Triterpenoid Aglycones Research Articles

Herbal Healer: A Comprehensive Review of the Overall Plant Profile and Medicinal Properties of Glycyrrhiza glabra

This review highlights the significance of licorice (Glycyrrhiza glabra) as a traditional medicinal plant with diverse therapeutic benefits. In India, where traditional remedies are widely preferred over allopathic medicines, thanks to its natural nature and fewer side effects, licorice has a notable position. Being one of the four "Medhya Rasayana" in Ayurveda, G. glabra has been used for memory enhancement, cognition, and nerve function improvements for over 4,000 years. Liquorice cultivation is widespread in several countries, and its chemical constituents include flavonoids, glycosides, triterpenoid aglycone, glycyrrhizin, and Glabridin. The plant has demonstrated multiple pharmacological activities such as, anti-inflammatory, antioxidant, memory enhancement, antistress, hepatoprotective, immunomodulation, antihyperglycemic, and anticancer effects. moreover, licorice shows antimicrobial, antinociceptive, dermatological, and neuroprotective properties. These diverse therapeutic effects have led to its potential use in various health-related concerns. To completely comprehend its modes of action, additional research is needed, define optimal dosages, and ensure long-term safety and efficacy. In conclusion, licorice stands as a significant herbal medicine with a rich history of use and remarkable potential for enhancing human health. Its multiple biological activities make it a valuable candidate for complementary and alternative medicine. Standardization of licorice extracts and rigorous quality control are essential for consistent therapeutic applications. As scientific research expands, licorice-based products are anticipated to play an increasingly vital role in holistic healthcare.

The effects of glycoside-rich green extract from Centella asiatica (L.) Urban on wound healing and anti-aging activity

BackgroundCentella asiatica (L.) Urban extracts contain triterpenoid compounds, namely, glycosides (madecassoside and asiaticoside) and aglycones (madecassic acid and asiatic acid), that possess skincare properties. The extract with high amounts of active components could guarantee the quality of extracts for application in the cosmeceutical industry. PurposeThis study investigated the dermatological benefits of glycoside-rich green extracts from C. asiatica and different triterpenoid combinations. MethodsSix C. asiatica green extracts with different triterpenoid contents were divided into two groups: glycoside-rich extracts (GRCs), which contained >10 % glycosides, and glycoside-low extracts (GLCs), which contained <10 % glycosides. The GRCs, the GLCs, and the triterpenoid components of the selected extract were diluted with 1 % DMSO to concentrations of 0.1, 1, 10, and 100 µg/ml for cell viability, cell migration and procollagen type I C-peptide (PIP) production assays. For the in vitro antiglycation assay, all the samples were diluted with 2 % ethanol to concentrations of 0.5, 0.75, and 1 mg/ml before testing. The best green extract at the optimum concentration was selected, and its activity was compared with that of its triterpenoid components. ResultsAt 10 µg/ml, GRCs promoted wound healing by stimulating fibroblast and keratinocyte motility and increasing collagen production. The main pharmacologically active compounds involved in wound healing were glycosides (madecassoside and asiaticoside). Regarding antiaging activity, 1 mg/ml GRC had a stronger antiglycation effect than combined or individual triterpenoid compounds. Therefore, the antiaging activity of GRC may be mainly attributable to compounds other than triterpenoids. ConclusionC. asiatica green extract containing >10 % glycosides has high development potential for use in the cosmeceutical industry due to its ability to promote wound healing and its antiaging properties.

Anti-inflammatory oleanane triterpenoids with mono-, di-, and tri-palmitoyl chains from the stamen of Nelumbo nucifera Gaertn

Ten undescribed compounds were isolated from the stamen of Nelumbo nucifera Gaertn., including seven oleanane triterpenoid glycosides with 1–3 palmitoyl chains (1–7), an oleanane triterpenoid aglycon (8), and two degraded cycloartane triterpenoids (9 and 10). In addition, seven known oleanane triterpenoids (11–17) were isolated. Among these compounds, 9 was an artificial and 14 was novel and natural product. The anti-inflammatory activity of the 10 undescribed compounds was evaluated by analyzing their inhibitory effects on the release of NO in LPS-induced RAW264.7 macrophages. Nelmnucifergenin A (8) and nelmnucifergenin B (9) showed the maximum inhibitory effects with IC50 values of 16.79 and 20.78 μM, respectively. Additionally, they inhibited the production of TNF-α and IL-6 and down-regulated the key inflammation-related enzymes (iNOS and COX-2).

Disruption of a licorice cellulose synthase-derived glycosyltransferase gene demonstrates its in planta role in soyasaponin biosynthesis

Key messageCRISPR–Cas9-mediated disruption of a licorice cellulose synthase-derived glycosyltransferase gene, GuCSyGT, demonstrated the in planta role of GuCSyGT as the enzyme catalyzing 3-O-glucuronosylation of triterpenoid aglycones in soyasaponin biosynthesis.Triterpenoid glycosides (saponins) are a large, structurally diverse group of specialized metabolites in plants, including the sweet saponin glycyrrhizin produced by licorice (Glycyrrhiza uralensis) and soyasaponins that occur widely in legumes, with various bioactivities. The triterpenoid saponin biosynthetic pathway involves the glycosylation of triterpenoid sapogenins (the non-sugar part of triterpenoid saponins) by glycosyltransferases (GTs), leading to diverse saponin structures. Previously, we identified a cellulose synthase-derived GT (CSyGT), as a newly discovered class of triterpenoid GT from G. uralensis. GuCSyGT expressed in yeast, which could transfer the sugar glucuronic acid to the C3 position of glycyrrhetinic acid and soyasapogenol B, which are the sapogenins of glycyrrhizin and soyasaponin I, respectively. This suggested that GuCSyGT is involved in the biosynthesis of glycyrrhizin and soyasaponin I. However, the in planta role of GuCSyGT in saponin biosynthesis remains unclear. In this study, we generated GuCSyGT-disrupted licorice hairy roots using CRISPR–Cas9-mediated genome editing and analyzed the saponin content. This revealed that soyasaponin I was completely absent in GuCSyGT-disrupted lines, demonstrating the in planta role of GuCSyGT in saponin biosynthesis.

Deciphering triterpenoid saponin biosynthesis by leveraging transcriptome response to methyl jasmonate elicitation in Saponaria vaccaria

Methyl jasmonate (MeJA) is a known elicitor of plant specialized metabolism, including triterpenoid saponins. Saponaria vaccaria is an annual herb used in traditional Chinese medicine, containing large quantities of oleanane-type triterpenoid saponins with anticancer properties and structural similarities to the vaccine adjuvant QS-21. Leveraging the MeJA-elicited saponin biosynthesis, we identify multiple enzymes catalyzing the oxidation and glycosylation of triterpenoids in S. vaccaria. This exploration is aided by Pacbio full-length transcriptome sequencing and gene expression analysis. A cellulose synthase-like enzyme can not only glucuronidate triterpenoid aglycones but also alter the product profile of a cytochrome P450 monooxygenase via preference for the aldehyde intermediate. Furthermore, the discovery of a UDP-glucose 4,6-dehydratase and a UDP-4-keto-6-deoxy-glucose reductase reveals the biosynthetic pathway for the rare nucleotide sugar UDP-d-fucose, a likely sugar donor for fucosylation of plant natural products. Our work enables the production and optimization of high-value saponins in microorganisms and plants through synthetic biology approaches.

Phytochemistry and Cytotoxic Activity of Aquilaria crassna Pericarp on MDA-MB-468 Cell Lines.

The extracts of Aquilaria crassna pericarp were investigated on the MDA-MB-468, a breast cancer cell line, at desired concentration (1-50 μg/mL). The results showed that the dichloromethane (DCM) extract exhibited the strongest toxicity and was carried out subsequently. A total of nine compounds were isolated from the DCM extract using column chromatography and recrystallization, of which their structures were determined. Intriguingly, in addition to the previously reported compounds, neocucurbitacin A, a cucurbitacin triterpenoid aglycone with a lactone in ring A, was reported for the first time in the Aquilaria genus. Among the isolated compounds, cucurbitacin E highly inhibited MDA-MB-468 cell growth in a dose-dependent manner. Owing to binding abilities with the SH2 domain in the molecular docking study, cucurbitacin E, neocucurbitan A, neocucurbitan B, and cucurbitacin E 2-O-β-d-glucopyranoside act as STAT3 inhibitors and are suitable for further research. This study suggests thatAquilaria crassnafruits could serve as a promising source of natural compounds with potential anticancer effects, particularly against breast cancer.

Nose-to-brain delivery of 18β-Glycyrrhetinic acid using optimized lipid nanocapsules: A novel alternative treatment for Alzheimer’s disease

Alzheimer’s disease (AD) is a neurodegenerative disorder and the most relevant form of dementia affecting people worldwide. AD was reported to be associated with increased oxidative stress ending up with neuronal damage. 18β-Glycyrrhetinic acid (GA), triterpenoid aglycone of glycyrrhizin, was reported for its powerful antioxidant activities. However, its high molecular weight and lipophilicity are two major obstacles that limit its use and cause very low brain bioavailability. The aim of the present study was to formulate the GA in lipid nanocapsules (LNCs) for enhanced nose-to-brain delivery, as well as to elucidate its potential neuroprotective effect in AD. The optimized GA-loaded LNCs exhibited nanometric size range, good stability over 6 months, sustained drug release over 24 h and high steady state flux and permeability coefficient across nasal mucosa over 8 h. In-vivo studies were conducted on five groups; control, scopolamine (SCOP)-treated, SCOP + GA-LNCs, SCOP + oral GA suspension, and SCOP + intranasal GA suspension groups. Intranasal administration of GA-LNCs, at a reduced dose of 1 mg/kg, improved scopolamine-induced memory impairment in rats evidenced by behavioral testing, histological examination, and oxidative stress markers; catalase and superoxide dismutase. Collectively, GA-loaded LNCs (with 50 times lower dose) may provide a promising remedy for AD patients worldwide.

Literature Review : The Effects of Antioxidant Saponins in Herbal Plants on Testicular Histology of Rats with Diabetes Mellitus and The Review of Islamic Perspective

Introduction: Diabetes mellitus is a metabolic disorder. Diabetes mellitus can cause a decrease in sperm count, sperm motility, testosterone hormone, erectile ability, libido and testicular weight. Antidiabetic drugs consumed long-term can cause side effects; therefore, alternative treatment is needed using herbal medicinal plants. Saponins in plants are a complex class of complex natural compounds with a large molecular mass, namely steroid or triterpenoid aglycones with one or more sugar/glycoside chains. Saponins function as antioxidants. This study aims to determine the effect of saponins as one of the antioxidants on the testicular organs of rats (Rattus norvegicus) Wistar strain-induced Streptozotocin. Methods: This study used the Literature Review method with a narrative literature review type. The data collection technique uses a search for several research databases through Google Scholar and Mendeley. This research has four journals that will review. Results: The results showed that herbal plants have bioactive compounds such as flavonoids, alkaloids, terpenoids, tannins, and saponins that have antidiabetic effects with different mechanisms in reducing blood glucose levels repairing damage to testicular tissue of diabetes mellitus rats. Conclusion: Antioxidant saponins in herbal plants influence improving and supporting the repair of testicular histology damage in diabetic cases. Allah SWT grows a wide variety of plants that have enormous benefits for humans, including food and medicine, because Allah SWT created various kinds of plants with multiple uses.

Bioactivity of Walnut: Investigating the Triterpenoid Saponin Extracts of Juglans regia Kernels for Antioxidant, Anti-diabetic, and Antimicrobial Properties

The increasing demand for plant-based medicines makes plant research attractive to find natural alternatives that can replace synthetic products or at least reduce their use. Saponins are a group of natural phytochemical compounds in most herbs, vegetables, and legumes. There are two different types of saponin compounds, which can be classified based on the nature of the aglycone bound to the oligosaccharide fragments, whether it is a steroid or triterpenoid. This paper is devoted to saponins with triterpenoid aglycone and aims to study the relationship between their content and several biological activities in different Juglans regia kernel extracts, including antioxidant, antimicrobial and antibacterial activities. Antioxidant activity was assessed against two free radicals: DPPH and ABTS. Oleanolic acid was used as a standard to quantify triterpenoid saponins, measured by the vanillin method, whereas Acarbose and Tetracycline were used as positive controls to evaluate the α-glucosidase inhibitory and antimicrobial activities, respectively, of walnut kernel extracts. Findings show that hydroalcoholic extract (EtOH 70%) has a considerable content of phenolic compounds, with 59.51 ± 0.26 mg GAE/g in total polyphenol contents, while the content of total flavonoids and condensed tannins were 3.14 ± 0.27 mg QE/g and 85.65 ± 0.37 mg CE/g of crude extract, respectively. In terms of antioxidant activity, the butanolic extract proved to be the most effective against DPPH with IC50 = 7.74 ± 1.49 µg/mL, while the precipitated extract showed the highest scavenging activity against the ABTS free radical with IC50 = 33.14 ± 2.96 µg/mL. In addition, butanolic and hydroalcoholic extracts of Juglans regia kernels showed an α-glucosidase inhibitory activity even more efficiently than synthetic drugs such as Acarbose, with IC50 values of 11.66 µg/mL and 16.17 µg/mL, respectively, versus 18.01 µg/mL in Acarbose. The evaluation of the antimicrobial activity against Bacillus subtilis, Escherichia coli and Klebsiella pneumonia strains revealed that some extracts could inhibit these bacteria. This study successfully assessed the bioactivities of the extracts, suggesting that the extracts of medicinal plants can demonstrate stronger bioactivity than pure synthetic compounds.

Novel Glycosylation by Amylosucrase to Produce Glycoside Anomers.

Simple SummaryAll livings are composed of cells, which contain lipid, proteins, nuclei acids, and saccharides. Saccharides include polysaccharides, oligo saccharides, disaccharides, which are linked by monosaccharides. Monosaccharides such as glucose exist in two forms, named α and β anomer, in solution. In addition, monosaccharides could be linked with lipid, proteins, nuclei acids or other saccharide to form glycosides through glycosylation. In nature, glycosylation is catalyzed by enzymes. Until now, all enzymes catalyzed glycosylation to form glycosides with either α or β form but not both. This study found an enzyme, amylosucrase from Deinococcus geothermalis (DgAS), could catalyze glycosylation of a kind of lipid named ganoderic acids triterpenoids from a medicinal fungus Ganoderma lucidum to form both α and β anomer of glycosides. This is the first report that enzymes could catalyze such glycosylation and a possible reaction mechanism was proposed.Glycosylation occurring at either lipids, proteins, or sugars plays important roles in many biological systems. In nature, enzymatic glycosylation is the formation of a glycosidic bond between the anomeric carbon of the donor sugar and the functional group of the sugar acceptor. This study found novel glycoside anomers without an anomeric carbon linkage of the sugar donor. A glycoside hydrolase (GH) enzyme, amylosucrase from Deinococcus geothermalis (DgAS), was evaluated to glycosylate ganoderic acid F (GAF), a lanostane triterpenoid from medicinal fungus Ganoderma lucidum, at different pH levels. The results showed that GAF was glycosylated by DgAS at acidic conditions pH 5 and pH 6, whereas the activity dramatically decreased to be undetectable at pH 7 or pH 8. The biotransformation product was purified by preparative high-performance liquid chromatography and identified as unusual α-glucosyl-(2→26)-GAF and β-glucosyl-(2→26)-GAF anomers by mass and nucleic magnetic resonance (NMR) spectroscopy. We further used DgAS to catalyze another six triterpenoids. Under the acidic conditions, two of six compounds, ganoderic acid A (GAA) and ganoderic acid G (GAG), could be converted to α–glucosyl-(2→26)-GAA and β–glucosyl-(2→26)-GAA anomers and α-glucosyl-(2→26)-GAG and β-glucosyl-(2→26)-GAG anomers, respectively. The glycosylation of triterpenoid aglycones was first confirmed to be converted via a GH enzyme, DgAS. The novel enzymatic glycosylation-formed glycoside anomers opens a new bioreaction in the pharmaceutical industry and in the biotechnology sector.

Ingadosides A-C, acacic acid-type saponins from Inga sapindoides with potent inhibitory activity against downy mildew

As part of a project aiming at the discovery of environmentally friendly alternatives to copper in organic agriculture, a 96% ethanolic extract from the leaves of Inga sapindoides showed potent inhibitory activity against grapevine downy mildew (Plasmopara viticola) in vitro (MIC100 25 μg/mL). Separation of the n-BuOH soluble fraction by silica gel column chromatography followed by a combination of RP18 and HILIC HPLC resulted in the isolation of a series of bidesmosidic saponins characterized by the presence of a monoterpenoid unit attached to a triterpenoid aglycone, a p-methoxycinnamoyl residue, and rare sugar residues such as N-acetyl-d-glucosamine, d-quinovose, and d-fucose. The isolated compounds inhibited the formation or activity of P. viticola zoospores with MIC100 values of 3 or 6 μg/mL, respectively. I. sapindoides, a tree which is often cultivated for shading coffee plantations in Central America, may represent a sustainable source of fungicidal products to be used in the replacement of copper.

The constitutions of terpenoids and hormones of leaves in red-flesh citrus mutants and their wild types

To study the profiles and relationships of terpenoids and phytohormones in leaves of red-flesh citrus, we examined four red-flesh mutants that accumulate lycopene in the fruit and their corresponding wild types. We compared their contents of monoterpenoid and sesquiterpenoid volatiles, triterpenoid limonoid aglycones, and tetraterpenoid carotenoids. The types and concentrations of these terpenoids in the leaves varied among genotypes, and the leaf terpenoid profiles differed between red-flesh mutants and their wild types. However, lycopene was not detected in citrus leaves of all eight varieties, including the four mutants. According to phytohormone accumulation in the leaves, the citrus varieties could be classified into a low-phytohormone group (‘Red Anliu’ sweet orange, ‘Anliu’ sweet orange, and ‘Cara Cara’ navel orange), a high-phytohormone group (‘Seike’ navel orange), and a high-jasmonic acid group (‘Red-flesh Guanxi’ pummelo, ‘Guanxi’ pummelo, ‘Chuhong’ pummelo, and ‘Feicui’ pummelo). The contents of terpenoid volatiles were very low in leaves of ‘Red-flesh Guanxi’ and ‘Guanxi’ pummelo; therefore, they are ideal materials for verifying the functions of genes related to terpenoid volatiles in overexpression analyses. Sesquiterpenoid volatiles were positively correlated with phytohormones of abscisic acid, jasmonic acid, and salicylic acid. Taken together, lycopene was undetected in the leaves of red-flesh citrus mutants with abundant lycopene in their juice sacs, which suggested a tissue-specific accumulation pattern of lycopene in citrus red-flesh mutants. Furthermore, leaf volatile profiles could be suitable to develop fingerprint chromatograms of citrus resources, since leaf volatile profiles were dominated by several compounds that varied among genotypes in their combinations and concentrations.

Protection function of 18β-glycyrrhetinic acid on rats with high-altitude pulmonary hypertension based on 1H NMR metabonomics technology

18β-Glycyrrhetinic acid (GA) is the triterpenoid aglycone component of glycyrrhizic acid, a natural product of traditional Chinese medicine, and has been proven to possess a variety of pharmacological effects. The protection function and the mechanism of GA on rats with high-altitude pulmonary hypertension (HAPH) are studied using proton nuclear magnetic resonance (1H NMR) metabonomics technology and biochemical analysis. An HAPH model is established, and 60 male rats are randomly divided into the following groups: Control(normal saline, 0.4 mL/100 g), model (normal saline, 0.4 mL/100 g), Nifedipine (nifedipine, 2.7 mg/kg), and high-, medium-, and low-dose GA groups (100, 50, and 25 mg/kg GA designated as GA.H, GA.M, and GA.L, respectively). Serum biochemical indicators of rats in each group are measured, and pathological changes in the pulmonary artery are observed. 1H NMR metabonomics technology is used for serum analysis. Results show that GA can significantly reduce pulmonary arterial pressure and malondialdehyde levels and increase the glutathione peroxidase and superoxide dismutase activities in HAPH rats. Pathological results show that GA can alleviate pulmonary artery injuries of HAPH rats. Metabolomics analytical findings show that GA can alleviate the metabolic disorder of HAPH rats through anti-oxidation and anti-inflammatory effects, improve their bodies’ ability to resist hypoxia, and restore various metabolic pathways (energy metabolism, amino acid metabolism, and lipid metabolism). GA has potential therapeutic effects on HAPH rats, but its target needs to be further studied.

An RP-LC-UV-TWIMS-HRMS and Chemometric Approach to Differentiate between Momordicabalsamina Chemotypes from Three Different Geographical Locations in Limpopo Province of South Africa.

Momordica balsamina leaf extracts originating from three different geographical locations were analyzed using reversed-phase liquid chromatography (RP-LC) coupled to travelling wave ion mobility (TWIMS) and high-resolution mass spectrometry (HRMS) in conjunction with chemometric analysis to differentiate between potential chemotypes. Furthermore, the cytotoxicity of the three individual chemotypes was evaluated using HT-29 colon cancer cells. A total of 11 molecular species including three flavonol glycosides, five cucurbitane-type triterpenoid aglycones and three glycosidic cucurbitane-type triterpenoids were identified. The cucurbitane-type triterpenoid aglycones were detected in the positive ionization mode following dehydration [M + H − H2O]+ of the parent compound, whereas the cucurbitane-type triterpenoid glycosides were primarily identified following adduct formation with ammonia [M + NH4]+. The principle component analysis (PCA) loadings plot and a variable influence on projection (VIP) analysis revealed that the isomeric pair balsaminol E and/or karavilagen E was the key molecular species contributing to the distinction between geographical samples. Ultimately, based on statistical analysis, it is hypothesized that balsaminol E and/or karavilagen E are likely responsible for the cytotoxic effects in HT-29 cells.

Antiplasmodial Oleanane Triterpenoids from Terminalia albida Root Bark

Phytochemical investigation of the n-BuOH extract of the roots of Terminalia albida Sc. Elliot (Combretaceae) led to the isolation and identification of 10 oleanane triterpenoids (1-10), among which six new compounds, i.e., albidanoside A (2), albidic acid A (4), albidinolic acid (5), albidienic acid (8), albidolic acid (9), and albidiolic acid (10), and two triterpenoid aglycones, i.e., albidic acid B (6) and albidic acid C (7), were isolated here for the first time from a natural source, along with two known compounds. The structures of these constituents were established by means of 1D and 2D NMR spectroscopy and ESI mass spectrometry. The isolated compounds were evaluated for their antiplasmodial and antimicrobial activity against the chloroquine-resistant strain Plasmodium falciparum K1, Candida albicans, and Staphylococcus aureus. Compounds 1-4, 6, 7, and 8 showed moderate antiplasmodial activity with IC50 values between 5 and 15 μM. None of the tested compounds were active against C. albicans or S. aureus. These findings emphasize the potential of T. albida as a source for discovery of new antiplasmodial compounds.

The Bioactive Compound and Mechanism of Action of Sea Cucumber (Holothuridae) as Anticancer: A Review

The extreme development and resistance towards cancer drugs, and also the high toxicity, drug resistance and side effects of cancer chemotherapy drug triggers us to develop new drugs as one of the alternative substitutes or combinations of cancer drugs, one of the resources come from marine biodiversity especially sea cucumber. The bioactive compound from sea cucumber can inhibit cancer cell growth with the various mechanism. This study aims to analyze chemical composition, bioactive compound from sea cucumber to inhibit cancer cell line and to analyze mechanism of action of sea cucumber as anticancer with the most recent research studies. The result shows sea cucumber contained protein 44-82%, amino acid, fatty acid, collagen, peptide, micro essential. Each sea cucumber species produced the different secondary metabolites that can use as anticancer. Sea cucumbers contain triterpene glycosides, saponins, holothurin A, stichoposides, frondoside, cucumariosides, dsechinoside, fucoidan, triterpenoid aglycones (philinopgeni), non-glycosaminoglycan, sulfated glycans, sulfated polysaccharides, non-glycosaminosides) that can inhibit cancer cell line. Those bioactive compounds have a various mechanism such as apoptosis in cell line and mitochondria, antioxidative mechanism and membranolytic.

Synthesis, Modification and Biological Activity of Diosgenyl β-d-Glycosaminosides: An Overview.

Saponins are a structurally diverse class of natural glycosides that possess a broad spectrum of biological activities. They are composed of hydrophilic carbohydrate moiety and hydrophobic triterpenoid or steroid aglycon. Naturally occurring diosgenyl glycosides are the most abundant steroid saponins, and many of them exhibit various pharmacological properties. Herein, we present an overview of semisynthetic saponins syntheses–diosgenyl β-d-glycosaminosides (d-gluco and d-galacto). These glycosides possess a 2-amino group, which creates great possibilities for further modifications. A wide group of glycosyl donors, different N-protecting groups and various reaction conditions used for their synthesis are presented. In addition, this paper demonstrates the possibilities of chemical modifications of diosgenyl β-d-glycosaminosides, associated with functionalisation of the amino group. These provide N-acyl, N-alkyl, N,N-dialkyl, N-cinnamoyl, 2-ureido and 2-thiosemicarbazonyl derivatives of diosgenyl β-d-glycosaminosides, for which the results of biological activity tests (antifungal, antibacterial, anti-cancer and hemolytic) are presented.

A cellulose synthase-derived enzyme catalyses 3-O-glucuronosylation in saponin biosynthesis

Triterpenoid saponins are specialised metabolites distributed widely in the plant kingdom that consist of one or more sugar moieties attached to triterpenoid aglycones. Despite the widely accepted view that glycosylation is catalysed by UDP-dependent glycosyltransferase (UGT), the UGT which catalyses the transfer of the conserved glucuronic acid moiety at the C-3 position of glycyrrhizin and various soyasaponins has not been determined. Here, we report that a cellulose synthase superfamily-derived glycosyltransferase (CSyGT) catalyses 3-O-glucuronosylation of triterpenoid aglycones. Gene co-expression analyses of three legume species (Glycyrrhiza uralensis, Glycine max, and Lotus japonicus) reveal the involvement of CSyGTs in saponin biosynthesis, and we characterise CSyGTs in vivo using Saccharomyces cerevisiae. CSyGT mutants of L. japonicus do not accumulate soyasaponin, but the ectopic expression of endoplasmic reticulum membrane–localised CSyGTs in a L. japonicus mutant background successfully complement soyasaponin biosynthesis. Finally, we produced glycyrrhizin de novo in yeast, paving the way for sustainable production of high-value saponins.

Review of Constituents and Biological Activities of Triterpene Saponins from Glycyrrhizae Radix et Rhizoma and Its Solubilization Characteristics.

Glycyrrhizae Radix et Rhizoma is regarded as one of the most popular and commonly used herbal medicines and has been used in traditional Chinese medicine (TCM) prescriptions for over 2000 years. Pentacyclic triterpene saponins are common secondary metabolites in these plants, which are synthesized via the isoprenoid pathway to produce a hydrophobic triterpenoid aglycone containing a hydrophilic sugar chain. This paper systematically summarizes the chemical structures of triterpene saponins in Glycyrrhizae Radix et Rhizoma and reviews and updates their main biological activities studies. Furthermore, the solubilization characteristics, influences, and mechanisms of Glycyrrhizae Radix et Rhizoma are elaborated. Solubilization of the triterpene saponins from Glycyrrhizae Radix et Rhizoma occurs because they contain the nonpolar sapogenin and water-soluble sidechain. The possible factors affecting the solubilization of Glycyrrhizae Radix et Rhizoma are mainly other crude drugs and the pH of the decoction. Triterpene saponins represented by glycyrrhizin from Glycyrrhizae Radix et Rhizoma characteristically form micelles due to amphiphilicity, which makes solubilization possible. This overview provides guidance regarding a better understanding of Glycyrrhizae Radix et Rhizoma and its TCM compatibility, alongside a theoretical basis for the further development and utilization of Glycyrrhizae Radix et Rhizoma.

Galactosylation of Monosaccharide Derivatives of Glycyrrhetinic Acid by UDP-Glycosyltransferase GmSGT2 from Glycine max.

Glycyrrhetinic acid (GA), a pentacyclic triterpenoid aglycone, is the major functional component in licorice which mainly exists in the form of functional glycosides in licorice. The introduction of a sugar moiety to the C-3 OH of GA to yield glycosylated derivatives has been reported, but the late-stage glycosylation of GA-3-O-sugar to form rare GA glycosides with more complexed glycosyl decoration has been rarely reported. In this study, a unique UDP-galactosyltransferase GmSGT2 from Glycine max was found to transfer a galactose to the C2 position of the sugar moiety of GA-3-O-monoglucuronide (GAMG) and GA-3-O-monoglucose. In addition to UDP-galactose, GmSGT2 also recognizes UDP-glucose, UDP-xylose, and UDP-arabinose with relative activities of 32.1-89.2%. Based on a test of 12 typical natural products, GmSGT2 showed high specificity toward the pentacyclic triterpenoid skeleton as the sugar acceptor. Molecular docking was performed to elucidate the substrate recognition mechanism of GmSGT2 toward GAMG.