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New Dammarane-type Glycosides from Gynostemma pentaphyllum
Abstract
Four novel dammarane glycosides were isolated from a MeOH extract of the aerial parts of Gynostemma pentaphyllum. Their structures were elucidated by 1D and 2D nmr experiments, including 1H-1H correlation spectroscopy (COSY, HOHAHA, NOESY) and 1H-13C heteronuclear correlation (HETCOR). The aglycone moieties are the new dammarane-type triterpenes (20S)-3 beta,20,23 xi-trihydroxydammar-24-en-21-oic acid-21,23-lactone for 1, the corresponding epimer at C-20(20R) for 2, (20S)-dammar-23-ene-3 beta-20,25,26- tetraol for 3, and (20R)-dammar-25-ene-3 beta,20,21,24 xi-tetraol for 4.
... Attachment of the glycosidic chain at C-3 was indi- cated by the signi®cant down®eld shift (d 90.60) observed for this carbon in 1±4 relative to the corre- sponding signal in similar compounds ( Kojima et al., 1987) and was subsequently con®rmed by 2D NMR experiments (Piacente, Pizza, De Tommasi, & De Simone, 1995). Acid methanolysis of 1 gave glucose, xylose and arabinose in ratio 2:1:1. ...
... COSY and HOHAHA permitted assignments of all spin correlations from H-1 to H-6 of the glucose unit and H-1 to H-5 of the xylose and arabinose units. These data, together with results obtained from HSQC and literature data (De Tommasi, Piacente, De Simone, Pizza, & Zhou, 1993;Piacente et al., 1995), established that the xylose and one glucose units were terminal, while glycosidation shifts were observed for C-2 and C-3 of glucose and C-2 of arabinose. The position of the sugar residues were unambiguously de®ned by 1D-ROESY exper- iments. ...
... Thus, the term- inal glucose and xylose were linked respectively to C-2 of arabinose and C-3 of glucoseI. Chemical shifts, mul- tiplicities, coupling constants and magnitude in the 1 H NMR spectrum, as well as 13 C NMR data indicated the b-con®guration at the anomeric positions for the xylose and glucose units, and the a-con®guration for arabinose ( Piacente et al., 1995). ...
Four new triterpene saponins were isolated from the methanol extract of the aerial parts of Alternanthera repens. Their structures have been elucidated using a combination of 1D and 2D NMR techniques as 2α,3β-dihydroxyurs-12,20(30)-dien-28 oic acid 3-O-{O-β-d-glucopyranosyl-(1→2)-O-α-l-arabinopyranosyl-(1→2)-O-[β-d-xylopyranosyl-(1→3)]β-d-glucopyranoside}; 2α,3β-dihydroxyurs-12,20(30)-dien-28 oic acid 3-O-{O-β-d-quinovopyranosyl-(1→2)-O-α-l-arabinopyranosyl-(1→2)-O-[β-d-xylopyranosyl-(1→3)]β-d-glucopyranoside}; 2α,3β-dihydroxyurs-12,20(30)-dien-28 oic acid 3-O-{O-α-l-arabinopyranosyl-(1→2)-O-[β-d-xylopyranosyl-(1→3)]β-d-glucopyranoside}; 2α,3β-dihydroxyurs-12,20(30)-dien-28 oic acid 3-O-{O-β-d-xylopyranosyl-(1→3)-β-d-glucopyranoside}.
... Chemical shifts of H-1 glc (δ 5.35) and C-1 glc (δ 95.4) indicated that this sugar unit was involved in an ester linkage with the C-28 carboxylic group. 18 The positions of the sugar residues in 1 were defined unambiguously by the HMBC experiment. 19 A cross-peak due to long-range correlations between C-3 (δ 90.5) of the aglycon and H-1 ara (δ 4.44) indicated that arabinose was the residue linked to C-3 of the aglycon; a cross-peak between C-2 ara (δ 76.3) and H-1 of the rhamnose I (δ 5.17) indicated that rhamnose was the second unit; and a crosspeak between C-3 rha I (δ 80.4) and H-1 of terminal glucose (δ 4.51) indicated that glucose was the third unit of the trisaccharide chain at C-3 of the aglycon. ...
... MHz for 13 C, and the UX-NMR software package was used for NMR measurements in CD3-OD solutions. The 2D experiments, 1 H-1 H DQF-COSY, 12 2D HOHAHA, 23 inverse detected 1 H-13 C HSQC, 16 HMBC, 18 and ROESY, 11 were obtained using UX-NMR software. 1D TOC-SY 10 spectra were acquired using waveform generator-based GAUSS shaped pulses, mixing time ranging from 100 to 120 ms and a MLEV-17 spin-lock field of 10 kHz preceded by a 2.5-ms trim pulse. ...
During the course of a study of plants of the family Araliaceae, antiproliferative activity was demonstrated by the crude saponin fraction of Trevesia palmata, After chromatographic purification, six near bisdesmosidic saponins (1-6), along with two known triterpenoid saponins, (7 and 8), were isolated. The structures of 1-6 were determined by H-1-H-1 correlation spectroscopy (COSY-DQF, 1D, TOCSY, 2D HOHAHA, 1D ROESY) and H-1-C-13 (HSQC, HMBC) spectroscopy. The antiproliferative activity of compounds 1-8 and of their prosapogenins (2a-7a) prepared by alkaline hydrolysis, was evaluated using three continuous culture cell lines.
... Characterisation of the aglycone has also been achieved with alkaline cleavage of the gypenosides and gas chromatography-MS (GC-MS) with trimethylsilated aglycones (Cui et al., 1998(Cui et al., , 1999. Spectral methods such as 1 H-1 H twodimensional 1 H correlation spectroscopy (COSY), 13 C distortionless enhancement by polarisation transfer (DEPT), homonuclear Hartmann-Hahn spectroscopy (HOHAHA), nuclear overhauser enhancement spectroscopy (NOESY), 13 C-1 H heteronuclear correlated spectroscopy (HETCOR) (Piacente et al., 1995), heteronuclear multiplequantum correlation (HMQC), heteronuclear multiple bond correlation (HMBC) and total correlation spectroscopy (TOCSY) NMR spectra and fast atom bombardment (FAB)-MS have also been applied to identify the chemical structure of intact saponins, thus avoiding the use of degradation methods (Hu et al., 1996. ...
... In a multicenter clinical trial of the serum lipidlowering effects of a Monascus purpureus (red yeast) rice preparation, G. pentaphyllum was used as a positive control consisting of a group of 94 patients. After 8 weeks, Gynostemma significantly Piacente et al. (1995) reduced the level of TC (by 6.7%), TG (by 12.8%), LDL cholesterol (by 8.3%) and ratio of non-HDL/ HDL cholesterol (by 10.4%) and increased the level of HDL cholesterol (by 8.4%) (P<0.001) (Wang et al., 1997a). ...
In traditional Chinese medicine, Gynostemma pentaphyllum (Thunb.) Makino is a herbal drug of extreme versatility and has been extensively researched in China. The dammarane saponins
isolated from Gynostemma pentaphyllum, namely gypenosides or gynosaponins, are believed to be the active components responsible for its various biological activities
and reported clinical effects. This review attempts to encompass the available literature on Gynostemma pentaphyllum, from its cultivation to the isolation of its chemical entities and a summary of its diverse pharmacological properties attributed
to its gypenoside content. Other aspects such as toxicology and pharmacokinetics are also discussed. In vitro and in vivo evidence suggests that Gynostemma pentaphyllum may complement the popular herbal medicine, Panax ginseng, as it also contains a high ginsenoside content and exhibits similar biological activities.
... The main differences were the chemical shifts of H-22 (ı 2.14 and 2.30 in 6 versus ı 2.04 and 2.47 in 7) in 1 H NMR spectrum. In the comparison with some dammarane compounds prompted us to hypothesize that the difference between the two should be confined to the stereochemistry at C-20. 6 in 6 versus ı 123.4 in 7) were in good agreement with those of published data for 20R epimer of 6 and 20S epimer of 7 (Piacente et al., 1995). On the basis of the foregoing data, the structures of compounds 6 and 7 were proposed to be (20S)-3,20,23-trihydroxydammarane-24-en-21-oic acid-21,23 lactone and (20R)-3,20,23-trihydroxydammarane-24-en-21-oic acid-21,23 lactone, respectively. ...
... On the basis of the foregoing data, the structures of compounds 6 and 7 were proposed to be (20S)-3,20,23-trihydroxydammarane-24-en-21-oic acid-21,23 lactone and (20R)-3,20,23-trihydroxydammarane-24-en-21-oic acid-21,23 lactone, respectively. By comparison of 1 H and 13 C NMR and other data of 6 and 7 with those of known dammarane-type triterpenes, it is evident that the chemical structures of 6 and 7 are similar with aglycone moiety of some triterpene glycosides, which were previously isolated from Gynostemma pentaphyllum (Piacente et al., 1995). However, this is the first time the former structures was isolated. ...
Gynostemma pentaphyllum (Thunb.) tea was used in Vietnamese folk medicine as anti-diabetic agent.
This study was aimed to investigate the inhibitory activities of fractions and constituents isolated from Gynostemma pentaphyllum on protein tyrosine phosphatase 1B (PTP1B) since it has been proposed as a treatment therapy for type 2 diabetes and obesity.
The 70% EtOH extract, CHCl3 fraction, EtOAc fraction, BuOH fraction, and seven isolated dammarane triterpenes were evaluated for their inhibitory activity in protein phosphatase enzymes (PTP1B and VHR).
CHCl3-soluble fraction showed a dose-dependent inhibitory activity of the PTP1B enzyme with the IC50 value of 30.5 microg/mL. Among seven tested compounds, compounds 6 showed the most potent PTP1B inhibitory activity with IC50 value of 5.3+/-0.4 microM compared to a range 15.7-28.5 microM for the other six compounds. The inhibition mode of 6 was competitive toward p-NPP with a K(i) value of 2.8 microM.
These study results suggested that the PTP1B inhibitory activity of these dammaranes may enable this plant to play an important role in the treatment of diabetes.
... f Based on a reference by Takemoto et al. [46]. g Based on a reference by Piacente et al. [47]. h Based on a reference by Takemoto et al. [48]. ...
... Compound t R (min) Retention factor (k) Separation factor (˛) Peak purity (%) Because of unavailability of the other saponin standards, peaks 5,6,8,9,12,13,[15][16][17][18][19]21, 29 and 31-33 were identified by determining their MS spectra with LC-MS-ESI and LC-MS-Q-TOF and comparing with values reported in literatures (Table 3) [40][41][42][43][44][45][46][47][48][49][50][51][52][53][54][55][56][57][58]. The amounts of 33 saponins in G. pentaphyllum are shown in Table 2, which ranged from 491.0 to 89,888.9 g g −1 . ...
Gynostemma pentaphyllum (Thunb.) Makino, a traditional Chinese herb possessing antitumor and antioxidant activities, has been shown to contain several functional components like saponins and flavonoids. However, their identities remain uncertain. The objectives of this study were to develop an appropriate extraction, purification and HPLC-MS method to determine saponins and flavonoids in G. pentaphyllum. Both flavonoids and saponins were extracted with methanol, followed by purification with a C18 cartridge to elute the former with 50% methanol and the latter with 100% methanol. A total of 34 saponins were separated within 40 min by a Gemini C18 column and a gradient mobile phase of acetonitrile and 0.1% formic acid in water, in which 18 saponins were identified by LC-MS with ESI mode and Q-TOF (LC/MS/MS). Similarly, a total of eight flavonoids were separated within 45 min by the same column and a gradient solvent system of methanol and 0.1% formic acid in water, with identification being carried out by a post-column derivatization method and LC-MS with ESI mode. The amounts of flavonoids in G. pentaphyllum ranged from 170.7 to 2416.5 mug g(-1), whereas saponins were from 491.0 to 89,888.9 mug g(-1).
... L-Arabinose in the pyranose form was evident from 13 C-NMR data; however, the value of its J H1-H2 coupling constant (5.2 Hz), midway between that reported for methyl-R-arabinopyranoside (4 Hz) and methyl--arabinopyranoside (8 Hz), was not diagnostic owing to the high conformational mobility of arabinopyranosides ( 4 C 1 T 1 C 4 ). As we also reported in previous work, 18,19 evidence of R-Larabinopyranoside was obtained from ROESY spectrum, which showed NOEs from C-1′′ to C-2′′, C-3′′, and C-5′′ indicative of R-L-arabinopyranoside in rapid conformational exchange from 4 C 1 T 1 C 4 conformation. were also present. ...
... 2D experiments: 1 H-1 H DQF-COSY, 11 inverse-detected 1 H-13 C HSQC 12 and HMBC, 13 and ROESY 14 were obtained by employing the conventional pulse sequences as described previously. 18,19,22 The selective excitation spectra, 1D TOCSY 16 were acquired using waveform generator-based GAUSS shaped pulses, mixing times ranging from 100 to 120 ms, and a MLEV-17 spin-lock field of 10 kHz preceded by a 2.5-ms trim pulse. Optical rotations were measured on a Perkin-Elmer 141 polarimeter using a sodium lamp operating at 589 nm in 1% w/v solutions in MeOH. ...
Three new bisdesmosidic triterpene saponins, zygophylosides I (1), L (2) and M (3), and three known quinovic acid glycosides were isolated from Zygophyllum gaetulum. The new compounds were determined to be 3 beta-O-alpha-L-rhamnopyranosyl-(1-->2)-alpha-L-arabinopyranosyl- (1-->2)-beta-d-glucopyranosylurs-20(21)-en-28-oic acid 28-O-[beta-D-2-O-sulfonylglucopyranosyl] ester (1),3 beta-O- [alpha-L-rhamnopyranosyl-(1-->2)-alpha-L-arabinopyranosyl- (1-->2)-beta-D-glucopyranosyl]urs-20(21)-en-28-oic acid 28-O-[beta-D-glucopyranosyl] ester (2), and 3 beta-O-beta-D-quinovopyranosyl-27-nor-olean-12-en-28-oic acid 28-O-beta-D-glucopyranosyl ester (3) by use of 1D and 2D NMR techniques.
... The oxymethine assignable to C-3 was observed at δ H 2.93 (dd, J = 11.5, 4.5 Hz) which indicated the αorientation of H-3. Chemical shifts, multiplicities, coupling constant magnitudes in the 1 H NMR spectrum along with 13 C NMR data indicated the α-configuration of the anomeric position for an arabinose unit [55][56][57][58]. The nature of the sugar was further validated upon 1 H NMR analysis of the sugar obtained after acid hydrolysis [59]. ...
Two new triterpenes, the seco-friedelane type secofriedelanophyllemblicine and the ursane-derived saponin ursophyllemblicoside were isolated from the roots of the edible fruit-producing Phyllanthus emblica. Their structures were unambiguously elucidated using extensive 1D and 2D NMR analyses, high resolution mass spectrometry and single-crystal X-ray crystallographic analyses along with comparison with literature data. Secofriedelanophyllemblicine represents the first 3,4-secofriedelane bearing a carboxylic acid group substituent at C-20. Ursophyllemblicoside, incorporating the rare 21α hydroxyursolic acid as a sapogenol represents the first example of saponin comprising this aglycone. Secofriedelanophyllemblicine displayed a moderate cytotoxicity against K562 and HepG2 cancer cell lines.
... It is used for treatment of inflammation, cough, hyperviscosity of sputums and chronic bronchitis (Jiang-Xu, 1979;Lin et al., 1993). Gypenosides, the total saponins with a dammaranetype basic structure (Piacente et al., 1995;Hu et al., 1996) isolated from jiaogulan, have been reported to decrease blood cholesterol, inhibit growth of tumor cells, heal peptic ulcer, relieve inflammation and pain and prevent platelet aggregation (Kimura et al, 1983;Li and Jin, 1989). Jiaogulan is also taken as tonic to improve the immune system. ...
Use of herbs as health and/or dietary supplements has increased worldwide. The most common usage of botanicals is to improve the immune system. Water extract of Gynostemma pentaphyllum Makino was studied for its effects on lymphocyte proliferation and natural killer (NK) cell activity. Lymphocyte proliferation of normal peripheral blood mononuclear cells (PBMC) in response to G. pentaphyllum extract was increased at concentrations of (in ng/mL) 1, 10, 100, and (in µg/mL) 1, 5, 10 and 100. Aqueous extract of G. pentaphyllum reduced lymphocyte proliferation at 1 µg/mL, suggesting immunomodulating activities on human immunocompetent PBMC. INTRODUCTION Jiaogulan (Gynostemma pentaphyllum Makino; Cucurbitaceae) is a perennial climber, widely growing in China, Japan, Korea and Southeast Asia. It is used for treatment of inflammation, cough, hyperviscosity of sputums and chronic bronchitis (Jiang-Xu, 1979; Lin et al., 1993). Gypenosides, the total saponins with a dammarane-type basic structure (Piacente et al., 1995; Hu et al., 1996) isolated from jiaogulan, have been reported to decrease blood cholesterol, inhibit growth of tumor cells, heal peptic ulcer, relieve inflammation and pain and prevent platelet aggregation (Kimura et al, 1983; Li and Jin, 1989). Jiaogulan is also taken as tonic to improve the immune system. The effects and mechanisms of the activities on the immune system have not been well-defined. The objectives of this study were to investigate its capabilities on cell-mediated immune response (CMIR) by studying their effects on lymphocyte proliferation and natural killer (NK) cell activity of human peripheral blood mononuclear cells (PBMC).
... The leaf and stem of the plant contain saponin glycosides and possess antioxidant activity. It has been reported that GP have identified the saponin glycosides as a series of dammarane-type saponin called gypenoside (Piacente and Pizza, 1995;Hu et al., 1997;Liu et al., 2004), closely related to the ginseng saponins (Cui et al., 1999). Pharmacological studies of GP and its isolated saponins indicate a variety of biological activities which include: anticancer, antioxidant, antitumor, cholesterol-lowering and immonopotientiating activities (Blumert and Liu, 2003). ...
Jiaogulan (Gynostemma pentaphyllum, GP) is a Chinese medicinal herb which can grow in Thailand. The objective of this study was to optimize the chemi- cal component, the sensory quality and consumer acceptance of Jiaogulan tea. The sensory descriptive analysis was conducted to describe the sensory properties of Jiaogulan tea. The hedonic scaling method was used to measure the consumer acceptability of this product (n=50). The chemical properties- total saponin and antioxidant activity- were analyzed. The two- -factors rotatable design (pentagon design) with saponin content (0-500 mg) and water (50-250 ml) was employed to optimize the results by using the Response Surface Methodology (RSM). The result showed that Jiaogulan tea could be described in terms of 13 attributes by the sensory descriptive analysis. Consumers' acceptability test indicated that they liked this tea if the saponin content was not too high. The optimization result of the maximum chemical components overlaid with the acceptability score (> 6). Based on response surface plots, the optimum dried Jiaogulan contained 292mg of saponin in 100 ml of hot water. In conclusion, this study suggests that the formulation of Jiaogulan tea should be in the optimum concentration so that consumers will accept this tea.
... All of the 1 H and 13 C NMR spectroscopic data of the aglycone were assigned based on 1 H-1H COSY, HSQC, HMBC, TOCSY and ROESY experiments (Supporting information S-1), and are comparable to those of the reported 3b,20S,29-trihydroxydammar-24-en-21-carboxylic acid. The absolute configuration of C-20 was confirmed to be ''S" by comparison of NMR spectroscopic data with those reported in the literature (Yang et al., 2007;Piacente et al., 1995;Yin and Hu, 2005). ...
Dammarane-type saponins (1-7), together with five known compounds, were isolated from the aerial parts of Gynostemma pentaphyllum. Compounds 1-4, 6 and 7 induced the phosphorylation of ERK protein in primary rat cortical neurons, which indicates their potential neuroactivity. On the other hand, no induction of ERK phosphorylation was observed for HEK293 cells following treatment with saponins 1, 3, 4 and 7.
... The 1 H-NMR spectrum of 1 exhibited resonances for the anomeric protons of the sugar moiety at d 4.32 (d, J = 6.8 Hz), 5.34 (d, J = 8.3 Hz) which were assigned to the anomeric protons of L-arabinose and D-glucose, respectively. Chemical shifts, multiplicities, coupling constants and magnitude in the 1 H-NMR spectrum, as well as 13 C-NMR, data indicated the a-con®guration at the anomeric position for the arabinose unit, and the b-con®guration for the glucose (Piacente et al., 1995). The signal of C-28 at d 177.95 further con®rmed the IR absorption at 1740 cm À1 , indicating the presence of an ester group rather than a free acid group (Durham et al., 1994). ...
Seven new triterpenoid saponins, randiasaponins I (1), II (2), III (3), IV (4), V (5), VI (6) and VII (7) as well as two known ones, ilexoside XXVII (8) and ilexoside XXXVII (9), were isolated from the methanolic extract of the leaves of Randia formosa. The structures of the new saponins were established as 3-O-alpha-L-arabinopyranosyl-3 beta,19 alpha,23-trihydroxyursa-12,20(30)-dien-28-oic acid 28-beta-D-glucopyranosyl ester (1), 3-O-beta-D-glucopyranosyl-(1-->3)-alpha-L-arabinopyranosyl rotundic acid (2), 3-O-beta-D-glucopyranosyl-(1-->3)-alpha-L-arabinopyranosyl pomolic acid 28-beta-D-glucopyranosyl ester (3), 3-O-alpha-L-rhamnopyranosyl-(1-->2)-alpha-L-arabinopyranosyl pomolic acid 28-beta-D-glucopyranosyl ester (4), 3-O-alpha-L-rhamnopyranosyl-(1-->2)-alpha-L-arabinopyranosyl siaresinolic acid 28-beta-D-glucopyranosyl ester (5), 3-O-alpha-L-arabinopyranosyl ilexosapogenin A 28-beta-D-glucopyranosyl ester (6), and 3-O-beta-D-glucopyranosyl ilexosapogenin A 28-beta-D-glucopyranosyl ester (7), based on spectral and chemical evidence. Besides the saponins, two common flavonoids kaempferol 3-O-rutinoside and rutin were also isolated.
Gynostemma pentaphyllum belongs to the family Cucurbitaceae which is native to China where it is also termed an immortal herb. It is an emerging herb gaining fame for its rich phytochemistry. It is loaded with superior phytochemicals with immense therapeutic potential. The key phytochemicals include saponins and sterols. Saponins are a wide class of bioactive found in Gynostemma pentaphyllum and 100 different saponins have been reported to date by different researchers in this herb. Several sterols have been demonstrated in this plant including ergostanol, sitosterol and stigmasterol. All these bioactive substances possess superior therapeutic and pharmacological properties that have been investigated in different studies as presented in this comprehensive review. Taxonomic classification, botanical description, and geographical distribution are briefly covered in the first section of this review. In contrast, the phytochemistry, therapeutic properties, and pharmacological features of Gynostemma pentaphyllum are thoroughly explained in the second section.
Eight previously undescribed triterpenoids, including four dammarane-type triterpenoids, named meliasenans A−D (1–4), four apotirucallane-type triterpenoids, named meliasenans E−H (5–8), along with nine known analogues (9–17) have been isolated from the stem bark of Melia toosendan. The structures of the new compounds were elucidated by IR, HRESIMS, 1D, 2D NMR, electronic circular dichroism (ECD) calculations, as well as single-crystal X-ray diffraction analysis. The results of bioassay showed that the new compounds 7 and 8 exhibited potential antibacterial effect on Pseudomonas solanacearum and Bacillus gasoformans, with MIC values of 117.2 μg mL⁻¹ and 118 μg mL⁻¹, respectively. Moreover, 8 and 11 showed apparent antibacterial activities against Bacillus subtilis (ATCC 6051) with MIC values of 118 μg mL⁻¹ and 92.1 μg mL⁻¹, respectively.
Fourteen new polyhydroxylated pregnane glycosides, cissasteroid A-N (1-14), and five known analogues (15-19), were isolated from the dried whole plant of Cissampelos pareira var. hirsuta. Their structures and stereochemistry were elucidated by extensive spectroscopic data, chemical hydrolysis, and ECD measurements. All the compounds were tested for their cytotoxicity against five human cancer cell lines, and inhibitory activity against NO release in LPS-induced RAW 264.7 cells. Compared with cisplatin, compound 7 showed more potent cytotoxicities against the HL-60, A549, SMMC-7721, MCF-7, and SW480 cell lines, with IC50 values of 2.19, 14.38, 2.00, 7.58, and 7.44 μM, respectively. The preliminary study of structure-activity relationship indicated that benzoic acid esterification at C-20 may have a negative effect on the cytotoxic activity of polyhydroxylated pregnane derivatives in these five human cancer cell lines. These results revealed the potential of compound 7 as an ideal antitumor lead compound.
Ocotillol (OT)-type ginsenosides, one subtype of ginsenosides, consist of a dammarane skeleton and a tetrahydrofuran ring. Most naturally-occurring OT-type ginsenosides exist in Panax species, particularly in Panax quinquefolius, which may be attributed to the warm and humid climate of its native areas. Till now, merely 28 types of naturally-occurring OT-type ginsenosides have been isolated. In contrast, semi-synthesized OT-type ginsenosides are attracted considerable attentions. These ginsenosides can be obtained through oxidation and cyclization of side chains of dammarane-type ginsenosides, and other methods, which may change their physical and chemical properties and further improve their bioavailabilities. It is also notable that the pharmacological activities of ginsenosides are closely related to the stereoisomers caused by the configuration at C-20. Semi-synthesis of OT-type ginsenosides can facilitate our understanding of the biosynthesis, transformation and metabolism of OT-type ginsenosides in the body. This review will systematically summarize the research progress on naturally-occurring and semi-synthetic OT-type ginsenosides, which provides a theoretical basis for their bioactivity-guided research.
Green synthesis of ZnO nanoparticles gained huge attention due to eco-friendly protocol to reduce the destructive effect of chemical synthesis mostly used in the industry. This study focused on green chemistry protocol to synthesis Gynostemma pentaphyllum zinc oxide nanoparticles (GP-ZnO-NPs) from Gynostemma plant extract using the co-precipitation method. The GP-ZnO-NPs decolorization performance was assessed by removing toxic dye Malachite Green (MG) under UV illumination. The hexagonal wurtzite structure with an average size of 35.41 nm was confirmed by X-ray powder diffraction (XRD) analysis. The FE-TEM analysis revealed the nanoparticles' hexagonal shape, and electron diffraction analysis (EDX) analyzes the percentage of Zn & oxygen of the nanostructures. The Fourier-transform infrared spectroscopy (FT-IR) analysis was revealed the functional group responsible for forming Gp-ZnO-NPs. Besides, the Photoluminescence study revealed the electron-hole pairs on the surface of the catalyst. The X-ray photoelectron spectroscopy (XPS) analysis exposed the chemical compositions (Zn, C & O) and the nanostructure's elemental state. The newly synthesized nano catalyst was applied to investigate the photocatalytic activity of Malachite Green dye under UV illumination. The photocatalyst (GP-ZnO-NPs) exhibited the decolorization of 89 % (10 mg/L) toxic MG dye within 180 min observation. The hexagonal nanoparticle structure creates a more active site to interact with the poisonous dye molecules to proceed the reaction fast. In addition, the nano catalyst can be used for five times without losing its activity. This study highly recommends the GP-ZnO-NPs to remove toxic dye for a safer environment as a greener nano catalyst.
Gynostemma pentaphyllum possesses the neuroprotective bioactivity. However, the effect of gypenosides on the hypoxia-induced neural damage remains obscure. In this study, Gyp, the active fraction extracted from G. pentaphyllum, and its bioactive compounds as well as the underlying molecular mechanisms were investigated. Eighteen dammarane-type saponins were isolated from Gyp. The absolute configurations of six unreported compounds (13-18) were assessed via ECD analyses. The results of cell viability assay showed that Gyp and its bioactive compounds (13-16 and 18) effectively protected PC12 cells from hypoxia injury. Gyp pre-treatment also improved mice spatial memory impairment caused by hypoxia exposure. At the molecular level, Gyp and its bioactive compounds could activate the signaling pathways of ERK, Akt, and CREB in vitro and in vivo. In summary, Gyp and its bioactive compounds could prevent hypoxia-induced injury via ERK, Akt and CREB signaling pathways.
Jiaogulan (Gynostemma pentaphyllum) has been widely used as herbal tea, dietary supplement, and as vegetable in Asian countries. In this study, six new gypenosides (1-6) were isolated from the aerial parts of G. pentaphyllum. Their molecular structures were elucidated through spectroscopic analysis and acid hydrolysis. Gypenosides 1 and 2 represented the first example of a dammar-21-O- glucopyranoside without any unsaturated functional group and a dammar-3-O-glucopyranosyl-25-O-glucopyranoside without any cyclization in the side chain, respectively. In addition, gypenosides 5 and 6 exhibited the first example of a 24-hydroperoxy-19-oxo-dammarane triterpenoid and 19-oxo-dammar-21-O-glucopyranoside with a saturated side chain, respectively. Gypenoside 5 was found to possess PTP1B inhibitory activity with IC50 value of 8.2 ± 0.9 µM and moderate cytotoxicity against human breast cancer cells MCF7, MCF7/ADR, and MDA-MB-231with IC50 values ranging from 10.5 ± 1.4 to 14.2 ± 2.6 µM. The outcome of the study provided crucial information regarding the structural diversity and health benefits of gypenosides.
Thirty-three new dammarane glycosides, together with nine known compounds, gypenosides IV, VIII, XLVIII, XLIX, LXIX, LXXI, gylongiposide I, allantion and vitexin were isolated from the methanol extract of the aerial parts of Gynostemma pentaphyllum. Their structures were elucidated by NMR spectroscopy and mass spectrometry, as well as by chemical degradation.
Five selective 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) competitive inhibitors, hupehenols A-E (1-5), were isolated from Viburnum hupehense. The structure elucidation indicated that compounds 1-5 are new 20,21,22,23,24,25,26,27-octanordammarane triterpenoids. Their structures were established on the basis of NMR spectroscopic and mass spectrometric analysis. Hupehenols A-E (1-5) showed inhibition against human 11β-HSD1, with hupehenols B (2) and E (5) having IC50 values of 15.3 and 34.0 nM, respectively. Moreover, hupehenols C (3) and D (4) are highly selective inhibitors of human 11β-HSD1 when compared to murine 11β-HSD1.
Folk drug Gynostemma pentaphyllum (Thunb.) Makino contains many biologically active phytochemicals which have been demonstrated to be effective against chronic diseases. As in vivo anti-tumor experiments of G. pentaphyllum extract (GP) show much stronger antitumor activities than in vitro, it is important and necessary to understand the metabolic study of GP. A sensitive and specific U-HPLC-MS method was utilized for the first time to rapidly identify gypenosides and its possible metabolites in rat serum, urine, and faeces after oral administration. Solid phase extraction was utilized in the sample preparation. Negative Electrospray ionisation (ESI) mass spectrometry was used to discern gypenosides and its possible metabolites in rat samples. As a result, after oral administration, a total of seven metabolites of G. pentaphyllum extract were assigned, two from the rat serum and seven both from the rat urine and faeces. As metabolites of G. pentaphyllum extract, all of them have never been reported before.
Heat-processed Gynostemma pentaphyllum and its main dammaran-type saponins, gypenoside L, gypenoside LI, damulin B, and damulin A, possess non-small cell lung carcinoma A549 cell inhibitory activity. We established in this study a method by ultra-high performance liquid chromatography with tandem mass spectrometry for determination of the saponins and also investigated their content change in heat-processed G. pentaphyllum. The main saponins increased with increasing heating temperature and time. Further investigation showed that they were produced from gypenoside XLVI and gypenoside LVI by undergoing hydrolysis during the heat treatment.
Thirteen new dammarane-type triterpenoids (1-13) and four known analogues, gentirigenic acid (14) and the gentirigeosides A, B, and E (15-17), were isolated from Gentianella azurea. Their structures were elucidated by detailed analysis of the NMR, MS, and X-ray crystallographic data. This is the first report of dammarane-type triterpenoids in the Gentianella genus. In addition, the known structures of gentirigenic acid (14) and the gentirigeosides A, B, and E (15-17) were revised based on the X-ray diffraction analysis. Gentirigeoside A (15) was found to inhibit nitric oxide production in RAW 264.7 macrophages with an IC50 value of 6.6 ± 2.1 μM.
Two novel 20-oxo-21-nordammar-22, 24-diene saponins, 21-norgypenosides A (1) and B (2), were characterized from the aerial parts of tetraploid Jiaogulan (Gynostemma pentaphyllum), a popular tea ingredient. Their structures, including the absolute configurations, were comprehensively elucidated by HRESIMS, 1D and 2D NMR data, chemical degradation and through comparison of the experimental and calculated electronic circular dichroism (ECD) spectra. The two compounds suppressed the expression of interleukin (IL)-1β, cyclooxygenase (COX)-2 and tumor necrosis factor (TNF)-α mRNAs in the lipopolysaccharide-induced RAW 264.7 mouse macrophage cells at 10 and 100 μg/mL, suggesting their potential anti-inflammatory effects.
Three novel dammarane glycosides together with six known compounds were isolated from a methanol extract of the aerial parts of Gynostemma pentaphyllum. Their structures were elucidated by one- and two-dimensional NMR experiments, including 1H1H correlation spectroscopy (DQFCOSY and TOCSY) and 1H13C heteronuclear correlation (HMQC and HMBC).
Five dammarane-type aglycones, released from gypenosides following an alkaline cleavage procedure previously developed for ginsenosides, were separated and characterized by gas chromatography-mass spectrometry (GC-MS) after trimethylsilylation. A satisfactory identification among isomers of 20(S)-protopanaxadiol or 20(S)-protopanaxatriol was obtained. © 1998 John Wiley & Sons, Ltd.
In this paper, the gypenoside-α-(1→6)-l-rhamnosidase from microorganisms was purified and characterized. The enzyme hydrolyzed the 20-C, α-(1→6)-l-rhamnoside of gypenoside-5 to produce ginsenoside Rd, but did not hydrolyzed the α-rhamnoside of ginsenoside Rg2, and only partially hydrolyzed the α-rhamnoside of p-nitrophenyl-α-l-rhamnoside (pNPR) which was a hemi-cellulase substrate. The enzyme was purified to homogeneity by SDS polyacrylamide gel electrophoresis, and its molecular weight was about 68 kDa. The optimum temperature of enzyme reaction was 50°C, and the optimum pH was 5. Metal ions activated the gypenoside-α-(1→6)-l-rhamnosidase activity.
To evaluate the safety of standardized extract of Gynostemma pentaphyllum in rats.
The water extract of G. pentaphyllum was prepared and standardized, the dry powder yielded 6% gypenosides. In the acute oral toxicity test, the single oral dose of 5,000 mg/kg of G. pentaphyllum extract was given to female Sprague-Dawley rats. In subchronic toxicity test, the oral dose of 1,000 mg/kg/day of the extract was given to rats in treatment and satellite groups for 90 days. Satellite groups of both sexes were kept for additional 28 days after 90-day treatment. Control rats received distilled water.
Standardized extract of G. pentaphyllum did not cause death or any toxic signs in rats. The daily administration of the extract for 90 days did not produce lethal or harmful effects. Although certain hematological and blood chemistry values (i.e., neutrophil, monocyte, glucose, and serum alkaline phosphatase levels) were found to be statistically different from the control group, however, these values were within the ranges of normal rats.
Standardized extract of G. pentaphyllum did not produce mortality or any abnormality in rats.
This work studied extractions of gypenosides from Gynostemma pentaphyllum using batch and continuous pressurized fluids. Temperature was found to be a dominant factor in extracting gypenosides from this plant material. Using low solid to solvent ratio (50 g/L) was evidenced to avoid a rate limitation on batch pressurized water extraction of gypenosides. Within 3 h of continuous pressurized water extraction at 1.48 MPa, 373 K, 10 mL/min, a high solid to solvent ratio (200 g/L) resulted in 106.7 mg/g gypenosides. Our experimental results showed that 100% recovery of gypenosides, i.e., 164 mg/g, was obtained following pressurized 80% ethanol extraction at the same operation condition. Purification of the extract using Amberlite XAD7-HP column chromatography indicated that the purity of gypenosides increased from 24% to 83% by weight. In the bioassay aspect, the effect of concentrations of gypenosides in the extracts on the growth inhibition of two cancer cells was examined.
Two new dammarane-type triterpene saponins, gypenbiosides A (1) and B (2), were isolated from the aerial parts of Gynostemma pentaphyllum (Thunb.) Makino. Their structural elucidations were accomplished mainly on the basis of the interrelation of spectroscopic methods, such as IR, HR-TOF-MS, and NMR. The cytotoxic activity was evaluated against one human cancer cell line HL-60 using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay.
The six new triterpene saponins 1–6 with a 21,23-lactone skeleton 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.
Three new dammarane-type triterpene saponins, 1–3, together with three known compounds, 4–6, were isolated from the aerial parts of Gynostemma pentaphyllum (Thunb.) Makino. By means of chemical and spectroscopic methods, their structures were established as (20S)-3β,20,21-trihydroxydammara-23,25-diene 3-O-[α-L-rhamnopyranosyl-(1→2)] [β-D-xylopyranosyl-(1→3)]-β-D-glucopyranosyl-21-O-β-D-glucopyranoside (1), (20R,23R)-3β,20-dihydroxy-19-oxodammar-24-en-21-oic acid 21,23-lactone 3-O-[α-L-rhamnopyranosyl-(1→2)] [β-D-xylopyranosyl-(1→3)]-α-L-arabinopyranoside (2), and (21S,23S)-3β,20ξ,21,26-tetrahydroxy-19-oxo-21,23-epoxydammar-24-ene 3-O-[α-L-rhamnopyranosyl-(1→2)] [β-D-xylopyranosyl-(1→3)]-α-L-arabinopyranoside (3).
Nine new dammarane triterpene glycosides (1-3 and 8-13) and 12 known analogues have been isolated from an ethanol extract of the roots of Machilus yaoshansis. Compounds 1-7 have an uncommon 20,23-dihydroxydammar-24-en-21-oic acid-21,23-lactone moiety that was previously reported in compounds isolated from Gynostemma pentaphyllum. The configurations of the lactone moieties in 1-3 were determined by comparison of the experimental ECD spectra of 1-3 and the hydrolysates, 1a and 1b, with the corresponding calculated ECD spectra. On the basis of NMR and ECD data analysis of 1-7, the previously reported C-20 and C-23 configurations of 4-7 and related derivatives from Gynostemma pentaphyllum were revised. In addition, the application of NMR data and Cotton effects to the determination of the relative and absolute configurations of the γ-lactone moiety in 3β,20,23-trihydroxydammar-24-en-21-oic acid-21,23-lactone derivatives is discussed.
Effects of gynostemma pentaphyllum (GP) on the bacteriophage λ induced by ultraviolet (UV) irradiation have been studied.
The results showed that GP could inhibit the UV induction of bacteriophage λ in lysogenic cells. The inhibitory effects were
dependent on the concentration and the reaction time of GP, and were efficient at 40∼125 μg ml−1 for 10 min. The inhibitory rate was higher than 70% when the GP concentration was 50 μg ml−1. By electron spin resonance (ESR) and spin-trapping techniques, the signals of free radicals were detected in the suspension
of the λ lysogenic bacteria induced by ultraviolet irradiation, but after the addition of GP the signals were decreased. These
results indicate that gynostemma pentaphyllum not only is a scavenger of free radicals, but also possesses the biological
function of anti-irradiation, and that there is a close relation between the UV irradiation of the bacteriaphage λ and free
radicals.
From an acid hydrolysate of the crude saponins of Gynostemma pentaphyllum, three triterpenes, including a new compound (23S)-3β-hydroxydammar-20,24-dien-21-oic acid 21,23-lactone (1) and two known aglycons (20S, 23R)-3β,20β-dihydroxydamma-24-dien-21-oic acid 21,23-lactone (2) and (20S, 24S)-20,24-epoxydammarane-3β,12β,25-triol (3), were isolated. Their structures were established on the basis of extensive spectral evidence (HR-ESI-MS, IR, 1D and 2D-NMR experiments). In bioactive assays in vitro, compound 1 was found to have potent cytotoxicity against the human breast cancer cells MDA-MB-435, whereas compounds 2 and 3 exhibited modest inhibitory activity toward porcine pancreatic lipase. The results indicated that acid treatment of G. pentaphyllum extract could produce diverse structures with interesting bioactivity.
A concise synthesis of naturally occurring betulinic acid saponins bearing an a-L-rhamnopyranosyl-(1->2)-a-L-arabinopyranoside moiety at the C-3 position is described. Betulinic acid 3b-O-a-L-rhamnopyranosyl-(1->2)-[b-D-glucopyranosyl-(1->4)]-a-L-arabinopyranoside isolated from Pulsatilla koreana and 28-O-b-D-glucopyranosyl betulinic acid 3b-O-a-L-rhamnopyranosyl-(1->2)-a-L-arabinopyranoside isolated
from Schefflera rotundifolia were easily synthesized for the first time using a stepwise glycosidation approach. The overall syntheses involved eight linear steps starting from allyl betulinate and commercially available L-arabinose, L-rhamnose and D-glucose. The syntheses of betulin and betulinic acid O-glycoside analogues containing an a-L-arabinose moiety are also reported. These results open the way to the synthesis of various lupane-type saponin derivatives as potentially bioactive compounds.
A new dammarane-type triterpene saponin was isolated from the aerial parts of Gynostemma pentaphyllum (Thunb.) Makino. Its structural elucidation was accomplished mainly on the basis of the interpretation of spectroscopic data, such as IR, HR-TOF-MS and NMR. Its cytotoxic activity was evaluated against one human cancer cell line HL-60 using MTT assay.
Four new dammarane-type triterpene saponins, 1-4, were isolated from the aerial parts of Gynostemma pentaphyllum (Thunb.) Makino. Their structural elucidations were accomplished mainly on the basis of spectroscopic methods, such as IR, HR-TOF-MS, and NMR. Compounds 1-4 showed moderate cytotoxic activities against cancer cell lines HL-60, Colon205, and Du145 in vitro.
Two new dammarane-type glycosides, 2alpha,3beta,12beta,20S-tetrahydroxydammar-24-ene-3-O-[beta-d-glucopyranosyl(1-->4)-beta-d-glucopyranosyl]-20-O-[beta-d-xylopyranosyl-(1-->6)-beta-d-glucopyranoside] (1) and 2alpha,3beta,12beta,20S-tetrahydroxydammar-24-ene-3-O-beta-d-glucopyranosyl-20-O-[beta-d-6-O-acetylglucopyranosyl-(1-->2)-beta-d-glucopyranoside] (2), were isolated from a MeOH extract of the leaves of Gynostemma pentaphyllum. Their structures were elucidated by 1D and 2D NMR spectroscopic interpretation as well as by chemical studies. The isolated compounds showed potential inhibitory effects on eotaxin expression in BEAS-2B bronchial epithelial cells.
A new dammarane-type glycoside and a new long chain sesquiterpene glycoside, along with nine known compounds 20(S)-ginsenoside Rh1 (3), 20(R)-ginsenoside Rh1 (4), ginsenoside F1 (4), amarantholidoside IV (6), ginsenoside Rc (7), 20(S)-ginsenoside Rg2 (8), 20(R)-ginsenoside Rg2 (9), ginsenoside Rd (10) and gypenoside XLVI (11) were isolated from Gynostemma yixingense. The structures of the new compounds were determined on the basis of spectroscopic analysis, including 1D-, 2D-NMR and ESI-MS techniques as well as by comparison of the spectral data with those of related compounds as 2 alpha,3beta,20(S)-trihydroxydammar-24-ene-3-O-[beta-D-glucopyranosyl((1-->2)-beta-D-glucopyranosyl]-20-O-[beta-D-xylopyranosyl((1-->6)-beta-D-glucopyranoside] (1) (2E,6E)-10-beta-D-glucopyranosyl-1,10,11-trihydroxy-3,7,11-trimethyldodeca-2,6-diene (2).
We conducted a phase I trial of Gynostemma pentaphyllum, grown in northern Thailand, to evaluate its safety in three groups of healthy volunteers. Fourteen, fifteen and fourteen volunteers respectively received the water extract of G. pentaphyllum in capsules at the doses of 50, 200 and 400 mg twice daily for two months. There were no major adverse events reported from any of the three groups throughout the study. Significant changes in hematological parameters, natural killer cell activities and the numbers of CD3+, CD4+ and CD8+ cells were not seen during taking the extract. Some biochemical parameters were significantly different from baseline data. Those values were, however, within normal limits and did not result in clinically significant conditions. Our results suggested that the water extract of G. pentaphyllum at the doses of 50, 200 or 400 mg twice daily given to healthy volunteers for two months was safe.
We assessed the effects of Cleistocalyx nervosum var paniala, Gynostemma pentaphyllum, Gynura procumbens, Houttuynia cordata, Hyptis suaveolens, Portulaca grandiflora, Phytolacca americana and Tradescantia spathacea on lymphocyte proliferation and the effects of C. nervosum, G. pentaphyllum, H. suaveolens and P. grandiflora on natural killer (NK) cells activity. All of the extracts significantly stimulated human lymphocyte proliferative responses at various concentrations depending on each extract. The extracts of C. nervosum and H. suaveolens were significantly enhanced NK cells activity while those of G. pentaphyllum and P. grandiflora did not alter NK cells function. Our results suggested that the extracts of those plants have stimulating activity on human lymphocytes and could be clinically useful for modulating immune functions of the body.
As a consequence of the renewed interest in the search for new substances of natural origin as potential candidates in drug development, since 1980 our research group has been investigating higher plants employed in Italian, Chinese, African and South American traditional medicine.
Three new triterpenoidal saponins (1-3), together with the known compound 4, were isolated from a MeOH extract of the aerial parts of Gynostemma pentaphyllum. Their structures were elucidated on the basis of chemical and spectral methods, such as 1H-1H DQFCOSY, HMQC, HMBC, and TOCSY NMR spectra. The aglycon moiety of 1 and 2 is a new dammarane-type triterpene 12-oxo-2 alpha, 3 beta, 20 (S)-trihydroxydammar- 24-ene.
Six new oleanene glycosides were isolated from the MeOH extract of the aerial parts of Spergularia ramosa. They possess gypsogenin or quillaic acid as the aglycons. The disaccharide moiety linked to C-3 of the aglycons is made up of galactose (or glucose) and glucuronic acid (or glucose); the pentasaccharide moiety linked to C-28 is made up of glucose (or galactose), xylose, rhamnose, fucose, and arabinose. Their structures were elucidated by 1D and 2D NMR experiments including 1H-1H (DQF-COSY, 1D TOCSY, 2D HOHAHA, ROESY) and 1H-13C (HSQC, HMBC) spectroscopy.
The MeOH extract of the aerial parts of Croton ruizianus afforded two new pregnane glycosides 1 and 2, together with the morphinandienone alkaloids flavinantine (3) and O-methylflavinantine (4). Their structures were elucidated by NMR experiments including 1H-1H (1D TOCSY and 2D DQF-COSY) and 1H-13C (HSQC, HMBC) spectroscopy. The proaggregating activity of the MeOH extract and the isolates were evaluated. Although the MeOH extract and pregnane glycosides (at different doses) were found to promote platelet aggregation, flavinantine (3) and O-methylflavinantine (4) showed only slight activity. The ability of the MeOH extract and the four compounds to act synergistically with thrombin was also evaluated. All the tested compounds were successful in augmenting the aggregating effect of thrombin, although to different degrees.
Saponins are complex molecules made up of sugars linked to a triterpenoid or a steroid or a steroidal alkaloid. These natural products are attracting much attention in recent years because of the host of biological activities they exhibit. The diversity of structural features, the challenges of isolation because of their occurrence as complex mixtures, the pharmacological and biological activities still to be discovered, and the prospect of commercialization — these all are driving the study of saponins. Triterpenoid saponins are dominating constituents of this class and occur widely throughout the plant kingdom including some human foods e.g. beans, spinach, tomatoes, and potatoes, and animal feed e.g. alfalfa and clover. Saponins were initially a rather neglected area of research primarily because of great difficulties in their isolation and characterization. With the advent of more sophisticated methods of isolation and structure elucidation through the last two decades, there has been increased interest in these natural products. Besides structure determination, research activities are now moving forward to clarify structure-activity relationships. Our previous reviews on triterpenoid saponins (1, (2) covered literature from 1979 to mid-1989. The literature on triterpenoid saponins up to 1988 has also been covered by two reviews by HILLER et al. (3, 4). This review incorporates newer trends in isolation and structure determination of triterpenoid saponins, new triterpenoid saponins isolated and biological properties of these products reported during the period late 1989–mid 1996.
Two new oleanene glycosides (1-2) possessing hederagenin as the aglycone were isolated from the methanolic extract of the aerial parts of Caltha polypetala together with four known glycosides. The saccharide portion linked to C-3 of the aglycone is made up of alpha-L-arabinopyranose, alpha-L-rhamnopyranose and galactopyranose in the new compounds; while compound 1 possesses linked to C-28 a trisaccharide moiety made up of two beta-D-glucopyranose and one alpha-L-rhamnopyranose unit, in compound 2 the 28-COOH group is free. The structures were elucidated by 1D and 2D NMR experiments including 1H-1H (DQF-COSY, 1D-TOCSY, 2D-ROESY) and 1H-13C (HSQC, HMBC) spectroscopy.
The aerial parts of Triumfetta flavescens H. (N. O. Tiliaceae) afforded a new alkaloidal steroid glycoside, characterized as stigma 5(6)-ene-7,22-dione-25-methylamino-3 beta,23 beta-diol-3-O-beta-D- glucoside and designated as triumfettoside (1); and a new sterol identified as stigma 5(6)-ene-7,22-dione-3 beta,23 beta-diol, designated as triumfettosterol (2). Their structures were elucidated on the basis of chemical and spectral analysis.
Six new lupane (1 - 4) and oleanane saponins (5 and 6) were isolated from the aerial parts of Schefflera fagueti Baill. (Araliaceae). Their structures were determined by 2D-NMR spectroscopy (DQF-COSY, 1D-TOCSY, 2D-HOHAHA, 1D-ROESY, HSQC, HMBC). The antiproliferative activity of compounds 1 - 6 and of their prosapogenins (1a - 6a) was evaluated using three continuous murine and human culture cell lines J774, HEK-293, WEHI-164. Oleanane saponins 5 and 6 were the most active, showing significant inhibitory effects on all cell lines, while their prosapogenins 5a and 6a demonstrated minor activity.
13C NMR spectra for a variety of α and β-anomeric series of d-mannopyranosides and l-rhamnopyranosides are presented and analyzed in comparison with those of D-glucopyranosides. The results obtained in the present study are valuable for the structure studies of plant-glycosides as well as carbohydrates, especially for determination of anomeric configurations of mannosides and rhamnosides which has been extremely difficult by other classical techniques.
From the stem bark of Commiphora dalzielii the isolation and identification of the 20,24-epoxydammarane triterpenes cabraleadiol 3-acetate, cabraleadiol and cabraleone and isofouquierone are reported. Both the acetate and isofouquierone appear to be novel. The chemotaxonomic implications of finding this type of triterpene in the Burseraceae are discussed.
In connection with structure studies on dammarane type triterpenes and their glycosides, assignments of 13C NMR signals of fifteen 20-hydroxy-dammarane derivatives including Ginseng sapogenins have been achieved by the aid of shift reagents and deuterated compounds. It has been found that the differences of the 17 C, 21 C and 22 C chemical shifts between pairs of C-20 epimers are remarkable especially in the case of 12β-hydroxy derivatives, being significant for the study of the C-20 stereochemistry.
Hydrolysis of the crude saponin extracted from the leaves of Panax notoginseng (Burk.) F. H. Chen yields five sapogenins which are separated by column chromatography. Two of these are identified to be panaxadiol and panaxatriol whose structures were elucidated earlier. The third sapogenin ist found to be Dammar-20(22)en-3beta, 12beta,-26-triol by carbon-13 NMR. The structure of the fourth sapogenin is established by X-ray diffractometry and carbon-13 NMR to be 20 ( R)-Dammaran-3beta, 12beta, 20, 25-tetrol.
The isolation and characterization of three novel triterpene glycosides 1-3 from the medicinal plant Ardisia japonica (Myrsinaceae) are described. The compounds are characterized by a branched oligosaccharide chain, composed of four sugar units. The oligosaccharide structures were determined by 1H-1H correlation spectroscopy (COSY, HOHAHA, ROESY) and 1H-13C heteronuclear correlation (HETCOR) nmr experiments. The aglycone moieties are the oleane-type triterpenes cyclamiretin A for 1 and the new 13,28-epoxy-30,30-dimethoxyolean-3 beta, 16 alpha-diol and 3 beta, 16 alpha-dihydroxy-13,28-epoxyolean-29-oic acid for 2 and 3, respectively.