Four new triterpenoid saponins from Conyza blinii

Spermacosides a and B, two new triterpenoid saponins from Spermacoce ocymoides burm.f

Two new triterpenoid saponins, named spermacosides A-B (1 - 2), together with two known oleanane-type triterpenoid saponins, 3-O-β-D-xylopyranosyl-(1→3)-β-D-glucopyranosylbayogenin (3) and 3-O-β-D-glucopyranosylbayogenin (4), were isolated from the ethyl acetate extract of Spermacoce ocymoides Burm.f. in a phytochemical investigation. Their chemical structures were elucidated by spectroscopic data analysis (1D and 2D NMR, and HR-ESI-MS), as well as comparison with reported data. All these compounds were evaluated for inhibiting nitric oxide production in lipopolysaccharide-stimulated RAW 264.7 cells. Among them, 1 showed a slight effect with an IC50 value of 108.65 ± 7.91 µM, and compounds 2-4 were inactive.

β-Amyrin synthase from Conyza blinii expressed in Saccharomyces cerevisiae

Conyza blinii H.Lév. is a widely used medicinal herb in southwestern China. The main pharmacological components of C. blinii are a class of oleanane-type pentacyclic triterpene glycosides known as conyzasaponins, which are thought to be synthesized from β-amyrin. However, no genes involved in the conyzasaponin pathway have previously been identified. Here, we identify an oxidosqualene cyclase (OSC), a β-amyrin synthase, which mediates cyclization of 2,3-oxidosqualene to yield β-amyrin. Ten OSC sequences were isolated from C. blinii transcript tags. Phylogenetic analysis was used to select the tag Cb18076 as the putative β-amyrin synthase, named CbβAS. The open reading frame of CbβAS is 2286 bp and encodes 761 amino acids. Its mature protein contains the highly conserved motifs (QXXXGXW/DCTAE) of OSCs and (MWCYCR) of β-amyrin synthases. Transcription of CbβAS was upregulated 4-24 h after treatment of the seedlings of the C. blinii cultivar with methyl jasmonate. Furthermore, expression of CbβAS in Saccharomyces cerevisiae successfully yielded β-amyrin. The chemical structures and concentrations of β-amyrin were confirmed by GC-MS/MS. The target yeast ultimately produced 4.432 mg·L^-1 β-amyrin. Thus, CbβAS is an OSC involved in conyzasaponin biosynthesis.

ESI-MS2 and Anti-inflammatory Studies of Cyclopropanic Triterpenes. UPLC-ESI-MS and MS2 Search of Related Metabolites from Donella ubanguiensis

INTRODUCTION

Triterpenes are one of the largest secondary metabolites groups spread in the plant kingdom with various skeletons. These metabolites have showed various bioactivities including anti-inflammatory activity.

OBJECTIVE

The study aims to explore the mass spectrometry fragmentation of donellanic acids A-C (DA A-C), three compounds identified from Donella ubanguiensis; in addition, the fragmentation behaviour of these metabolites will serve as a fingerprint to search and characterise triterpenes congeners in fruits, bark and wood crude extracts of D. ubanguiensis. This work was prompted by the anti-inflammatory activity on leukocyte migration, exudate concentrations and myeloperoxidase activity obtained for DA A-B.

METHODOLOGY

The bioactivity was performed on mouse model of pleurisy induced by carrageenan and the parameters were analysed by veterinarian automated cell counter and colorimetric assays. While the tandem mass analyses of DA A-C were carried out by a direct infusion ESI-QTOF-MS/MS, the extracts were studied by UPLC-ESI-QTOF-MS and UPLC-ESI-QTOF-MS/MS.

RESULTS

DA A displayed interesting anti-inflammatory activity by inhibiting leukocyte migration, exudate concentrations and myeloperoxidase activity (p < 0.05) while DA B was weakly active (p > 0.05). Moreover, the diagnostic of the MS² behaviour of DA A-C in conjunction with the chromatograms and the obtained MS² data of the crude extract led to the characterisation of three cyclopropane triterpenes (T1-T3) and six saponins (T4-T9) from the fruits, the bark, and the wood extracts.

CONCLUSIONS

Donella species deserve more investigation since metabolites related to the anti-inflammatory compound (DA A) could be identified. Copyright © 2016 John Wiley & Sons, Ltd.

A triterpenoidal saponin fraction of Conyza blinii H.Lév. is a dual-targeting autophagy inhibitor for HeLa cells

Autophagy is a highly conserved cellular process in eukaryotic cells. The triterpenoidal saponin fraction (Conyza blinii saponins, CBS) isolated from medicinal plant Conyza blinii H.Lév. is a dual-targeting autophagy inhibitor for HeLa cells.

Evaluation of the anti-cancer activity of the triterpenoidal saponin fraction isolated from the traditional Chinese medicine Conyza blinii H. Lév

Triterpenoidal saponins fraction isolated from a traditional Chinese medicine Conyza blinii H. Lév. demonstrates anti-cancer activity both in vitro and in vivo.

The protective activity of Conyza blinii saponin against acute gastric ulcer induced by ethanol

ETHNOPHARMACOLOGICAL RELEVANCE

Conyza blinii H.Lév., is a type of natural plant. Its dried overground section is used to treat infections and inflammations in traditional Chinese medicine. Triterpenoidal saponins have a wide range of bioactivities, for instance, anti-cancer, anti-virus and anti-anaphylaxis. Conyza blinii saponin (CBS), mainly composed of triterpenoidal saponins, is the total saponin of Conyza blinii H.Lév. It has been reported that CBS also has gastric mucous membrane protection activity. This study aims to test CBS׳s protective activity of gastric׳s mucous membrane against ethanol. This investigation may lead to the development of novel drug from natural products as anti-ulcer agent, or as gastric mucous protective against chemical damage.

MATERIALS AND METHODS

CBS (Conyza blinii saponin) is the total saponin of Conyza blinii H.Lév., which was obtained as described previously. We tested the protective activity of CBS against ethanol-induced ulcer. Thirty six rats were grouped randomly as 'NORMAL', 'CONTROL', 'MODEL', 'LOW DOSE', 'MEDIUM DOSE' and 'HIGH DOSE'. The 'NORMAL' group were rats with no pathological model established within it. The 'CONTROL' group was administrated with colloidal bismuth subcitrate, while 'MODEL' group was not given any active agents apart from absolute ethanol in order to obtain gastric ulcer model. The three 'DOSE' groups were treated with different concentrations of CBS (5, 10, 20mg/mL) before administration followed by absolute ethanol. All rats were sacrificed after the experiment to acquire the gastric tissue. The ulcer index (UI), malondialdehyde (MDA) and superoxide dismutase (SOD) were measured to monitor the activity of CBS. Besides, the rat gastric tissue was made to paraffin section and stained using the Hematoxylin-Eosin (HE) method. The histopathology examination was carried out to examine CBS efficacy in terms of gastric mucous protection.

RESULTS

We found that CBS had a profound protection activity against acute gastric ulcer induced by ethanol and this activity displayed a concentration-dependent manner. The efficacy of 10 and 20mg/mL CBS was comparable with colloidal bismuth subcitrate (P<0.05). All three level of CBS tested were able to significantly reduce UI, MDA and enhance SOD level (P<0.05).

CONCLUSIONS

It was deduced that the mechanism for such activity would be anti-lipid peroxidation, facilitating free radicals clearance. In addition , histopathology examination of the gastric mucous membrane supported the same conclusion, that CBS can efficiently suppress the inflammatory reactions, bleeding and protect the gastric mucosa.

Structural elucidations and spectral assigments of two novel triterpene glycosides from Cephalaria paphlagonica

Two novel triterpene glycosides, paphlagonoside A (1) and B (2), were characterised as 28-O-[beta-D-glucopyranosyl(1 --> 2)-alpha-L-arabinopyranosyl(1 --> 4)-beta-D-glucopyranosyl]-hederagenin (1) and 28-O-[beta-D-xylopyranosyl(1 --> 4)-alpha-L-rhamnopyranosyl(1 --> 3)-beta-D-xylopyranosyl (1 --> 6)-beta-D-glucopyranosyl(1 --> 2)-beta-D-glucopyranosyl]-hederagenin (2) from Cephalaria paphlagonica (Dipsacaceae). In addition to these, a common natural product (hederagenin) (3) was also isolated. The structures of all compounds were identified by spectroscopic and chemical methods. The antimicrobial and antioxidant activities of the plant extracts were examined by MIC and DPPH activity methods, respectively.

Rapid characterization of triterpene saponins from Conyza blinii by liquid chromatography coupled with mass spectrometry

Conyza blinii Le'vl is a medicinal herb used for the treatment of inflammation in Chinese folk medicine. Its major bioactive constituents are triterpene saponins, most of which contain 6-8 sugar residues. In this report, electrospray ionization tandem mass spectrometry fragmentation behaviors of bisdesmosidic triterpene saponins (conyzasaponin A, B, and C) were studied in both positive and negative ion modes with an ion-trap mass spectrometer. In full scan mass spectrometry, these saponins gave predominant [M-H](-) and [M+Na](+) ions, which determined the molecular weights. In tandem mass spectrometry (MS(n), n = 2-4), the [M-H](-) and [M+Na](+) ions yielded fragments [Y(0α)-H](-) and [B(α)+Na](+), which were diagnostic for the structures of the triterpene skeleton and sugar chains. The structural elucidation was approved by accurate mass data using IT-TOF-MS. An interpretation guideline based on MS(n) (n = 2-4) diagnostic ions was proposed in order to elucidate the chemical structures of unknown triterpene saponins in C. blinii extract. The saponins in C. blinii were separated by liquid chromatography with a methanol/acetonitrile/water solvent system, and then analyzed by ion-trap and IT-TOF mass spectrometers. Based on the interpretation guideline, a total of 35 triterpenoid saponins were tentatively identified. Among them, 15 saponins had been previously reported, and the other 20 saponins were reported from Conyza species for the first time. This study indicates that LC/MS is a powerful technology for the rapid characterization of complicated saponins in herbal extracts.

Antimicrobial triterpenoid glycosides from Cephalaria scoparia

Five new oleanane-type triterpenoid glycosides (1-5), named scoposides A-E, along with one known bisdesmosidic triterpene glycoside, were isolated from the aerial parts of Cephalaria scoparia. Three prosapogenins (2a-4a) were also obtained after alkaline hydrolysis of the bisdesmosidic compounds 2-4. The structures of compounds 1-5 were determined by spectroscopic (1D and 2D NMR, HRESIMS) and chemical methods. The antimicrobial effects of compounds 1-5 were evaluated against a small panel of Gram-positive and Gram-negative bacteria.

A Novel Glycoside from Acanthus hirsutus (Acanthaceae)

A novel glycoside, hirsutusoide (1), characterized as 2-( o-hydroxyphenyl)-2-hydroxyethenyl- O-β-glucopyranoside, was isolated from the endemic Acanthus hirsutus Boiss. In addition to compound 1, three known glycosides, luteolin-7- O-β-D-glucuronide (2), β–sitosterol-3- O-β-D-glucopyranoside (3) and (2 R)-2- O-β-D-glucopyranosyl-2 H-1,4-benzoxazin-3(4 H)-one (4), were also isolated. Compound 2 was the first report from this genus. Antimicrobial and antioxidant activity of the extracts and the novel compound were investigated by determining MIC (μg/mL) and IC50 (μg/mL) values, respectively.

Analysis of carbohydrates and glycoconjugates by matrix-assisted laser desorption/ionization mass spectrometry: an update covering the period 2001-2002

This review is the second update of the original review on the application of MALDI mass spectrometry to the analysis of carbohydrates and glycoconjugates that was published in 1999. It covers fundamental aspects of the technique as applied to carbohydrates, fragmentation of carbohydrates, studies of specific carbohydrate types such as those from plant cell walls and those attached to proteins and lipids, studies of glycosyl-transferases and glycosidases, and studies where MALDI has been used to monitor products of chemical synthesis. Use of the technique shows a steady annual increase at the expense of older techniques such as FAB. There is an increasing emphasis on its use for examination of biological systems rather than on studies of fundamental aspects and method development and this is reflected by much of the work on applications appearing in tabular form.

Biological activities and distribution of plant saponins

Plant saponins are widely distributed amongst plants and have a wide range of biological properties. The more recent investigations and findings into their biological activities were summarized. Isolation studies of saponins were examined to determine which are the more commonly studied plant families and in which families saponins have been identified.

A new nitroethylphenolic glycoside from Semiaquilegia adoxoides

The isolation of a new nitroethylphenolic glycoside, 4-hydroxy-1-(2-nitroethyl) benzene 4-O-(6'-O-beta-D-xylopyranosyl)-beta-D-glucopyranoside (1), from the roots of Semiaquilegia adoxoides is reported.