Saponins from Chinese medicinal plants. (I). Isolation and structures of hemslosides

Hemolysis by Saponin Is Accelerated at Hypertonic Conditions

Saponins are a large group of organic amphiphilic substances (surfactants) mainly extracted from herbs with biological activity, considered as one of the main ingredients in numerous remedies used in traditional medicine since ancient times. Anti-inflammatory, antifungal, antibacterial, antiviral, antiparasitic, antitumor, antioxidant and many other properties have been confirmed for some. There is increasing interest in the elucidation of the mechanisms behind the effects of saponins on different cell types at the molecular level. In this regard, erythrocytes are a very welcome model, having very simple structures with no organelles. They react to changing external conditions and substances by changing shape or volume, with damage to their membrane ultimately leading to hemolysis. Hemolysis can be followed spectrophotometrically and provides valuable information about the type and extent of membrane damage. We investigated hemolysis of erythrocytes induced by various saponin concentrations in hypotonic, isotonic and hypertonic media using measurements of real time and end-point hemolysis. The osmotic pressure was adjusted by different concentrations of NaCl, manitol or a NaCl/manitol mixture. Unexpectedly, at a fixed saponin concentration, hemolysis was accelerated at hypertonic conditions, but was much faster in NaCl compared to mannitol solutions at the same osmotic pressure. These findings confirm the colloid-osmotic mechanism behind saponin hemolysis with pore formation with increasing size in the membrane.

Identification and Isolation of α-Glucosidase Inhibitors from Siraitia grosvenorii Roots Using Bio-Affinity Ultrafiltration and Comprehensive Chromatography

The discovery of bioactive compounds from medicinal plants has played a crucial role in drug discovery. In this study, a simple and efficient method utilizing affinity-based ultrafiltration (UF) coupled with high-performance liquid chromatography (HPLC) was developed for the rapid screening and targeted separation of α-glucosidase inhibitors from Siraitia grosvenorii roots. First, an active fraction of S. grosvenorii roots (SGR2) was prepared, and 17 potential α-glucosidase inhibitors were identified based on UF-HPLC analysis. Second, guided by UF-HPLC, a combination of MCI gel CHP-20P column chromatography, high-speed counter-current countercurrent chromatography, and preparative HPLC were conducted to isolate the compounds producing active peaks. Sixteen compounds were successfully isolated from SGR2, including two lignans and fourteen cucurbitane-type triterpenoids. The structures of the novel compounds (4, 6, 7, 8, 9, and 11) were elucidated using spectroscopic methods, including one- and two-dimensional nuclear magnetic resonance spectroscopy and high-resolution electrospray ionization mass spectrometry. Finally, the α-glucosidase inhibitory activities of the isolated compounds were verified via enzyme inhibition assays and molecular docking analysis, all of which were found to exhibit certain inhibitory activity. Compound 14 exhibited the strongest inhibitory activity, with an IC₅₀ value of 430.13 ± 13.33 μM, which was superior to that of acarbose (1332.50 ± 58.53 μM). The relationships between the structures of the compounds and their inhibitory activities were also investigated. Molecular docking showed that the highly active inhibitors interacted with α-glucosidase through hydrogen bonds and hydrophobic interactions. Our results demonstrate the beneficial effects of S. grosvenorii roots and their constituents on α-glucosidase inhibition.

Anti-Inflammatory and anti-proliferative oleanane-type triterpene glycosides from the vine of Momordica cochinchinensis

This research isolated two new oleanane-type triterpene glycosides, named mocochinosides A (1) and B (2), together with ten known compounds as chikusetsusaponin IVa ethyl ester (3), momordin Ib (4), momordin IIb (5), momordin II (6), calenduloside G (7), calenduloside H (8), elatoside A (9), elatoside C (10), calendulaglycoside C 6'-O-7-butyl ester (11), and hederagenin 3-O-β-D-glucuronopyranoside (12) and characterized them from the vines of Momordica cochinchinensis. The new structures of both glycosides 1-2 were elucidated by spectroscopic analysis including 2 D NMR and MS, followed by an analysis of their anti-inflammatory and cytotoxic activities. Compounds 1, 4, and 11 showed moderate inhibitions for NO production on RAW264.7 macrophages induced by LPS at IC₅₀ 5.41 ∼ 11.28 μM. Compounds 3, 4, and 7 (IC₅₀ 8.42 ∼ 19.74 μM) exhibited potential anti-proliferative activities against both of WiDr and MCF-7 human tumor cell lines.

Two New Oleanane-type Saponins from Hydrocotyle multifida

A phytochemical study of a Venezuelan species Hydrocotyle multifida led to the isolation of five oleanane-type glycosides: two previously undescribed and three known ones. Their structures were established by 2D NMR spectroscopic techniques and mass spectrometry as 3- O-β-D-galactopyranosyl-(1→2)-[α-L-arabinopyranosyl-(1→3)]-β-D-glucuronopyranosyloleanolic acid and 3- O-β-D-glucopyranosyl-(1→2)-β-D-glucopyranosyl-(1→2)-β-D-glucuronopyrano-syloleanolic acid. These results represent a significative contribution to the chemotaxonomy of the Hydrocotyle genus.

Digging Deep for New Compounds from the Compass Plant, Silphium laciniatum

The compass plant, Silphium laciniatum, is an iconic perennial plant of the North American tallgrass prairie. The plants of the tallgrass prairie historically have been subjected to a number of biological and environmental stresses. Among the adaptations developed by S. laciniatum is a large deep taproot. An investigation of the secondary metabolites found in the root of a S. laciniatum specimen has led to the identification of 15 new terpenoids (3-8, 10-17, and 22), which were screened for cytotoxic activity in the NCI-H460 human large-cell lung carcinoma cell line.

Rapid characterisation and comparison of saponin profiles in the seeds of Korean Leguminous species using ultra performance liquid chromatography with photodiode array detector and electrospray ionisation/mass spectrometry (UPLC-PDA-ESI/MS) analysis

The present work was reported on investigation of saponin profiles in nine different legume seeds, including soybean, adzuki bean, cowpea, common bean, scarlet runner bean, lentil, chick pea, hyacinth bean, and broad bean using ultra performance liquid chromatography with photodiode array detector and electrospray ionisation/mass spectrometry (UPLC-PDA-ESI/MS) technique. A total of twenty saponins were characterised under rapid and simple conditions within 15min by the 80% methanol extracts of all species. Their chemical structures were elucidated as soyasaponin Ab (1), soyasaponin Ba (2), soyasaponin Bb (3), soyasaponin Bc (4), soyasaponin Bd (5), soyasaponin αg (6), soyasaponin βg (7), soyasaponin βa (8), soyasaponin γg (9), soyasaponin γa (10), azukisaponin VI (11), azukisaponin IV (12), azukisaponin II (13), AzII (14), AzIV (15), lablaboside E (16), lablaboside F (17), lablaboside D (18), chikusetusaponin IVa (19), and lablab saponin I (20). The individual and total saponin compositions exhibited remarkable differences in all legume seeds. In particular, soyasaponin βa (8) was detected the predominant composition in soybean, cowpea, and lentil with various concentrations. Interestingly, soybean, adzuki bean, common bean, and scarlet runner bean had high saponin contents, while chick pea and broad bean showed low contents.

A new feruloyl tyramine glycoside from the roots of Achyranthes bidentata

AIM

To study the chemical constituents of the roots of Achyranthes bidentata Bl.

METHODS

The chemical constituents were isolated and purified by macroporous adsorptive resin D101, silica gel, and ODS column chromatographies and preparetive HPLC. Their structures were elucidated on the basis of 1D and 2D NMR analyses.

RESULTS

Two feruloyl tyramine glycosides and seven triterpenoid saponins were obtained and identified as N-trans-feruloyl-3-methoxytyramine-4'-O-β-D-glucopyranoside (1), N-trans-feruloyl-3-methoxytyra mine-4-O-β-D-glucopyranoside (2), PJS-1 (3), chikusetsusaponin IVa (4), oleanolic acid 3-O-[β-D-glucuronopy ranoside-6-O-methyl ester]-28-O-β-D-glucopyranoside (5), oleanolic acid 3-O-[β-D-glucuronopyran-oside-6-O-ethylester]-28-O-β-D-glucopyranoside (6), oleanolic acid 3-O-[β-D-glucuronopyranoside-6-O-butyl ester]-28-O-β-D-glucopyranoside (7), ginsenoside R(0) (8) and hederagenin-28-O-β-D-glucopyranosyl ester (9).

CONCLUSION

Compound 1 is a new feruloyl tyramine glycoside, while compounds 2 and 9 are reported from A. bidentata for the first time.

Oleanane-triterpenoids from Panax stipuleanatus inhibit NF-κB

In continuation of our research to find biological components from Panax stipuleanatus, four oleanane-type triterpenes (12 to 15) were isolated successively. Fifteen oleanane-type saponins (1 to 15) were evaluated for nuclear factor (NF)-κB activity using a luciferase reporter gene assay in HepG2 cells. Compounds 6 to 11 inhibited NF-κB, with IC₅₀ values between 3.1 to 18.9 μM. The effects on inducible nitric oxide synthase and cyclooxygenase-2 by compounds 8, 10, and 11 were also examined using reverse transcription-polymerase chain reaction. Three compounds (8, 10, and 11) inhibited NF-κB activity by reducing the concentration of inflammatory factors in HepG2 cells.

Antioxidant and Cytotoxic Constituents from Wisteria sinensis

Chromatographic separation of an aqueous MeOH extract of Wisteria sinensis leaves has yielded six known flavonoids, two triterpene aglycones and the new acylated flavone glycoside chrysoeriol-7-O-[2''-O-(5'''-O-caffeoyl)-β-D-apiofuranosyl]-β-D-glucopyranoside (1). All metabolites were isolated for the first time from the genus Wisteria. Their structures were established on the basis of their chromatographic properties, chemical and physicochemical methods including acid hydrolysis analysis, spectroscopic (UV, ¹H- and ¹³C-NMR) data and confirmed by ESI-MS analysis, as well as two-dimensional NMR (¹H-¹HCOSY, HMQC and HMBC). Biological studies of the defatted aqueous 80% methanol leaf extract and the major isolates 1, 6 and 7 were undertaken and they are reported herein for the first time to have significant cytotoxic activity against the Hep-G2 tumor cell line in addition to antioxidant activity.

Bioactive constituents from the roots of Panax japonicus var. major and development of a LC-MS/MS method for distinguishing between natural and artifactual compounds

Two new saponins, panajaponol (1) and pseudoginsenoside RT1 butyl ester (2), together with 35 known compounds (3-37), were isolated from the roots of Panax japonicus var. major. The structures of 1 and 2 were elucidated on the basis of spectroscopic analysis and chemical methods. Furthermore, a LC-MS/MS method was developed for confirming 2, 3, and 8 as natural compounds containing a butyl ester group. This method should be useful for distinguishing between minor natural and artifactual compounds in Panax species. Moreover, compounds 3, 6, 8, 9, 11, 13, and 15 exhibited strong inhibition of superoxide anion generation and elastase release by human neutrophils in response to formyl-l-methionyl-l-leucyl-l-phenylalanine/cytochalasin B (fMLP/CB), with IC(50) values ranging from 0.78 to 43.6 μM. In addition, 1 showed greater than 2- to 3-fold selective cytotoxic activity against KB and DU145 cancer cell lines.

New triterpene saponins from Duranta repens Linn. and their cytotoxic activity

From the leaves of Duranta repens (Verbenaceae) two new triterpene saponins, named durantanin IV (1) and V (2) were isolated. In addition, ten known compounds were isolated, namely a bidesmosidic saponin, oleanolic acid, three phenylethanoids and five flavonoids. All metabolites were isolated for the first time from this genus except for 3 (oleanolic acid) and 7 (E/Z acteoside). The structures were determined mainly by spectroscopic methods (UV, IR, HRESI-MS, ¹H-, ¹³C-NMR, ¹H-¹H COSY, HSQC and HMBC). Cytotoxic screening of the chloroform, ethyl acetate and methanol extracts was carried out on brine shrimps. In addition, the investigated methanol extract and compounds 1, 2 and 7 showed significant cytotoxic activity against a HepG2 cell line.

[Studies on the constituents of cucurbitaceous plants]

I have an opportunity to have co-operative studies with Chinese group of Kunming Institute of Botany. Since then, I have investigated the chemical constituents of a number of Chinese plants of Araliaceae, Umbelliferae, Labiatae, Cucurbitaceae and other families. This review describes the structural elucidation of the cucurbitane, oleanane and dammarane glycosides, and their biological activities under the joint studies on cucurbitaceous plants, Bolbostemma, Hemsleya, Siraitia and Neoalsomitra species. New oleanane glycosides having novel cyclic structure were isolated from Bolbostemma paniculatum. The potent solubilizing effect of these compounds was investigated. A number of cucurbitane glycosides were isolated from Hemsleya carnosiflora, H. panacis-scandens, Siraitia grosvenorii and S. siamensis. Some of these glycosides taste sweet, bitter or tasteless. The structure-taste relationships of the glycosides of a 3-alpha-hydroxy-cucurbit-5-ene-type triterpene have been discussed. Anti-tumor-promotion effects as well as the ecdysteroid agonist and antagonist activities of these cucurbitane glycosides were investigated. New dammarane glycosides were isolated from Neoalsomitra integrifoliola.

Octanorcucurbitane and cucurbitane triterpenoids from the tubers of Hemsleya endecaphylla with HIV-1 inhibitory activity

Two new cucurbitacins, endecaphyllacins A (1) and B (2), together with six known analogues (3-8), were isolated from the tubers of Hemsleya endecaphylla. The structures of 1 and 2 were elucidated by NMR and MS spectroscopic analysis. The relative stereochemistry of 1 was determined by single-crystal X-ray diffraction. Compound 4 (cucurbitacin B) showed potent anti-HIV-1 in C8166 cells (EC=0.09 microg/mL) with a selectivity index of 16.7.

Simultaneous determination of main phytoecdysones and triterpenoids in radix achyranthis bidentatae by high-performance liquid chromatography with diode array-evaporative light scattering detectors and mass spectrometry

A liquid chromatographic method was developed for simultaneous determination of two main types of bioactive compounds: four phytoecdysones and eight triterpenoids in radix achyranthis bidentatae (RAB), i.e., polypodine B (1), ecdysterone (2), 25-R inokosterone (3), 25-S inokosterone (4), ginsenoside Ro (5), chikusetsusaponin IVa (6), zingibroside R1 (7), chikusetsusaponin IVa ethyl ester (8), 28-deglucosyl-chikusetsusaponin IVa (9), PJS-1 (10), 28-deglucosyl-chikusetsusaponin IVa butyl ester (11), and oleanolic acid (12). Optimum separations were obtained with a Zorbax C18 column, using a gradient elution with 0.08% aqueous formic acid (containing 5% isopropyl alcohol) and acetonitrile as mobile phase. Phytoecdysones were detected by diode array detector (DAD) at 242 nm, whereas triterpenoids were monitored by evaporative light scattering detector (ELSD) connected in series with DAD, temperature for the drift tube was 110 degrees C and the nitrogen flow rate was 3.2 L min(-1). The identity of the analytes was confirmed using retention times, ultraviolet absorbance and mass spectral data in comparison with reference compounds. The method was validated for acceptable precision (intra- and inter-day variation < or = 4.87%), accuracy (recovery > or = 88.9%) and sensitivity (LOD < or = 0.43 microg mL(-1) (DAD) and 26.0 microg mL(-1) (ELSD), LOQ < or = 0.97 microg mL(-1) (DAD) and 46.5 microg mL(-1) (ELSD), respectively). This rapid and reliable method was applied for the analysis of four cultivated and ten commercial samples. The results demonstrated that the method is suitable for routine analysis and quality control of RAB.

Simultaneous qualification and quantification of eight triterpenoids in Radix Achyranthis Bidentatae by high-performance liquid chromatography with evaporative light scattering detection and mass spectrometric detection

An HPLC with evaporative light scattering detection (ELSD) and ESI-MS was established for the simultaneous determination of eight triterpenoids in Radix Achyranthis Bidentatae. The optimal chromatographic conditions were achieved on a Zorbax C18 column by linear gradient elution with 0.08% v/v aqueous formic acid and ACN as the mobile phase at the flow rate of 0.8 mL/min. Temperature for the detector drift tube was set at 101 degrees C and the nitrogen flow rate was 2.8 L/min. The identities of the analytes were accomplished by comparing retention times and mass data with those of reference compounds. The validation of the method included tests of linearity, sensitivity, repeatability, recovery, and stability. All the calibration curves of the eight triterpenoids showed good linear regression (R2 >0.997) within the test ranges. The method provides desirable repeatability with overall intra- and interday variations of less than 4.9%. The obtained recoveries varied between 93.6 and 98.1% while the RSDs were below 3.9% (n = 3). The analysis results indicate that the content of investigated triterpenoids in Radix Achyranthis Bidentatae from different locations was greatly diverse, and the triterpenoids could be used as chemical markers for the discrimination of genuine and ungenuine crude drugs.

Saponins, classification and occurrence in the plant kingdom

Saponins are a structurally diverse class of compounds occurring in many plant species, which are characterized by a skeleton derived of the 30-carbon precursor oxidosqualene to which glycosyl residues are attached. Traditionally, they are subdivided into triterpenoid and steroid glycosides, or into triterpenoid, spirostanol, and furostanol saponins. In this study, the structures of saponins are reviewed and classified based on their carbon skeletons, the formation of which follows the main pathways for the biosynthesis of triterpenes and steroids. In this way, 11 main classes of saponins were distinguished: dammaranes, tirucallanes, lupanes, hopanes, oleananes, taraxasteranes, ursanes, cycloartanes, lanostanes, cucurbitanes, and steroids. The dammaranes, lupanes, hopanes, oleananes, ursanes, and steroids are further divided into 16 subclasses, because their carbon skeletons are subjected to fragmentation, homologation, and degradation reactions. With this systematic classification, the relationship between the type of skeleton and the plant origin was investigated. Up to five main classes of skeletons could exist within one plant order, but the distribution of skeletons in the plant kingdom did not seem to be order- or subclass-specific. The oleanane skeleton was the most common skeleton and is present in most orders of the plant kingdom. For oleanane type saponins, the kind of substituents (e.g. -OH, =O, monosaccharide residues, etc.) and their position of attachment to the skeleton were reviewed. Carbohydrate chains of 18 monosaccharide residues can be attached to the oleanane skeleton, most commonly at the C3 and/or C17 atom. The kind and positions of the substituents did not seem to be plant order-specific.

Phytochemical constituents and hepatoprotective activity of Viburnum tinus

From the leaves of Viburnum tinus L. (Adoxaceae) two acylated iridoid glucosides (viburtinoside A and B), a coumarin diglucoside scopoletin 7-O-beta-D-sophoroside and a natural occurred dinicotinic acid ester 2,6-di-C-methyl-nicotinic acid 3,5-diethyl ester were isolated. In addition to these, 10 known compounds were isolated, namely two bidesmosidic saponins, a hexamethoxy-flavone and five flavonol glycosides, as well as suspensolide A and oleanolic acid were isolated for the first time in this genus and species, respectively. The structures were determined mainly by spectroscopic methods (UV, IR, ESI-MS, 1H-, 13C NMR and DEPT). Toxicity of the investigated extract was determined (LD50=500 mg/kg). CCl4-induced hepatotoxicity has been evaluated in terms of the determination of alanine aminotransferase (ALT), aspartate aminotransferase (AST), lipid peroxide and nitric oxide levels in serum and compared using adult male rats weighing 150-180 g. Their highly elevated levels were significantly reduced by treatment with the investigated aqueous methanol extract in dose-dependent manner.

A Korean herbal medicine, Panax notoginseng, prevents liver fibrosis and hepatic microvascular dysfunction in rats

We assessed the prevention of hepatic fibrogenesis by water-extract of Panax notoginseng Buck F.H. Chen. (Arialiaceae) root (PNS) in Long-Evans rats with cinnamon coat color (LEC rats). LEC rats were divided into three groups A, fed on a basal diet (BD); B, fed on BD plus 1% PNS; and C), fed on BD plus 0.005% lycopene as a control. All rats were sacrificed at 26 weeks of age. The percentage of the total area involved by fibrosis was 1.46 +/- 0.47 in group A, 0.83 +/- 0.10 in B (P=0.0030, B vs A) and 0.91 +/- 0.45 in C (P=0.0035, C vs. A). The percentage of the total area that was stained for alpha-SMA was 0.56 +/- 0.34 in group A, 0.15 +/- 0.02 in B (P=0.0016, B vs. A and 0.11 +/- 0.01 in C (P=0.0025, C vs. A. In group B, malondialdehyde (MDA) in the liver was lower than in group C (P=0.007). In group C, the concentration of iron in the liver was lower than in group A (P=0.0053). Thus, PNS suppressed fibrogenesis through reduced generation of lipid peroxides. The mechanisms of this preventive effect of fibrogenesis with PNS were suggested to inhibit the stellate cell activity. Second objective of this study was to determine whether PNS affects hepatic microvascular dysfunction elicited by gut ischemia and reperfusion (I/R), since gut I/R causes hepatic microvascular dysfunction, and to investigate the role of nitric oxide (NO). Male Wistar rats were exposed to 30 min of gut ischemia followed by 60 min of reperfusion. Intravital microscopy was used to monitor the number of non-perfused sinusoids (NPS). In another set of experiments, PNS (1 g/kg per day intragastrically) was administered to rats for 7 days. In some experiments, dexamethasone (ST) (2 mg/kg per day intravenously) was administered. In control rats, gut I/R elicited increases in the number of NPS, and plasma TNF-alpha and ALT activities, and these changes were mitigated by the pretreatment with PNS. Pretreatment with an NO synthase inhibitor diminished the protective effects of PNS on the increase in NPS and plasma TNF-alpha levels, but not its effect on the increase in plasma ALT activities. Pretreatment with PNS increased plasma nitrite/nitrate levels. The responses caused by gut I/R were attenuated by the pretreatment with ST. Pretreatment with an NO synthase inhibitor did not affect the effect of ST. These results suggest that PNS attenuates the gut I/R-induced hepatic microvascular dysfunction and inflammatory responses such as TNF-alpha production in the early phase via enhancement of NO production, and sequential hepatocellular damage via its anti-inflammatory effect.

Bioactive crude plant seed extracts from the NCAUR oilseed repository

Over four-hundred crude extracts from 202 plant species distributed among 131 plant families were evaluated for their bioactivity against brine shrimp (Artemia salina). Activity was determined for both the organic (CH2Cl2:MeOH) and aqueous extracts against A. salina in a 96 well-plate assay. Of the greater than four-hundred extracts tested, 21 organic and 6 aqueous extracts demonstrated potent cytotoxic activity (LC50 = < 100 microg/ml). Three of these organic extracts (Crateva religiosa, Diospyros dichrophylla, and Olax subscorpioidea) were chosen for chemical investigations due to their high activity and a lack of prior investigations. Chemical analysis of these extracts resulted in the isolation of oleanolic acid (1) and 4-epi-hederagenin (2) from C. religiosa, isodiospyrin (3) from D. dichrophylla, and santalbic acid (4) from O. subscorpioidea.

Identification of triterpene saponins in Quercus robur L. and Q. petraea Liebl. Heartwood by LC-ESI/MS and NMR

A detailed structural study of the major acidic triterpene saponins from European oak heartwood, Quercus robur L. and Q. petraea Liebl., revealed the presence of 2 alpha,3 beta,19 alpha-trihydroxyolean-12-ene-24,28-dioic acid (1), 2 alpha,3 beta,19 alpha-23-tetrahydroxyolean-12-ene-24,28-dioic acid (2), and their corresponding glycosides, 28-beta-D-glucopyranosyl-2 alpha,3 beta,19 alpha-trihydroxyolean-12-ene-24,28-dioic acid (3), and 28-beta-D-glucopyranosyl-2 alpha,3 beta,19 alpha,23-tetrahydroxyolean-12-ene-24,28-dioic acid (4). Compounds were isolated and purified by successive flash chromatography and semi-preparative HPLC, and structurally determined by NMR and LC-ESI/MS in the negative ion mode. Compounds 2 and 4 have been identified for the first time in Quercus species and are new compounds.

Saponins from Pisonia umbellifera

Six saponins were isolated from the leaves of Pisonia umbellifera. Three are new oleanolic acid saponins, and two of them contain an unusual seco-glycopyranosyl moiety. Their structures were determined using a combination of 1H and 13C NMR, and mass spectrometry as 3-O-{beta-D-glucopyranosyl(1-->2)[beta-D-glucopyranosyl (1-->2)-beta-D-xylopyranosyl(1-->3)]-beta-D-glucuronopyranosyl} 28-O-beta-D-glucopyranosyl olean-12-en-3 beta-ol-28-oic acid, 3-O-{2'-(2"-O-glycolyl)-glyoxylyl-beta-D-glucuronopyranos yl} 28-O-beta-D-glucopyranosyl olean-12-en-3 beta-ol-28-oic acid and 3-O-{2'-O-glycolyl)-glyoxylyl-beta-D-glucuronopyranosyl++ +} olean-12-en-3 beta-ol-28-oic acid.

Seco-glycosides of oleanolic acid from Beta vulgaris

Two new oleanolic acid saponins were isolated from the leaves and roots of Beta vulgaris. Both contained the unusual feature of a 3,4 seco-glycopyranosyl moiety. Their structures were established by a combination of 2D NMR experiments and of Californium plasma desorption mass spectrometry.

Triterpenoid saponins from Madhuca butyracea

Further investigation of the seeds of Madhuca butyracea yielded two new triterpenoid saponins, namely butyrosides C and D whose structures were established by means of chemical and spectral analyses as 3-O-beta-D-glucuronopyranosyl protobassic acid 28-O-alpha-L-rhamnopyranosyl(1-->3)-beta-D- xylopyranosyl(1-->4)-alpha-L-rhamnopyranosyl(1-->2)-alpha-L-arabinopy ranoside and 3-O-beta-D-glucuronopyranosyl 16 alpha-hydroxy protobassic acid 28-O-beta-D-apiofuranosyl(1-->3)-beta-D-xylopyranosyl(1-->4)-alpha -L- rhamnopyranosyl(1-->2)-alpha-L-arabinopyranoside, respectively.

Saponins from leaves of Acanthopanax sieboldianus

Two new triterpenoid saponins named sieboldianoside A and B were isolated from the leaves of Acanthopanax sieboldianus together with five known triterpenoid saponins, kalopanax-saponins A and B, saponin A, CP3, sapindoside B, and a known flavonol glycoside, kaempferol 3-O-rutinoside. On the basis of chemical and spectral evidence, the structures of the new saponins (sieboldianoside A and B) were concluded to be alpha-L-rhamnopyranosyl(1-->4)-beta-D-glucopyranosyl(1-->6)- beta-D-glucopyranosyl esters of hederagenin and oleanolic acid 3-O-beta-D- xylopyranosyl(1-->3)-alpha-L-rhamnopyranosyl(1-->2)-alpha-L-arabinopy ranosides, respectively.