Dammarane-type saponins from Ziziphus jujube and their inhibitory effects against TNF-α release in LPS-induced RAW 246.7 macrophages

Four new dammarane-type saponins jujubosides F–J, together with six known compounds were isolated from the seeds of Ziziphus jujube. Their structures were elucidated on the basis of chemical and spectroscopic evidences. Compounds 1–10 showed moderate inhibitory effects against pro-inflammatory cytokine TNF-α release in LPS-induced RAW 246.7 macrophages.     

Characterization of quillaja bark extracts and evaluation of their purity using liquid chromatography–high resolution mass spectrometry

In the course of development of semi-preparative liquid chromatographic methods for the isolation of individual quillaja saponins from Quillaja saponaria (L.), some commercially available quillaja bark extracts revealed a distinctive and characteristic pattern of additional peaks in the chromatogram that could not be attributed to saponins commonly present in quillaja. To identify these peaks, analytical procedures based on HPLC coupled with high resolution MS detection were optimized which allowed the identification of the additional saponins Mi saponin A, Mi saponin B, Mi saponin C, madhucoside A and madhucoside B. These compounds are known to be the main saponins of the Indian plant Madhuca longifolia (L.). Tandem MS experiments were performed for the unambiguous assignment of the sapogenin. Madhuca saponins yielded a characteristic fragment of protobassic acid, whereas quillaja saponins showed a fragment of quillaic acid as expected. In addition, samples from madhuca seed kernels were analysed to verify the origin of the characteristic chromatographic peak pattern observed frequently in commercially available quillaja bark extracts.     

Molluscicidal saponins from Gundelia tournefortii

From the roots of Gundelia tournefortii seven saponins have been isolated mainly by DCCC. The main saponins (A and B) were characterized, mainly by ¹³C and ¹H NMR spectroscopy, as oleanolic acid 3-O-(2-[α-l-arabinopyranosyl(1 → 3) -β-d-gentiotriosyl(1 → 6) -β-d-glucopyranosyl]gb-d-xylopyranoside) (saponin A) and oleanolic acid 3-O-(2-[α-l-arabinopyranosyl] (1 → 3)-β-d-gentiobiosyl (1 → 6)-β-d-glucopyranosyl β-d-xylopyranoside) (saponin B). The other saponins are also derived from oleanolic acid and contain more sugar units. The saponin mixture and the saponins A and B possess strong molluscicidal activity against the schistosomiasis transmitting snail Biomphalaria glabrata.     

Saponins of two alfalfa cultivars

A saponin mixture was separated from the forage of DuPuits and Lahontan cultivars of Medicago sativa and found to contain about 30 saponins. Glucose, galactose, xylose, arabinose and rhamnose, were the principal sugars; the sapogenins comprised soyasapogenols A and B, lucernic acid, medicagenic acid together with four unidentified but related triterpenoids. Medicagenic acid was the predominant sapogenin of the DuPuits cultivar, whereas soyasapogenot A was prominent in Lahontan saponins. Galactose was found in the saponins of monocarboxylic or nonacidic sapogenins but was absent in those containing dicarboxylic sapogenins, such as medicagenic acid.     

Genetic and chemical analysis of a key biosynthetic step for soyasapogenol A, an aglycone of group A saponins that influence soymilk flavor

Although certain saponins in soybean seeds have been reported to have health benefits, group A acetyl saponins cause undesirable bitter and astringent tastes in soy products. Therefore, reduction or elimination of group A saponins is an important target for soybean breeders. A wide survey of cultivated and wild soybean germplasm identified a mutant line that lacked group A saponins. The absence of soyasapogenol A, a group A saponin aglycone, is controlled by a single recessive allele, sg-5 that mapped genetically near the SSR marker, Satt117, on soybean chromosome 15 (linkage group E). The locus is epistatic to Sg-1, which controls the terminal sugar variation on the C-22 sugar chain of soyasapogenol A, and allelic differences at this locus lead to changes in the amount of DDMP saponins and their derivatives group B and E products. These findings provide a new insight into the biosynthetic pathway of soybean saponins, and identify a genetic approach that can be applied to improve the quality of foods produced from soybean.     

Nebulosides A–B,novel triterpene saponins from under-ground parts of Gypsophila arrostii Guss. var. nebulosa

A bioassay-guided phytochemical analysis of the triterpene saponins from under ground parts of Gypsophila arrostii var. nebulosa allowed the isolation of two triterpene saponins; nebuloside A, B based on gypsogenin and quillaic acid aglycone. Two new oleanane type triterpenoid saponins (nebuloside A, B) and three known saponins (1–3) were isolated from the root bark of Gypsophila arrostii var. nebulosa. The structures of the two new compounds were elucidated as 3-O-β-d-galactopyranosyl-(1→2)-[β-d-xylopyranosyl-(1→3)]-β-d-glucuronopyranosyl quillaic acid 28-O-β-d-glucopyranosyl-(1→3)-[β-d-xylopyranosyl-(1→3)-β-d-xylopyranosyl-(1→4)]-α-l-rhamnopyranosyl-(1→2)-β-d-fucopyranosyl ester (nebuloside A) and 3-O-β-d-xylopyranosyl-(1→3)-[β-d-galactopyranosyl(1→3)-β-d-galactopyranosyl-(1→2)]-β-d-glucuronopyranosyl gypsogenin 28-O-β-d-glucopyranosyl-(1→3)-[β-d-xylopyranosyl-(1→3)-β-d-xylopyranosyl-(1→4)]-α-l-rhamnopyranosyl-(1→2)-β-d-fucopyranosyl ester (nebuloside B), on the basis of extensive spectral analysis and chemical evidence. Nebuloside A and B showed toxicity enhancing properties on saporin a type-I RIP without causing toxicity by themselves at 15 μg/mL.     

Role of glycosidases in the membranlytic,antifungal action of saponins

In studies on the membranlytic action of various saponins on mycelium of Botrytis cinerea and Rhizoctonia solani digitonin, α-hederin and tomatin caused considerable leakage of free amino acids, while aescin and theasaponin were less effective. Cyclamin significantly damaged cell membranes of R. solani, but did not change the selective permeability of B. cinerea. Cell membrane disruption was accompanied by an enzymatic conversion of saponins into their corresponding aglycones in cell membrane vicinity, an effect which was significantly inhibited by aldonolactones, known inhibitors of β-glycosidases. These results lead to the conclusion that the hardly water soluble aglycones are the active part of the saponin molecules, the saponins themselves being only water soluble transport forms. It follows, that the presence of appropriate glycosidases in cell membranes, capable of converting saponins into their aglycones, is a prerequisite for the membranlytic action of saponins. The similarity of the membranlytic effects of sapoinins towards fungi and erythrocytes is discussed.     

Antifungal saponins from bulbs of garlic,Allium sativum L. var. Voghiera

A bioassay-guided phytochemical analysis of the polar extract from the bulbs of garlic, Allium sativum L., var. Voghiera, typical of Voghiera, Ferrara (Italy), allowed the isolation of ten furostanol saponins; voghieroside A1/A2 and voghieroside B1/B2, based on the rare agapanthagenin aglycone; voghieroside C1/C2, based on agigenin aglycone; and voghieroside D1/D2 and E1/E2, based on gitogenin aglycone. In addition, we found two known spirostanol saponins, agigenin 3-O-trisaccharide and gitogenin 3-O-tetrasaccharide. The chemical structures of the isolated compounds were established through a combination of extensive nuclear magnetic resonance, mass spectrometry and chemical analyses. High concentrations of two eugenol diglycosides were also found for the first time in Allium spp. The isolated compounds were evaluated for their antimicrobial activity towards two fungal species, the air-borne pathogen Botrytis cinerea and the antagonistic fungus Trichoderma harzianum.     

Steroidal saponins from the rhizomes of Paris delavayi

Two new steroidal saponins, padelaosides A (1) and B (2), along with two other known steroidal saponins (3 and 4) were isolated from the rhizomes of Paris delavayi. Their structures were elucidated by 1D and 2D NMR techniques, HRFTMS, physical data and chemical methods. The two different absolute configurations of fucose, assigned as l and d that were found on compounds 1 and 2, respectively, were simultaneously reported in a natural medicine for the first time.     

Two new oleanane-type triterpene saponins from the leaves of Schefflera sessiliflora De P. V.

From the leaves of Schefflera sessiliflora De P. V., two new oleanane-type triterpene saponins, named scheffleraside A (1), scheffleraside B (2); together with two known saponins, chikusetsusaponin IVa (3), 3-O-[α-l-rhamnopyranosyl-(1 → 3)]-β-d-glucuronopyranosyl hederagenin (4) were isolated by various chromatography methods. Its chemical structure was elucidated by IR, UV, HR-ESI-MS, NMR 1D and 2D experiments and comparison of their NMR data with previous reported data.     

A new sapogenin in the saponins of Zizyphus jujuba,Hovenia dulcis and Bacopa monniera

Acid hydrolysis of the saponin of the seeds of Zizyphus jujuba afforded ebelin lactone, which yielded the sapogenin, jujubogenin, on Smith-de Mayo degradation. The mechanism of conversion of jujubogenin into ebelin lactone has been elucidated. Hovenoside G of Hovenia dulcis and bacoside A of Bacopa monniera which produce ebelin lactone on acid hydrolysis have also been found to yield jujubogenin on Smith-de Mayo degradation.     

Steroidal saponins from the rhizomes and roots of Smilax scobinicaulis

Two new spirostane-type steroidal saponins, named smilscobinosides A (1) and B (2), together with a known congener (3), have been isolated from the EtOH extract of the rhizomes and roots of Smilax scobinicaulis. The structures of the new compounds were determined by means of chemical evidence and 1D- and 2D-NMR spectroscopic analysis, FABMS and HRESIMS.     

Steroidal saponins from Dioscorea floribunda: Structures of floribundasaponins A and B

Two steroidal saponins, floribundasaponins A and B isolated from the yams of Dioscorea floribunda, have been characterized as pennogenin-3-O-β-d-glucopyranoside and pennogenin-3-O-α-l-rhamnopyranosyl(1→4)-β-d-glucopyranoside.     

Five new triterpenoid saponins from the Roots of Camellia oleifera C. Abel with cytotoxic activities

Five new triterpenoid saponins, oleiferosides P–T (1–5) were isolated from the EtOH extract of the roots of Camellia oleifera C. Abel. The structures of saponins 1–5 were elucidated on the basis of integrated spectroscopic techniques. All the compounds were characterized to be oleanane-type saponins with sugar moieties linked to the C-3 of the aglycone. By using the MTT assay, an in vitro analysis of the cytotoxic activities of these saponins on the human tumor cell lines (lung adenocarcinoma A549 cells, hepatic carcinoma SMMC-7721 cells and breast cancer MCF-7 cells). Among them, compound 4 showed a certain cytotoxic activity against all the tested cell lines.     

Steroidal saponins with cytotoxic activity from the rhizomes of Paris polyphylla var. yunnanensis

Two previously unreported spirostanol saponins, dianchonglouosides A and B (1 and 2), along with 7 known steroidal saponins (3–9) were isolated from the rhizomes of Paris polyphylla var. yunnanensis. Their structures were elucidated by extensive spectroscopic analysis (MS, 1D, and 2D NMR), and chemical methods. The cytotoxic activities of the isolated compounds 1–9 were also evaluated against two human cancer cell lines (HEK293 and HepG2). The results showed that compound 7 had the strongest cytotoxic activity against the two cancer cell lines with the IC₅₀ values of 0.6 and 0.9 μM, respectively.     

Real-time analysis of membrane permeabilizing effects of oleanane saponins

Saponins are a group of plant and marine derived glycosides with numerous biological functions. Two important characteristics of certain plant saponins are their ability to enhance cytotoxicity of type I ribosome inactivating proteins and stimulation of the immune system. The main objective of the present study was to investigate in real-time the permeabilizing effects of saponins on cell membrane. A set of oleanane saponins (glycyrrhizinic acid, Gypsophila, Saponaria and Quillaja saponins) and a steroid saponin (digitonin) were tested. The effects of these saponins on lysosomal membranes and hemolysis, along with their charge were also studied. Real-time monitoring of cell membrane permeabilization facilitated a highly sensitive analysis of the cellular kinetics. Saponins showed variable permeabilizing effects on cellular and lysosomal membranes at concentrations from 6 μM and hemolysis from 3 μM. Further, the results suggest that charge of the saponin may be relevant for permeabilizing effects of oleanane saponins.     

Antifungal saponins from bulbs of white onion,Allium cepa L.

Three saponins, named ceposide A, ceposide B, and ceposide C were isolated from the bulbs of white onion, Allium cepa L. Elucidation of their structure was carried out by comprehensive spectroscopic analyses, including 2D NMR spectroscopy and mass spectrometry, and chemical evidences. The structures of the compounds were identified as (25R)-furost-5(6)-en-1β,3β,22α,26-tetraol 1-O-β-d-xylopyranosyl 26-O-α-d-rhamnoyranosyl-(1 → 2)-O-β-d-galactopyranoside (ceposide A), (25R)-furost-5(6)-en-1β,3β,22α,26-tetraol 1-O-β-d-xylopyranosyl 26-O-α-d-rhamnoyranosyl-(1 → 2)-O-β-d-glucopyranoside (ceposide B), and (25R)-furost-5(6)-en-1β,3β,22α,26-tetraol 1-O-β-d-galactopyranosyl 26-O-α-d-rhamnoyranosyl-(1 → 2)-O-β-d-galactopyranoside (ceposide C). The isolated compounds, alone and in combinations, were evaluated for their antimicrobial activity on ten fungal species. Antifungal activity of all three saponins increased with their concentration and varied with the following rank: ceposide B > ceposide A–ceposide C. We found a significant synergism in the antifungal activity of the three ceposides against Botrytis cinerea and Trichoderma atroviride, because growth of these fungi was strongly inhibited when the three saponins were applied in combination. In contrast, Fusarium oxysporum f. sp. lycopersici, Sclerotium cepivorum and Rhizoctonia solani were very little affected by saponins.     

Chemotaxonomic study of the genus Paris based on steroidal saponins

The study of saponins from the genus Paris (Trilliaceae) has led to the isolation of over 70 steroidal saponins. Their distributions in different species are summarised and possible patterns in the modifications of the aglycone moiety, based on a biosynthetic pathway for steroidal saponins, were reviewed in this study. The chemotaxonomic value of these secondary metabolites has been evaluated, and it is suggested that Paris thibetica, Paris vietnamensis, Paris delavayi and Paris pseudothibetica, which contain more active saponins, could be an ideal substitution material for Paris polyphylla Smith var. chinensis, and Paris polyphylla Smith var. yunnanensis. Distribution of the same types of saponins amongst the Trilliaceae suggests a close relationship between the Trillium and Paris.     

Two new triterpene saponins from the anti-inflammatory saponin fraction of Ilex pubescens root

The saponin fraction from the ethanolic extracts of the root of Ilex pubescens Hook. et Arn. (Ilexaceae) was found to exhibit potent anti-inflammatory effects on carrageenan-induced paw edema in rats. Two novel triterpene saponins, pubescenosides C and D (1 and 2, resp.), together with five known saponins were isolated from this saponin fraction. The structures of 1 and 2 were elucidated as (20beta)-3-O-[beta-D-glucopyranosyl-(1-->2)-beta-D-xylopyranosyl]ursa-12,18-dien-28-oic acid 28-O-beta-D-glucopyranosyl ester, and (20beta)-3-O-[alpha-L-rhamnopyranosyl-(1-->2)-beta-D-glucopyranosyl-(1-->2)-beta-D-xylopyranosyl]ursa- 12,18-dien-28-oic acid 28-O-beta-D-glucopyranosyl ester, respectively, on the basis of chemical and spectroscopic data. Five known saponins isolated from the saponin fraction were identified as ilexsaponin B(1), B(2), B(3), A(1), and chikusetsusaponin IV(a).     

Pro-apoptotic activity of acylated triterpenoid saponins from the stem bark of Albizia chevalieri harms

As a continuation of our interest in apoptosis-inducing triterpenoid saponins from Albizia genus, phytochemical investigation of the stem bark of Albizia chevalieri led to the isolation of three new oleanane-type saponins, named chevalierosides A–C (1–3). Their structures were established on the basis of extensive analysis of 1D and 2D NMR (¹H-, ¹³C NMR, DEPT, COSY, TOCSY, ROESY, HSQC and HMBC) experiments, HRESIMS studies, and by chemical evidence. The pro-apoptotic effect of the three saponins was evaluated on two human cell lines (pancreatic carcinoma AsPC-1 and hematopoietic monocytic THP-1). Cytometric analyses showed that saponins 1–3 induced apoptosis of both human cell lines (AsPC-1 and THP-1) in a dose-dependent manner.