Explore the vast range of titles available.

A rapid, selective and sensitive UPLC-MS/MS assay was established to determine the plasma concentrations of four steroidal saponins. Sprague-Dawley rats were allocated to four groups which were orally administered Anemarrhena asphodeloides extracts (ASE), ASE combined with macromolecular fraction (ASE-MF), ASE combined with small molecule fraction (ASE-SF) and ASE combined with small molecule and macromolecular fraction (ASE-SF-MF) containing approximately the same dose of ASE. At different time points, the concentration of timosaponin BII, anemarsaponin BIII, timosaponin AIII and timosaponin E1 in rat plasma were determined and main pharmacokinetic parameters including Cmax, Tmax, T1/2, AUC were calculated using the DAS 3.2 software package. The statistical analysis was performed using the Student’s t-test with p < 0.05 as the level of significance. MF had no effect on the pharmacokinetic behaviors and parameters of four steroidal saponins. It was found that Cmax and AUC of four steroidal saponins in group ASE-SF and ASE-SF-MF, were significantly increased compared with those in group ASE. These results indicate that SF in A. asphodeloides extracts could increase the absorption and improve the bioavailability of the steroidal saponins.

It has been previously reported that a glucoamylase from Curvularia lunata is able to hydrolyze the terminal 1,2-linked rhamnosyl residues of sugar chains at C-3 position of steroidal saponins. In this work, the enzyme was isolated and identified after isolation and purification by column chromatography including gel filtration and ion-exchange chromatography. Analysis of protein fragments by MALDI-TOF/TOF proteomics Analyzer indicated the enzyme to be 1,4-alpha-D-glucan glucohydrolase EC 3.2.1.3, GA and had considerable homology with the glucoamylase from Aspergillus oryzae. We first found that the glucoamylase was produced from C. lunata and was able to hydrolyze the terminal rhamnosyl of steroidal saponins. The enzyme had the general character of glucoamylase, which hydrolyze starch. It had a molecular mass of 66 kDa and was optimally active at 50 degrees C, pH 4, and specific activity of 12.34 U mg of total protein(-1) under the conditions, using diosgenin-3-O-alpha-L-rhamnopyranosyl(1-->4)-[alpha-L-rhamnopyranosyl (1-->2)]-beta-D-glucopyranoside (compound II) as the substrate. Furthermore, four kinds of commercial glucoamylases from Aspergillus niger were investigated in this work, and they had the similar activity in hydrolyzing terminal rhamnosyl residues of steroidal saponin.

Saponins are steroid and triterpenoid glycosides that display diverse biological activities. The wide-spread occurrence in plants as well as the potential for pharmaceutical application has led to saponin extraction and identification in numerous species. Although these efforts are important to extend our knowledge of naturally occurring saponin structures, recent attention has been given to the biosynthesis and distribution in plants. In this review, we present recent advances on saponin production and distribution and highlight studies showing effects on the growth and development.

Summary OSW‐1 is a cholestane saponin uniquely produced in Ornithogalum saundersiae and exhibits a potential antitumor activity. The enzymes responsible for OSW‐1 biosynthesis in O. saundersiae, however, remain unclear. Herein, cholesterol was confirmed to be the precursor of OSW‐1 using stable‐isotope labeling method. Next, two cytochrome P450s, OsCYP90B94 and OsCYP90G11, and their partner cytochrome P450 reductase OsCPR2 were mined by comparable transcriptome analysis and demonstrated to be involved in OSW‐1 biosynthesis. Specifically, OsCYP90B94 catalyses cholesterol to 22R‐hydroxycholesterol, which is then converted to 16β‐hydroxy‐22‐oxo‐cholesterol, a precursor of OSW‐1 by the second P450 OsCYP90G11 via two consecutive oxidation reactions. Unlike their homologues, OsCYP90G11 and OsCYP90B94 displayed broader catalytic promiscuity. OsCYP90B94 recognizes both cholesterol and 7β‐hydroxycholesterol, while OsCYP90G11 can react with cholesterol, 22R‐hydroxycholesterol and 16β,22R‐dihydroxycholesterol, suggesting their involvement in more than one pathway besides OSW‐1 biosynthesis. This study lays a foundation for the complete characterization of OSW‐1 biosynthesis.

Cancer is a global health burden responsible for an exponentially growing number of incidences and mortalities, regardless of the significant advances in its treatment. The identification of the hallmarks of cancer is a major milestone in understanding the mechanisms that drive cancer initiation, development, and progression. In the past, the hallmarks of cancer have been targeted to effectively treat various types of cancers. These conventional cancer drugs have shown significant therapeutic efficacy but continue to impose unfavorable side effects on patients. Naturally derived compounds are being tested in the search for alternative anti-cancer drugs. Steroidal saponins are a group of naturally occurring compounds that primarily exist as secondary metabolites in plant species. Recent studies have suggested that steroidal saponins possess significant anti-cancer capabilities. This review aims to summarize the recent findings on steroidal saponins as inhibitors of the hallmarks of cancer and covers key studies published between the years 2014 and 2024. It is reported that steroidal saponins effectively inhibit the hallmarks of cancer, but poor bioavailability and insufficient preclinical studies limit their utilization.

Transient expression in Nicotiana benthamiana offers a powerful and versatile platform for rapid production of complex specialized metabolites. Steroidal glycoalkaloids (SGAs) and steroidal saponins produced by members of the Solanaceae family are known for their diverse structures and activities including antimicrobial, anticancer, antiviral, and anti‐inflammatory. Attempts to reconstitute their complete biosynthetic pathway have been unsuccessful to date. In this study, we identified a different tomato ( Solanum lycopersicum ) GLYCOALKALOID METABOLISM2 (SlGAME2‐NEW) enzyme as a xylosyltransferase in the penultimate step of α ‐tomatine and dehydrotomatine biosynthesis. The discovery of SlGAME2‐NEW facilitated the engineering of tomato SGAs and steroidal saponin biosynthesis in N. benthamiana . Expressing from 9 to 15 genes in combination we efficiently engineered a total of 20 steroidal ‘end products’ (both alkaloids and saponins) typically produced by tomato and eggplant and ones merely found in wild tomato species. Furthermore, we engineered the biosynthetic pathway of the steroidal saponins uttroside B, dehydrouttroside B, and their stereoisomers [25( S )‐uttroside B and 25( S )‐dehydrouttroside B]. Production of these metabolites in N. benthamiana opens broad possibilities for examining and exploring their therapeutic potential. This study therefore makes a significant contribution to the application of synthetic biology for producing high‐value steroidal metabolites in heterologous plant hosts.

Two new compounds named 4,4′-bis(β-D-glucopyranosyloxy)biphenyl (1) and spirostane-25(27)-en-2α,3β-diol-3-O-β-D-xylopyranosyl(1→3)-β-D-glucopyranosyl(1→4)-β-D-galactopyranoside (2) were isolated from n-butanol extraction part of 80% ethanol extract of Allii Macrostemonis Bulbus. Alongside these, ten known compounds (3–12) were also identified, including a flavonoid glycoside (3), seven steroids (4–10), a nucleoside (11), and a phenylpropanoid glycoside (12) were found. Notably, compounds 3–6 were isolated from this plant for the first time. The structures of all compounds were confirmed using high-resolution electrospray ionization mass spectrometry (HR-ESI-MS), 1D, and 2D NMR spectroscopy. Some of these compounds showed strong antioxidant activity, and compound 1 demonstrated the most potent reduction of ferric ions (Fe3+) with an IC50 value of 0.59 ± 0.18 mg/mL. Compounds 2 and 3 exhibited the highest scavenging activity against superoxide anion radicals (O2−·) with an IC50 value of 0.02 ± 0.01 mg/mL. Additionally, compound 3 displayed substantial scavenging activity against 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) with IC50 values of 0.21 ± 0.17 mg/mL and 0.02 ± 0.01 mg/mL, respectively. The discovery of these two new compounds is a reference for identifying Allii Macrostemonis Bulbus quality markers. Moreover, their exceptional antioxidant activity offers a promising avenue for uncovering novel natural antioxidants.

Steroidal saponins are an important type of plant-specific metabolite that are essential for plants’ responses to biotic and abiotic stresses. Because of their extensive pharmacological activities, steroidal saponins are also important industrial raw materials for the production of steroidal drugs. In recent years, more and more studies have explored the biosynthesis of steroidal saponins in plants, but most of them only focused on the biosynthesis of their molecular skeleton, diosgenin, and their subsequent glycosylation modification mechanism needs to be further studied. In addition, the biosynthetic regulation mechanism of steroidal saponins, their distribution pattern, and their molecular evolution in plants remain unclear. In this review, we summarized and discussed recent studies on the biosynthesis, molecular regulation, and function of steroidal saponins. Finally, we also reviewed the distribution and molecular evolution of steroidal saponins in plants. The elucidation of the biosynthesis, regulation, and molecular evolutionary mechanisms of steroidal saponins is crucial to provide new insights and references for studying their distribution, diversity, and evolutionary history in plants. Furthermore, a deeper understanding of steroidal saponin biosynthesis will contribute to their industrial production and pharmacological applications.

The fruits of Solanum torvum Swartz, a wild relative of eggplant, are consumed as a wild vegetable in tropical regions of Africa, Asia, and South America. In traditional Chinese medicine, it is believed to have anti-inflammatory and sedative effects. In the Philippines, water decoction is used to treat hyperactivity disorder. Twenty-two steroidal saponins were isolated and purified from the fruits grown in Yunnan, China, including six new compounds: torvosides U–Z (1–6). During drying and cooking, the saponins may undergo transformation, resulting in small amounts of sapogenins. These transformations can include dehydration of hydroxyl groups at position C22, formation of double bonds at position 20, 22 or 22, 23, and even formation of peroxide products. Saponin compounds torvoside X (4), torvoside Y (5), torvoside A (7), and (25S)-3-oxo-5α-spirostan-6α-yl-O-β-d-xylopyranoside (20), which are glycosylated at C-6, showed certain anti-epileptic activity in a pentylenetetrazole-induced zebrafish seizure model. No antiproliferative activity was detected when tested on the cancer cell line HepG2, and no hepatotoxic effect was noted on normal liver cell line LO2.

In the present study, a simple and environmentally friendly extraction method based on natural deep eutectic solvents (NADESs) was established to extract four bioactive steroidal saponins from Dioscoreae Nipponicae Rhizoma (DNR). A total of twenty-one types of choline chloride, betaine, and L-proline based NADESs were tailored, and the NADES composed of 1:1 molar ratio of choline chloride and malonic acid showed the best extraction efficiency for the four steroidal saponins compared with other NADESs. Then, the extraction parameters for extraction of steroidal saponins by selected tailor-made NADES were optimized using response surface methodology and the optimal extraction conditions are extraction time, 23.5 min; liquid–solid ratio, 57.5 mL/g; and water content, 54%. The microstructure of the DNR powder before and after ultrasonic extraction by conventional solvents (water and methanol) and the selected NADES were observed using field emission scanning electron microscope. In addition, the four steroidal saponins were recovered from NADESs by D101 macroporous resin with a satisfactory recovery yield between 67.27% and 79.90%. The present research demonstrates that NADESs are a suitable green media for the extraction of the bioactive steroidal saponins from DNR, and have a great potential as possible alternatives to organic solvents for efficiently extracting bioactive compounds from natural products.