Topic
Sterol
About: Sterol is a research topic. Over the lifetime, 8117 publications have been published within this topic receiving 309926 citations. The topic is also known as: sterols & sterol lipids.
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TL;DR: The observed correlation between increased levels of regulatory oxysterols and repression of 3-hydroxy-3-methylglutaryl-CoA reductase in cholesterol-fed mice is consistent with a hypothesis that intracellular oxysterol metabolites regulate the level of the reduct enzyme.
101 citations
TL;DR: In this article, potato chips fried in palm oil, sunflower oil, and high-oleic sunflower oils were studied for the content of different phytosterol oxides during 0 to 25 weeks of storage in the dark.
Abstract: Potato chips fried in palm oil, sunflower oil, and high-oleic sunflower oil were studied for the content of different phytosterol oxides during 0 to 25 weeks of storage in the dark. Oxidation products of sitosterol (24α-ethyl-5-cholesten-3β-ol) and campesterol (24α-methyl-t-cholesten-3β-ol) were synthesized to help identify the phytosterol oxides. The oxides of phytosterols were analyzed by preparative thin-layer chromatography, solid-phase extraction, capillary column gas chromatography (GC), and GC-mass spectrometry. Epimers of 7-hydroxysitosterol and 7-hydroxycampesterol; 7-ketositosterol and 7-ketocampesterol; epimers of 5,6-epoxy-sitosterol and 5,6-epoxy-campesterol; 24α-ethylcholestane-3β,5,6β-triol (dihydroxysitosterol) and 24α-methylcholestane-3β,5,6β-triol (dihydroxycampesterol) were detected and quantitated in the samples of chips fried in different vegetable oils. Potato chips fried in palm oil had the lowest level of total sterol oxides, ranging from 5 to ca. 9 ppm in the lipids from time 0 to 25 wk of storage. The level of total sterol oxides in chip samples fried in sunflower oil ranged from 46 to 47 ppm, and the lipids in samples fried in high-oleic sunflower oil ranged from 35 to 58 ppm from 0 time to 25 wk of storage. During 25 wk of storage no considerable increase in sterol oxides was observed in the samples of chips fried in palm oil and sunflower oil. The chip samples fried in high-oleic sunflower oil had slightly higher levels of sterol oxides after 10 and 25 weeks of storage. In addition to the levels of individual sterol oxides, a new method for enrichment of phytosterol oxides from the unsaponifiables and full-scan mass spectra of various oxidation products of sitosterol and campesterol are reported in this paper.
101 citations
TL;DR: Two experiments showed that time degree of saturation of time fat did indeed! play a role in cholesterol-indumced atherosclerosis in rabbits and that the diet containing cholesterol plus corn oil was considerably less atherogenic tlman that containing shortening.
Abstract: ginmming of timis cemmtmmrythat cholesterol feeding of rabbits led to atimeronmata, a large ntmmber of chmolesterol-feed!ing experiments have been carried oumt. In these experiments timis sterol was usually administered! in an oil (fat) suspension, but comparison of different types of fat was not cairied out. About 15 years ago we began to compare the effect of the cholesterol vehicle upon cisolesterol-induced atherosclerosis. In the first of these experiments, cholesterol was ad!dedl dlirectly to time rabbit chow or was fed together with a partially saturated fat (vegetable shortening; iodine value, 72) or a hmighmly unsaturated fat (cormm oil; iodine value, 130). We observed that the diet containing cholesterol plus corn oil was considerably less atherogenic tlman that containing shortening (1). Time shortening cholesterol regimen was slightly less atheu-ogenic tisan was tise dhet containing no fat. A second! experiment showed that time degree of saturation of time fat did indeed! play a role in cholesterol-indumced atherosclerosis in rabbits. A diet containing cholesterol and methyl stearate (iodine value, 0) was more athmerogenic than one containing methyl oleate (iodine value, 90) and this diet was, in turn, more atimerogenic
101 citations
TL;DR: The fluorescence properties of dehydroergosterol and cholesta-5,7,9-trien-3 beta-ol have been studied in organic solution, in aqueous dispersions and incorporated into aqueously lipid dispersions, and possible structures for 1 : 1 mixtures are presented.
101 citations
TL;DR: Nine new relatively polar triterpene alcohol and sterol esters were characterized by their retention behaviors in LC and ESI-MS data from both negative- and positive-ion mode, providing the first evidence for the presence of hydroxylated ferulate esters and caffeate esters as part of gamma-oryzanol in rice bran.
Abstract: Ferulic acid esters of triterpene alcohols and sterols in rice bran oil have been extensively studied and reported to possess important pharmacological actions. Inconsistent results on the numbers and structures of ferulates have been reported, primarily because of the analytical procedures employed. Conventional methods for analysis of phytosterol content in oil are carried out by characterization of trimethylsilylated derivatives (TMS) using GC-EI-MS after saponification of oils or individual compound isolated from oils. This study developed an LC-MS/MS method for the direct analysis of triterpene alcohol and sterol esters in rice bran oil. In addition to verifying the results of previous research, nine new relatively polar triterpene alcohol and sterol esters were characterized by their retention behaviors in LC and ESI-MS data from both negative- and positive-ion mode. This is the first evidence for the presence of hydroxylated ferulate esters and caffeate esters as part of gamma-oryzanol in rice bran. The method enables rapid and direct on-line characterization of triterpene alcohol and sterol esters in oils. LC-MS/MS equipped with reverse-phase LC and ESI-MS should be well-suited for identification and quantification of the polar metabolites of phytosterols in biological fluids after consumption of rice bran oil or other oils.
101 citations