Five new triterpene saponins, polygalasaponins XXVIII-XXXII from the root of Polygala japonica Houtt

Therapeutic potential of Polygala saponins in neurological diseases

BACKGROUND

There are many types of neurological diseases with complex etiologies. At present, most clinical drugs can only relieve symptoms but cannot cure these diseases. Radix Polygalae, a famous traditional Chinese medicine from the root of plants of the genus Polygala, has the traditional effect of treating insomnia, forgetfulness, and palpitation and improving intelligence and other symptoms of neurological diseases. Saponins are important bioactive components of plants of the genus Polygala and exhibit neuroprotective effects.

PURPOSE

This review aimed to summarize the traditional use of Polygala species and discuss the latest phytochemical, pharmacological, and toxicological findings, mainly with regard to Polygala saponins in the treatment of neurological disorders.

METHODS

Literature was searched and collected using databases, including PubMed, Science Direct, CNKI, and Google Scholar. The search terms used included "Polygala", "saponins", "neurological diseases", "Alzheimer's disease", "toxicity", etc., and combinations of these keywords. A total of 1202 papers were retrieved until August 2022, and we included 135 of these papers on traditional uses, phytochemistry, pharmacology, toxicology and other fields.

RESULTS

This literature review mainly reports on the traditional use of the Polygala genus and prescriptions containing Radix Polygalae in neurological diseases. Phytochemical studies have shown that plants of the genus Polygala mainly include saponins, flavonoids, oligosaccharide esters, alkaloids, coumarins, lignans, flavonoids, etc. Among them, saponins are the majority. Modern pharmacological studies have shown that Polygala saponins have neuroprotective effects on a variety of neurological diseases. Its mechanism of action involves autophagic degradation of misfolded proteins, anti-inflammatory, anti-apoptotic, antioxidative stress and so on. Toxicological studies have shown that Polygala saponins trigger gastrointestinal toxicity, and honey processing and glycosyl disruption of Polygala saponins can effectively ameliorate its gastrointestinal side effect.

CONCLUSION

Polygala saponins are the major bioactive components in plants of the genus Polygala that exhibit therapeutic potential in various neurological diseases. This review provides directions for the future study of Polygala saponins and references for the clinical use of prescriptions containing Radix Polygalae for the treatment of neurological diseases.

Natural sucrose esters: Perspectives on the chemical and physiological use of an under investigated chemical class of compounds

The present review describes the chemistry and physiological properties of the sucrose esters (SEs) obtained from natural or synthetic pathways, with emphasis on those that have aliphatic and phenylpropanoid substituents on their sucrose moiety. Synthesis, extraction and characterization methods for the SEs and NSEs are discussed in terms of synthetic procedures, separation techniques and spectroscopic methods. The physiological properties are discussed taking into account the nature of the substituent groups and their regiochemistry (position and number of substitutions) on the sucrose moiety.

Polygalasaponin F treats mice with pneumonia induced by influenza virus

BACKGROUND

Influenza is an acute viral respiratory illness that causes high morbidity and mortality globally. Therapeutic actions are limited to vaccines and a few anti-viral drugs. Polygala (P.) japonica herba is rich in Polygalasaponin F (PSF, C₅₃H₈₆O₂₃), used for acute bronchitis, pharyngitis, pneumonia, amygdalitis, and respiratory tract infections treatment in China. Hypercytokinemia is often correlated with severe pneumonia caused by several influenza viruses. PSF was reported to have anti-inflammatory effects and its mechanism is associated with the nuclear factor (NF)-κB signaling pathway. The action of PSF to alleviate pulmonary inflammation caused by influenza A virus (IAV) infection requires careful assessment. In the present study, we evaluated the effect and mechanism of PSF on mice with pneumonia caused by influenza H1N1 (A/FM/1/47).

METHODS

Mice were infected intranasally with fifteen 50% mouse lethal challenge doses (MLD₅₀) of influenza virus. BALB/c mice were treated with PSF or oseltamivir (oral administration) for 2 h post-infection and received concomitant treatment for 5 days after infection. On day 6 post-infection, 10 mice per group were killed to collect related samples, measure body weight and lung wet weight, and detect the viral load, cytokine, prostaglandins, pathological changes, and cell pathway protein expression in the lungs. In addition, the survival experiments were carried out to investigate the survival of mice. The expression profile of cell pathway proteins was detected and analyzed using a broad pathway antibody array and confirmed the findings from the array by western blotting.

RESULTS

Polygalasaponin F and oseltamivir can protect against influenza viral infection in mice. PSF and oseltamivir significantly relieved the signs and symptoms, reduced body weight loss, and improved the survival rate of H1N1-infected mice. Moreover, PSF efficiently decreased the level of interleukin (IL)-1β, tumor necrosis factor (TNF)-α, IL-4, interferon (IFN)-γ, thromboxane A₂ (TXA₂), and prostaglandin E₂ (PGE₂) in lung tissues of mice infected with influenza virus (p < 0.05-0.01). Oseltamivir had a similar effect to lung cytokine of PSF, but did not decrease the levels of TXA₂ and PGE₂. There was a twofold or greater increase in four cell pathway protein, namely NF-κB p65 (2.68-fold), I-kappa-B-alpha (IκBα) (2.56-fold), and MAPK/ERK kinase 1 (MEK1) (7.15-fold) assessed in the array induced by influenza virus. Western blotting showed that the expression of these proteins was significantly decreased in lung after influenza virus challenge in PSF and oseltamivir-treated mice (p < 0.05-0.01).

CONCLUSION

Polygalasaponin F appears to be able to augment protection against IAV infection in mice via attenuation of pulmonary inflammatory responses. Its effect on IAV-induced pulmonary inflammation was associated with suppression of Raf/MEK/ERK and NF-κB expressions.

Two new noroleanane-type triterpenoid saponins from the stems of Stauntonia chinensis

Two new noroleanane-type triterpenoid saponins, 3β,20α,24-trihydroxy-29-norolean-12-en-28-oic acid 24-O-β-L-fucopyranosyl-(1→2)-[β-D-xylopyranosyl-(1→3)]-β-D-glucopyranoside (1) and 3β,20α,24-trihydroxy-29-norolean-12-en-28-oic acid 24-O-β-D-glucopyranosyl-(1→2)-[α-L-arabinopyranosyl-(1→3)]-β-D-glucopyranoside (2) were isolated from the stems of Stauntonia chinensis DC., together with three known compounds, brachyantheraoside B₂ (3), eupteleasaponin Ⅷ (4) and fargoside B (5). Their structures were elucidated by spectroscopic and chemical methods. The cytotoxic activities of compounds 1 and 2 were evaluated against five human tumor cell lines (HCT-116, HepG2, BGC-823, NCI-H1650, and A2780). Compounds 1 and 2 showed moderate cytotoxic activities toward the tested cell lines with IC₅₀ values ranging from 12.71 to 32.04 μM.

Determination of the phytochemical composition of Jingning fang and the in vivo pharmacokinetics of its metabolites in rat plasma by UPLC-MS/MS

Jingning fang (JNF) is an effective Traditional Chinese Medicine (TCM) which is used for the treatment of Attention Deficit Hyperactivity Disorder (ADHD). To clarify the bioactive constituents of JNF, a Thermo Q Exactive™ Plus Orbitrap™ mass spectrometer was used in this study. More than 127 chemical compounds were isolated and identified tentatively in the JNF extract, while 42 prototype constituents with 4 potential metabolites were identified tentatively in rat plasma. A method for simultaneous determination of polygalaxanthone III (PAIII), sibiricose A5 (A5), sibiricose A6 (A6), 3, 6'-disinapoyl sucrose (3,6'-DISS), tenuifoliside C (TEC), tenuifolin B (TNB), verbascoside (VCE), heterophyllin B (HEB) and schisandrin (SCH) in rat was developed and validated using polydatin (PLN) and psoralen (PSN) as internal standards. All calibration curves proved favorable linearity (R2≥0.9923) in linear ranges. The lower limit of quantification (LLOQ) was 2.5ng/mL for PAIII, A5, 3, 6'-DISS, TNB, VCE, HEB and SCH, 1.0ng/mL for A6 and TEC, respectively. Intra-day and inter-day precisions didn't exceed 14.0% for all the analytes. Extraction recoveries and matrix effects of analytes and IS were acceptable. The validated method has been successfully applied to the pharmacokinetics (PK) studies of the nine compounds in JNF. These findings are useful for predicting the bioactive components of JNF, and will aid in optimizing dose regimens of the drug.

Three new coumarin glycosides from the stems of Hydrangea paniculata

Three new coumarin glycosides (1-3), together with three known compounds (4-6), have been obtained from the stems of Hydrangea paniculata Sieb. Their structures were elucidated based on spectroscopic data and chemical evidence. In addition, compounds 1-3 were screened for their neuroprotective effects against serum deprivation-induced PC12 cell damage, hepatoprotective activities against DL-galactosamine-induced toxicity in HL-7702 cells and their ability to inhibit LPS-induced nitric oxide production in the murine microglia BV2 cell line, but they were inactive.

Naturally Occurring Cinnamic Acid Sugar Ester Derivatives

Cinnamic acid sugar ester derivatives (CASEDs) are a class of natural product with one or several phenylacrylic moieties linked with the non-anomeric carbon of a glycosyl skeleton part through ester bonds. Their notable anti-depressant and brains protective activities have made them a topic of great interest over the past several decades. In particular the compound 3′,6-disinapoylsucrose, the index component of Yuanzhi (a well-known Traditional Chinese Medicine or TCM), presents antidepressant effects at a molecular level, and has become a hotspot of research on new lead drug compounds. Several other similar cinnamic acid sugar ester derivatives are reported in traditional medicine as compounds to calm the nerves and display anti-depression and neuroprotective activity. Interestingly, more than one third of CASEDs are distributed in the family Polygalaceae. This overview discusses the isolation of cinnamic acid sugar ester derivatives from plants, together with a systematic discussion of their distribution, chemical structures and properties and pharmacological activities, with the hope of providing references for natural product researchers and draw attention to these interesting compounds.

Polygalasaponin XXXII, a triterpenoid saponin from Polygalae Radix, attenuates scopolamine-induced cognitive impairments in mice

AIM

Recent studies show that the extract of a Chinese herb Polygalae Radix exerts cognition-enhancing actions in rats and humans. The aim of this study was to characterize the pharmacological profiles of active compounds extracted from Polygalae Radix.

METHODS

Two fractions P3 and P6 and two compounds PTM-15 and polygalasaponin XXXII (PGS32) were prepared. Neuroprotective effects were evaluated in primary cortical neurons exposed to high concentration glutamate, serum deficiency or H2O2. Anti-dementia actions were assessed in scopolamine-induced amnesia in mice using step-through avoidance tests and channel water maze tests. After conducting the channel water maze tests, TrkB phosphorylation in mouse hippocampus was detected using Western blotting. Long-term potentiation (LTP) was induced in the dentate gyrus in adult rats; PGS32 (5 μL 400 μmol/L) was injected into the lateral cerebral ventricle 20 min after high frequency stimulation (HFS).

RESULTS

Compared to the fraction P6, the fraction P3 showed more prominent neuroprotective effects in vitro and cognition-enhancing effects in scopolamine-induced amnesia in mice. One active compound PGS32 in the fraction P3 exerted potent cognition-enhancing action: oral administration of PGS32 (0.125 mg·kg(-1)·d(-1)) for 19 days abolished scopolamine-induced memory impairment in mice. Furthermore, PGS32 (0.5 and 2 mg·kg(-1)·d(-1)) significantly stimulated the phosphorylation of TrkB in the hippocampus. Intracerebroventricular injection of PGS32 significantly enhanced HFS-induced LTP in the dentate gyrus of rats.

CONCLUSION

PGS32 attenuates scopolamine-induced cognitive impairments in mice, suggesting that it has a potential for the treatment of cognitive dysfunction and dementia.

Identification of novel autophagic Radix Polygalae fraction by cell membrane chromatography and UHPLC-(Q)TOF-MS for degradation of neurodegenerative disease proteins

With its traditional use in relieving insomnia and anxiety, our previous study has identified onjisaponin B from Radix Polygalae (RP), as a novel autophagic enhancer with potential neuroprotective effects. In current study, we have further identified a novel active fraction from RP, contains 17 major triterpenoid saponins including the onjisaponin B, by the combinational use of cell membrane chromatography (CMC) and ultra-performance liquid chromatography coupled to (quadrupole) time-of-flight mass spectrometry {UHPLC-(Q)TOF-MS}. By exhibiting more potent autophagic effect in cells, the active fraction enhances the clearance of mutant huntingtin, and reduces protein level and aggregation of α-synuclein in a higher extent when compared with onjisaponin B. Here, we have reported for the first time the new application of cell-based CMC and UHPLC-(Q)TOF-MS analysis in identifying new autophagy inducers with neuroprotective effects from Chinese medicinal herb. This result has provided novel insights into the possible pharmacological actions of the active components present in the newly identified active fraction of RP, which may help to improve the efficacy of the traditional way of prescribing RP, and also provide new standard for the quality control of decoction of RP or its medicinal products in the future.

Three new compounds from the leaves of Liquidambar formosana

Two new flavan glycosides, (2S)-5,7,4'-trihydroxyflavan-7-O-β-D-glucopyranoside and (2S)-5,7,4'-trihydroxyflavan-5-O-β-D-glucopyranoside, and a new neolignan, (7S,8S)-3-methoxyl-3'-O-β-D-glucopyrannosyl-4':8,5':7-diepoxyneolignan-4,9'-diol, were isolated from the leaves of Liquidambar formosana Hance. Their structures were elucidated on the basis of spectroscopic data and chemical evidence.

Analysis of multiple constituents in Cong-Ming-Tang, a Chinese herbal formula for the treatment of amnesia, by high-performance liquid chromatography with quadrupole time-of-flight mass spectrometry

INTRODUCTION

Cong-Ming-Tang (CMT), named smart-soup in English, is a well-known traditional Chinese medicine formula for the treatment of amnesia in China. However, the isolation, purification and identification procedures of the major bioactive constituents in CMT are difficult and time consuming.

OBJECTIVE

To establish a rapid and sensitive high-performance liquid chromatography/electrospray ionisation with quadrupole time-of-flight tandem mass spectrometry (HPLC-QTOF/MS/MS) method that could be applied to rapidly separate and identify the major bioactive constituents in CMT.

METHODS

Methanolic extract of CMT was used for HPLC-QTOF/MS/MS analysis. Separation was performed on an Agilent Poroshell 120 EC- C18 column (2.7 ×100 mm .i.d., 2.7 µm) with 0.1% formic acid aqueous solution and acetonitrile as the mobile phase under gradient conditions. Both positive and negative ion modes were employed.

RESULTS

This analytical tool allowed the identification of 55 compounds from CMT formulae by comparing their retention times and MS spectra with those of authentic compounds or literature data in both positive and negative ion modes, including 4 xanthone C-glycosides, 4 sucrose esters, 11 oligosaccharide multi-esters,15 triterpene saponins, 15 triterpene acids, 2 lignans and 4 phenylpropanoids. Onjisaponin MF was tentatively elucidated as a new triterpene saponin based on the summarised fragmentation rules.

CONCLUSION

HPLC-QTOF/MS/MS provides a new powerful approach to identify the major chemical constituents in CMT rapidly and accurately. This study proposed a series of potential bioactive components without preparative isolation from the crude extract of CMT and indicated that the HPLC-QTOF/MS/MS method also can be a promising tool for the analysis of other traditional Chinese medicines.

A new protopanaxadiol-type ginsenoside from the roots of Panax notoginseng

A new protopanaxadiol-type ginsenoside, 6-O-β-d-glucopyranosyl-20-O-β-d-glucopyranosyl-20(S)-protopanaxadiol-3-one (1), along with three known compounds, was isolated from the roots of Panax notoginseng. Their structures were determined based on some pieces of spectroscopic and chemical evidence. Compound 1 exhibited cytotoxic activity against five human cancer cell lines, with IC50 values ranging from 5.4 to 8.6 μg/ml.

Potential anti-inflammatory constituents of the stems of Gordonia chrysandra

Eight new oleanane-type triterpenoid glycosides, gordonosides I-P (1-8), and two new phenolic glycosides (9 and 10) were isolated from the stems of Gordonia chrysandra. Their structures were elucidated by spectroscopic and chemical methods. In an in vitro bioassay, compound 1 showed a strong inhibitory effect on nitric oxide production in LPS-activated macrophages with an IC50 value of 0.14 μM.

Acylated triterpene saponins from the roots of Securidaca longepedunculata

Four triterpene saponins, 3-O-beta-D-glucopyranosylpresenegenin 28-O-beta-D-apiofuranosyl-(1-->3)-beta-d-xylopyranosyl-(1-->4)-[beta-D-apiofuranosyl-(1-->3)]-alpha-L-rhamnopyranosyl-(1-->2)-{4-O-[(E)-3,4,5-trimethoxycinnamoyl]}-beta-D-fucopyranosyl ester, 3-O-beta-D-glucopyranosylpresenegenin 28-O-beta-D-apiofuranosyl-(1-->3)-beta-D-xylopyranosyl-(1-->4)-[beta-D-apiofuranosyl-(1-->3)]-alpha-L-rhamnopyranosyl-(1-->2)-[(6-O-acetyl)-beta-D-glucopyranosyl-(1-->3)]-{4-O-[(E)-3,4,5-trimethoxycinnamoyl]}-beta-D-fucopyranosyl ester, 3-O-beta-D-glucopyranosylpresenegenin 28-O-beta-D-apiofuranosyl-(1-->3)-beta-D-xylopyranosyl-(1-->4)-[beta-D-apiofuranosyl-(1-->3)]-alpha-L-rhamnopyranosyl-(1-->2)-[beta-D-galactopyranosyl-(1-->3)]-{4-O-[(E)-3,4,5-trimethoxycinnamoyl]}-beta-D-fucopyranosyl ester, and 3-O-beta-D-glucopyranosylpresenegenin 28-O-beta-D-apiofuranosyl-(1-->3)-[alpha-L-arabinopyranosyl-(1-->4)]-beta-D-xylopyranosyl-(1-->4)-[beta-D-apiofuranosyl-(1-->3)]-alpha-L-rhamnopyranosyl-(1-->2)-{4-O-[(E)-3,4,5-trimethoxycinnamoyl]}-beta-D-fucopyranosyl ester, were isolated from the roots of Securidaca longepedunculata, together with three known compounds. Their structures were established mainly by 2D NMR techniques and mass spectrometry.

Polygalasaponin XXXII from Polygala tenuifolia root improves hippocampal-dependent learning and memory

AIM

The aim of this study was to investigate the cognition-enhancing activity and underlying mechanisms of a triterpenoid saponin (polygalasaponin XXXII, PGS32) isolated from the roots of Polygala tenuifolia Willd.

METHODS

The Morris water maze was used to evaluate the spatial learning and memory of mice. To detect the basic properties of synaptic transmission and long-term potentiation (LTP) in the dentate gyrus of rats, electrophysiological recordings were made of evoked potentials. Western blotting analysis and immunofluorescence assays were used to determine the phosphorylation of extracellular signal-regulated kinase (ERK), cAMP response element-binding protein (CREB), synapsin I and the expression of brain derived neurotrophic factor (BDNF).

RESULTS

When administered at 0.125, 0.5, or 2 mg/kg, PGS32 could significantly prevent scopolamine-induced cognitive impairments in mice. Intracerebroventricular (icv) administration of PGS32 greatly enhanced basic synaptic transmission in the dentate gyrus of rats and induced LTP. In primary hippocampal neurons, as well as in the hippocampus of maze-trained mice, PGS32 activated the mitogen-activated protein (MAP) kinase cascade by promoting phosphorylation of ERK, CREB and synapsin I. The expression of BDNF was also greatly enhanced in the hippocampus.

CONCLUSION

Our findings suggest that PGS32 can improve hippocampus-dependent learning and memory, possibly through improvement of synaptic transmission, activation of the MAP kinase cascade and enhancement of the level of BDNF. Therefore, PGS32 shows promise as a potential cognition-enhancing therapeutic drug.

A novel triterpenoid saponin from Polygala tenuifolia Willd

A new triterpenoid saponin, tenuifoside A, was isolated together with three known triterpenoid saponins 2, 3, and 4 from the roots of Polygala tenuifolia Willd. With the help of chemical and spectral analyses (IR, MS, 1D-NMR, and 2D-NMR), the structure of the new saponin was elucidated as 3-O-beta-d-glucopyranosyl presenegenin 28-O-beta-d-xylopyranosyl-(1 --> 3)-beta-d-xylopyranosyl-(1 --> 4)-[beta-D-apiofuranosyl-(1 --> 3)]-alpha-L-rhamnopyranosyl-(1 --> 2)-[4-O-p-methoxycinnamoyl]-[alpha-l-rhamnopyranosyl-(1 --> 3)]-beta-d-fucopyranosyl ester (1). Three known triterpenoid saponins (2-4) were identified on the basis of spectroscopic data.

Oligosaccharide polyester and triterpenoid saponins from the roots of Polygala japonica

An oligosaccharide polyester, 1-O-(E)-p-coumaroyl-(3-O-benzoyl)-beta-D-fructofuranosyl-(2-->1)-[6-O-(E)-feruloyl-beta-D-glucopyranosyl-(1-->2)]-[6-O-acetyl-beta-D-glucopyranosyl-(1-->3)-(4-O-acetyl)-beta-D-glucopyranosyl-(1-->3)]-4-O-[4-O-alpha-L-rhamnopyranosyl-(E)-p-coumaroyl]-alpha-D-glucopyranoside (polygalajaponicose I), and four triterpenoid saponins, 3beta, 23, 27-trihydroxy-29-O-beta-D-glucopyranosyl-(1-->2)-beta-D-glucopyranosyl-olean-12-en-28-oic acid (polygalasaponin XLVII), 3-O-beta-D-glucopyranosyl presenegenin 28-O-alpha-L-rhamnopyranosyl-(1-->2)-beta-D-fucopyranosyl ester (polygalasaponin XLVIII), 3-O-beta-D-glucopyranosyl presenegenin 28-O-beta-D-galactopyranosyl-(1-->5)-beta-D-apiofuranosyl-(1-->4)-beta-D-xylopyranosyl-(1-->4)-alpha-L-rhamnopyranosyl-(1-->2)-beta-D-glucopyranosyl ester (polygalasaponin XLIX) and 2beta, 27-dihydroxy-3-O-beta-D-glucopyranosyl 11-oxo-olean-12-en-23, 28-dioic acid 28-O-beta-D-galactopyranosyl-(1-->5)-beta-D-apiofuranosyl-(1-->4)-beta-D-xylopyranosyl-(1-->4)-alpha-L-rhamnopyranosyl-(1-->2)-beta-D-fucopyranosyl ester (polygalasaponin L), in addition to five known compounds have been isolated from the roots of Polygala japonica.

Anti-inflammatory activities of triterpenoid saponins from Polygala japonica

Bioassay-guided investigation was performed to identify the active constituents from a methanol extract of Polygala japonica, a folk medicinal plant widely used in China to treat inflammatory diseases. The n-BuOH and EtOAc fractions of the P. japonica methanol extract, which show significant anti-inflammatory activity in in vivo test, were further subjected to column chromatography to afford six triterpene glycosides, marked here as saponins 1-6. All compounds were evaluated for their anti-inflammatory activity in the carageenan-induced mouse paw edema test, and saponins 1, 4 and 5 showed significantly anti-inflammatory effects on both phases of carageenan-induced acute paw edema in mice. Saponin 5 was also found to significantly inhibit the production of inflammatory mediators - nitric oxide (NO) in LPS-stimulated RAW264.7 macrophages, with no obvious effects on macrophage viability.

Quality evaluation of Polygala japonica through simultaneous determination of six bioactive triterpenoid saponins by HPLC-ELSD

Polygala japonica Houtt (Polygalaceae), a traditional Chinese herb, has been used as expectorant, anti-inflammatory, antibacterial and antidepressant agent. To evaluate the quality of P. japonica, a high performance liquid chromatography (HPLC) with evaporative light scattering detector (ELSD) method was developed for the simultaneous determination of six active triterpenoid saponins. With a Discovery C(18) analytical column, the analytes were separated efficiently using acetonitrile-methanol-0.05% trifluoroacetic acid (TFA) as mobile phase in a gradient program. The evaporator tube temperature of ELSD was set at 105 degrees C, and with the nebulizing gas flow-rate of 2.6l/min. All calibration curves showed good linear regression (gamma>0.9991) within the tested range. Additionally, reproducibility for the quantification of six saponins in P. japonica with intra- and inter-day variations of less than 5.0% was observed. Quantification of the six active saponins in P. japonica from different locations was performed by this newly developed method, which provides a new tool for the assessment of quality of P. japonica.

New acylated triterpene saponins from Polygala tenuifolia willd

Two new acylated presenegenin glycosides E-onjisaponin H (5) and Z-onjisaponin (6) together with seven known saponins were isolated from the roots of Polygala tenuifolia Willd. Compounds 5 and 6 were obtained as a pair of isomers due to trans and cis-p-methoxycinnamoyl. Their structures were elucidated mainly by 2D-NMR techniques including 1H-1HCOSY, TOCSY, HSQC, HMBC as 3-O-(beta-D-glucopyranosyl) presenegenin 28-[O-beta-D-apiofuranosyl-(1 --> 3)-O-[beta-D-xylopyranosyl-(1 --> 4)]-O-alpha-L-rhamnopyranosyl-(1 --> 2)-O-[alpha-L-rhamnopyranosyl-(1 --> 3)]-4-O-[(E)-p-methoxycinnamoyl]-beta-D-fucopyranosyl] ester (5) and its (Z)-isomer (6).

A new cerebroside from Polygala japonica

The isolation of a new cerebroside, 1-O-beta-d-glucopyranosyl-(2S,3S,4R,11E)-2-[(2'R)-2'-hydroxypalmitoylamino]-11-octadecene-1,3,4-triol (polygalacerebroside) (1), from the aerial part of Polygala japonica is reported.

Xanthone O-glycosides from Polygala tenuifolia

Four xanthone O-glycosides, polygalaxanthones IV-VII were isolated from the roots of Polygala tenuifolia Willd., together with eight known compounds. The structures of the four xanthone O-glycosides were established as 6-O-[alpha-L-rhamnopyranosyl-(1-->2)-beta-D-glucopyranosyl]-1-hydroxy-3,7-dimethoxyxanthone (polygalaxanthone IV), 6-O-[alpha-L-rhamnopyranosyl-(1-->2)-beta-D-glucopyranosyl]-1,3-dihydroxy-7-methoxyxanthone (polygalaxanthone V), 6-O-(beta-D-glucopyranosyl)-1,2,3,7-tetramethoxyxanthone (polygalaxanthone VI), and 3-O-[alpha-D-rhamnopyranosyl-(1-->2)-beta-D-glucopyranosyl]-1,6-dihydroxy-2,7-dimethoxyxanthone (polygalaxanthone VII), respectively, on the basis of analysis of spectroscopic evidence.

Polygalasaponins XLII-XLVI from roots of Polygala glomerata

Five new oleanane-type saponins, polygalasaponins XLII-XLVI, along with two known saponins were isolated from the roots of Polygala glomerata Lour. The structures of polygalasaponins XLII-XLVI were elucidated as 3-O-beta-D-glucopyranosyl presenegenin 28-O-beta-D-xylopyranosyl-(1-->4)-alpha-L-rhamnopyranosyl- (1-->2)-{4-O-[(E)-3,4-dimethoxycinnamoyl]}-beta-D-fucopyranosyl ester, 3-O-beta-D-glucopyranosyl presenegenin 28-O-beta-D-galactopyranosyl-(1-->4)-beta-D-xylopyranosyl-(1-->4)- alpha-L-rhamnopyranosyl-(1-->2)-[alpha-L-arabinopyranosyl- (1-->3)]-[4-O-(E)-p-methoxycinnamoyl]-beta-D-fucopyranosyl ester, 3-O-beta-D-glucopyranosyl presenegenin 28-O-beta-D-galactopyranosyl-(1-->4)-beta-D-xylopyranosyl-(1-->4)- alpha-L-rhamnopyranosyl-(1-->2)-[beta-D-glucopyranosyl- (1-->3)]-{4-O-[(E)-3,4-dimethoxycinnamoyl]}-beta-D-fucopyranosyl ester, 3-O-beta-D-glucopyranosyl presenegenin 28-O-beta-D-galactopyranosyl-(1-->4)-beta-D-xylopyranosyl-(1-->4)- alpha-L-rhamnopyranosyl-(1-->2)-[6-O- acetyl-beta-D-glucopyranosyl-(1-->3)]-{4-O- [(E)-3,4-dimethoxycinnamoyl]}-beta-D-fucopyranosyl ester, 3-O-beta-D- glucopyranosyl presenegenin 28-O-beta-D-galactopyranosyl-(1-->4)- beta-D-xylopyranosyl-(1-->4)-alpha-L-rhamnopyranosyl- (1-->2)-[6-O-acetyl-beta-D-glucopyranosyl-(1-->3)]-{4-O-[(Z)-3, 4-dimethoxycinnamoyl]}-beta-D-fucopyranosyl ester, respectively, on the basis of spectroscopic and chemical evidence.