Analysis of molecular species of glycolipids in fruit pastes of red bell pepper (Capsicum annuum L.) by high-performance liquid chromatography-mass spectrometry

Capsicum annuum L. and its bioactive constituents: A critical review of a traditional culinary spice in terms of its modern pharmacological potentials with toxicological issues

Capsicum annuum L., commonly known as chili pepper, is used as an important spice globally and as a crude drug in many traditional medicine systems. The fruits of C. annuum have been used as a tonic, antiseptic, and stimulating agent, to treat dyspepsia, appetites, and flatulence, and to improve digestion and circulation. The article aims to critically review the phytochemical and pharmacological properties of C. annuum and its major compounds. Capsaicin, dihydrocapsaicin, and some carotenoids are reported as the major active compounds with several pharmacological potentials especially as anticancer and cardioprotectant. The anticancer effect of capsaicinoids is mainly mediated through mechanisms involving the interaction of Ca²⁺ -dependent activation of the MAPK pathway, suppression of NOX-dependent reactive oxygen species generation, and p53-mediated activation of mitochondrial apoptosis in cancer cells. Similarly, the cardioprotective effects of capsaicinoids are mediated through their interaction with cellular transient receptor potential vanilloid 1 channel, and restoration of calcitonin gene-related peptide via Ca²⁺ -dependent release of neuropeptides and suppression of bradykinin. In conclusion, this comprehensive review presents detailed information about the traditional uses, phytochemistry, and pharmacology of major bioactive principles of C. annuum with special emphasis on anticancer, cardioprotective effects, and plausible toxic adversities along with food safety.

Speculation of Sphingolipids in Capsanthin by Ultra-Performance Liquid Chromatography Coupled with Electrospray Ionization-Quadrupole-Time-of-Flight Mass Spectrometry

Sphingolipids are constituents of cellular membranes and play important roles in cells. As nutraceutical compounds in foods, sphingolipids have been proven to be critical for human health. Therefore, the sphingolipids content of capsanthin was established based on ultra-performance liquid chromatography coupled with electrospray ionization-quadrupole-time-of-flight mass spectrometry. A total number of 40 sphingolipids were successfully identified, including 20 Glucosylceramides and 20 Ceramides. The predominant GlcCers contain 4-hydroxy-8-sphingenine t18:1 (8) with different structures of α-OH fatty acids. For the Cers, the main long-chain bases are 4-hydroxy-8-sphingenine t18:1 (8) and 4-hydroxysphingenine (t18:0) with different structures of α-OH or α, β-di (OH) fatty acids.

Discovery of Flazin, an Alkaloid Isolated from Cherry Tomato Juice, As a Novel Non-Enzymatic Protein Glycation Inhibitor via in Vitro and in Silico Studies

Both overproduced reactive oxygen species/reactive nitrogen species and hyperglycemic conditions accompany a significant increase in protein glycation and nitration that contribute to the initiation and progression of diabetic complications and neuronal disorders. In this study, 19 compounds, including steroidal saponins, alkaloids, cerebroside, phenolic compounds, sterols, and nucleosides, were isolated from cherry tomato (Solanum lycopersicum var. cerasiforme) juice, of which flazin showed good inhibition on monosaccharide-induced non-enzymatic bovine pancreas insulin and bovine serum albumin (BSA) glycation. Molecular dynamics simulations revealed that flazin continuously interacts with Phe1, Val2, Tyr26, and Lys29 insulin residues, which play a key role in insulin glycation/dimerization. In addition, depending upon the flazin dose, this blocked the tyrosine nitration of BSA via scavenging peroxynitrite anions. Taken together, our novel findings suggest that flazin could be a lead compound for the treatment of diabetes and neuronal disorders via the inhibition of non-enzymatic protein glycation and the elimination of peroxynitrite.

Isolation and compositional analysis of galactoglycerolipids from perilla [Perilla frutescens (L.) Britton] leaves and comparison to the galactoglycerolipids from spinach and parsley

The aim of this study was to isolate monogalactosyldiacylglycerols (MGDGs) and digalactosyldiacylglycerols (DGDGs) from perilla [Perilla frutescens (L.) Britton] and to investigate their fatty acid profiles. Perilla displayed the greatest total MGDG and DGDG content among the three types of leaf vegetables tested, that is, spinach, parsley, and perilla, containing 0.16 g/100 g MGDG and 0.04 g/100 g DGDG (on wet weight basis). High purity MGDG (approximately 97 g/100 g) and DGDG (approximately 86 g/100 g) were isolated from perilla chloroform/methanol (2:1, v/v) extracts by two-step silica gel column chromatography. MGDGs were primarily composed of 18:3n-3 and 16:3n-3, predominantly located at the sn-1 and sn-2 positions, respectively. In DGDG, 18:3n-3 and 16:0 were the most abundant fatty acids and were primarily found at the sn-1 and sn-2 positions, respectively. PRACTICAL APPLICATION: MGDGs and DGDGs are the most prevalent forms of galactoglycerolipids found in leaf vegetables including perilla and have been shown to exert health-beneficial effects, such as antitumor, anti-inflammatory, anticancer, and appetite-suppressing activities. Both MGDGs and DGDGs possess emulsifying properties. The present study may help better understand the health-beneficial effects of MGDG and DGDG from perilla, by providing total composition and positional distribution of the fatty acids. The present study also successfully established a protocol to isolate high purity MGDG and DGDG from perilla, thereby increasing their possible use as an ingredient in foods and nutraceuticals.

Molecular species determination of oligosaccharides and glycoconjugates in soybean lecithin powders

BACKGROUND

Oligosaccharides and glycoconjugates in soybean lecithin powder are very important for the properties and functions of the materials that contain it. Oligosaccharides can trigger infusion reactions and color changes in soybean lecithin during medical injections; glycoconjugates in the form of glycolipids can also change the physical behavior of lecithin. The molecular components of oligosaccharides and glycoconjugates in soybean lecithin powder were studied in this paper.

RESULTS

Three oligosaccharides and 21 glycoconjugates were verified in soybean lecithin powders for the first time. Raffinose, sucrose, and stachyose were detected as the principal components of oligosaccharides by high-performance liquid chromatography (HPLC). Twenty-one glycoconjugates, including four steryl glucosides (SG), 13 acyl steryl glucosides (ASG), one digalactosyl diacylglycerol (DGDG), one monogalactosyl diacylglyceride (MGDG), one glucocerebroside (Glucer), and one glucose palmitate were analyzed by gas chromatography (GC), gas chromatography-mass spectrometry (GC-MS) and RP-UPLC-Q-TOF-ESI-MS. Glycoconjugates were constructed in soybean lecithin powder after separation by column chromatography, thin-layer chromatography, and color reactions.

CONCLUSION

The determination of molecular species of oligosaccharides and glycoconjugates provided a new direction for the exploration of novel functions and uses of soybean lecithin powder. © 2018 Society of Chemical Industry.

Phytochemistry and gastrointestinal benefits of the medicinal spice, Capsicum annuum L. (Chilli): a review

Dietary spices and their active constituents provide various beneficial effects on the gastrointestinal system by variety of mechanisms such as influence of gastric emptying, stimulation of gastrointestinal defense and absorption, stimulation of salivary, intestinal, hepatic, and pancreatic secretions. Capsicum annuum (Solanaceae), commonly known as chilli, is a medicinal spice used in various Indian traditional systems of medicine and it has been acknowledged to treat various health ailments. Therapeutic potential of chilli and capsaicin were well documented; however, they act as double-edged sword in many physiological circumstances. In traditional medicine chilli has been used against various gastrointestinal complains such as dyspepsia, loss of appetite, gastroesophageal reflux disease, gastric ulcer, and so on. In chilli, more than 200 constituents have been identified and some of its active constituents play numerous beneficial roles in various gastrointestinal disorders such as stimulation of digestion and gastromucosal defense, reduction of gastroesophageal reflux disease (GERD) symptoms, inhibition of gastrointestinal pathogens, ulceration and cancers, regulation of gastrointestinal secretions and absorptions. However, further studies are warranted to determine the dose ceiling limit of chilli and its active constituents for their utilization as gastroprotective agents. This review summarizes the phytochemistry and various gastrointestinal benefits of chilli and its various active constituents.

Improved enzyme-mediated synthesis and supramolecular self-assembly of naturally occurring conjugates of β-sitosterol

Naturally occurring acylated β-sitosteryl glucosides have been investigated for their novel properties. The synthetic protocol based on the literature data was improved and optimized. The main improvement consists in employing systems of ionic liquids combined with organic solvents in lipase-mediated esterification of (3β)-stigmast-5-en-3-yl β-d-glucopyranoside to get (3β)-stigmast-5-en-3-yl 6-O-acyl-β-d-glucopyranosides. Maximum yields of these products were achieved with Candida antarctica lipase B immobilized on Immobead 150, recombinant from yeast, in absolute THF and in the presence of either ionic liquid [1-butyl-3-methyl imidazolium tetrafluoroborate ([BMIM]BF₄) or 1-butyl-3-methyl imidazolium hexafluorophosphate ([BMIM]PF₆)] employed. Pharmacological activity of (3β)-stigmast-5-en-3-yl 6-O-acyl-β-d-glucopyranosides was studied in tests on MCF7 tumor cell lines; the compounds displayed moderate activity which was higher than the activity of β-sitosterol. Supramolecular characteristics were discovered at (3β)-stigmast-5-en-3-yl 6-O-dodecanoyl-β-d-glucopyranoside that formed supramolecular polymer through multiple H-bonds in a methanol/water system (60/40). Its formation was confirmed by the independent UV-vis measurements during certain time period, by variable temperature DOSY-NMR measurement in deuteriochloroform, and visualized by transmission electron microscopy (TEM) and atomic force microscopy (AFM) showing chiral helical structures and complex superassembly systems based on fibrous supramolecular polymer. In contrary, no such properties have been observed for the other two (3β)-stigmast-5-en-3-yl 6-O-acyl-β-d-glucopyranosides under the given experimental conditions.

Analytical methods in sphingolipidomics: Quantitative and profiling approaches in food analysis

In recent years, sphingolipidomics has emerged as an interesting omic science that encompasses the study of the full sphingolipidome characterization, content, structure and activity in cells, tissues or organisms. Like other omics, it has the potential to impact biomarker discovery, drug development and systems biology knowledge. Concretely, dietary food sphingolipids have gained considerable importance due to their extensively reported bioactivity. Because of the complexity of this lipid family and their diversity among foods, powerful analytical methodologies are needed for their study. The analytical tools developed in the past have been improved with the enormous advances made in recent years in mass spectrometry (MS) and chromatography, which allow the convenient and sensitive identification and quantitation of sphingolipid classes and form the basis of current sphingolipidomics methodologies. In addition, novel hyphenated nuclear magnetic resonance (NMR) strategies, new ionization strategies, and MS imaging are outlined as promising technologies to shape the future of sphingolipid analyses. This review traces the analytical methods of sphingolipidomics in food analysis concerning sample extraction, chromatographic separation, the identification and quantification of sphingolipids by MS and their structural elucidation by NMR.

Rapid and highly accurate detection of steryl glycosides by ultraperformance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS)

This study describes the development and validation of a fast, accurate, and precise UPLC-Q-TOF-MS method for the analysis of steryl glycosides (SGs). The best combination of separation and sensitivity was obtained with a methanol/water gradient and formic acid as additive, using electrospray ionization (ESI). SGs were detected almost exclusively as sodiated adducts, allowing identification of the intact molecule, including the sugar moiety. The TOF-MS system offered high mass accuracy (1.3 ppm), providing a valuable tool for SG identification. The method was used to quantify single SG species in oat bran and whole wheat, and it was demonstrated that reliable quantification requires accounting for the matrix effect, which may reduce the SG signal by up to 50% in some samples. The level of matrix effect also depends on food matrices with various SG contents, indicating that it should be individually considered for each sample.

Application of lipid extracts from Solidago canadensis to phytomonitoring of PCB126 in transgenic Arabidopsis plants

The aim of this study is to elucidate the effect of lipid extracts from Solidago canadensis for phytomonitoring of polychlorinated biphenyl (PCB) 126 in the transgenic Arabidopsis plant XgD2V11-6 carrying the recombinant guinea pig (g) aryl hydrocarbon receptor (AhR)-mediated β-glucuronidase (GUS) reporter gene expression system. A lipid extract was prepared from S. canadensis and separated into simple lipid, glycolipid, and phospholipid fractions by silica gel column chromatography. Sterylglucoside (SG), monogalactosyldiacylglycerol (MGDG), digalactosyldiacylglycerol (DGDG), and glucosyl ceramide were found in the glycolipid fraction. When the transgenic Arabidopsis plants were treated with the glycolipid fraction together with PCB126, PCB126-induced GUS activity significantly increased in the whole plant. Moreover, S. canadensis-derived SG, MGDG, and DGDG also significantly increased PCB126-induced GUS activity. These results indicated that glycolipids in S. canadensis enhanced the sensitivity of this monitoring assay.

Generic characterization of apolar metabolites in red chili peppers (Capsicum frutescens L.) by orbitrap mass spectrometry

The aim of the present study was to develop a generic analytical method for the identification and quantitation of apolar plant metabolites in biomass using liquid chromatography-photodiode array-accurate mass mass spectrometry (LC-PDA-amMS). During this study, a single generic sample preparation protocol was applied to extract apolar plant metabolites. Compound identification was performed using a single generic screening method for apolar compounds without the need for dedicated fractionation. Such a generic approach renders vast amounts of information and is virtually limited by only the solubility and detector response of the metabolites of interest. Method validation confirmed that this approach is applicable for quantitative purposes. Furthermore, an identification-quantitation strategy based on amMS and molar extinction coefficients was used for carotenoids, eliminating the need for reference standards for each carotenoid. To challenge the validated method, chili peppers (Capsicum frutescens L.) were analyzed to unravel their complex phytochemical composition (carotenoids, glycolipids, glycerolipids, capsaicinoids, lipid-soluble vitamins).

Improving Method Reliability in Carotenoid Analysis through Selective Removal of Glycerolipid Interferences by Lipase Treatment

Saponification is most often used to hydrolyze glycerolipid interferences during carotenoid analysis. Ester bonds of other plant metabolites such as carotenoids are, however, also hydrolyzed during saponification, thus altering the natural carotenoid composition. A straightforward and selective cleanup procedure was therefore developed involving the enzymatic hydrolysis of matrix glycerolipids. The optimized procedure (100 μL of extracted vegetable or algal oil in 20 mL of 50:50 phosphate buffer/methanol with 25 μL of sodium n-octyl sulfate, 30 mg of bile salts, and 250 μL of NaCl solution (5 mM), magnetic stirring for 2 h at 40 °C with 1 mL of Lipozyme TL 100 L and 1 mL of Lipozyme CALB L) removed the greater part of triglycerides (94.8-100.0%) and diglycerides (88.2-99.8%) while preserving the natural carotenoid composition.

Structure elucidation and chemical profile of sphingolipids in wheat bran and their cytotoxic effects against human colon cancer cells

Sphingolipids are known to have diverse properties and physiological functions. These distinctive lipids have been identified in wheat bran, a food well-known for its chemopreventive activity. However, the complete profile of sphingolipids in wheat bran and their contributions to the cancer preventive effect of wheat bran have not been fully explored until this study. Twelve sphingolipids (1-12) were purified from wheat bran extract and characterized by analyzing their 1D and 2D NMR spectra, and seven sphingolipids (13-19) were characterized based on their tandem mass spectra (MS(n): n = 2-4). To the best of our knowledge, this is the first report of sphingolipids 1, 6-9, 11-14, and 16-19 in wheat bran. In particular, 2-N-(2'-hydroxy-15'-tricosenoyl)-4-hydroxysphinganine (peak 17) is a novel compound. Additionally, compounds 2-4 were reported with complete NMR data for the first time. Sphingolipids (1-12) showed little growth inhibition against human colon cancer cell lines (HCT-116 and HT-29) in vitro.

Glycolipid composition of Hevea brasiliensis latex

Glycolipids of fresh latex from three clones of Hevea brasiliensis were characterized and quantified by HPLC/ESI-MS. Their fatty acyl and sterol components were further confirmed by GC/MS after saponification. The four detected glycolipid classes were steryl glucosides (SG), esterified steryl glucosides (ESG), monogalactosyl diacylglycerols (MGDG) and digalactosyl diacylglycerols (DGDG). Sterols in SG, ESG and total latex unsaponifiable were stigmasterol, β-sitosterol and Δ⁵-avenasterol. The latter was found instead of fucosterol formerly described. Galactolipids were mainly DGDG and had a fatty acid composition different from that of plant leaves as they contained less than 5% C18:3. Glycolipids, which represented 27-37% of total lipids, displayed important clonal variations in the proportions of the different fatty acids. ESG, MGDG and DGDG from clone PB235 differed notably by their higher content in furan fatty acid, which accounted for more than 40% of total fatty acids. Clonal variation was also observed in the relative proportions of glycolipid classes except MGDG (8%), with 43-51% DGDG, 30-34% SG and 7-19% ESG. When compared with other plant cell content, the unusual glycolipid composition of H. brasiliensis latex may be linked to the peculiar nature of this specialized cytoplasm expelled from laticiferous system, especially in terms of functional and structural properties.

Administration of tomato and paprika beverages modifies hepatic glucose and lipid metabolism in mice: a DNA microarray analysis

To examine whether the expression of hepatic genes, including biomarkers, is affected by the ingestion of tomato or paprika, mice were given tomato beverage (TB), paprika beverage (PB), or water (control) ad libitum for 6 weeks. The body weights in the TB and PB groups were significantly lower than those in the control group. Administration of PB significantly increased the plasma high-density lipoprotein-cholesterol level. Hepatic gene expression was investigated using DNA microarrays. The ingestion of TB or PB up-regulated the expression of 687 and 1045 genes and down-regulated the expression of 841 and 653 genes, respectively (false discovery rate<0.05). These changes in gene expression suggest that TB ingestion promotes glycogen accumulation and stimulates some specific steps in fatty acid oxidation. PB ingestion promoted the entire glucose and fatty acid metabolic pathways to improve lipid profiles. These results provide useful genetic information about a variety of biochemical processes by which vegetables can contribute to good health.

The identification of mono-, di-, tri-, and tetragalactosyl-diacylglycerols and their natural estolides in oat kernels

Oat kernels were extracted with methanol, and glycolipid-enriched fractions were prepared using silica solid phase extraction. Using direct infusion electrospray ionization (ESI) tandem mass spectrometry (MS), high performance liquid chromatography (HPLC)-ESI-MS, and HPLC-atmospheric pressure chemical ionization (APCI)-MS, we confirmed previous reports that digalactosyldiacylglycerol (DGDG) was the most abundant glycolipid in oat kernels and confirmed a previous report of the presence of a DGDG mono-estolide in oat kernels. In the current study we also identified several additional natural galactolipid estolides: two new DGDG estolides (di- and tri-estolides), two trigalactosyldiacylglycerol (TriGDG) estolides (mono- and di-estolides), and one tetragalactosyldiacylglycerol (TetraGDG) estolide (mono-estolide). The levels of total galactolipid estolides in oat kernels were estimated to be about 29% of the total glycolipid fraction. To our knowledge, this report is the first evidence of natural di- and tri-estolides of polar lipids.

Simultaneous analysis of glycolipids and phospholids molecular species in avocado (Persea americana Mill) fruit

The molecular species of phospholipids (PLs) and glycolipids (GLs) were simultaneously characterized in the pulp and almond of the avocado fruit (Persea americana Mill) of four varieties by means of high performance liquid chromatography-electrospray ionisation ion-trap tandem mass spectrometry. In the pulp, the predominant species of monoglycosyldiglycerides (MGD) were m/z 796.6 (oleic/linolenic and linoleic/linoleic acids) and m/z 800.4 (stearic/linoleic and oleic/oleic acids). One of the main diglycosyldiglycerides (DGD) both in the pulp and almond was m/z 958.5 (oleic/linolenic); however, the pulp was also rich of m/z 962.4 (oleic/oleic), whereas in the almond, m/z 934.5 (palmitic/linoleic and palmitoleic/oleic) and m/z 960.5 (oleic/linoleic and stearic/linolenic) were more abundant. In the almond, the main PL classes (phosphatidic acid (PA), phosphatidylcholine (PC), phosphatidylethanolamine (PE) and phosphatidylinositol (PI)) contained always palmitic/linoleic acids. Alpha-linolenic acid was contained as MGD (linolenic/linolenic) and DGD (linolenic/linolenic), more present in the pulp than in the almond. The major molecular species of glycocerebrosides (GCer) in the pulp and almond carried hydroxy-palmitic acid (C(16h:0))/4,8-sphyngadienine (d(18:2)).

Cerebrosides from the roots of Serratula chinensis

A new cerebroside, 1-O-beta-D-glucopyranosyl-(2S,3R,8E)-2-[(2'R)-2-hydroxy- palmitoylamino]-8-octadecene-1,3-diol, along with aralia cerebroside and 1-O-beta-D- glucopyranosyl-(2S,3S,4R,8E)-2-[(2'R)-2-hydroxybehenoylamino]-8-octadecene-1,3,4-triol were isolated from the roots of Serratula chinensis S. Moore. The structure of the new cerebroside was established by spectroscopic and chemical means. Occurrence of cerebrosides in Serratula is reported here for the first time.

Tumor cell proliferation and cyclooxygenase enzyme inhibitory compounds in Amaranthus tricolor

Amaranthus tricolor is consumed as a vegetable in Asia. Bioassay-directed isolation of leaves and stems of A. tricolor yielded three galactosyl diacylglycerols (1-3) with potent cyclooxygenase and human tumor cell growth inhibitory activities. The purified compounds were characterized by spectroscopic methods. In addition, the fatty acid moieties in diacyl galactosyl glyerols were characterized by GC-MS analyses. The galactosyl diacylglycerols 1-3 inhibited the cyclooxygenase-1 (COX-1) enzyme by 78, 63, and 93% and the cyclooxygenase-2 (COX-2) enzyme by 87, 74, and 95%, respectively. These compounds were tested for antiproliferative activity using human AGS (gastric), CNS (central nervous system; SF-268), HCT-116 (colon), NCI-H460 (lung), and MCF-7 (breast) cancer cell lines. Compound 1 inhibited the growth of AGS, SF-268, HCT-116, NCI-H460, and MCF-7 tumor cell lines with IC50 values of 49.1, 71.8, 42.8, 62.5, and 39.2 mug/mL, respectively. For AGS, HCT-116, and MCF-7 tumor cell lines, the IC50 values of compounds 2 and 3 were 74.3, 71.3, and 58.7 microg/mL and 83.4, 73.1, and 85.4, respectively. This is the first report of the COX enzyme inhibitory activity for galactosyl glycerols and antiproliferative activities against human colon, breast, lung, stomach, and CNS tumor cell lines.

Spelt (Triticum spelta L.) and winter wheat (Triticum aestivum L.) wholemeals have similar sterol profiles, as determined by quantitative liquid chromatography and mass spectrometry analysis

From a nutritional point of view, cereal lipids include valuable molecules, such as essential fatty acids, phytosterols, and fat-soluble vitamins. Spelt (Triticum spelta L.) is an alternative hulled bread cereal mostly grown in Belgium, where it is mainly intended for animal feed but should increasingly be used for human consumption. The present research focused on phytosterol quantification by LC/APCI-MS2 in saponified wholemeal extracts of 16 dehulled spelt and 5 winter wheat (Triticum aestivum L.) varieties grown in Belgium during 2001-2002 at the same location. Glycosylated sterols and free and formerly esterified sterols could be determined in saponified extracts. Results show that the mean phytosterol content is comparable in both cereals (whereas other lipids, such as oleic and linoleic acids, are increased in spelt wholemeal): spelt extract has, on average, 527.7 microg of free and esterified sterols g(-1) of wholemeal and 123.8 microg of glycosylated sterols g(-1) of wholemeal versus 528.5 and 112.6 microg x g(-1) in winter wheat (values not corrected for recoveries). This is the first report on the application and validation of an LC/MS2 method for the quantification of phytosterols in spelt and winter wheat.

An antiinflammatory galactolipid from rose hip (Rosa canina) that inhibits chemotaxis of human peripheral blood neutrophils in vitro

The galactolipid (2S)-1,2-di-O-[(9Z,12Z,15Z)-octadeca-9,12,15-trienoyl]-3-O-beta-d-galactopyranosyl glycerol (1) isolated from dried and milled fruits of Rosa canina by bioassay-guided fractionation is an antiinflammatory agent with inhibitory effects on chemotaxis of human peripheral blood neutrophils in vitro. The inhibition of cell migration is not related to toxicity. The presence of 1 in rose hips may explain the clinically observed antiinflammatory properties of rose hip herbal remedies.

Phytosterols, phytostanols, and their conjugates in foods: structural diversity, quantitative analysis, and health-promoting uses

Phytosterols (plant sterols) are triterpenes that are important structural components of plant membranes, and free phytosterols serve to stabilize phospholipid bilayers in plant cell membranes just as cholesterol does in animal cell membranes. Most phytosterols contain 28 or 29 carbons and one or two carbon-carbon double bonds, typically one in the sterol nucleus and sometimes a second in the alkyl side chain. Phytostanols are a fully-saturated subgroup of phytosterols (contain no double bonds). Phytostanols occur in trace levels in many plant species and they occur in high levels in tissues of only in a few cereal species. Phytosterols can be converted to phytostanols by chemical hydrogenation. More than 200 different types of phytosterols have been reported in plant species. In addition to the free form, phytosterols occur as four types of "conjugates," in which the 3beta-OH group is esterified to a fatty acid or a hydroxycinnamic acid, or glycosylated with a hexose (usually glucose) or a 6-fatty-acyl hexose. The most popular methods for phytosterol analysis involve hydrolysis of the esters (and sometimes the glycosides) and capillary GLC of the total phytosterols, either in the free form or as TMS or acetylated derivatives. Several alternative methods have been reported for analysis of free phytosterols and intact phytosteryl conjugates. Phytosterols and phytostanols have received much attention in the last five years because of their cholesterol-lowering properties. Early phytosterol-enriched products contained free phytosterols and relatively large dosages were required to significantly lower serum cholesterol. In the last several years two spreads, one containing phytostanyl fatty-acid esters and the other phytosteryl fatty-acid esters, have been commercialized and were shown to significantly lower serum cholesterol at dosages of 1-3 g per day. The popularity of these products has caused the medical and biochemical community to focus much attention on phytosterols and consequently research activity on phytosterols has increased dramatically.