization of the 15-15 cis double bond of phytoene produced in dark-grown tissues as well as in stressed photosynthetic tissues. Therefore, desaturation of phytoene to lycopene involves a two-step desaturation by PDS, followed l5-cis isomerization by Z-ISO, and then each pair of double bonds introduced by ZDS is followed by CRT-ISO-mediated isomerization of the resulting conjugated double bond pair. 

Ferruzzi, M.G. et ah. Analysis of lycopene geometrical isomers in biological microsamples by liquid chromatography with coulometric array detection, J. Chromatogr. B Biomed. ScL Appl. 760, 289, 2001. 

Topal, U. et al.. Extraction of lycopene from tomato skin with supercritical carbon dioxide effect of operating conditions and solubility analysis, J. Agric. Food Chem., 54, 5604, 2006. 

Goo YA, Li Z, Pajkovic N, Shaffer S, Taylor G, Chen J, Campbell D, Arnstein L, Goodlett DR and van Breemen R. 2007. Systematic investigation of lycopene effects in LNCaP cells by use of novel large-scale proteomic analysis software. Proteomics Clin Appl 1 513-523. 

SFE may also be coupled to GC and HPLC systems [28] for a simple on-line extraction and analysis system. Lycopene is determined in food products such as tomatoes and tomato products, using SFE coupled to HPLC with an HPLC column used for trapping and analysis. The method is short, requires small sample amounts, and has good linearity and sensitivity. Because the entire system is closed, there is little chance for the lycopene to degrade. 

Figure F2.4.1 Liquid chromatography/mass spectrometry (LC/MS) analysis of isomeric carotenes in a hexane extract from 0.5 ml human serum. Positive ion electrospray ionization MS was used on a quadrupole mass spectrometer with selected ion monitoring to record the molecular ions of lycopene, p-carotene, and a-carotene at m/z (mass-to-charge ratio) 536. A C30 HPLC column was used for separation with a gradient from methanol to methyl-ferf-butyl ether. The a -trans isomer of lycopene was detected at a retention time of 38.1 min and various c/ s isomers of lycopene eluted between 27 and 39 min. The all-frans isomers of a-carotene and P-carotene were detected at 17.3 and 19.3 min, respectively.

Figure F2.4.3 Flow-injection positive ion atmospheric pressure chemical ionization (APCI) mass spectrum of -1 pmol lycopene. The carrier solvent for flow injection analysis consisted of metha-nol/methyl-ferf-butyl ether (50 50 v/v) at a flow rate of 200 ul/min. The lycopene standard was isolated from tomatoes. The a -trans isomer of lycopene is shown, which is the most abundant isomer found in the tomato. This carotene is the familiar red pigment of the tomato.

ANALYSIS OF LYCOPENE STEREOISOMERS IN TOMATO EXTRACTS AND HUMAN SERUM... 

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