Isolation Of Sterols Research Articles

Structure Of Stigmasterols in Bran of Red Rice from Minahasa Regency, North Sulawesi, Indonesia

Rice bran contained important bioactive phytochemical components such as tocopherol, tocotrienol, and γ-oryzanol, and one of the components of γ-oryzanol is stigmasterol. The aim of the present study was to isolate and identify stigmasterol in native red rice bran extract. The isolation of sterol from red rice bran extract was performed by using Thin Layer Chromatography (TLC) and followed by identification by Fourier Transformed Infrared Spectroscopy (FTIR) and Nuclear Magnetic Resonance (NMR). The TLC single spot originated from crude red rice hexane extract was observed at 365 nm UV and the FTIR spectra analysis result showed that the OH group was indicated by 3436,9 cm-1 absorption. While absorption regions of 2931,6 to 2852,5 cm-1 indicate the presence of single bond CH. The data of 1H-, 13C- and 2D-NMR of rice bran sterol indicated that the single spot obtained in TLC analysis was stigmasterol. It can be concluded that native red rice variety of North Sulawesi contained stigmasterol and potential as a native antioxidant sources.

Antimalarial Activity of Leaf Extract, Fractions and Isolation of Sterol from Alstonia boonei

a peer-reviewed, open access online international journal which publishes original research papers. The journal welcomes submission from scholars and experts for possible publication from all over the world. The scope of the journal includes: Pharmaceutical research, chemistry and biochemistry of naturally occurring compounds, biological evaluation of crude extracts, ethnomedicine, traditional and complementary medicine, ethnopharmacology, biomedical research, Biotechnology, Evaluation of natural substances of land and sea and of plants, microbes and animals, pharmacognosy, bioavailability, clinical, pharmacological, toxicological studies and pharmacokinetics of phytochemicals, Isolation and characterization of compounds, structure elucidation, synthesis and experimental biosynthesis of natural Product as well as developments of methods in these areas are welcomed in the journal.

Isolation of Sterols from Cowpea (Vigna sinensis) Seeds and Their Promotion Activity on HO-1

Cowpea (Vigna sinensis K.) seeds were extracted with 80% aqueous methanol. Concentrated extracts were partitioned with ethyl acetate, butanol, and H2O, successively. The repeated silica gel and octadecyl silica gel (ODS) column chromatographic separations for the butanol fraction led to isolation of four sterols, whose chemical structures were determined as 7β-hydroxysitosterol (1), 7α-hydroxysitosterol (2), 7-ketositosterol (3), and stigmasterol 3-O-β-D-glucopyranoside (4) from the interpretation of spectroscopic data including NMR, mass spectroscopy, and infrared spectroscopy (IR). This paper reports the first isolation of compounds 1 and 2 from V. sinensis seeds. All compounds were evaluated for the effect on heme oxygenase-1 (HO-1) expression, which is considered to be an antioxidant enzyme that catabolizes heme into carbon monoxide, free iron, and biliverdin. All sterols increased the expression of HO-1 in HepG2 cells.

Isolation of sterols from sunflower oil deodorizer distillate

A new method for isolating sterols from sunflower oil deodorizer distillate (DOD) was developed. The most salient feature of which is that, unlike most alternatives, it requires no distillation. Briefly, the method uses methanol in the presence of p-toluenesulphonic acid as catalyst to convert free fatty acids and acyl glycerides in DOD into fatty acid methyl esters (FAMEs). The resulting glycerin and excess reagents are removed by washing with water and, finally, the product is cooled in the absence of solvents to obtain sterols in 92 ± 2% purity.

Quantification of Three Cholesterol Oxidation Products in Raw Meat and Chicken

ABSTRACTRaw veal, beef, pork, and chicken muscle tissues were extracted by a modified dry column procedure in which silicic acid was incorporated in the trap of the column. This method separated cholesterol derivatives from the bulk of neutral lipids, phospholipids and cholesterol. Isolation of sterols by preparative thin layer chromatography followed by quantification by direct on‐column capillary gas chromatography permitted measurement of 7‐ketocholesterol, cholesterol 5α, 6α‐epoxide, and cholesterol 5β 6β‐epoxide at concentrations less than 1 ppm. All muscle tissues contained the three cholesterol products in measurable quantities. 7‐Ketocholesterol constituted more than 50% of the oxidation products in all samples.

Validation of a quantitative procedure for the extraction of sterols from edible oils using radiolabelled compounds.

The work described in this paper is integrated in an analytical programme organised by the Community Bureau of Reference with the aim of developing reference materials certified for sterol content. Preliminary inter-comparison of methods showed that the level of agreement of the results was insufficient for certification purposes. Errors could occur in the different steps before the final determination by gas-liquid chromatography. It was, therefore, decided to validate a quantitative procedure for the isolation of sterols. A well defined saponification-extraction method was tested using labelled sterols ([3H]cholesterol and [3H]cholesteryl oleate) and radiochemical measurements. The study has shown that total cholesterol recovery reached 100.5 +/- 1.4%, that cholesteryl ester was saponified quantitatively and that there were no appreciable amounts of degradation products. The procedure has been used as the basis for the certification of three reference materials and it has been shown that the saponification and extraction procedure leads to the quantitative recovery of sterols regardless of the nature of the fatty material tested.

Isolation of sterols with cyclopropyl-containing side chains from the cultured marine alga [formula omitted][formula omitted

The sterol fraction of the cultured dinoflagellate Peridinium foliaceum contains in addition to cholesterol, 24-methylcholesterol, 4,24-dimethylcholesterol and dinosterol ( 3c ) small amounts of the cyclopropyl-containing sterols gorgosterol ( 1a ) and 5α-gorgostanol ( 1b ) as well as 4α-methylgorgostanol ( 1c ) and E-4α,22ξ,23ξ (or 24ξ)-trimethylcholest-17(20)-en-3β-ol ( 6c or 7c ). The biosynthetic implications of the first isolation of such sterols from a free-living alga are emphasized.

Absorbability of β-sitosterol in humans

Tritium labeled β-sitosterol was administered orally to 5 normal humans and to 5 terminal patients. Isolation of tritium-labeled sterols from plasma and red blood cells of normal male subjects showed some absorption had occurred, but it was much less than for comparable doses of labeled cholesterol. The highest level observed after a single 50-mg. dose of β-sitosterol was about 0.015 mg. per 100 ml. of blood in the total sterol fraction. These values are uncorrected for dilution by any unlabeled β-sitosterol present in the diet and are therefore minimum values. The disappearance rate from blood was slightly higher than for labeled cholesterol. Larger doses of tritium labeled β-sitosterol administered to a series of terminal patients gave similar results for blood levels and disappearance rates. Isolation of sterols from a variety of tissues showed β-sitosterol to be widely distributed. High specific activity values were observed in bile sterols, suggesting that β-sitosterol is selectively excreted by this route. Aorta and other blood vessels had lower amounts of tritium labeled sterols than most other tissues. The total amount of β-sitosterol present in blood and principal visceral organs (excluding intestine) was estimated in one patient as about 0.5 per cent of a single dose of 258 mg. given 5 days previously. Although the distribution pattern of absorbed β-sitosterol was similar to that of fed labeled cholesterol, it did not become esterified to as great an extent.