Triterpenoid saponins discovered between 1987 and 1989.

Triterpenoid saponins isolated and characterized from various sources are reviewed. The recent techniques used in their isolation and structure elucidation are discussed. A compilation of the triterpenoid saponins isolated during the period from 1987 to mid-1989, together with their occurrence, available physical data and spectroscopy used for their characterization is included. The biological activities of the triterpenoid saponins are also covered.     

Saponins of Chlorophytum Species

The genus Chlorophytum (Liliaceae) owing to the presence of pharmacologically important saponins has attracted interest of the scientific community to investigate the chemistry of the saponins and study their cytotoxicity. Chloromaloside-A having cytotoxicity against cancer cell lines has been isolated from C. malayense, while saponins from C. borivilianum are gaining popularity as substitute for viagra. The paper presents a review of different saponins isolated from the Chlorophytum species and their pharmacological importance.     

Triterpenoid saponins from the fruits of Aesculus pavia

The compounds, named aesculiosides Ia-Ie, IIa-IId, and IVa-IVc, were isolated from an ethanol extract of the fruits of North American Aesculus pavia, along with two known compounds. Their structures were characterized as polyhydroxyoleanene pentacyclic triterpenoid saponins by spectroscopic and chemical analyses. These saponins were divided into three elution zones by chromatography according to the polarity because of the acyl substitution at C-21 and C-22 of the aglycone saponins moiety. These are structurally different from those isolated from Eurasian Aesculus hippocastanum and Aesculus chinensis in their oligosaccharide moieties.     

Adjuvant activities of saponins from the root of Polygala senega L

Eight pure triterpenoid saponin compounds isolated from the root of Polygala senega L., a plant indigenous to the Canadian prairies, were evaluated for their immunological activity in mouse models. The specific antibody responses of the IgG2a subclass increased significantly when isolated P. senega saponins were used as adjuvants in the immunization of mice with OVA antigen. In addition, increased IL-2 levels were observed in spleen cell cultures from P. senega saponin-immunized mice after in vitro secondary antigen stimulation. The saponins were tested for their toxicity in mice by using a haemolytic activity assay and found to be less toxic than Quillaja saponaria saponins that have long been used as adjuvants in vaccine formulations. This study has shown the potential of P. senega saponins to be considered as a natural source of vaccine adjuvants with biological activity equivalent to the current commercially available saponin adjuvants.     

银莲花属植物的化学及药理研究概况

本文简要综述了银莲花属植物的化学和药理研究。迄今已有多被银莲花等10余种该属植物的化学成分和药理活性研究报道,共分离鉴定了抗癌活性成分竹节香附素A等以三萜皂苷为主的近100个化学成分,其中约50个为从该属植物中首先发现的新化合物。     

Immunostimulating complexes incorporating Eimeria tenella antigens and plant saponins as effective delivery system for coccidia vaccine immunization

Immunostimulating complexes (ISCOMs) are unique, multimolecular structures formed by encapsulating antigens, lipids, and triterpene saponins of plant origin, and are an effective delivery system for various kinds of antigens. The uses of ISCOMs formulated with saponins from plants collected in Kazakhstan, with antigens from the poultry coccidian parasite Eimeria tenella, were evaluated for their potential use in developing a vaccine for control of avian coccidiosis. Saponins isolated from the plants Aesculus hippocastanum and Glycyrrhiza glabra were partially purified by HPLC. The saponin fractions obtained from HPLC were evaluated for toxicity in chickens and chicken embryos. The HPLC saponin fractions with the least toxicity, compared to a commercial saponin Quil A, were used to assemble ISCOMs. When chicks were immunized with ISCOMs prepared with saponins from Kazakhstan plants and E. tenella antigens, and then challenged with E. tenella oocysts, significant protection was conveyed compared to immunization with antigen alone. The results of this study indicate that ISCOMs formulated with saponins isolated from plants indigenous to Kazakhstan are an effective antigen delivery system which may be successfully used, with low toxicity, for preparation of highly immunogenic coccidia vaccine.     

杜茎山属植物的三萜皂苷及其生物活性

综述了紫金牛科杜茎山属植物的三萜皂苷类化学成分及其生物活性;为植物的系统分类提供化学依据,并为全面评价该属植物的药用价值提供参考.     

Saponins from Trifolium repens.

From the whole plant of white clover, Trifolium repens, five new triterpenoid saponins, designated cloversaponins I-V, were isolated together with four known saponins, beta-D-glucoronopyranosylsoyasapogenol B, soyasaponin I, soyasaponin II and azukisaponin II as their methyl esters. Their structures were determined by 2H NMR and 13C NMR spectroscopy and chemical evidence.     

Bioactive polar natural compounds from garlic and onions

Bioactive natural compounds from garlic and onions have been the focus of researches for decades, firstly due to their pharmacological effects, and secondly due to their defence properties against plant diseases. In fact, garlic and onion, belonging to Allium genus, are among the oldest food plants known since ancient times and used as ingredient of many recipes and for therapeutic properties. These plants are well known to produce bioactive apolar sulphur compounds but less is known about their polar natural compounds, such as phenols, sapogenins and saponins, that are more stable to cooking, So, we continued our work on the discovery of polar bioactive metabolites from Allium with the isolation of a number of sapogenins and saponins from the wild onion species Allium elburzense, Allium hirtifolium, Allium atroviolaceum, and Allium minutiflorum, and, more recently, from the cultivated white onion, Allium cepa, and garlic, Allium sativum. In particular, the sapogenins and saponins isolated from A. elburzense and A. hirtifolium, named elburzensosides and hirtifoliosides respectively, exhibited significant antispasmodic properties. In addition, the saponins named minutosides isolated from A. minutiflorum showed promising antimicrobial activity. More recently the phytochemical analysis of A. cepa and A. sativum has been undertaken and afforded the characterization of saponins, phenols and N-cynnamic amides which showed significant antifungal activity.     

Triterpene saponins from Chenopodium quinoa Willd

Twenty triterpene saponins (1-20) have been isolated from different parts of Chenopodium quinoa (flowers, fruits, seed coats, and seeds) and their structures have been elucidated by analysis of chemical and spectroscopic data including 1D- and 2D-NMR. Four compounds (1-4) were identified: 3beta-[(O-beta-d-glucopyranosyl-(1-->3)-alpha-l-arabinopyranosyl)oxy]-23-oxo-olean-12-en-28-oic acid beta-d-glucopyranoside (1), 3beta-[(O-beta-d-glucopyranosyl-(1-->3)-alpha-l-arabinopyranosyl)oxy]-27-oxo-olean-12-en-28-oic acid beta-d-glucopyranoside (2), 3-O-alpha-l-arabinopyranosyl serjanic acid 28-O-beta-d-glucopyranosyl ester (3), and 3-O-beta-d-glucuronopyranosyl serjanic acid 28-O-beta-d-glucopyranosyl ester (4). The following known compounds have not previously been reported as saponin constituents from the flowers and the fruits of this plant: two bidesmosides of serjanic acid (5,6), four bidesmosides of oleanolic acid (7-10), five bidesmosides of phytolaccagenic acid (11-15), four bidesmosides of hederagenin (16-19), and one bidesmoside of 3beta,23,30-trihydroxy olean-12-en-28-oic acid (20). The cytotoxicity of these saponins and their aglycones was tested in HeLa cells. Induction of apoptosis in Caco-2 cells by bidesmosidic saponins 1-4 and their aglycones I-III was determined by flow cytometric DNA analysis. The saponins with an aldehyde group were most active. The relationships between structure and cytotoxic activity of saponins and their aglycones are discussed.     

Structure characterization and identification steroidal saponins from Ophiopogon japonicus Ker-Gawler (Liliaceae) by high-performance liquid chromatography with ion trap mass spectrometry

Introduction – Steroidal saponins are the main active constituents in Ophiopogon japonicus Ker‐Gawler (Liliaceae). However, because of their high polarity, non‐chromophores and low content in plants, steroidal saponins are difficult to be isolated from O. japonicus by conventional phytochemical methods. Objective – To develop a sensitive and rapid approach towards the structural analysis of steroidal saponins using HPLC/ESI‐MSⁿ. Methodology – The fragmentation behaviors of six known steroidal saponins in negative ESI‐MSⁿ were used to deduce their mass spectral fragmentation mechanisms. By using HPLC/ESI‐MSⁿ, the important structural information on aglycone types, sugar types and saccharide sequences can be obtained. Results – According to the HPLC retention behaviour, the molecular structural characteristics provided by multistage mass spectrometry spectra and the literature, a total of 8 steroidal saponins were tentatively identified or characterized in O. japonicus rapidly. Conclusion – This work has shown that HPLC‐ESI‐MSⁿ may be used as an effective and rapid method for the characterization and identification of steroidal saponins from O. japonicus. Copyright © 2010 John Wiley & Sons, Ltd.     

Immuno-stimulating properties of diosgenyl saponins isolated from Paris polyphylla

The effects of three diosgenyl saponins isolated from Paris polyphylla on the immuno-stimulating activity in relation to phagocytosis, respiratory burst, and nitric oxide production in mouse macrophage cells RAW 264.7 have been investigated. Our results showed that all three diosgenyl saponins significantly enhanced phagocytic activity that increased with the concentration of saponins to reach a maximum, and then tended to decrease with higher concentrations. Saponins with sugar moiety directly induced respiratory burst response in RAW 264.7 cells that increased with the concentrations and reached a maximum, then decreased with higher concentrations after 2-h incubations, however, diosgenin had no PMA-triggered respiratory burst response. Treatment of RAW 264.7 cells with saponins with sugar moiety for 24-h caused a significant increase in the production of nitric oxide, while diosgenin had no effect at all. Consequently, relationship between molecular structures of three diosgenyl saponins and their immunomodulatory activities was discussed, and a possible mechanism of immuno-stimulating function of diosgenyl saponins was accordingly explored.     

O‐glycoside sequence of pentacyclic triterpene saponins from Phytolacca bogotensis using HPLC‐ESI/multi‐stage tandem mass spectrometry

Introduction – The lack of pharmacopoeial methodologies for the quality control of plants used for therapeutic purposes is a huge problem that impacts directly upon public health. In the case of saponins, their great structural complexity, weak glycoside bonds and high polarity hinder their identification by conventional techniques. Objective – To apply high‐performance liquid chromatography–electrospray tandem mass spectrometry (HPLC‐ESI/MSⁿ) to identify the O‐glycoside sequence of saponins from the roots of Phytolacca bogotensis. Methodology – Saponins were isolated by preparative HPLC and characterised by NMR spectroscopic experiments. Collision‐induced dissociation (CID) of isolated saponins was performed producing typical degradation reactions that can be associated with several glycosidic bonds as empirical criteria. A method using solid‐phase extraction (SPE) and HPLC/ESI‐MSⁿ for the characterisation of saponins and identification of novel molecules is described. Results – Three saponins reported for the first time in P. bogotensis were isolated and characterised by NMR spectroscopy. Characteristic cross ring cleavage reactions have been used as empirical criteria for the characterisation of the glycosidic bonds most frequently reported for Phytolacca saponins. One new saponin was proposed on the basis of empirical criteria, and other five saponins were identified for the first time for P. bogotensis using HPLC‐ESI/MSⁿ. Conclusion – Electrospray ionisation in combination with tandem mass spectrometry has been established as a powerful tool for the profiling of saponins from roots of P. bogotensis. CID proved to be a useful tool for the characterisation and identification of known and novel saponins from the plant family Phytolaccaceae and can be used for quality control purposes of crude plant extracts. Copyright © 2009 John Wiley & Sons, Ltd.     

New triterpenoid saponins with strong alpha-glucosidase inhibitory activity from the roots of Gypsophila oldhamiana

Seven new triterpenoid saponins (1-7), have been isolated and elucidated from the roots of Gypsophila oldhamiana together with five known triterpenoid saponins (8-12). These saponins which could be classified into three series: 3-O-monoglucosides (1, 8, 9), 28-O-monoglucosides (2-4, 12) and 3, 28-O-bidesmosides (5-7, 10, 11), have been evaluated for their alpha-glucosidase inhibition activity. As a result, the preliminary structure-activity relationships were discussed based on the position of sugar linkage attached to the aglycone, and 28-O-monoglucosides 2-4 and 12 showed significant inhibitory activities on alpha-glucosidase.     

Steroidal saponins from the tuber of Ophiopogon japonicus

Eight novel steroidal saponins, ophiopogonins H-O (1-8), along with seven known steroidal saponins (9-15) were isolated from the tubers of Ophiopogon japonicus. The structures of these new compounds were determined by detailed spectroscopic analysis, including extensive 1D and 2D NMR data, and the analysis of hydrolytic reaction products. For the first time, rare furostanol saponins with disaccharide moiety linked at position C-26 of the aglycone were reported to be isolated from a natural source.     

Melongoside L and melongoside M,steroidal saponins from Solanum melongena seeds

Two new steroidal saponins, melongoside L and melongoside M, have been isolated from a methanolic extract of Solanum melongena seeds and their structures elucidated.     

Antifungal activity and mode of action of saponins from Madhuca butyracea Macb

The antifungal activity of saponins isolated as a byproduct from the defatted cake of M. butyracea oil seed is reported. The inhibitory concentrations against plant pathogenic fungi ranged from 500 to 2000 ppm. Maximum sensitivity to saponins was shown by Penicillium expansum. Cephalosporium acrimonium, Helminthosporium oryzae and Trichoderma viride. The saponins caused leakage of cell components and underwent degradation by fungus, Trichoderma viride. The usefulness of saponins as antimycotic agents is discussed.     

Pennogenyl Saponins from Paris quadrifolia L. Induce Extrinsic and Intrinsic Pathway of Apoptosis in Human Cervical Cancer HeLa Cells

Pennogenyl saponins are the active compounds of large number of plant species and consequently many polyherbal formulations. Hence, great interest has been shown in their characterization and in the investigation of their pharmacological and biological properties, especially anticancer. This present study reports on the evaluation of cytotoxic effects and explanation of the molecular mechanisms of action of the two pennogenyl saponins (PS 1 and PS 2) isolated from Paris quadrifolia L. rhizomes on human cervical adenocarcinoma cell line HeLa. To determine the viability of the cells treated with the compounds we used real-time cell proliferation analysis and found that the pennogenyl saponins PS 1 and PS 2 strongly inhibited the tumor cells growth with IC50 values of 1.11 ± 0.04 μg/ml and 0.87 ± 0.05 μg/ml, respectively. The flow cytometry analysis indicated that the two compounds induced apoptosis in a dose-dependent manner and decreased mitochondrial membrane potential in HeLa cells in the early stage of apoptosis. Quantitative PCR and Western Blot analysis showed that the two saponins significantly increased mRNA expression of FADD and BID as well as induced caspase-8 via increased of procaspase-8 processing in the treated cells. The results of this study suggest that both the extrinsic death receptor and intrinsic mitochondrial pathways are involved in the programmed cell death.     

杉科的细胞分类学和系统演化研究

根据杉科的核型资料,本文(1)提出“1B”可能是一个新的高等植物核型类型;(2)讨论了各属的有关分类学问题及相互亲缘关系,它们的进化顺序可能是柳杉属、水松属、落羽杉属、水杉属、巨杉属、红杉属、杉木属(密叶杉属与之近缘)、台湾杉属;(3)支持金松属分立成金松科,它可能比杉科各属原始;(4)红杉(AAAABB)的亲本可能是二个古代种水杉”和“巨杉”,它们的直接后裔或留下的近缘是水杉和巨杉;(5)杉科存在A和L两条进化路线,前者包括柳杉属、水松属、落羽杉属、台湾杉属,后者包括水杉属、巨杉属、红杉属、杉木属(密叶杉属);(6)提出一个杉科新系统(包括一个新亚科)：I．柳杉亚科(柳杉属),II．落羽杉亚科(水松属、落羽杉属),III．红杉亚科(冰杉属、巨杉属、红杉属),Ⅳ.杉木亚科(杉木属、密叶杉属),V．台湾杉亚科,新亚科(台湾杉属)。本文还对前人的杉科系统作了讨论。     

Saponins from Allium minutiflorum with antifungal activity

Three saponins, named minutoside A (1), minutoside B (2), minutoside C (3), and two known sapogenins, alliogenin and neoagigenin, were isolated from the bulbs of Allium minutiflorum Regel. Elucidation of their structure was carried out by comprehensive spectroscopic analyses, including 2D NMR spectroscopy and mass spectrometry. The structures of the new compounds were identified as (25R)-furost-2alpha,3beta,6beta,22alpha,26-pentaol 3-O-[beta-D-xylopyranosyl-(1-->3)-O-beta-D-glucopyranosyl-(1-->4)-O-beta-D-galactopyranosyl] 26-O-beta-D-glucopyranoside (1), (25S)-spirostan-2alpha,3beta,6beta-triol 3-O-beta-D-xylopyranosyl-(1-->3)-O-beta-D-glucopyranosyl-(1-->4)-O-beta-D-galactopyranoside (2), and (25R)-furost-2alpha,3beta,5alpha,6beta,22alpha,26-esaol 3-O-[beta-D-xylopyranosyl-(1-->3)-O-beta-D-glucopyranosyl-(1-->4)-O-beta-D-galactopyranosyl] 26-O-beta-D-glucopyranoside (3). The isolated compounds were evaluated for their antimicrobial activity. All the novel saponins showed a significant antifungal activity depending on their concentration and with the following rank: minutoside B>minutoside C>minutoside A. No appreciable antibacterial activity was recorded. The possible role of these saponins in plant-microbe interactions is discussed.