Triterpenoid saponins from the fruits and galls of Sapindus mukorossi

Triterpenoid Saponins from Washnut (Sapindus mukorossi Gaertn.)—A Source of Natural Surfactants and Other Active Components

Sapindus mukorossi Gaertn., also called the washnut, is a tropical tree of the Sapindaceae family. The plant owes its name to its cleaning and washing properties used by the local population as a natural detergent. The most important ingredients of the plant are triterpenoid saponins contained in many parts of the plant, inducing fruits, galls, or roots. The tree also contains other valuable, biologically active compounds that are obtained by extraction methods. Raw or purified extract and isolated saponins are valuable plant products that can be used in the food, pharmaceutical, cosmetic, and chemical industries. This review includes the most important biological and surfactant properties of extracts and isolated saponins obtained from various parts of the plant.

Leaf Structural Traits Vary With Plant Size in Even-Aged Stands of Sapindus mukorossi

Sapindus mukorossi Gaertn., an important oleaginous woody plant, has garnered increasing research attention owing to its potential as a source of renewable energy (biodiesel). Leaf structural traits are closely related to plant size, and they affect the fruit yield and oil quality. However, plant size factors that predominantly contribute to leaf structural traits remain unknown. Therefore, the purpose of this study was to understand the associations between leaf structural traits and plant size factors in even-aged stands of S. mukorossi. Results showed that leaf length (LL) and leaf area (LA) markedly increased with the increasing diameter at breast height (DBH) and tree height (TH), although other leaf structural traits did not show noticeable changes. Difference in slopes also indicated that the degree of effect of plant size factors on leaf structural traits was in the order of TH > DBH. Leaf structural traits showed no systematic variation with crown width (CW). LA was significantly positively correlated with LL, leaf width (LW), LL/LW, and leaf thickness (LT) and was significantly but negatively correlated with leaf tissue density (LTD) and leaf dry mass content (LDMC). Specific leaf area showed a significantly negative correlation with LT, LDMC, and LTD. LTD showed a significantly positive correlation with LDMC, but a negative correlation with LT. The results were critical to understand the variability of leaf structural traits with plant size, can provide a theoretical foundation for further study in the relationship between leaf structural traits and fruit yield, and regulate leaf traits through artificial management measures to promote plant growth and fruit yield.

Plant triterpenoid saponins: biosynthesis, in vitro production, and pharmacological relevance

The saponins are a diverse class of natural products, with a broad scale distribution across different plant species. Chemically characterized as triterpenoid glycosides, they posses a 30C oxidosqualene precursor-based aglycone moiety (sapogenin), to which glycosyl residues are subsequently attached to yield the corresponding saponin. Based on the chemically distinct aglycone moieties, broadly, they are divided into triterpenoid saponins (dammaranes, ursanes, oleananes, lupanes, hopanes, etc.) and the sterol glycosides. This review aims to present in detail the biosynthesis patterns of the different aglycones from a common precursor and their glycosylation patterns to yield the functionally active glycoside. The review also presents recent advances in the pharmacological activities of these saponins, particularly as potent anti-neoplastic pharmacophores, antioxidants, or anti-viral/antibacterial agents. Since alternate production pedestals for these pharmacologically important triterpenes via cell and tissue cultures are an attractive option for their sustainable production, recent trends in the variety and scale of in vitro production of plant triterpenoids have also been discussed.

Inhibition of Candida albicans and induced vaginitis by sapindus water extract

In this study, water extract of Sapindus mukorossi Gaertn. pericarps against Candida albicans was evaluated through in vitro and in vivo studies. The most abundant active ingredient was triterpenoid saponins determined by UPLC-TOF-MS analysis. The minimum inhibitory concentration (MIC) was 0.039 mg/mL by using agar double dilution methods. The percentage of inhibition was 93.07% when C. albicans was treated for 4 h using a 1 mg/mL in vitro dose. A vaginitis model was developed by infecting mice with C. albicans. The fungal burden was tracked, which indicated that 10 mg/mL triterpenoid saponins reduced fungal quantity ranging from 3.0 to 1.84 Log CFU/100 μL. Moreover, the subsequent studies regarding four biomarkers with an enzyme-linked immunosorbent assay were conducted. It was confirmed that interleukin IL-1β, IL-6, IL-8, and lactate dehydrogenase (LDH) were lower than untreated group, and vaginal pathology was significantly improved in tissue sections.

The Phenological Growth Stages of Sapindus mukorossi According to BBCH Scale

Sapindus mukorossi is a native tree in southern China that has multiple useful functions, including high landscaping, ecological, esthetic, and economic values. More importantly, its fruits are being rapidly developed as raw materials for bioenergy and saponin production in southern China. To provide a standardized phenological description of the species, this study firstly used the BBCH (Biologische Bundesanstalt, Bundessortenamt und CHemische Industrie) scale. In total, eight principal stages—i.e., bud, leaf and shoot development, inflorescence emergence, flowering, fruit development, fruit maturity, senescence and beginning of dormancy—and 58 secondary stages were described. It ranges from vegetative bud dormancy to the onset of the next beginning of the dormancy, using a two-digit numerical coding system. In addition to the descriptions, we provide photographic images of some major developmental stages to standardize morphological characteristics and the phenological observation of S. mukorossi. This study will be an asset for biological researches and cultivation management in Sapindus, and will provide valuable information for other fruit trees.

New Dammarane-type Saponins from Gynostemma pentaphyllum

Six new dammarane-type saponins, gypenosides CP1-6 (16), along with 19 known compounds 7⁻25, were isolated and characterized from the aerial parts of Gynostemma pentaphyllum. Among these compounds, eight dammarane-type saponins, 2, 5, 6, 7, 11, 12, 13, and 15, exhibited the greatest antiproliferative effects against two human tumor cell lines (A549 and HepG2).

Antifungal Activity of Saponins from the Fruit Pericarp of Sapindus mukorossi against Venturia inaequalis and Botrytis cinerea

The antifungal activity of an aqueous extract (AE) and the solid fraction of a chloroform-methanol fruit pericarp extract (CME) of Sapindus mukorossi resolved in water was tested for the first time against Venturia inaequalis and Botrytis cinerea-two important fungal pathogens worldwide. In the greenhouse, a CME (1% vol/vol) spray significantly reduced V. inaequalis symptoms and sporulation (99%) on apple seedling leaves (P ≤ 0.05). In field trials, applications of AE (1% vol/vol) reduced the disease severity of B. cinerea on grape, on average, by 63%. Extracts were fractionated by high-performance liquid chromatography and the bioefficacy of the fractions was tested in vitro. Some components of the most fungicidal fraction were identified by liquid chromatography-high resolution mass spectrometry as saponins: sapindoside B (accounting for ≥98% of the total constituents), hederagenin-pentosylhexoside, and oleanolic acid-hexosyl-deoxyhexosyl-hexoside. This fraction inhibited the mycelial growth of V. inaequalis and B. cinerea by 45 and 43%, respectively.

Triterpenoid saponins from the pulp of Sapindus mukorossi and their antifungal activities

Under the guidance of anti-fungal bioassay, four previously undescribed oleanane-type and one lupane-type triterpenoid saponins, along with twelve known analogues, were isolated from the extract of Sapindus mukorossi pulps. Their structures were determined on the basis of spectroscopic analysis and chemical methods. In vitro biotests, oleanolic acid 3-O-β-D-xylopyranosyl-(1 → 3)-α-L-rhamnopyranosyl-(1 → 2)-α-L-arabinopyranoside showed inhibitory activity against Trichophyton rubrum with MIC₈₀ value of 8 μg/mL, while oleanolic acid 3-O-α-L-arabinopyranosyl-(1 → 3)-α-L-rhamnopyranosyl-(1 → 2)-α-L-arabinopyranoside exhibited inhibitory activity against both Trichophyton rubrum and Candida albicans with MIC₈₀ values of 8 μg/mL.

Structure Identification of Triterpene from the Mushroom Pleurotus eryngii with Inhibitory Effects Against Breast Cancer

Breast cancer is the leading cause of death among women, with approximately 1 million diagnoses annually. Triterpenoids, which have cancer preventive or anti-tumour efficacy towards various tumour cells, may play a role in breast cancer prevention. In our previous study, an acetic ether (EtOAc) fraction from the sporocarp of the edible mushroom Pleurotus eryngii (P. eryngii) exhibited significant tumour cell growth inhibition both in vitro and in vivo. In this study, three pentacyclic triterpenoid compounds (1-3) were isolated from EtOAc extracts using chromatographic separation and were identified using nuclear magnetic resonance (NMR) and mass spectrometry (MS). The compounds were 2, 3, 6, 23-tetrahydroxy-urs-12-en-28 oic acid (1), 2,3,23-trihydroxy-urs-12-en-28 oic acid (2) and lupeol (3). All three purified triterpenes showed significant inhibitory activity against breast cancer MCF-7 cell lines in vitro, with the greatest activity exhibited by compound 1, followed by compound 2 and 3. The IC(50) values were 15.71, 48 and 66.89 μM, respectively. Our study may help elucidate the health benefits of P. eryngii mushroom consumption.

Randainins A-D, Based on Unique Diterpenoid Architectures, from Callicarpa randaiensis

Four new compounds, randainins A-D (1-4), were isolated from the leaves and twigs of Callicarpa randaiensis, which is an endemic species in Taiwan. Compounds 1 and 2 are diterpenoids with an unusual trans-7/5 ring system, whereas compounds 3 and 4 are diterpenoids possessing a trans-5/7 ring scaffold. The structures of the new compounds were established based on NMR and MS data analyses. Anti-inflammatory activities and cytotoxicity were tested and evaluated for these compounds. Compound 4 exhibited moderate inhibition of superoxide-anion generation with an IC50 value of 21.5 ± 2.5 μM.

Cytotoxic saponin poliusaposide from Teucrium polium

Three saponin glycosides have been isolated and characterized from Teucrium polium L. (Lamiaceae).

A new triterpenoid saponin and an oligosaccharide isolated from the fruits of Sapindus mukorossi

A new triterpenoid saponin (1) and a new oligosaccharide (2), together with three known saponins (3-5), have been isolated from n-BuOH extract of the fruits of Sapindus mukorossi Gaertn. The structures were elucidated using detailed analysis of one- and two-dimensional nuclear magnetic resonance spectra along with their mass spectrometric data and the results of acid hydrolysis. Of the isolated compounds 1 and 3-5 displayed cytotoxic effects against human cancer cell lines in A-549 (lung carcinoma), MDA-231 (breast carcinoma) and PC-3 (prostatic carcinoma).

Saponins: a renewable and biodegradable surfactant from its microwave-assisted extraction to the synthesis of monodisperse lattices

Synthetic surfactants are widely used in emulsion polymerization, but it is increasingly desirable to replace them with naturally derived molecules with a reduced environmental burden. This study demonstrates the use of saponins as biodegradable and renewable surfactants for emulsion polymerization. This chemical has been extracted from soapnuts by microwave assisted extraction and characterized in terms of surfactant properties prior to emulsion polymerization. The results in terms of particle size distribution and morphology control have been compared to those obtained with classical nonionic (NP40) or anionic (SDS) industrial surfactants. Microwave-extracted saponins were able to lead to latexes as stable as standard PS latex, as shown by the CMC and CCC measurements. The saponin-stabilized PS particles have been characterized in terms of particle size and distribution by Dynamic Light Scattering and Asymmetrical Flow Field Flow Fractionation. Monomodal and monodispersed particles ranging from 250 to 480 nm in terms of diameter with a particle size distribution below 1.03 have been synthesized.

A New Triterpenoid Saponin and Antimicrobial Activity of Ethanolic Extract fromSapindus mukorossiGaertn

A new acetylated triterpenoid saponin elucidated as hederagenin-3-O-β-D-xylopyranosyl (2→1)-[3-O-acetyl-α-L-arabinopyranosyl-28-O-α-L-rhamnopyranosylester has been isolated from pericarps ofSapindus mukorossiGaertn. The structure of the compound was determined by means of chemical and spectral analysis including advanced 2D NMR studies. The ethanolic extract from pericarps of the plant showed significantin vitroantimicrobial activity against various test organisms by Agar well diffusion method.

Pharmacological effects of Sapindus mukorossi

Sapindus mukorossi is an extremely valuable medicinal plant, distributed in tropical and sub-tropical regions of Asia. The aim of present review is to form a short compilation of the phytochemical composition and pharmacological properties of this multipurpose tree. The main phytoconstituents isolated and identified from different parts of this plant are triterpenoidal saponins of oleanane, dammarane and tirucullane type. The structure and chemical names of all the types of triterpenoidal saponins reported in Sapindus mukorossi are included in this review. Many research studies have been conducted to prove the plant's potential as being spermicidal, contraceptive, hepatoprotective, emetic, anti-inflammatory and anti-protozoal. The present review highlights some of the salient pharmacological uses of Sapindus mukorossi.

Indiosides G-K: steroidal glycosides with cytotoxic and anti-inflammatory activities from Solanum violaceum

Five new steroidal glycosides (1-5) and nine known compounds were isolated from Solanum violaceum. Indiosides G (1) and H (2) are spirostene saponins with an iso-type F ring, indioside I (3) is a spirostane saponin, and indiosides J (4) and K (5) are unusual furostanol saponins with a deformed F ring. These structures represent rare naturally occurring steroidal skeletons. The structures of the new compounds were elucidated using 1D and 2D spectroscopic techniques and acid hydrolysis. Compounds 2, 3, and 7-9 exhibited cytotoxic activity against six human cancer cell lines (HepG2, Hep3B, A549, Ca9-22, MDA-MB-231, and MCF-7) with IC(50) values of 1.83-8.04 μg/mL. Steroidal saponins 3, 8, and 9 showed inhibitory effects on superoxide anion generation with IC(50) values of 2.84 ± 0.18, 0.62 ± 0.03, and 1.62 ± 0.59 μg/mL, respectively. Saponins 8 and 9 also inhibited elastase release with IC(50) values of 111.05 ± 7.37 and 4.04 ± 0.51 μg/mL, respectively. Structure-activity relationship correlations of these compounds with respect to cytotoxic and anti-inflammatory effects are discussed.

Saponins as cytotoxic agents: a review

Saponins are natural glycosides which possess a wide range of pharmacological properties including cytotoxic activity. In this review, the recent studies (2005-2009) concerning the cytotoxic activity of saponins have been summarized. The correlations between the structure and the cytotoxicity of both steroid and triterpenoid saponins have been described as well as the most common mechanisms of action.

Structure-biological activity relationships in triterpenic saponins: the relative activity of protobassic acid and its derivatives against plant pathogenic fungi

BACKGROUND

Triterpenic saponins from Sapindus mukorossi Gaertn. and Diploknema butyracea JF Gmelin were evaluated for in vitro antifungal activity against four phytopathogenic fungi. The study of the structure-antifungal activity relationships of protobassic acid saponins was widened by including semi-synthetic derivatives.

RESULTS

Diploknema butyracea saponins exhibited significant antifungal activity against three fungi (ED(50) 230-455 microg mL(-1)), whereas S. mukorossi saponin was effective against two fungi (ED(50) 181-407 microg mL(-1)). The n-butanol extract after preparative HPLC separation provided two saponins from D. butyracea saponin mixture: 3-O-[beta-D-glucopyarnosyl-beta-D-glucopyranosyl]-16-alpha-hydroxyprotobassic acid-28-O-[arabinopyranosyl-glucopyranosyl-xylopyranosyl]-arabinopyranoside (MI-I), and 3-O-beta-D-glucopyranosyl-glucopyranosyl-glucopyranosyl-16-alpha-hydroxyprotobassic acid-28-O-[arabinopyranosyl-xylopyranosyl-arabinopyranosyl]-apiofuranoside (MI-III). The single saponin extracted from S. mukorossi saponin mixture was identified as 3-O-[O-acetyl-beta-D-xylopyranosyl-beta-D-arabinopyranosyl-beta-D-rhamnopyranosyl] hederagenin-28-O[beta-D-glucopyranosyl-beta-D-glucopyranosyl-beta-D-rhamnopyranosyl] ester (SM-I). Monodesmosides resulting from the partial degradation of hederagenin and hydroxyprotobassic acid bisdesmosides exhibited significant reduction in antifungal effect. Further removal of sugar moiety yielded complete loss in activity. The antifungal activity of the triterpenic saponins was associated with their aglycone moieties, and esterification of the hydroxyl group led to change in antifungal activity.

CONCLUSION

Sapindus mukorossi saponin, which is effective against Rhizoctonia bataticola (Taub.) Briton Jones and Sclerotium rolfsii Sacc., can be exploited for the development of a natural fungicide. A sugar moiety is a prerequisite for the antifungal activity of triterpenic saponin.

The hederagenin saponin SMG-1 is a natural FMLP receptor inhibitor that suppresses human neutrophil activation

The pericarp of Sapindus mukorossi Gaertn is traditionally used as an expectorant in Japan, China, and Taiwan. Activated neutrophils produce high concentrations of the superoxide anion (O(2)(-)) and elastase known to be involved in airway mucus hypersecretion. In the present study, the anti-inflammatory functions of hederagenin 3-O-(3,4-O-di-acetyl-alpha-L-arabinopyranoside)-(1-->3)-alpha-l-rhamnopyranosyl-(1-->2)-alpha-l-arabinopyranoside (SMG-1), a saponin isolated from S. mukorossi, and its underlying mechanisms were investigated in human neutrophils. SMG-1 potently and concentration-dependently inhibited O(2)(*-) generation and elastase release in N-Formyl-Met-Leu-Phe (FMLP)-activated human neutrophils. Furthermore, SMG-1 reduced membrane-associated p47(phox) expression in FMLP-induced intact neutrophils, but did not alter subcellular NADPH oxidase activity in reconstituted systems. SMG-1 attenuated FMLP-induced increase of cytosolic calcium concentration and phosphorylation of p38 MAPK, ERK, JNK, and AKT. However, SMG-1 displayed no effect on cellular cAMP levels and activity of adenylate cyclase and phosphodiesterase. Significantly, receptor-binding analysis showed that SMG-1 inhibited FMLP binding to its receptor in a concentration-dependent manner. In contrast, neither phorbol myristate acetate-induced O(2)(*-) generation and MAPKs activation nor thapsigargin-caused calcium mobilization was altered by SMG-1. Taken together, our results demonstrate that SMG-1 is a natural inhibitor of the FMLP receptor, which may have the potential to be developed into a useful new therapeutic agent for treating neutrophilic inflammatory diseases.

Chemical study and medical application of saponins as anti-cancer agents

Saponins are a group of naturally occurring plant glycosides, characterized by their strong foam-forming properties in aqueous solution. The presence of saponins has been reported in more than 100 families of plants out of which at least 150 kinds of natural saponins have been found to possess significant anti-cancer properties. There are more than 11 distinguished classes of saponins including dammaranes, tirucallanes, lupanes, hopanes, oleananes, taraxasteranes, ursanes, cycloartanes, lanostanes, cucurbitanes and steroids. Due to the great variability of their structures, saponins always display anti-tumorigenic effects through varieties of antitumor pathways. In addition, there are a large amount of saponins that still either remain to be trapped or studied in details by the medicinal chemists. This article reviews many such structures and their related chemistry along with the recent advances in understanding mechanism of action and structure-function relationships of saponins at the molecular and cellular levels. These aglycones have been described and their classification and distribution have been listed in the review. Some special saponins with strong antitumor effects have also been exhibited. Ginsenosides, belonging to dammaranes, have been found beneficial targeted on inhibition of tumor angiogenesis by suppressing its inducer in the endothelial cells of blood vessels, and then on prevention of adhering, invasion, and metastasis of tumor cells. Dioscin, one of the steroidal saponins, and its aglycone diosgenin also have been extensively studied on its antitumor effect by cell cycle arrest and apoptosis. Other important molecules discussed include oleanane saponins such as avicins, platycodons, saikosaponins, and soysaponins along with tubeimosides.

Triterpenoids

This review covers the isolation and structure determination of triterpenoids including squalene derivatives, protostanes, lanostanes, holostanes, cycloartanes, dammaranes, euphanes, tirucallanes, tetranortriterpenoids, lupanes, oleananes, friedelanes, ursanes, hopanes, isomalabaricanes and saponins; 574 references are cited.

Cardenolide glycosides of Thevetia peruviana and triterpenoid saponins of Sapindus emarginatus as TRAIL resistance-overcoming compounds

A screening study for TRAIL resistance-overcoming activity was carried out, and activity-guided fractionations of Thevetia peruviana and Sapindus emarginatus led to the isolation of four cardenolide glycosides (1-4) and four triterpenoid saponins (5-8), respectively. In particular, cardenolide glycosides (1 and 2) from T. peruviana were shown to have a significant reversal effect on TRAIL resistance in human gastric adenocarcinoma cells, and real-time PCR showed that thevefolin (2) enhanced mRNA expression of death receptor 4 (DR4) and DR5. In addition, 1H and 13C NMR characterizations are shown for thevefolin (2) for the first time.

Cespihypotins Q-V, verticillene diterpenoids from Cespitularia hypotentaculata

Chemical investigation of the soft coral Cespitularia hypotentaculata resulted in the isolation of six new diterpenes, cespihypotins Q-V. The new metabolites comprised five verticillane-type diterpenes and one nor-verticillane derivative. Their structures were determined through detailed spectroscopic analyses, especially HRESIMS and 2D NMR techniques. The relative configuration was deduced by interpretation of NOESY spectra. Cespihypotin T exhibited significant cytotoxic activity against human Daoy and WiDr tumor cell lines.