<?xml version="1.0" encoding="UTF-8"?><xml><records><record><source-app name="Biblio" version="6.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Putzbach, Karsten</style></author><author><style face="normal" font="default" size="100%">Krucker, Manfred</style></author><author><style face="normal" font="default" size="100%">Albert, Klaus</style></author><author><style face="normal" font="default" size="100%">Michael A Grusak</style></author><author><style face="normal" font="default" size="100%">Guangwen Tang</style></author><author><style face="normal" font="default" size="100%">Gregory G Dolnikowski</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Structure determination of partially deuterated carotenoids from intrinsically labeled vegetables by HPLC-MS and 1H NMR</style></title><secondary-title><style face="normal" font="default" size="100%">Journal of Agricultural and Food Chemistry</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">beta Carotene</style></keyword><keyword><style  face="normal" font="default" size="100%">Carotenoids</style></keyword><keyword><style  face="normal" font="default" size="100%">Chromatography</style></keyword><keyword><style  face="normal" font="default" size="100%">Daucus carota</style></keyword><keyword><style  face="normal" font="default" size="100%">Deuterium</style></keyword><keyword><style  face="normal" font="default" size="100%">High Pressure Liquid</style></keyword><keyword><style  face="normal" font="default" size="100%">Isotope Labeling</style></keyword><keyword><style  face="normal" font="default" size="100%">Lutein</style></keyword><keyword><style  face="normal" font="default" size="100%">Magnetic Resonance Spectroscopy</style></keyword><keyword><style  face="normal" font="default" size="100%">Mass Spectrometry</style></keyword><keyword><style  face="normal" font="default" size="100%">Molecular Structure</style></keyword><keyword><style  face="normal" font="default" size="100%">Spinacia oleracea</style></keyword><keyword><style  face="normal" font="default" size="100%">Vegetables</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2005</style></year></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://www.ncbi.nlm.nih.gov/pubmed/15686418</style></url></web-urls></urls><number><style face="normal" font="default" size="100%">3</style></number><volume><style face="normal" font="default" size="100%">53</style></volume><pages><style face="normal" font="default" size="100%">671–677</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">The structures of biosynthetic deuterated carotenoids in labeled vegetables were investigated: (all-E)-lutein and (all-E)-beta-carotene from spinach, and (all-E)-beta-carotene and (all-E)-alpha-carotene from carrots. The vegetables were grown hydroponically using a nutrient solution enriched with deuterium oxide (D(2)O) and were extracted using matrix solid-phase dispersion (MSPD). Deuterium enrichment in the carotenoid molecules was determined by liquid chromatography-mass spectrometry (LC-MS). (all-E)-Lutein and (all-E)-beta-carotene in spinach showed partial deuteration from (2)H(1) to (2)H(12), with the abundance maximum at (2)H(5). (all-E)-beta-Carotene and (all-E)-alpha-carotene from carrots showed partial deuteration from (2)H(1) to (2)H(17), with the abundance maximum at (2)H(11). The (1)H NMR spectra of the four deuterated carotenoids showed additional signals for all methyl groups and decreased signal intensity for the olefinic protons and the methylene protons in the ring. These differences are due to isotopic effects and are based on the substitution of protons by deuterium atoms. The deuteration was distributed randomly throughout the carotenoid molecules.</style></abstract><notes><style face="normal" font="default" size="100%">{PMID:} 15686418</style></notes></record></records></xml>