Dammarane Glycosides Research Articles

Two new triterpenoid glycosides from leaves of Cyclocarya paliurus

Two dammarane glycosides (1-2) were isolated from the leaves of Cyclocarya paliurus. The structures of new compounds were established by application of spectroscopic methods, including one-dimensional and two-dimensional NMR, HRESIMS, and chemical hydrolysis. When evaluated against seven human cancer cell lines, the two compounds exhibited selective cytotoxicity to MCF-7 cells.

New dammarane-type triterpenoid glycosides from Gynostemma burmanicum

The chemical composition of Gynostemma burmanicum King ex Chakrav. was investigated for the first time in this study. Nine dammarane glycosides (1‒9) were isolated from the EtOH extract of the aerial parts of G. burmanicum. Their structures were elucidated by 1D and 2D NMR spectroscopic interpretation as well as by chemical studies. The new compounds were 3β,20S-dihydroxydammar-24-ene-3-O-β-D-glucopyranosyl-20-O-[β-D-xylopyranosyl-(1→6)-β-D-glucopyranoside] (1), 3β,12β,20S-trihydroxydammar-24-ene-3-O-β-D-xylopyranosyl-20-O-[β-D-xylopyranosyl-(1→6)-β-D-glucopyranoside] (2), and 12-oxo-3β,20S-dihydroxydammar-24-ene-3-O-[β-D-glucopyranosyl(1→2)-β-D-glucopyranosyl]-20-O-[β-D-xylopyranosyl-(1→6)-β-D-glucopyranoside] (3).

Insulin Mimetic Activity of 3,4- Seco and Hexanordammarane Triterpenoids Isolated from Gynostemma longipes.

As part of ongoing research to find new antidiabetic agents from medicinal plants, the chemical composition of Gynostemma longipes, an ethnomedicinal plant used to treat type 2 diabetes mellitus by local communities in Vietnam, was investigated. Ten new dammarane triterpenes, including two 3,4- seco-dammarane analogues, secolongipegenins S1 and S2 (1 and 2), a 3,4- seco-hexanordammarane, secolongipegenin S3 (3), two hexanordammarane glycosides, longipenosides ND1 and ND2 (4 and 5), and five other dammarane glycosides, longipenosides GL1-GL5 (6-10), were isolated from a 70% EtOH extract of the whole G. longipes plant. The structures of the new compounds were elucidated using diverse spectroscopic methods. All of the isolates were evaluated for their stimulatory activities on glucose uptake in differentiated 3T3-L1 adipocyte cells using 2-[ N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl)amino]-2-deoxy-d-glucose as a fluorescent-tagged glucose probe. The stimulant activities on glucose uptake by the test compounds were mediated via the activation of the AMPK pathway using differentiated mouse C2C12 skeletal myoblasts. Consequently, compounds 1, 2, and 4 enhanced glucose uptake and GLUT4 translocation significantly by regulating the AMPK signaling pathway.

Transformation of Ginsenosides from Notoginseng by Artificial Gastric Juice Can Increase Cytotoxicity toward Cancer Cells

Multicomponent metabolic profile of notoginseng saponins in artificial gastric juice was qualitatively and quantitatively investigated, showing that ginsenosides were transformed via multiple pathways including deglycosylation, dehydration, hydration, and oxygenation. A total of 83 metabolites was identified by using UPLC-Q-TOF-MS, among which 16 new dammarane glycosides were further characterized by comparing with synthesized authentic compounds. Transformation time-course of notoginseng saponins in artificial gastric juice was quantitatively measured for the first time, showing rapid degradation of primary ginsenosides and concomitant formation of deglycosylation, hydration, and dehydration products. It was further demonstrated that the resultant metabolites exhibited enhanced cytotoxicity toward cancer cells. The extensive metabolism of ginsenosides within a transit time span in stomach, together with the formation of metabolites with diversified chemical structures possessing enhanced biological activities, indicated an important role of transformation in gastric juice in the systematic effects of ginsenosides.

Dammarane-type saponins from Gynostemma pentaphyllum

Seven dammarane glycosides, gypenosides GC1 to GC7, together with ten known compounds, gypenosides V, XIV, XLII–XLVI, gynosaponins TN-1, -2, and gymnemaside VI, were isolated from the methanol extract of the aerial parts of Gynostemma pentaphyllum. Their structures were elucidated by both analysis of 1D and 2D NMR spectra and chemical degradation.

Three new dammarane glycosides from Betula alnoides

Twenty compounds including three new dammarane glycosides, named betalnoside A ( 7), betalnoside B ( 8), and betalnoside C ( 11) were isolated from Betula alnoides Buch. -Ham. ex D. Don (Betulaceae), of which 13 ( 1– 13) were from the leaves, seven ( 14– 20) from the stem bark, and three ( 2, 16, and 17) from the twigs. Their structures were determined using spectroscopic analyses.

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.

Glycosides of 20-Deoxy Derivatives of Jujubogenin and Pseudojujubogenin from Bacopa monniera

A detailed phytochemical investigation of an extract of Bacopa monniera resulted in the isolation of two new dammarane glycosides along with eight known compounds. They have been identified as glycosides of the 20-deoxy derivatives of jujubogenin and pseudojujubogenin. The structures were established by different spectroscopic methods that included 1D and 2D NMR experiments. The compounds were tested for their cytotoxicity, antileishmanial, antimalarial, antioxidant, and anti-inflammatory activities. Only few compounds exhibited mild to moderate cytotoxicity towards non-cancerous kidney cell lines.

Triterpene Saponins from Gynostemma cardiospermum

Six new dammarane glycosides (1-6) and four known compounds, rutin, kaempferol, quercetin, and linalool 3-O-beta-D-glucopyranoside, were isolated from an ethanol extract of the aerial parts of Gynostemma cardiospermum. The structures of 1-6 were elucidated by 1D and 2D NMR spectroscopic interpretation as well as by chemical degradation. Triterpene aglycons containing carbonyl groups at both C-21 and C-28, as found in compounds 1-5, are being reported in the family Cucurbitaceae for the first time.

New Dammarane Triterpenoidal Saponins from Bacopa monniera

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Dammarane and Ceanothane Triterpenes from Zizyphus glabrata

From the leaves of Zizyphus glabrata, a new dammarane-type triterpene, pseudojujubogenin -3-O- β -D-glucopyranoside, along with the known ceanothane triterpenes, granulosic acid, ceanothic acid and daucosterol were isolated. The structures of the compounds were fully characterized by detailed NMR investigations including 1H and 13C NMR, HSQC, COSY, HMBC and NOESY experiments. In addition, the dammarane glycoside was tested for its potential to inhibit various bacteria and was found to possess significant bactericidal activity. The 1H, 13C and full 2D-NMR data on granulosic acid has also been presented. This is the first report on the chemical constituents of the leaves of Z. glabrata.

A Dammarane Glycoside Derived from Ginsenoside Rb3

A dammarane glycoside, designated compound Mx (C-Mx), was isolated from the hydrolysate of 20(S)-protopanaxadiol type ginsenosides containing G-Rb(3) from Panax notoginseng leaves with crude snailase. Its chemical structure was elucidated to be 20-O-beta-D-xylopyranosyl(1-->6)-beta-D-glucopyranosyl-20(S)-protopanaxadiol on the basis of spectral analysis. Its cytotoxicity against breast cancer cell line MCF-7 and effects on the sensitivity to doxocubicin of doxocubicin-resistant MCF-7 cells were also investigated. The new compound showed moderate cytotoxicity and partial reversal of doxocubicin resistance.

Dammarane-type glycosides from Gynostemma pentaphyllum.

Fifteen new dammarane glycosides (1-15), together with four known compounds, gypenosides IV, VIII, LXXI, and XLIX, were isolated from the MeOH extract of the aerial parts of Gynostemma pentaphyllum. Their structures were elucidated by 1D and 2D NMR spectra interpretation as well as by chemical degradation.

Hydrolytic Reaction of Plant Extracts to Generate Molecular Diversity: New Dammarane Glycosides from the Mild Acid Hydrolysate of Root Saponins of Panax notoginseng

AbstractMolecular diversity was generated by hydrolyzing the crude root saponins of Panax notoginseng (Burk.) F. H. Chen under mild acidic condition (AcOH/EtOH 1 : 1). From the acid hydrolysate, five new dammarane glycosides, named notoginsenoside T1 (=(3β,6α,12β,20E,23RS)‐24,25‐epoxy‐6‐[(β‐D‐glucopyranosyl)oxy]‐dammar‐20(22)‐ene‐3,12,23‐triol; 1), notoginsenoside T2 (=(3β,6α,12β,20E,23RS)‐24,25‐epoxy‐6‐[(β‐D‐glucopyranosyl)oxy]‐23‐methoxydammar‐20(22)‐ene‐3,12‐diol; 2), notoginsenoside T3 (=(3β,6α,12β,20S)‐6‐[(β‐D‐glucopyranosyl)oxy]‐20‐ethoxydammar‐24‐ene‐3,12‐diol; 3), notoginsenoside T4 (=(3β,6α,12β,20S,22E,24RS)‐6‐[(β‐D‐glucopyranosyl)oxy]dammar‐22‐ene‐3,12,20,24,25‐pentol; 4), and notoginsenoside T5 (=(3β,6α,12β, 24E)‐6‐[(β‐D‐xylopyranosyl‐(1→2)‐β‐D‐glucopyranosyl)oxy]dammara‐20(21),24‐diene‐3,12‐diol; 5), were isolated, together with 15 known dammarane glycosides, and their structures were elucidated on the basis of spectroscopic evidence. Among the known compounds, ginsenosides Rg3 and Rh1 were isolated as major constituents, in addition to ginsenosides Rg5, Rh4, and a mixture of (20R)‐ and (20S)‐25‐hydroxyginsenoside Rh1, all of which were obtained from P. notoginseng for the first time.

Novel Dammarane-Type Glycosides from Gynostemma pentaphyllum

Three new dammarane glycosides (1-3), together with five known compounds, gypenoside LXIX (4), gylongiposide I (5), gypenoside XLVIII (6), allantion (7) and vitexin (8) were isolated from the MeOH extract of the aerial parts of Gynostemma pentaphyllum. Compounds 5, 7, and 8 were isolated from this plant for the first time. Their structures were elucidated by 1D and 2D NMR spectra interpretation as well as by chemical degradation.

Three new dammarane glycosides from heat processed ginseng.

Three new dammarane glycosides were isolated from the processed ginseng (SG; Sun Ginseng). Their structure were determined to be 3beta,12beta-dihydroxydammar-20(21),24-diene-3-O-beta-D-glucopyranosyl(1 --> 2)-beta-D-glucopyranoside; 3beta,12beta-dihydroxydammar-20(21),24-diene-3-O-beta-D- glucopyranoside and 3beta,6alpha,12beta-trihydroxydammar-20(21),24-diene-6-O-beta-D-glucopyranoside based on spectroscopic evidences. The compounds were named as ginsenoside Rk1, Rk2, and Rk3 respectively.

Cytotoxic dammarane glycosides from processed ginseng.

Steaming ginseng at high temperature increased its cytotoxicity to SK-Hep-1 hepatoma cancer cells. HPLC separation and fractionation followed by MTT assay revealed that ginsenosides Rg3, Rg5, Rk1, Rs5, and Rs4 are the active principles. Their 50% growth inhibition concentration (GI50) values were 41, 11, 13, 37, and 13 microM, respectively. Cisplatin had a GI50 of 84 microM in the same assay conditions.

Leaves of North American ginseng, Panax quinquefolius L.: A renewable source of certain ginsenosides

Quantities of both malonylated and non-malonylated ginsenosides in mature P. quinquefolius leaves were determined weekly near the end of the growing season (late September–early October). Ginsenosides Rb3, mRb3, Rd, mRd, and Re were the major dammarane glycoside components observed in the leaf extracts. Levels of total ginsenosides remained high throughout the period studied when leaf harvest would be expected to have little effect on the roots. Only ginsenoside PG-F,11 appeared to decrease with the approach of leaf senescence. It is concluded that P. quinquefolius leaves represent an excellent source of certain ginsenosides. Key words: Panax quinquefolius, ginseng, leaf ginsenosides

Dammarane derivatives protect cultured rat cortical cells from glutamate-induced neurotoxicity.

We previously reported that ginsenosides Rb1 and Rg3, dammarane glycosides, of Panax ginseng C. A. Meyer (Araliaceae), significantly attenuated glutamate-induced neurotoxicity in primary cultures of rat cortical cells. To seek more potent neuroprotective compounds, we attempted to modify the chemical structure of dammarane glycosides and obtained six derivatives, MA-11, PT-11, PT-111, POA-101, POA-111 and N-001. The neuroprotective activity of these dammarane derivatives were evaluated employing primary cultures of rat corticoid cells. The glutamate-induced neuronal cell damage was significantly reduced by a pre-treatment with protopanaxadiol, MA-11 or PT-11 at concentrations ranging from 100 nM to 10 microM. Both MA-11 and PT-11, preserved the levels of catalase and inhibited decreases in glutathione reductase in glutamate-injured cells. Furthermore, the dammarane derivatives reduced the content of intracellular peroxide in glutamate-intoxicated cells. Finally, they inhibited the formation of malondialdehyde, a compound produced during lipid peroxidation, in glutamate-insulted cells. These results show that the dammarane derivatives, MA-11 and PT-11, exert significant neuroprotective effects on cultured cortical cells by a mechanism seemingly distinct from that afforded by ginsenosides Rb1 and Rg3. As such, the dammarane derivatives may be efficacious in protecting neurons from oxidative damage caused by exposure to excess glutamate.

Ginsenoside Rf2, a new dammarane glycoside from Korean red ginseng (Panax ginseng).

A new dammarane glycoside named ginsenoside Rf2 has been isolated from Korean red ginseng (Panax ginseng) and its chemical structure has been elucidated as 6-O-[alpha-L-rhamnopyranosyl (1-->2) beta-D-glucopyranosyl]dammarane-3 beta, 6 alpha, 12 beta, 20(R), 25-pentol by chemical and spectral methods.