Determination and purification of sesamin and sesamolin in sesame seed oil unsaponified matter using reversed-phase liquid chromatography coupled with photodiode array and tandem mass spectrometry and high-speed countercurrent chromatography

Byproducts of Sesame Oil Extraction: Composition, Function, and Comprehensive Utilization

Sesame is principally used to generate oil, which is produced by chemical refining or pressing. Sesame meal, as a main byproduct of sesame oil extraction, is usually discarded, causing resource waste and economic loss. Sesame meal is rich in sesame protein and three types of sesame lignans (sesamin, sesamolin, and sesamol). Sesame protein extracted via a physical method and an enzymic method has balanced amino acid composition and is an important protein source, and thus it is often added to animal feed and used as a human dietary supplement. Extracted sesame lignan exhibits multiple biological activities such as antihypertensive, anticancer, and cholesterol-lowering activities, and therefore it is used to improve the oxidative stability of oils. This review summarizes the extraction methods, functional activities, and comprehensive utilization of four active substances (sesame protein, sesamin, sesamolin, and sesamol) in sesame meal with the aim to provide theoretical guidance for the maximum utilization of sesame meal.

Extraction Techniques and Analytical Methods for Isolation and Characterization of Lignans

Lignans are a group of natural polyphenols present in medicinal plants and in plants which are a part of the human diet for which more and more pharmacological activities, such as antimicrobial, anti-inflammatory, hypoglycemic, and cytoprotective, are being reported. However, it is their cytotoxic activities that are best understood and which have shed light on this group. Two anticancer drugs, etoposide, and teniposide, were derived from a potent cytotoxic agent—podophyllotoxin from the roots of Podophyllum peltatum. The evidence from clinical and observational studies suggests that human microbiota metabolites (enterolactone, enterodiol) of dietary lignans (secoisolariciresinol, pinoresinol, lariciresinol, matairesinol, syringaresinol, medioresinol, and sesamin) are associated with a reduced risk of some hormone-dependent cancers. The biological in vitro, pharmacological in vivo investigations, and clinical studies demand significant amounts of pure compounds, as well as the use of well-defined and standardized extracts. That is why proper extract preparation, optimization of lignan extraction, and identification are crucial steps in the development of lignan use in medicine. This review focuses on lignan extraction, purification, fractionation, separation, and isolation methods, as well as on chromatographic, spectrometric, and spectroscopic techniques for their qualitative and quantitative analysis.

Plant- and Animal-Based Antioxidants' Structure, Efficacy, Mechanisms, and Applications: A Review

Antioxidants are compounds that normally prevent lipid and protein oxidation. They play a major role in preventing many adverse conditions in the human body, including inflammation and cancer. Synthetic antioxidants are widely used in the food industry to prevent the production of adverse compounds that harm humans. However, plant- and animal-based antioxidants are more appealing to consumers than synthetic antioxidants. Plant-based antioxidants are mainly phenolic compounds, carotenoids, and vitamins, while animal-based antioxidants are mainly whole protein or the peptides of meat, fish, egg, milk, and plant proteins. Plant-based antioxidants mainly consist of aromatic rings, while animal-based antioxidants mainly consist of amino acids. The phenolic compounds and peptides act differently in preventing oxidation and can be used in the food and pharmaceutical industries. Therefore, compared with animal-based antioxidants, plant-based compounds are more practical in the food industry. Even though plant-based antioxidant compounds are good sources of antioxidants, animal-based peptides (individual peptides) cannot be considered antioxidant compounds to add to food. However, they can be considered an ingredient that will enhance the antioxidant capacity. This review mainly compares plant- and animal-based antioxidants’ structure, efficacy, mechanisms, and applications.

Current Research Trends and Prospects for Yield and Quality Improvement in Sesame, an Important Oilseed Crop

Climate change is shifting agricultural production, which could impact the economic and cultural contexts of the oilseed industry, including sesame. Environmental threats (biotic and abiotic stresses) affect sesame production and thus yield (especially oil content). However, few studies have investigated the genetic enhancement, quality improvement, or the underlying mechanisms of stress tolerance in sesame. This study reveals the challenges faced by farmers/researchers growing sesame crops and the potential genetic and genomic resources for addressing the threats, including: (1) developing sesame varieties that tolerate phyllody, root rot disease, and waterlogging; (2) investigating beneficial agro-morphological traits, such as determinate growth, prostrate habit, and delayed response to seed shattering; (3) using wild relatives of sesame for wide hybridization; and (4) advancing existing strategies to maintain sesame production under changing climatic conditions. Future research programs need to add technologies and develop the best research strategies for economic and sustainable development.

The inhibitory effects of sesamol and sesamolin on the glycidyl esters formation during deodorization of vegetables oils

BACKGROUND

Glycidyl esters (GEs) have attracted worldwide attention for their potential harm to human health. The GEs in edible oils mainly form during the deodorization of the oil refining processes. We used sesamol and sesamolin to inhibit the formation of GEs in model corn oil (MCO), model palm oil (MPO) and model rice bran oil (MRO) during a deodorization process.

RESULTS

The results showed that, in the three model oils, the total GE content was in the following order from highest to lowest: MRO (1437.98 μg kg^-1 ) > MPO (388.64 μg kg^-1 ) > MCO (314.81 μg kg^-1 ). The inhibitory effect of the three antioxidants on the formation of GEs in the MCO was in the following order from strongest to weakest: tert-butylhydroquinone (TBHQ) > sesamol > sesamolin.

CONCLUSION

When the mass percentage of sesamol was 0.05%, its inhibition percentage on GEs was close to the inhibition percentage of 0.02% added TBHQ. The present study provides a foundation for understanding how to inhibit the formation of GEs in oils by adding sesamol during the deodorization process.

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.

Simultaneous and rapid determination of sesamin and sesamolin in sesame oils using excitation-emission matrix fluorescence coupled with self-weighted alternating trilinear decomposition

BACKGROUND

Sesamin and sesamolin are two typical and important lignans isolated from sesame oil. Various studies have shown the bioactivity, physiological activity, and potential health benefits of the two components. In this study, a rapid method for the simultaneous determination of sesamin and sesamolin in sesame oils was proposed. The excitation-emission fluorescence spectra of the oils were obtained after a simple pretreatment, then self-weighted alternating trilinear decomposition was used to extract the quantitative information from the very overlapping spectra.

RESULTS

It was found that reasonable quantification results could be obtained with the limits of detection for the two lignans. These limits were 0.05 mg/g and 0.24 mg/g, and the limits of quantitation were 0.14 mg/g and 0.74 mg/g, respectively. The average recoveries for sesamin and sesamolin were 99.05% and 94.97%.

CONCLUSION

The results indicate that, with simple sample pretreatment, the application for combining excitation-emission fluorescence spectra and self-weighted alternating trilinear decomposition can be a useful and sensitive tool for the determination of lignans in sesame oil. © 2020 Society of Chemical Industry.

Rapid and nondestructive determination of sesamin and sesamolin in Chinese sesames by near-infrared spectroscopy coupling with chemometric method

Sesame was one of the most important crops in Africa and east Asia. The sesamin and sesamolin in sesames have shown various pharmacological, biological and physiologic activities. In this study, a rapid and nondestructive method for determination of sesamin and sesamolin in Chinese sesames by near-infrared spectroscopy coupled with chemometric method was proposed. The near infrared spectra of sesame samples from three different Chinese areas were collected and the partial least squares (PLS) was used to construct the quantitative models. The spectral preprocessing and variable selection methods were adopted to improve the predictability and stability of the model. Reasonable quantitative results can be obtained when the samples used for model construction and prediction were harvested in same years. For sesamin and sesamolin, the correlation coefficient (R) and root mean square error prediction (RMSEP) were 0.9754, 0.9636 and 151.2951, 39.7720, respectively. The optimized models seem less effective when they were used to predict the samples harvested in other years or countries. However, acceptable results can still be obtained.

Sesamin Enhances Nrf2-Mediated Protective Defense against Oxidative Stress and Inflammation in Colitis via AKT and ERK Activation

Ulcerative colitis (UC) is a major form of inflammatory bowel disease (IBD) with high incidence and prevalence in many countries. Patients with UC usually suffer from a lifetime of debilitating physical symptoms. Therefore, developing effective therapeutic strategy that can manage this disease better and improve patients' life quality is in urgent need. Sesamin (SSM) is a lignan derived from sesame seeds. In this study, the protective effect of SSM against UC and the underlying mechanism were investigated in vitro and in vivo. Our data showed that SSM protected Caco-2 cells from H₂O₂-induced oxidative stress injury via GSH-mediated scavenging of reactive oxygen species (ROS). Dual luciferase reporter assay showed that the transcriptional activity of nuclear factor erythroid-related factor 2 (Nrf2) was significantly increased by SSM, and the ability of SSM to activate Nrf2-targeted genes was further confirmed in Caco-2 cells using western blot and quantitative real-time PCR (qRT-PCR). In contrast, Nrf2 knockdown abolished the protective effect of SSM. Additionally, we found that SSM also activated advanced protein kinase B (AKT) and extracellular signal-regulated kinase (ERK) in Caco-2 cells, while either AKT or ERK inhibition can prevent SSM-mediated nuclear translocation of Nrf2. Furthermore, SSM displayed a better protective effect against dextran sulfate sodium- (DSS-) induced UC compared with 5-aminosalicylic acid (5-ASA) in C57BL/6 mice. The enhanced Nrf2 signaling and activated AKT/ERK were also observed in the colon of mice after SSM administration. These results first demonstrate the protective effect of SSM against UC and indicate that the effect is associated with AKT/ERK activation and subsequent Nrf2 signaling enhancement. This study provides a new insight into the medicinal value of SSM and proposes it as a new natural nutrition for better managing the symptoms of UC.

Application of High-speed Countercurrent Chromatography for the Purification of High-purity Illudin S from Omphalotus japonicus

Illudin S from mushroom, such as Omphalotus japonicus and illudens, is a natural sesquiterpene analog with strong anti-tumor and antiviral activities. These illudins compounds are highly effective against various drug-resistant cancers that show extreme cytotoxicity an in vitro assay. However, it is difficult to obtain a sufficient amount of highly pure illudin S from a natural product by simple, efficient and low-cost purification techniques. Here, we offer to apply the high-speed countercurrent chromatography for the preparative purification of illudin S from mushroom extract. For a two-solvent system, the optimal condition of hexane/ethyl acetate/methanol/water (1/5/1/5, v/v/v/v) was optimized to obtain pure illudin S from a crude extract. This purified component was evaluated by liquid chromatography (high-purity >99%) and tandem mass spectrometry. The yield amounts of illudin S (1.3 mg/about 10 g Omphalotus japonicus) at one running are determined by liquid chromatographic calibration. It is concluded that by requiring a natural material and cost-effectiveness, our method represents a significant improvement over complicated techniques for the purification of illudin S from natural materials.