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European Journal of Biochemistry Dec 1971
Topics: Carbon Isotopes; Esters; Ethanol; Methylation; Myxomycetes; Oxidation-Reduction; Sterols; Tritium
PubMed: 5167779
DOI: 10.1111/j.1432-1033.1971.tb01652.x -
Journal of Pharmaceutical and... Jun 2006A validated and repeatable high performance liquid chromatography (HPLC) method with online evaporative light scattering (ELSD) was developed for the analysis of two...
Determination of stigmasterol, beta-sitosterol and stigmastanol in oral dosage forms using high performance liquid chromatography with evaporative light scattering detection.
A validated and repeatable high performance liquid chromatography (HPLC) method with online evaporative light scattering (ELSD) was developed for the analysis of two sterols, stigmasterol, beta-sitosterol and a stanol, stigmastanol, found to be common in many herbal formulations and health care supplements. The method is based on the separation of the three marker compounds on a C8 column (Phenomenex Luna, 5 microm, 150 mmx4.6 mm i.d.) using methanol:water (95:5 v/v) as the mobile phase, and a flow rate of 1 ml/min to separate all the marker compounds within 12 min. Cholesterol (50 microg/ml) was used as internal standard and methanol as the extraction solvent. The ELSD response parameters were optimised and the limits of detection (LOD) and quantification (LOQ) were calculated to be 2 and 5 microg/ml, respectively, which is more sensitive than obtained by photo diode array detection (5 and 7 microg/ml). Using ELSD, the percentage relative standard deviation (%R.S.D.) of intra-day and inter-day (3 days) precision for each marker was better than 3%, the accuracy data were within 97-103% and the recovery data were found to be within 95-107% for the five commercially available products examined. This method was used to assay commercially available products formulated as oral dosage forms purported to contain African Potato and associated sterols and stanol and proved to be suitable for the routine analysis and quality control of such products.
Topics: Administration, Oral; Chromatography, High Pressure Liquid; Dosage Forms; Light; Reference Standards; Reproducibility of Results; Scattering, Radiation; Sensitivity and Specificity; Sitosterols; Stigmasterol
PubMed: 16487675
DOI: 10.1016/j.jpba.2005.12.030 -
The New England Journal of Medicine Nov 1995
Topics: Anticholesteremic Agents; Cholesterol, LDL; Coronary Disease; Humans; Hypercholesterolemia; Male; Pravastatin; Sitosterols
PubMed: 7566029
DOI: 10.1056/NEJM199511163332010 -
European Heart Journal Nov 1999
Topics: Anticholesteremic Agents; Cholesterol, LDL; Dietary Supplements; Esters; Humans; Margarine; Sitosterols
PubMed: 10529318
DOI: 10.1053/euhj.1999.1824 -
Current Opinion in Lipidology Dec 1997The basis for treatment of lipid disorders in patients with non-insulin-dependent diabetes mellitus is weight reduction by diet and exercise, and additional control of... (Review)
Review
The basis for treatment of lipid disorders in patients with non-insulin-dependent diabetes mellitus is weight reduction by diet and exercise, and additional control of glycaemic condition with oral antidiabetics, alone or in combination with insulin. Hypercholesterolaemic, mildly hypertriglyceridaemic non-insulin-dependent diabetes mellitus patients respond to cholesterol malabsorption caused by dietary sitostanol ester margarine, while long-term statin treatment of respective coronary patients significantly lowers the recurrence of coronary events, in addition to improving the lipid disorder. However, no information is available concerning the preventive effect of long-term improvement of lipid disorders in non-insulin-dependent diabetes mellitus patients without coronary heart disease, or in patients with the 'classical' type of diabetic lipid disorder, that is, hypertriglyceridaemia with low HDL and normal-low LDL-cholesterol levels. In this group of patients, beneficial lipid effects can be obtained (although perhaps not normalization) with fibrates alone or, especially, in combination with current statins.
Topics: Anticholesteremic Agents; Diabetes Mellitus, Type 2; Diet; Exercise; Humans; Hyperlipidemias; Hypoglycemic Agents; Hypolipidemic Agents; Sitosterols
PubMed: 9412774
DOI: 10.1097/00041433-199712000-00004 -
Biochimica Et Biophysica Acta Jan 1992Cholesterol, stigmastanol, and stigmastanyl-phosphorylcholine (ST-PC) were incorporated into model membranes composed of 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine...
Cholesterol, stigmastanol, and stigmastanyl-phosphorylcholine (ST-PC) were incorporated into model membranes composed of 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) or 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC). POPC and ST-PC were deuterated at the lipid headgroup, DOPC at the cis-double bonds. The influence of the three sterols on the motion and conformation of the lipid headgroups and the hydrocarbon chains was monitored with 2H- and 31P-NMR. All three sterols were freely miscible with the lipid matrix in concentrations of up to 50 mol% without inducing phase separations or nonbilayer structures. However, the molecules exert quite different effects on the phospholipid bilayer. Cholesterol and stigmastanol are largely buried in the hydrocarbon part of the membrane, distinctly restricting the flexing motions of the fatty acyl chains whereas the conformation of the phospholipid headgroups is little affected. In contrast, ST-PC is anchored with its headgroup in the layer of phospholipid dipoles, preventing an extensive penetration of the sterol ring into the hydrocarbon layer. Hence ST-PC has almost no effect on the hydrocarbon chains but induces a characteristic conformational change of the phospholipid headgroups. The 2H- and 31P-NMR spectra of mixed phospholipid/ST-PC membranes further demonstrate that the PC headgroup of ST-PC has a similar orientation as the surrounding phosphatidylcholine headgroups. For both types of molecules the -P-N+ dipole is essentially parallel to the membrane surface. Addition of ST-PC induces a small rotation of the POPC headgroup towards the water phase.
Topics: Cholesterol; Hypolipidemic Agents; Lipid Bilayers; Magnetic Resonance Spectroscopy; Membranes, Artificial; Phosphatidylcholines; Phospholipids; Phosphorus Isotopes; Phosphorylcholine; Sitosterols
PubMed: 1730022
DOI: 10.1016/0005-2736(92)90058-t -
Journal of Medicinal Chemistry Nov 1971
Topics: Administration, Oral; Adrenal Glands; Amines; Animals; Cholestanes; Cholesterol; Liver; Male; Rats; Rats, Inbred Strains; Sterols
PubMed: 5115200
DOI: 10.1021/jm00293a006 -
Advances in Nutrition (Bethesda, Md.) Nov 2013Foods with added phytosterols/phytostanols (PS) are recommended to lower LDL cholesterol (LDL-c) concentrations. Manufacturers have incorporated PS into a variety of... (Review)
Review
Foods with added phytosterols/phytostanols (PS) are recommended to lower LDL cholesterol (LDL-c) concentrations. Manufacturers have incorporated PS into a variety of common foods. Understanding the cholesterol-lowering impact of the food matrix and the PS characteristics would maximize their success and increase the benefit to consumers. This review systematically examines whether the PS characteristics and the fatty acid composition of foods with added PS affects serum LDL-c. A total of 33 studies published between the years 1998 and 2011 inclusive of 66 individual primary variables (strata) were evaluated. The functional food matrices included margarine, mayonnaise, yogurt, milk, cheese, meat, grain, juice, and chocolate. Consistently, ≥10% reductions in LDL-c were reported when the characteristics of the food matrix included poly- and monounsaturated fatty acids known to lower LDL-c. Also, >10% mean reductions in LDL-c were reported when β-sitostanol and campestanol as well as stanol esters were used. These characteristics allow both low-fat and high-fat foods to successfully incorporate PS and significantly lower LDL-c.
Topics: Anticholesteremic Agents; Cholesterol, LDL; Diet; Dietary Fats; Fatty Acids, Unsaturated; Functional Food; Humans; Hypercholesterolemia; Phytosterols; Phytotherapy; Plant Extracts; Sitosterols
PubMed: 24228192
DOI: 10.3945/an.113.004507 -
International Journal For Vitamin and... Mar 2003Normal human diet contains small amounts of phytosterols, mainly sitosterol and campesterol. Intestinal absorption of these plant sterols is low, about one tenth of that... (Review)
Review
Normal human diet contains small amounts of phytosterols, mainly sitosterol and campesterol. Intestinal absorption of these plant sterols is low, about one tenth of that of cholesterol, such that their serum concentrations are also low, about 0.1 to 1% of the cholesterol levels. Like cholesterol they are transported by lipoproteins, mainly by LDL, and secreted unchanged in bile. Addition of plant sterols, or especially of their delta-5 saturated derivatives plant stanols into diet as fat-soluble esters inhibit cholesterol absorption and lower serum cholesterol similarly in short-term studies. Long-term consumption of plant stanol esters lowers serum cholesterol to the extent expected to reduce clinical manifestation of coronary heart disease by over 20% without detectable side effects, cholesterol lowering being especially effective in combination with cholesterol synthesis inhibitors statins.
Topics: Anticholesteremic Agents; Cholesterol; Diet; Humans; Intestinal Absorption; Lipids; Lipoproteins; Phytosterols; Plants, Edible; Sitosterols
PubMed: 12747220
DOI: 10.1024/0300-9831.73.2.127 -
Journal of Agricultural and Food... Jan 2021The recombinant lipase of (OPEr) is characterized by its prominent sterol esterase activity. The protein was immobilized on magnetic nanoparticles, giving four enzyme...
The recombinant lipase of (OPEr) is characterized by its prominent sterol esterase activity. The protein was immobilized on magnetic nanoparticles, giving four enzyme variants that have been tested in solvent-free transesterification of methyl oleate and sitostanol. The yields of stanol esters reached 85%, and the catalysts can be reused. Stanol esters were also obtained in a two-step cascade reaction; a mixture of fatty acid methyl esters was enzymatically synthesized from cooking oil wastes and then used for stanol transesterification. An 85% conversion was achieved in 2 h from the second cycle onward, maintaining the activity over 5 cycles. The biocatalysts can be safely used since they don't release toxic compounds for HeLa and A549 cell lines. These procedures comply with the principles of green chemistry and contribute to the sustainable production of these nutraceuticals from secondary raw materials, like the lipid fraction from industrial or agricultural residues.
Topics: Biocatalysis; Cell Line; Enzymes, Immobilized; Fungal Proteins; Green Chemistry Technology; Humans; Lipase; Oleic Acids; Ophiostoma; Plant Oils; Sitosterols; Waste Products
PubMed: 33375783
DOI: 10.1021/acs.jafc.0c06581