gamma-sitosterol and cycloartenol

Hyperglycemia is a major public health problem worldwide and there is increasing demand for prevention of postprandial hyperglycemia in diabetic, prediabetic, and healthy humans.. We investigated whether rice bran and triterpene alcohol and sterol preparation (TASP) lowered hyperglycemia in mice and humans. Brown rice and white rice supplemented with TASP lowered the postprandial hyperglycemia in humans. TASP and its components (cycloartenol [CA], 24-methylene cycloartanol, β-sitosterol, and campesterol) decreased postprandial hyperglycemia in C57BL/6J mice. Glucose transport into everted rat intestinal sacs and human HuTu80 cells transfected with sodium-glucose cotransporter-1 (SGLT1) was significantly reduced by the addition of CA. Intracellular localization analysis suggested that SGLT1 translocation to the apical plasma membrane was inhibited when the cells were treated with CA.. We demonstrated for the first time that TASP from rice bran lowered postprandial hyperglycemia in mice and humans. The smaller increase in blood glucose following TASP consumption may be due to the CA-induced decrease in glucose absorption from the intestine, which may be related to decreased membrane translocation of SGLT1.

Topics: Adult; Animals; Blood Glucose; Body Mass Index; Body Weight; Cell Line, Tumor; Cholesterol; Dietary Fiber; Humans; Hyperglycemia; Insulin; Male; Mice; Mice, Inbred C57BL; Oryza; Phytosterols; Rats; Rats, Wistar; Single-Blind Method; Sitosterols; Sodium-Glucose Transporter 1; Sterols; Triterpenes

HPLC fingerprint analysis combined with chemometrics was developed to discriminate between the red and the white rice bran grown in Indonesia. The major component in rice bran is γ-oryzanol which consisted of 4 main compounds, namely cycloartenol ferulate, cyclobranol ferulate, campesterol ferulate and β-sitosterol ferulate. Separation of these four compounds along with other compounds was performed using C18 and methanol-acetonitrile with gradient elution system. By using these intensity variations, principal component and discriminant analysis were performed to discriminate the two samples. Discriminant analysis was successfully discriminated the red from the white rice bran with predictive ability of the model showed a satisfactory classification for the test samples. The results of this study indicated that the developed method was suitable as quality control method for rice bran in terms of identification and discrimination of the red and the white rice bran.

Topics: Cholesterol; Chromatography, High Pressure Liquid; Indonesia; Oryza; Phenylpropionates; Phytosterols; Sitosterols; Triterpenes

Non-drug varieties of Cannabis sativa L., collectively namely as "hemp", have been an interesting source of food, fiber, and medicine for thousands of years. The ever-increasing demand for vegetables oils has made it essential to characterize additional vegetable oil through innovative uses of its components. The lipid profile showed that linoleic (55%), α-linolenic (16%), and oleic (11%) were the most abundant fatty acids. A yield (1.84-1.92%) of unsaponifiable matter was obtained, and the most interesting compounds were β-sitosterol (1905.00 ± 59.27 mg/kg of oil), campesterol (505.69 ± 32.04 mg/kg of oil), phytol (167.59 ± 1.81 mg/kg of oil), cycloartenol (90.55 ± 3.44 mg/kg of oil), and γ-tocopherol (73.38 ± 2.86 mg/100 g of oil). This study is an interesting contribution for C. sativa L. consideration as a source of bioactive compounds contributing to novel research applications for hemp seed oil in the pharmaceutical, cosmetic food, and other non-food industries.

Topics: Cannabis; Phytosterols; Plant Oils; Seeds; Sitosterols; Tocopherols; Triterpenes

Withanolides biosynthesis in the plant Withania somnifera (L.) Dunal is hypothesized to be diverged from sterol pathway at the level of 24-methylene cholesterol. The conversion and translocation of intermediates for sterols and withanolides are yet to be characterized in this plant. To understand the influence of mevalonate (MVA) and 2-C-methyl-d-erythritol-4-phosphate (MEP) pathways on sterols and withanolides biosynthesis in planta, we overexpressed the WsHMGR2 and WsDXR2 in tobacco, analyzed the effect of transient suppression through RNAi, inhibited MVA and MEP pathways and fed the leaf tissue with different sterols. Overexpression of WsHMGR2 increased cycloartenol, sitosterol, stigmasterol and campesterol compared to WsDXR2 transgene lines. Increase in cholesterol was, however, marginally higher in WsDXR2 transgenic lines. This was further validated through transient suppression analysis, and pathway inhibition where cholesterol reduction was found higher due to WsDXR2 suppression and all other sterols were affected predominantly by WsHMGR2 suppression in leaf. The transcript abundance and enzyme analysis data also correlate with sterol accumulation. Cholesterol feeding did not increase the withanolide content compared to cycloartenol, sitosterol, stigmasterol and campesterol. Hence, a preferential translocation of carbon from MVA and MEP pathways was found differentiating the sterols types. Overall results suggested that MVA pathway was predominant in contributing intermediates for withanolides synthesis mainly through the campesterol/stigmasterol route in planta.

Topics: Base Sequence; Biosynthetic Pathways; Carbon; Cholesterol; Erythritol; Gene Expression; Gene Expression Regulation, Plant; Mevalonic Acid; Molecular Sequence Data; Nicotiana; Phylogeny; Phytosterols; Plant Leaves; Plant Proteins; Plants, Genetically Modified; Sequence Analysis, DNA; Sitosterols; Sterols; Stigmasterol; Sugar Phosphates; Triterpenes; Withania; Withanolides

Previous methods for the quantitative analysis of phytosterols have usually used GC-MS and require elaborate sample preparation including chemical derivatization. Other common methods such as HPLC with absorbance detection do not provide information regarding the identity of the analytes. To address the need for an assay that utilizes mass selectivity while avoiding derivatization, a quantitative method based on LC-tandem mass spectrometry (LC-MS-MS) was developed and validated for the measurement of six abundant dietary phytosterols and structurally related triterpene alcohols including brassicasterol, campesterol, cycloartenol, β-sitosterol, stigmasterol, and lupeol in edible oils. Samples were saponified, extracted with hexane and then analyzed using reversed phase HPLC with positive ion atmospheric pressure chemical ionization tandem mass spectrometry and selected reaction monitoring. The utility of the LC-MS-MS method was demonstrated by analyzing 14 edible oils. All six compounds were present in at least some of the edible oils. The most abundant phytosterol in all samples was β-sitosterol, which was highest in corn oil at 4.35 ± 0.03 mg/g, followed by campesterol in canola oil at 1.84 ± 0.01 mg/g. The new LC-MS-MS method for the quantitative analysis of phytosterols provides a combination of speed, selectivity and sensitivity that exceed those of previous assays.

Topics: Cholestadienols; Cholesterol; Chromatography, Liquid; Molecular Structure; Pentacyclic Triterpenes; Phytosterols; Plant Oils; Reproducibility of Results; Sitosterols; Stigmasterol; Tandem Mass Spectrometry; Triterpenes

The chemical fingerprinting of the unsaponifiable fraction of different Punica granatum seed oils was performed in order to evaluate their potential as a functional food ingredient. Qualitative and quantitative determinations of tocopherol, aliphatic alcohol (including policosanol), squalene, phytosterols and triterpene contents were performed by GC-MS. A high yield (3.1-4.2%) of unsaponifiable matter was obtained and consistent levels of squalene (up to 800 mg/kg) and policosanol (118-185 mg/kg) were noticed. β-sitosterol (up to 8069 mg/kg) and cycloartenol (5916-7766 mg/kg) were predominant in phytosterol and triterpene fractions, while β- and δ-tocopherol were the most abundant vitamin E forms. Some minor variations were noticed between samples. From the results obtained, it can be suggested that the seed oil of P. granatum can be considered an interesting alimentary source of substances of nutraceutical value involved in the modulation of cholesterol metabolism.

Topics: beta-Tocopherol; Dietary Supplements; Fatty Alcohols; Functional Food; Lythraceae; Phytosterols; Plant Oils; Seeds; Sitosterols; Squalene; Tocopherols; Triterpenes

The differences between the biosynthesis of sterols in higher plants and yeast/mammals are believed to originate at the cyclization step of oxidosqualene, which is cyclized to cycloartenol in higher plants and lanosterol in yeast/mammals. Recently, lanosterol synthase genes were identified from dicotyledonous plant species including Arabidopsis, suggesting that higher plants possess dual biosynthetic pathways to phytosterols via lanosterol, and through cycloartenol. To identify the biosynthetic pathway to phytosterol via lanosterol, and to reveal the contributions to phytosterol biosynthesis via each cycloartenol and lanosterol, we performed feeding experiments by using [6-(13)C(2)H(3)]mevalonate with Arabidopsis seedlings. Applying (13)C-{(1)H}{(2)H} nuclear magnetic resonance (NMR) techniques, the elucidation of deuterium on C-19 behavior of phytosterol provided evidence that small amounts of phytosterol were biosynthesized via lanosterol. The levels of phytosterol increased on overexpression of LAS1, and phytosterols derived from lanosterol were not observed in a LAS1-knockout plant. This is direct evidence to indicate that the biosynthetic pathway for phytosterol via lanosterol exists in plant cells. We designate the biosynthetic pathway to phytosterols via lanosterol "the lanosterol pathway." LAS1 expression is reported to be induced by the application of jasmonate and is thought to have evolved from an ancestral cycloartenol synthase to a triterpenoid synthase, such as beta-amyrin synthase and lupeol synthase. Considering this background, the lanosterol pathway may contribute to the biosynthesis of not only phytosterols, but also steroids as secondary metabolites.

Topics: Arabidopsis; Arabidopsis Proteins; Chromatography, High Pressure Liquid; Gas Chromatography-Mass Spectrometry; Intramolecular Transferases; Lanosterol; Mevalonic Acid; Phytosterols; Seedlings; Sitosterols; Triterpenes

A comparative study was performed to determine the free sterols content and composition during the development of three varieties of linseed (H52, O116 and P129). Seed samples were collected at regular intervals from 7 to 60 days after flowering (DAF). Ten compounds were identified: cholesterol, campesterol, brassicasterol, stigmasterol, beta-sitosterol, Delta5-avenasterol, cycloartenol; 24-methylene cycloartanol, obtusifoliol, citrostadienol. The maximum level of 4-desmethylsterols (1,515 mg/100g oil) was reached at 7 DAF in P129 variety. H52 had the highest level of 4-4 dimethylsterols (355 mg/100g oil) at 28 DAF. The greatest amount of 4-monomethylsterols (35 mg/100g oil) was detected in H52 at 14 DAF. During linseed development, beta sitosterol (830 mg/100g oil) was the major 4-desmethylsterols, followed by campesterol (564 mg/100g oil) and stigmasterol (265 mg/100g oil). Some of these compounds followed nearly the same accumulation pattern during linseed maturation.

Topics: Cholestadienols; Cholesterol; Chromatography, Thin Layer; Flax; Flowers; Gas Chromatography-Mass Spectrometry; Phytosterols; Seeds; Sitosterols; Species Specificity; Stigmasterol; Time Factors; Triterpenes

To study the chemical constituents of Ervatamia hainanensis.. The compounds were separated and purified by column chromatography with silica gel, and identified by IR, MS, NMR and 2D-NMR.. Five compounds were identified as I (isolariciresinol 9-O-beta-D-glucopyranoside), II (cycloartenol), III (beta-amyrin acetate), IV (beta-sitosterol), V (daucosterol), respectively.. All the compounds were isolated from this plant for the first time.

Topics: Apocynaceae; Glucosides; Oleanolic Acid; Phytosterols; Plant Roots; Plants, Medicinal; Sitosterols; Triterpenes

The first committed step in the conversion of cycloartenol into Delta(5) C24-alkyl sterols in plants is catalyzed by an S-adenosyl-methionine-dependent sterol-C24-methyltransferase type 1 (SMT1). We report the consequences of overexpressing SMT1 in tobacco (Nicotiana tabacum), under control of either the constitutive carnation etched ring virus promoter or the seed-specific Brassica napus acyl-carrier protein promoter, on sterol biosynthesis in seed tissue. Overexpression of SMT1 with either promoter increased the amount of total sterols in seed tissue by up to 44%. The sterol composition was also perturbed with levels of sitosterol increased by up to 50% and levels of isofucosterol and campesterol increased by up to 80%, whereas levels of cycloartenol and cholesterol were decreased by up to 53% and 34%, respectively. Concomitant with the enhanced SMT1 activity was an increase in endogenous 3-hydroxy-3-methylglutaryl coenzyme A reductase activity, from which one can speculate that reduced levels of cycloartenol feed back to up-regulate 3-hydroxy-3-methylglutaryl coenzyme A reductase activity and thereby control the carbon flux into sterol biosynthesis. This potential regulatory role of SMT1 in seed sterol biosynthesis is discussed.

Topics: Biological Transport; Carbon; Cholesterol; Cloning, Molecular; Gene Expression Regulation, Enzymologic; Gene Expression Regulation, Plant; Hydroxymethylglutaryl CoA Reductases; Methyltransferases; Nicotiana; Phytosterols; Plant Leaves; Plants, Genetically Modified; Seeds; Sitosterols; Stigmasterol; Triterpenes

To study the chemical constituents from the fruit of Fragaria ananassa.. Using chromatographic methods to isolate compounds and chemical and spectral methods to elucidate their structures.. Three compounds, 9, 19-cyclolanost-24-en-3-ol(1), 14-methyl-stigmasta-7, 24(28)-dien-3-ol(2) and beta-sitosterol(3) were isolated from the freeze-dried powder.. All of the compounds were obtained from this plant for the first time.

Topics: Fragaria; Fruit; Phytosterols; Plants, Medicinal; Sitosterols; Triterpenes

The tetracyclic sterol precursors, cyclolaudenol, cycloartenol and lanosterol, inhibit efficiently the tetrahymanol biosynthesis in the ciliate Tetrahymena pyriformis, as reported earlier for cholesterol and other sterols. The prokaryotic bacteriohopanetetrols have little effect, and diplopterol, another hopanoid, as well as the carotenoid, canthaxanthin, have no effect. In the presence of triparanol, a hypocholesterolemic drug inhibiting the squalene cyclase of T. pyriformis and modifying the fatty acid metabolism, the cells do not grow further, but growth can be restored by the addition to the culture medium of suitable polyterpenoids. Thus, growth in presence of triparanol (13 microM) is almost normal after addition of a sterol such as sitosterol and cyclolaudenol, and longer lag times and lower absorbances than those of untreated cultures are observed in presence of cyclartenol, lanosterol, euphenol (a lanosterol isomer), bacteriohopanetetrols and three carotenoids. No growth at all is observed in the presence of tetrahymanol and diplopterol, although these triterpenoids are the normal reinforcers of the ciliate, probably because of a poor bioavailability. Thus, structurally different polyterpenoids are (at least partially) functionally equivalent and capable of replacing tetrahymanol or sterols and might act as membrane reinforcers in T. pyriformis cells.

Topics: Animals; Cholesterol; Lanosterol; Phytosterols; Polymers; Sitosterols; Squalene; Tetrahymena pyriformis; Triparanol; Triterpenes