Characterization and Analysis of Sesamolinol Diglucoside in Sesame Seeds

Sesame Seeds: A Nutrient-Rich Superfood

Sesame seeds (Sesamum indicum L.) have been cultivated for thousands of years and have long been celebrated for their culinary versatility. Beyond their delightful nutty flavor and crunchy texture, sesame seeds have also gained recognition for their remarkable health benefits. This article provides an in-depth exploration of the numerous ways in which sesame seeds contribute to overall well-being. Sesame seeds are a powerhouse of phytochemicals, including lignans derivatives, tocopherol isomers, phytosterols, and phytates, which have been associated with various health benefits, including the preservation of cardiovascular health and the prevention of cancer, neurodegenerative disorders, and brain dysfunction. These compounds have also been substantiated for their efficacy in cholesterol management. Their potential as a natural source of beneficial plant compounds is presented in detail. The article further explores the positive impact of sesame seeds on reducing the risk of chronic diseases thanks to their rich polyunsaturated fatty acids content. Nevertheless, it is crucial to remember the significance of maintaining a well-rounded diet to achieve the proper balance of n-3 and n-6 polyunsaturated fatty acids, a balance lacking in sesame seed oil. The significance of bioactive polypeptides derived from sesame seeds is also discussed, shedding light on their applications as nutritional supplements, nutraceuticals, and functional ingredients. Recognizing the pivotal role of processing methods on sesame seeds, this review discusses how these methods can influence bioactive compounds. While roasting the seeds enhances the antioxidant properties of the oil extract, certain processing techniques may reduce phenolic compounds.

Influence of sesame cake on physicochemical, antioxidant and sensorial characteristics of fortified wheat breads

Incorporation of two sesame cake preparations, differing in fat, 11 % (LF) and 17 % (HF), and protein, 51 % (LF) and 44 % (HF), contents, respectively, into breads at 6, 12 and 20 % wheat flour substitution levels, led to enriched end-products with antioxidants, suitable also to carry the 'high protein' and 'fiber source' nutrition claims (at ≥ 12 % substitution level). Sesame cake decreased wheat dough resistance to mixing and extension, and peak viscosity (empirical rheology), in a concentration-dependent manner, being more pronounced for LF formulations. Breads with LF incorporation ≥ 12 % had lower specific volumes and harder crumb (texture analysis) throughout storage, than control (100 % wheat flour); however, such adverse effects were diminished in HF bread formulations due to the plasticizing and emulsifying action of the sesame cake fat. Calorimetry showed that the sesame cake had no effect on starch retrogradation, but enhanced amylose-lipid complex formation. Antioxidant activity (ABTS, DPPH and FRAP assays), and phenolic acids (ferulic, p-coumaric and sinapic) and lignan (sesaminol glucosides and sesamolin) contents, determined by HPLC-DAD-MS, were higher in LF breads than their HF counterparts. The presence of some sulfur (off-flavor) and pyrazine (nutty flavor) compounds (SPME-GC-MS), as well as the sesame flavor and bitterness (sensory analysis) were of higher intensity in HF breads, while the 6 % LF product received the highest overall acceptability score among all fortified products. Overall, the sesame cake can be a promising ingredient for production of functional wheat bread depending on its composition and fortification level.

α-Glucosidase Inhibitors from Cold-Pressed Black Sesame (Sesamum indicum) Meal: Characterization of New Furofuran Lignans, Kinetic Study, and In Vitro Gastrointestinal Digestion

Black sesame (Sesamum indicum) meal is an agricultural waste obtained after oil extraction. It is used as a key protein source in animal feed. Previous investigations have indicated that its health benefits, such as antidiabetic activity, are mainly due to its high lignan content. In the present study, we applied α-glucosidase inhibitory guided isolation to identify the active components responsible for the above claim. Twenty-nine compounds, mostly lignans, were isolated and identified, of which five (2-3, 12-13, and 28) were newly isolated. Of the isolated compounds, 20 and 21 were the most potent inhibitors, retarding enzyme function in noncompetitive and uncompetitive manners. Structure-activity relationship analysis suggested that the number of phenolic hydroxyl groups in the structures was significantly related to the inhibitory effect against α-glucosidase. A gastrointestinal digestion study of the major lignan sesaminol triglucoside (STG, 9) suggested that the transformation of dioxymethylene and glucoside moieties gradually began in the late process, thus enhancing the α-glucosidase inhibitory effect.

Effects of sesame dehulling on physicochemical and sensorial properties of its oil

At present, sesame oil is extracted from un-hulled white sesame seeds by using cold press lubrication machines in local stores in Iran. This study aimed to evaluate the physicochemical properties and safety parameters of the hulled and un-hulled white sesame oils. The fatty acid composition, antioxidant activity, oxalates content, total phenolic content, carotenoid content, acid value, peroxide value, p-anisidine value, value total oxidation value (TOTOX), aflatoxins and pesticides residue, smoke point, color, relative density, and refractive index of oil sample were examined immediately after extracting the oil. The peroxide, p-anisidine, and TOTOX value of the hulled and un-hulled sesame oil samples were also examined periodically. After 7 months, the quality parameters were high and the oil samples were not consumable. Linoleic and oleic acids were the predominant fatty acids in the hulled and un-hulled sesame oils. The results of this study showed that the oil extracted from raw un-hulled sesame had a lower initial quality than hulled sesame oil and was oxidized more rapidly than it during the storage period. Virgin oils contained impurities acting like prooxidants and reduced their stability and shelf life. In addition, the un-hulled sesame oil contained higher amounts of antinutrient compounds (e.g., oxalate and pesticide residues) than the hulled sesame oil. Aflatoxin was not detected in our oil samples.

Comparative metabolite fingerprinting of chia, flax and sesame seeds using LC-MS untargeted metabolomics

Chia, flax, and sesame seeds are well known for their nutritional quality and are commonly included in bakery products. So far, the development of methods to verify their presence and authenticity in foods is a requisite and a raised need. In this work we applied untargeted metabolomics to propose authenticity markers. Seeds were analyzed by HPLC-MS/MS and 9938 features in negative mode and 9044 in positive mode were obtained by Mzmine. After isotopes grouping, alignment, gap-filling, filtering adducts, and normalization, PCA was applied to explore the dataset and recognize pre-existent classification patterns. OPLS-DA analysis and S-Plots were used as supervised methods. Twenty-five molecules (12 in negative mode and 13 in positive mode) were selected as discriminant for the three seeds, polyphenols and lignans were identified among them. To the best of our knowledge, this is the first approach using non-target HPLC-MS/MS for the authentication of chia, flax and sesame seeds.

Lignans of Sesame (Sesamum indicum L.): A Comprehensive Review

Major lignans of sesame sesamin and sesamolin are benzodioxol--substituted furofurans. Sesamol, sesaminol, its epimers, and episesamin are transformation products found in processed products. Synthetic routes to all lignans are known but only sesamol is synthesized industrially. Biosynthesis of furofuran lignans begins with the dimerization of coniferyl alcohol, followed by the formation of dioxoles, oxidation, and glycosylation. Most genes of the lignan pathway in sesame have been identified but the inheritance of lignan content is poorly understood. Health-promoting properties make lignans attractive components of functional food. Lignans enhance the efficiency of insecticides and possess antifeedant activity, but their biological function in plants remains hypothetical. In this work, extensive literature including historical texts is reviewed, controversial issues are critically examined, and errors perpetuated in literature are corrected. The following aspects are covered: chemical properties and transformations of lignans; analysis, purification, and total synthesis; occurrence in Seseamum indicum and related plants; biosynthesis and genetics; biological activities; health-promoting properties; and biological functions. Finally, the improvement of lignan content in sesame seeds by breeding and biotechnology and the potential of hairy roots for manufacturing lignans in vitro are outlined.

Insights into Lignan Composition and Biosynthesis in Stinging Nettle (Urtica dioica L.)

Stinging nettle (Urtica dioica L.) has been used as herbal medicine to treat various ailments since ancient times. The biological activity of nettle is chiefly attributed to a large group of phenylpropanoid dimers, namely lignans. Despite the pharmacological importance of nettle lignans, there are no studies addressing lignan biosynthesis in this plant. We herein identified 14 genes encoding dirigent proteins (UdDIRs) and 3 pinoresinol-lariciresinol reductase genes (UdPLRs) in nettle, which are two gene families known to be associated with lignan biosynthesis. Expression profiling of these genes on different organs/tissues revealed a specific expression pattern. Particularly, UdDIR7, 12 and 13 displayed a remarkable high expression in the top internode, fibre tissues of bottom internodes and roots, respectively. The relatively high expression of UdPLR1 and UdPLR2 in the young internodes, core tissue of bottom internode and roots is consistent with the high accumulation of lariciresinol and secoisolariciresinol in these tissues. Lignan quantification showed a high abundance of pinoresinol in roots and pinoresinol diglucosides in young internodes and leaves. This study sheds light on lignan composition and biosynthesis in nettle, providing a good basis for further functional analysis of DIRs and PLRs and, ultimately, engineering lignan metabolism in planta and in cell cultures.

Gene isolation, heterologous expression, purification and functional confirmation of sesamin synthase from Sesamum indicum L

Members of Cytochromes P450 super family of enzymes catalyse important biochemical reactions in plants. Some of these reactions are so important that they contribute to enormous chemical diversity seen in plants. Many unique secondary metabolites formed by mediation of these enzymes play key role in plant defence and often contribute to maintenance of human health. In oilseed crop Sesamum indicum, the reaction leading to the formation of clinically important sesamin is catalyzed by a unique methylene-di-oxy bridge forming Cytochrome P450 enzyme sesamin synthase. It is encoded by the gene CYP81Q1. In order to elucidate the structure - function relationship of this enzyme and to apply biotechnological tools for enhancing the production of sesamin in the crop, it was intended to clone and express the enzyme in a heterologous system. In this paper we present our results on synthesis of cDNA, cloning, expression and purification of CYP81Q1 from the developing seeds of sesame crop. Following the same procedure we have also cloned a CYP reductase1 (CPR1) gene (CPR1) to facilitate transfer of electron from NADPH to CYP81Q1 enzyme from the same crop. Functional characterization was performed by expressing the recombinant proteins in E. coli (pET28a/BL21-DE3 codon plus) and its activity was evaluated in vitro by HPLC. We demonstrate that purified CYP81Q1 enzyme, on its own, has limited level of activity in the conversion of pinoresinol to sesamin. Its activity gets considerably enhanced in the presence of CPR1.

Production of sesaminol and antioxidative activity of fermented sesame with Lactobacillus plantarum P8, Lactobacillus acidophilus ATCC 4356, Streptococcus thermophilus S10

This study was carried out to select the most competent bacterial cultures that could convert sesaminol glycosides to aglycone by β-glucosidase produced by lactic acid bacteria such as Lactobacillus acidophilus, Lactobacillus plantarum (LP), and Streptococcus thermophilus in sesame fermented at 37°C for 24 h. The pH of fermented sesame was decreased compared to non-fermented controls. The pH of LP was lower than that of the other two during fermentation. Fermented sesame had higher antioxidant activity compared to non-fermented controls during the entire fermentation time. Total phenol content, DPPH free radical scavenging assay, reducing power assay of sesame fermented by LP was the highest compared to the others. In addition, sesame fermented by LP had more bioconversion of sesaminol glycoside to aglycone compared to the others. Therefore, LP was the best bacterial culture of the three strains studied for producing functional fermented sesame for good health.

A critique on the structural analysis of lignins and application of novel tandem mass spectrometric strategies to determine lignin sequencing

This review is devoted to the application of MS using soft ionization methods with a special emphasis on electrospray ionization, atmospheric pressure photoionization and matrix-assisted laser desorption/ionization MS and tandem MS (MS/MS) for the elucidation of the chemical structure of native and modified lignins. We describe and critically evaluate how these soft ionization methods have contributed to the present-day knowledge of the structure of lignins. Herein, we will introduce new nomenclature concerning the chemical state of lignins, namely, virgin released lignins (VRLs) and processed modified lignins (PML). VRLs are obtained by liberation of lignins through degradation of vegetable matter by either chemical hydrolysis and/or enzymatic hydrolysis. PMLs are produced by subjecting the VRL to a series of further chemical transformations and purifications that are likely to alter their original chemical structures. We are proposing that native lignin polymers, present in the lignocellulosic biomass, are not made of macromolecules linked to cellulose fibres as has been frequently reported. Instead, we propose that the lignins are composed of vast series of linear related oligomers, having different lengths that are covalently linked in a criss-cross pattern to cellulose and hemicellulose fibres forming the network of vegetal matter. Consequently, structural elucidation of VRLs, which presumably have not been purified and processed by any other type of additional chemical treatment and purification, may reflect the structure of the native lignin. In this review, we present an introduction to a MS/MS top-down concept of lignin sequencing and how this technique may be used to address the challenge of characterizing the structure of VRLs. Finally, we offer the case that although lignins have been reported to have very high or high molecular weights, they might not exist on the basis that such polymers have never been identified by the mild ionizing techniques used in modern MS.

Purification and fermentation in vitro of sesaminol triglucoside from sesame cake by human intestinal microbiota

Sesaminol triglucoside (STG), the most abundant lignan glycoside existing in sesame cake/meal, has exhibited various biological activities. However, little information about its in vitro fermentation with intestinal microbiota is available. Therefore, the effect of STG from sesame cake on the fermentation of human fecal microbiota was evaluated. First, high-purity STG was successfully prepared from defatted sesame cake by extraction with 80% ethanol and simple purification procedures of polyamide column chromatography and Toyopearl HW-40S column chromatography. Then the influence of STG on intestinal microbiota was conducted by monitoring bacterial populations and analyzing the concentrations of short-chain fatty acids (SCFA). We found that STG could significantly induce an increase in numbers of Lactobacillus - Enterococcus group and Bifidobacterium in fermentation in vitro with human fecal microbiota, while it did not stimulate the bacterial growth of Eubacterium rectale - Clostridium coccoides group, Clostridium histolyticum group, and Bacteroides - Prevotella group. Furthermore, it was found that concentrations of formic, acetic, propionic, and butyric acids in STG culture increased significantly during the fermentation, and its total SCFA concentration was relatively higher than those of the control and glucose cultures at 6 and 12 h fermentation. Our findings provided further evidence for the importance of human intestinal bacteria in the bioactivity of STG and its metabolites in the maintenance of human health.

(+)-Pinoresinol is a putative hypoglycemic agent in defatted sesame (Sesamum indicum) seeds though inhibiting α-glucosidase

Defatted sesame seeds have been reported for hypoglycemic effect in mice and T2DM women. An attempted to identify active components responsible for this effect was conducted using α-glucosidase-guided fractionation, resulting in the isolation of various lignans. Of compounds isolated, only (+)-pinoresinol showed inhibitory activity against rat intestinal maltase with an IC(50) value of 34.3 μM. The kinetic study indicated that enzymatic hydrolysis of maltose is inhibited by (+)-pinoresinol through competitive and noncompetitive manners. However, a lower dissociation constant (k(i) 288 M) of EI complex suggested that competitive inhibition is predominant over noncompetitive mode (k'(i) 1342 M).

Sesamolinol glucoside, disaminyl ether, and other lignans from sesame seeds

The application of a procedure based on XAD-4 adsorption resin permitted the obtainment of an enriched polyphenolic extract from Sesamum indicum seeds. Chemical analysis of the obtained extract led to the identification of 12 lignans. Among them, 2 lignans, (+)-sesamolinol-4'-O-β-D-glucoside and disaminyl ether, are reported for the first time as natural compounds. Their structure has been determined by spectroscopic methods, mainly by the application of one-dimensional (1D) and two-dimensional (2D) nuclear magnetic resonance (NMR) techniques [heteronuclear multiple-quantum coherence (HMQC), heteronuclear multiple-bond correlation (HMBC), and nuclear Overhauser effect spectrometry (NOESY)] and mass spectroscopy. The isolated compounds were evaluated for their antimutagenic activity. Among the tested lignans, the most active lignan was found to be sesamolin, followed by sesamolinol and samin, against H(2)O(2). Additionally, some of the tested lignans showed desmutagenic activity against benzo[a]pyrene (BaP).

Changes in the metabolic profile of rat liver after α-tocopherol deficiency as revealed by metabolomics analysis

Metabolomics is an approach in which the profiles of metabolites in different tissues and/or biofluids are investigated to understand the changes induced following a modulation. We used this approach to investigate the biochemical effects of α-tocopherol in the liver using a rat model. Rats (21-day-old) were fed either an α-tocopherol-sufficient control (n = 10) or an α-tocopherol-deficient (n = 10) diet for 2 months before sacrifice. Livers were homogenized in methanol-chloroform-water (3 : 1 : 1, v/v/v), and the polar phase extracts of the liver samples were analyzed using (1) H NMR. Multivariate statistical analysis of the data was performed using principal component analysis and orthogonal partial least squares-discriminant analysis. Identification of (1) H NMR signals was performed primarily using the Human Metabolome Database, Biological Magnetic Resonance Data Bank and previous literature, and confirmed by spiking with metabolites and applying two-dimensional NMR. The statistical analysis revealed that α-tocopherol deficiency caused an increase in carnitine, choline, L-valine, L-lysine, tyrosine and inosine content and a reduction in glucose and uridine 5'-monophosphate content. Changes in carnitine and glucose suggest a possible shift in energy metabolism.

Comparison of atmospheric pressure chemical ionization and electrospray ionization mass spectrometry for the detection of lignans from sesame seeds

In sesame seeds, high concentrations of lignans are present. When these lignans are fermented in the human colon, a range of structurally different lignans is formed. A good liquid chromatography/mass spectrometry (LC/MS) protocol for the analysis of lignans in complex mixtures is lacking. In order to develop such a protocol, electrospray ionization (ESI)-MS and atmospheric pressure chemical ionization (APCI)-MS, both in the positive and negative ionization mode, were compared. An extract from defatted sesame meal was analyzed by APCI-MS and ESI-MS, before and after deglucosylation. APCI-MS was found to be a more generic method than ESI-MS because lignans, especially sesamolin, sesamin and pinoresinol, were better detected by APCI-MS than by ESI-MS. Positive and negative ionization modes had to be combined in order to detect all lignans in a bacterial culture grown on aglyconic, acid-treated lignans from sesame oil and defatted sesame meal. Lignans with methylenedioxy-bridged furanofuran structures mostly lack phenolic hydroxyl groups and were, therefore, optimally detected in positive ionization mode. Dibenzylbutadiene lignans, which were formed during fermentation, carry hydroxyl groups and were better detected in negative ionization mode.

Sequential glucosylation of a furofuran lignan, (+)-sesaminol, by Sesamum indicum UGT71A9 and UGT94D1 glucosyltransferases

(+)-Sesaminol 2-O-triglucoside is the most abundant water-soluble furofuran lignan in sesame seeds (Sesamum indicum) and is considered to be a beneficial compound for human health. The biosyntheses and physiological roles of lignan glycosides, however, remain elusive. Here we report the molecular identification and biochemical characterization of two Sesamum uridine diphosphate (UDP) glucose:lignan glucosyltransferases. Sesamum indicum UGT71A9 preferentially glucosylated at the 2-hydroxyl group of (+)-sesaminol, resulting in (+)-sesaminol 2-O-glucoside. Similarly, two UGT71A9 homologs from Sesamum radiatum (UGT71A10) and Sesamum alatum (UGT71A8) also showed (+)-sesaminol glucosylating activity, evidencing the functional conservation of (+)-sesaminol 2-O-glucosyltransferases in the Sesamum genus. In addition, S. indicum UGT94D1 specifically glucosylated at the 6'-hydroxyl group of the sugar moiety of (+)-sesaminol 2-O-glucoside but not at that of flavonoid glucosides. The gene expression patterns of UGT71A9 and UGT94D1 during seed development were correlated with the glucosylating activities toward (+)-sesaminol in planta, suggesting that the two lignan UDP-glycosyltransferases participate in the sequential glucosylation steps in the biosynthesis of (+)-sesaminol 2-O-triglucoside.

Quantitative NMR analysis of a sesamin catechol metabolite in human urine

Sesamin, the major sesame oil lignan, is recognized for its health-promoting effects, including the lowering of cholesterol and elevation of gamma-tocopherol in rats and humans. However, little is known about the absorption and metabolism of sesamin in humans. In this study, 6 healthy volunteers took a single dose of sesame oil (508 micromol sesamin) and their urine was collected for four 12-h periods. The urine samples were treated with beta-glucuronidase/sulphatase and extracted with chloroform. The major urinary sesamin metabolite in the chloroform extract was collected using HPLC diode array detector and characterized as (1R,2S,5R,6S)-6-(3,4-dihydroxyphenyl)-2-(3,4-methylenedioxyphenyl)-3,7-dioxabicyclo-[3,3,0]octane using NMR and mass spectroscopy. A quantitative (1)H-NMR technique, based on the methylenedioxyphenyl protons signal (delta 5.91), was used for the quantification of the metabolite in the chloroform extracts of urine. The excretion of the sesamin catechol metabolite ranged from 22.2 to 38.6% (mean +/- SD, 29.3 +/- 5.6) of the ingested dose and happened mainly in the 1st 12 h after ingestion.