Pterocephin A, a novel Triterpenoid Saponin from Pterocephalus hookeri induced liver injury by activation of necroptosis

BACKGROUND

Pterocephalus hookeri (C. B. Clarke) Höeck, a Tibetan medicine widely used for treatment of rheumatoid arthritis, was recorded in Chinese Pharmacopoeia (2020 version) with slight toxicity. The liver injury was observed in mice with administration of n-butanol extract (BUE) in our previously study. However, the toxic components and the mechanism were still unrevealed.

PURPOSE

The present study was aimed to isolate and structural elucidate of the toxic compound pterocephin A (PA), as well as evaluate its liver toxicity and investigate its mechanism.

METHODS

PA was isolated from the BUE of P. hookeri. Its structure was determined by analysis of HRMS, NMR and ECD data. L-02 cellular viability, LDH, ALT, AST, ROS, intracellular Ca²⁺ and the fluidity of cell membrane were assessed by multifunctional microplate reader. The PI staining, cell membrane permeability assessment, and mitochondrial fluorescence staining analysis were determined through the fluorescence microscope. Liver samples for mice were assessed by pathological and immunohistochemistry analysis. Expression levels of indicated proteins were measured by western blotting assays.

RESULTS

PA was determined as a previously undescribed oleanolane-type triterpenoid saponin. In vitro study revealed PA significantly induced hepatotoxicity by inhibition of L-02 cell growth, abnormally elevation of ALT and AST. Mechanically, PA induced the damage of cell membrane, fragmentation of mitochondria, and subsequently increase of intracellular Ca²⁺ and ROS levels, which trigged by necroptosis with the activation of RIP1 and NF-κB signaling pathways. In vivo study confirmed PA could induce liver injury in mice with observation of the body weight loss, increasing of serum ALT and AST, and the histopathological changes in liver tissues.

CONCLUSION

Our present study indicated that PA was an undescribed toxic constituent in P. hookeri to induce liver injury in mice by activation of necroptosis and inflammation. And the findings are of great significance for the clinical use safely of this herb.

[Investigation on intestinal absorption ingredients and their absorption characteristics in Pterocephali Herba by everted intestinal sac method]

The intestinal absorption characteristics of ten iridoid glycosides and phenolic acids in the Pterocephali Herba were evaluated via rat intestinal valgus model. The intestinal sac fluids at different time after administration of high,medium and low concentrations of Pterocephali Herba extract were collected and ten chemical components in fluid samples were detected by UPLC-PDA. Accumulative absorbed doses( Q) and absorption rate constants( Ka) of ten chemical constituents were calculated,while proportions between Pterocephali Herba extract and intestinal absorption liquid were compared. The results showed that the intestinal absorption of 10 chemical components was linear absorption( R2>0. 9) at different concentrations,which accorded with the zero-order absorption rate. The absorption rate constant was related to the concentration of the drug and the intestinal site,which indicated that intestinal adsorption mechanism of the components were passive diffusion and active transport. Proportions of chemical constituents in intestinal sac fluid were different from those in Pterocephali Herba extract. Therefore,those ten chemical components in Pterocephali Herba extract can be absorbed in whole intestine. Everted intestinal sac model can be used to evaluate intestinal absorption characteristics of ingredients in Pterocephali Herba extract effectively.

Attraction of Culex pipiens pallens (Diptera: Culicidae) to Floret Volatiles and Synthetic Blends of Its Nectar Host Plant Abelia chinensis (Rubiales: Caprifoliaceae)

Abelia chinensis R. Br. (Dipsacales: Caprifoliaceae) is one of the preferred nectar host plants for Culex pipiens pallens Coquillett (Diptera: Culicidae). However, the volatile compounds of its flowers that might be involved in directing mosquitoes' orientation to its nectaries remain unknown. In the present study, the volatile compounds released by A. chinensis florets were collected by solid phase microextraction fiber and analyzed by gas chromatography-mass spectrometry system. Based on the major component species in the volatile profile, a synthetic phytochemical blend (Blend B, composed of six compounds at their most attractive concentrations) was formulated, and its attractiveness was tested against the pentane extract of A. chinensis florets at most attractive concentration (Blend A) and a formerly developed synthetic phytochemical blend (Blend C) in the olfactometer, respectively. The results revealed that the volatile profile of A. chinensis florets was mainly composed of aromatic compounds, most of which had been reported to be attractive to other mosquito species. The synthetic Blend B was as attractive as Blend A (10-1-fold of the crude pentane extract) in the olfactometer bioassays, but they were not as attractive as the formerly developed Blend C. The present study indicated that quantitative and qualitative differences in the constituents of phytochemical blends could significantly affect their attractiveness to Cx. pipiens pallens, and the capture efficiency of phytochemical attractants deserves further research before being applied in the field.

Antinociceptive and anti-inflammatory activities of a standardizedextract of bis-iridoids from Pterocephalus hookeri

ETHNOPHARMACOLOGICAL RELEVANCE

Pterocephalus hookeri (C.B. Clarke) Höeck, one of the most popular Tibetan herbs, has been widely applied in Tibetan medicine prescriptions. Chemical investigations have led to the isolation of many bis-iridoids. However, the pharmacological activities of bis-iridoid constituents of this plant have never been reported before.

AIM OF THE STUDY

This study evaluated the anti-inflammatory and analgesic activities of afraction of bis-iridoid constituents of P. hookeri (BCPH) in order to provide experimental evidence for its traditional use, such as for cold, flu, and rheumatoid arthritis.

MATERIALS AND METHODS

The analgesic effects of BCPH were investigated using the hot-plate test and acetic acid-induced writhing test. The anti-inflammatory activities were observed using the following models: carrageenin-induced edema of the hind paw of rats and xylene-induced ear edema in mice. The effects of dexamethasone administration were also studied.

RESULTS

BCPH significantly increased the hot-platepain threshold and reduced acetic acid-induced writhing response in mice. Moreover, BCPH remarkably inhibited xylene-induced ear edema and reduced the carrageenin-induced rat paw edema perimeter.

CONCLUSION

The results reveal that BCPH has central, peripheral analgesic activities as well as anti-inflammatory effects, supporting the traditional application of this herb in treating various diseases associated with inflammation and pain.

The anti-arthritic activity of total glycosides from Pterocephalus hookeri, a traditional Tibetan herbal medicine

CONTEXT

Pterocephalus hookeri (C. B. Clarke) Hock., a traditional Tibetan herbal medicine rich in glycosides, has been used to treat several diseases including rheumatoid arthritis.

OBJECTIVE

To evaluate the anti-arthritic activity of total glycosides from P. hookeri, and its possible mechanisms of action.

MATERIALS AND METHODS

Anti-arthritic activity of total glycosides from P. hookeri (oral administration for 30 days at 14-56 mg/kg) was evaluated using paw swelling, arthritis scores and histopathological measurement in adjuvant-induced arthritis (AA) Sprague-Dawley rats. The NF-κB p65 expression in synovial tissues, and serum superoxide dismutase (SOD) activity, malondialdehyde (MDA) and nitric oxide (NO) levels was measured in AA rats, respectively. Further assessment of anti-inflammatory and analgesic activities of these glycosides were carried out using inflammation and hyperalgesia models induced by xylene, carrageenan, agar and acetic acid, respectively.

RESULTS

Total glycosides (56 mg/kg) decreased the paw swelling (38.0%, p < 0.01), arthritis scores (25.3%, p < 0.01) and synovial inflammation in AA rats. The glycosides significantly (p < 0.05-0.01) attenuated the inflammation induced by xylene, carrageenan, acetic acid and agar, increased the pain threshold in acetic acid-induced writhing in mice and mechanical stimuli-induced hyperalgia in AA rats. The glycosides (14, 28, 56 mg/kg) also suppressed the NF-κB p65 expression (33.1-78.2%, p < 0.05-0.01), reduced MDA (21.3-35.9%, p < 0.01) and NO (20.3-32.4%, p < 0.05-0.01) levels, respectively, enhanced the SOD activity (7.8%, p < 0.05) at 56 mg/kg in AA rats.

DISCUSSION AND CONCLUSION

Our findings confirmed the anti-arthritic property of the total glycosides from P. hookeri, which may be attributed to its inhibition on NF-κB signalling and oxidative stress.

Heavy metals in the soils and plants from a typical restored coal-mining area of Huainan coalfield, China

This study was conducted to pursue the heavy metals in the soil and plants of a typical restored coal-mining area, China. The average concentrations of Cu, Zn, Cr, Ni, and Pb in soil were 26.4, 76.1, 188.6, 34.3, and 50.2 mg kg^-1, respectively, implying a significant accumulation of Cr, Ni, and Pb compared with the background values. Contamination factor indicates that the soil underwent none to medium pollution by Cu and Zn, medium to strong by Cr, none to strong by Pb, and medium pollution by Ni while the pollution load index means that the soil was subjected to intermediate contamination. Based on the critical threshold values to protect the plants, the investigated metals were unable to affect the plants. One-way ANOVA analysis shows that Cu, Zn, and Pb in plants varied with plant tissues. Cu-Cr, Cu-Ni, Zn-Ni, Zn-Pb, Cr-Ni, and Ni-Pb pairs had significant positive correlation both in soil and in plants due to the similar soil characteristics and plant physiologies. Correspondence analysis indicates that Pb was more likely to be accumulative in stems and leaves. In addition, the levels of Cu and Cr in plant followed an order of roots > stems > leaves; Zn and Ni leaves ≥ stems > roots; and Pb followed stems ≥ leaves > roots. Generally, this study suggests that the plants like Ligustrum lucidum Aiton and Weigela hortensis, which are capable of accumulating Cr, Ni, and Pb, should be the predominant species in the studied area.

Variability in the production of tannins and other polyphenols in cell cultures of 12 Nordic plant species

The polyphenol profiles of 18 cell cultures from 12 plant species were screened. The detected polyphenol fingerprints were diverse and differed from polyphenol profiles typically found in corresponding plant species. Cell cultures originating from 12 different plant species growing or grown in the Nordic countries were screened for their ability to synthesize polyphenols to assess their suitability for future studies and applications. The focus was on plant families Rosaceae and Ericaceae. On average, the Rosaceae cultures were the most efficient to produce hydrolysable tannins and the Ericaceae cultures were the most efficient to produce proanthocyanidins. This is in line with the general trend of polyphenols found in Rosaceae and Ericaceae leaves and fruits, even though several individual cell cultures differed from natural plants in their polyphenolic composition. Overall, several of the studied cell cultures exhibited capability in producing a large variety of polyphenols, including tannins with a high molecular weight, thus also showing promise for further studies concerning, for example, the accumulation of specific polyphenols or biosynthesis of polyphenols in the cell cultures.

Immunomodulatory, hemolytic properties and cytotoxic activity potent of triterpenoid saponins from Cephalaria balansae

Phytochemical investigations on n-butanol extract of Cephalaria balansae Raus. (Caprifoliaceae) led to the isolation of four previously undescribed triterpenoid saponins based on hederagenin type aglycone, namely, balansoides A-D, along with ten known compounds. Their structures were proposed based on 1D and 2D NMR spectroscopic data, HRESIMS analysis and chemical evidence as 3-O-α-L-rhamnopyranosyl-(1 → 3)-β-D-xylopyranosyl-(1 → 3)-α-L-rhamnopyranosyl-(1 → 2)-α-L-arabinopyranosyl hederagenin, 3-O-α-L-rhamnopyranosyl-(1 → 3)-β-D-xylopyranosyl-(1 → 3)-α-L-rhamnopyranosyl-(1 → 2)-α-L-arabinopyranosyl hederagenin 28-O-β-D-glucopyranosyl ester, 3-O-α-L-rhamnopyranosyl-(1 → 3)-β-D-xylopyranosyl-(1 → 3)-α-L-rhamnopyranosyl-(1 → 2)-α-L-arabinopyranosyl hederagenin 28-O-β-D-galactopyranosyl-(1 → 6)-β-D-glucopyranosyl ester and 3-O-α-L-rhamnopyranosyl-(1 → 3)-β-D-xylopyranosyl-(1 → 3)-α-L-rhamnopyranosyl-(1 → 2)-α-L-arabinopyranosyl hederagenin 28-O-β-D-glucopyranosyl-(1 → 6)-β-D-glucopyranosyl ester. The four saponins were evaluated for their potential cytotoxic activity against HEK-293, A-549, HeLa cells and for hemolytic properties on human blood cells. Balansoide A displayed significant inhibitory effects on cancerous A-549 and HeLa cells, and non-cancerous HEK-293 cells with IC₅₀ values of 12, 15 and 8 μM, respectively. Balansoides A-D together with n-butanol extract exhibited considerable hemolysis in human erythrocyte cells. Immunomodulatory properties of balansoides A-D were also evaluated in activated whole blood cells by PMA plus ionomycin. While balansoides A-C increased IL-1β concentration with values of 1004.47, 991.57 and 966.50 pg/ml, only balansoide B augmented a slight IFN-γ secretion with value of 5219.14 pg/ml. None of the compounds changed IL-2 levels significantly.

[Simultaneous determination of ten major compounds including iridoid glycosides and phenolic acids in Pterocephalus hookeri by UPLC-PDA]

This study is to develop an UPLC-PDA method for determination of 10 major components in Pterocephalus. The UPLC-PDA assay was performed on a Waters Acquity UPLCR BEH C₁₈（2.1 mm ×100 mm,1.7 μm）, and the column temperature was at 30 ℃. The mobile phase consists of water containing 0.2% phosphoric acid (A) and acetonitrile (B) in gradient elution at a flow rate of 0.4 mL•min⁻¹. The detection wave length was set at 237 and 325 nm, and the injection volume was 1 μL in the UPLC system. The linear range of 10 detected compounds were good (r≥0.999 7), and the overall recoveries ranged from 96.30% to 103.0%, with the RSD ranging from 0.72% to 2.9%. The method was simple, accurate and reproducible, which can be used for the simultaneous determination of the content of ten major components in P. hookeri.

Oleanolic acid and hederagenin glycosides from Weigela stelzneri

Four previously undescribed and one known oleanolic acid glycosides were isolated from the roots of Weigela stelzneri, and one previously undescribed and three known hederagenin glycosides were isolated from the leaves. Their structures were elucidated mainly by 2D NMR spectroscopic analysis and mass spectrometry as 3-O-β-D-glucopyranosyl-(1 → 2)-[β-D-xylopyranosyl-(1 → 4)]-β-D-xylopyranosyl-(1 → 4)-β-D-xylopyranosyl-(1 → 3)-α-L-rhamnopyranosyl-(1 → 2)-α-L-arabinopyranosyloleanolic acid, 3-O-β-D-glucopyranosyl-(1 → 2)-[β-D-xylopyranosyl-(1 → 4)]-β-D-xylopyranosyl-(1 → 4)-β-D-xylopyranosyl-(1 → 3)-α-L-rhamnopyranosyl-(1 → 2)-β-D-xylopyranosyloleanolic acid, 3-O-β-D-glucopyranosyl-(1 → 2)-[β-D-glucopyranosyl-(1 → 4)]-β-D-xylopyranosyl-(1 → 4)-β-D-xylopyranosyl-(1 → 3)-α-L-rhamnopyranosyl-(1 → 2)-β-D-xylopyranosyloleanolic acid, 3-O-β-D-glucopyranosyl-(1 → 2)-[β-D-xylopyranosyl-(1 → 4)]-β-D-xylopyranosyl-(1 → 4)-β-D-xylopyranosyl-(1 → 3)-α-L-rhamnopyranosyl-(1 → 2)-α-L-arabinopyranosyloleanolic acid 28-O-β-D-glucopyranosyl-(1 → 6)-β-D-glucopyranosyl ester, and 3-O-β-D-glucopyranosyl-(1 → 2)-α-L-arabinopyranosylhederagenin 28-O-β-D-xylopyranosyl-(1 → 6)-[α-L-rhamnopyranosyl-(1 → 2)]-β-D-glucopyranosyl ester. The majority of the isolated compounds were evaluated for their cytotoxicity against two tumor cell lines (SW480 and EMT-6), and for their anti-inflammatory activity. The compounds 3-O-β-D-glucopyranosyl-(1 → 2)-[β-D-xylopyranosyl-(1 → 4)]-β-D-xylopyranosyl-(1 → 4)-β-D-xylopyranosyl-(1 → 3)-α-L-rhamnopyranosyl-(1 → 2)-α-L-arabinopyranosyloleanolic acid and 3-O-β-D-glucopyranosyl-(1 → 2)-[β-D-xylopyranosyl-(1 → 4)]-β-D-xylopyranosyl-(1 → 4)-β-D-xylopyranosyl-(1 → 3)-α-L-rhamnopyranosyl-(1 → 2)-β-D-xylopyranosyloleanolic acid exhibited the strongest cytotoxicity on both cancer cell lines. They revealed a 50% significant inhibitory effect of the IL-1β production by PBMCs stimulated with LPS at a concentration inducing a very low toxicity of 23% and 28%, respectively.

[Study on genetic-chemical relation of Pterocephali Herba based on DNA barcode and UFLC]

DNA barcoding technique in combination with UFLC analysis technology was used to evaluate the quality of Tibetan medicine Pterocephalus hookeri from species identification and chemical qualitative and other aspects. Hybrid identification was established by DNA barcoding; UFLC-PDA was adopted to analyse fingerprint of different parts of Pterocephali Herba, and SPSS and Grey relation software were used for data analysis. The result showed that DNA barcoding is an accurate and reliable method in origin identification of Pterocephalus hookeri. The compounds in overground is more than underground by analysis of the different part fingerprint by UFLC. The genetic gene may be involved in the secondary metabolites of iridoid glycosides. Pertinence between gene and chemical component, as a new model established, could be suited for quality evaluation and resources protection.

[UFLC-PDA fingerprint of Tibetan medicine Pterocephalus hookeir]

This study was aimed to establish an UFLC fingerprint of Tibetan medicine Pterocephalus hookeir samples from different habitats. UFLC-PDA was adopted to analyse 21 batches of P. hookeir samples from different habitats. The chromatographic condition was as follow: Agilent proshell 120 SB-C18 column (4.6 mm x 100 mm, 2.7 microm) eluted with the mobile phases of acetonitrile and 0.2% phosphoric acid water in gradient mode. The flow rate was 1.0 mL x min(-1), and the detection wavelength was set at 238 nm. The fingerprints of 21 batches P. hookeir were carried out by similarity comparation, and 15 chromatographic peaks were extracted as the common peaks of fingerprint, of which 5 peaks were identified as chlorogenic acid, loganin, sweroside, sylvestroside III, triplostoside A. The similarity degrees of 18 batchs of samples were above 0.9, and the other 3 batchs of samples were below 0.9. This is the first established fingerprint of P. hookeir by using UFLC-PDA. This method has good precision, stability and repeatability that it could provide basis for quality control and evaluation of P. hookeir.

[Spectrum-effect correlation analysis of traditional Tibetan medicine "Morina nepalensis" on nitric oxide production inhibition]

OBJECTIVE

To establish an HPLC-ELSD fingerprint of the whole herbs of Morina nepalensis and perform the correlation analysis of chemical components of the herb and nitric oxide (NO) production inhibition.

METHOD

HPLC-ELSD assay was performed to evaluate 10 batches of M. nepalensis herbs. The chromatographic conditions were as following: Eclipse XDB C18 column (4.6 mm x 150 mm, 5 microm), water (A) and acetonitrile (B) as a gradient mobile phases, flow rate 1.0 mL x min(-1), and column temperature at 35 degress C. Evaporative light-detection conditions: atomization temperature at 104 degrees C, the flow rate of N2 2.8 L x min(-1) and 10 microL sample injection. Chromatographic fingerprint was developed, and the inhibition activity of production of NO in lipopolysaccharide-induced macrophages was also analyzed. The similarity and correlation analysis between the HPLC-ELSD fingerprints and NO production inhibition were carried out by PLS method.

RESULT

The common mode for M. nepalensis herb fingerprint was established, including 15 common characteristic peaks. Among them, 7 peaks were positively correlated with the NO production inhibition. According to the assessment on the similarity of 10 batches of samples, a similarity of over 0.90 were shown in HPLC-ELSD fingerprint and all samples were separated into two groups.

CONCLUSION

This method can be used to assess the quality of M. nepalensis, which provides a reliable method for scientific assessment and quality control.

Two new ursolic acid saponins from Morina nepalensis var. alba Hand-Mazz

A saponin-enriched fraction was prepared from the EtOH extract of the whole plant of Morina nepalensis var. alba Hand-Mazz. It showed α-glucosidase inhibitory activity, from which two new triterpene saponins (1 and 2), along with one known saponin (3), were isolated. The structures of the new saponins were identified by spectroscopic analysis, including extensive 1D and 2D NMR techniques and hydrolysis followed by chromatographic analysis. The three saponins were assayed for α-glucosidase inhibitory activities.

[Change of the content of chemical constituents and anti-oxidative action of the decoction of radix ginseng combined with Flos Lonicerae, radix Polygoni Multiflori and Radix Astragali]

Ginsenosides in the decoction of Radix Ginseng, Radix Ginseng with Flos Lonicerae, Radix Polygoni Multiflori or Radix Astragali have been investigated by high performance liquid chromatography (HPLC) and electrospray ionization mass spectrometric method (ESI-MS). Change of the content of ginsenosides was nonlinear in diverse combinative proportion of Radix Ginseng with Flos Lonicerae, while the stripping of ginsenosides was promoted by a small amount of Radix Polygoni Multiflori. In the combinative decoction of Radix Ginseng with Radix Astragali, ginsenosides contents were increased compared to single decoction of Radix Ginseng. Besides, ferric reducing antioxidant power (FRAP) method was developed for determination of the total antioxidative activity of n-butanol and water-soluble extracts from the decoction. The experimental results showed that antioxidative activity was better in the combinative decoction than that in single decoction, and the FRAP values of n-butanol extract were also greater compared with that of water extract.

Stimulation of glucose uptake by triterpenoids from Weigela subsessilis

Four ursane-type triterpenoids, corosolic acid (1), ilekudinol B (2), ursolic acid (3) and pomolic acid (4), were isolated from an EtOAc-soluble extract of the leaves of Weigela subsessilis. These bioactive compounds were evaluated for their glucose uptake activity and produced moderate to strong enhancement both in basal- and insulin-stimulated L6 muscle cells. In particular, corosolic acid exhibited the most potent activity, increasing uptake by basal- and insulin-stimulated myotubes by 2.63- and 3.33-fold, respectively; ilekudinol B produced 1.6- and 2.9-fold, ursolic acid produced 1.84- and 2.64-fold, and pomolic acid produced 1.6- and 2.8-fold increases. No cytotoxicities were observed for corosolic acid, ursolic acid and ilekudinol B in myoblasts, while pomolic acid at doses of 25 and 50 microm reduced cell viability by 19% and 21.8% upon 24 h treatment and by 48.6% and 54.1% upon 48 h treatment, respectively. These results suggest that ursane-type triterpenoids from W. subsessilis might enhance glucose uptake by acting as insulin mimics and as insulin sensitizers and that they could be useful as nontoxic diabetes treatment agents.

Protectivity of blue honeysuckle extract against oxidative human endothelial cells and rat hepatocyte damage

The effect of Lonicera caerulea L. (blue honeysuckle) phenolic fraction (18.5% anthocyanins) on cell viability and against oxidative damage in low density lipoproteins (oxLDL), in rat microsomes and in primary cultures of rat hepatocytes and human umbilical vein endothelial cells (HUVEC), was tested. The phenolic fraction was nontoxic to rat hepatocytes and HUVEC at tested concentrations (1-1000 microg/mL) and time intervals up to 24 h inclusive. Phenolic fraction inhibited rat liver microsome peroxidation, induced by tert-butyl hydroperoxide (tBH), with IC(50) values of 160 +/- 20 microg/mL. The fraction at 0.5, 1.0, and 2.0 microg/mL delayed LDL oxidation, induced by Cu(2+), by 130 +/- 20%, 200 +/- 30%, and 400 +/- 10%, respectively. The treatment of HUVEC with oxidatively modified LDL induced an increase in lactate dehydrogenase (LDH) leakage and thiobarbituric acid reactive substances (TBARS) formation, and resulted in lower formazan formation from 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) uptake, most pronounced for 200 microg/mL (24 h oxidation) after 2 h of incubation. The protective effect of the phenolic fraction against cell damage caused by oxLDL was noted at 0.1 microg/mL for HUVEC and against tBH at 1000 microg/mL for both HUVEC and hepatocytes. The observed protective effects were probably due to the antioxidant properties of L. caerulea constituents, mainly anthocyanins. Microsome peroxidation and LDL oxidation inhibition results provide promising perspectives into the prevention of some oxidative stress-associated diseases. Other data are important in in vitro systems but seem to be accidental in vivo.

[The applications of fourier transform infrared spectroscopy in resolving some taxonomic doubts of Caprifoliaceae]

Fourier transform infrared spectroscopy (FTIR) provides biochemical profiles containing overlapping signals from a majority of the compounds that are present when whole.samples are analyzed. The spectra of the xylem of 112 samples belonging to 12 species and 5 genera in Caprifoliaceae were determined directly with FTIR spectrometry and OMNI-sampler. Based on the indices of wave number -absorbance, the phylogenetic relationships of the 12 species were analyzed by the methods of principal coordinate analysis (PCO) and cluster analysis. The results showed that the infrared spectra of the 12 plant species are finger-print-like patterns which are highly typical for different taxa. Genus Heptacodium has close relation with the tribe Linnaeeae, and Lonicereae, showing that its systematic position is probably located between the two tribes. There is no obvious difference between Viburnum and Sambucus, so the authors thought it would be better to put the two genera in Caprifoliaceae. Therefore, the infrared spectra are of taxonomic value at the level of species and genera, and this technique could be widely used for identification and classification of other taxa when standard spectra are available.

Lonicera Implexa leaves bearing naturally laid eggs of the specialist herbivore Euphydryas Aurinia have dramatically greater concentrations of iridoid glycosides than other leaves

We tested in the field the hypothesis that the specialist butterfly Euphydryas aurinia (Lepidoptera: Nymphalidae, Melitaeinae) lays eggs on leaves of Lonicera implexa (Caprifoliaceae) plants with greater iridoid concentrations. We conducted our investigations in a Mediterranean site by analyzing leaves with and without naturally laid egg clusters. There were no significant differences in iridoid glycoside concentrations between leaves from plants that did not receive eggs and the unused leaves from plants receiving eggs, a fact that would seem to indicate that E. aurinia butterflies do not choose plants for oviposition by their iridoid content. However, the leaves of L. implexa that bore egg clusters had dramatically greater (over 15-fold) concentrations of iridoid glycosides than the directly opposite leaves on the same plant. These huge foliar concentrations of iridoids (15% leaf dry weight) may provide specialist herbivores with compounds that they either sequester for their own defense or use as a means of avoiding competition for food from generalist herbivores. Nevertheless, it may still be possible that these high concentrations are detrimental to the herbivore, even if the herbivore is a specialist feeder on the plant.

Inhibitory effect on TNF-alpha-induced IL-8 production in the HT29 cell of constituents from the leaf and stem of Weigela subsessilis

Twelve compounds were isolated from the MeOH extract of the leaf and stem of the Korean endemic plant Weigela subsessilis L. H. Bailey. Their chemical structures were elucidated on the basis of physicochemical and spectroscopic data and by comparison with those of published literatures. These compounds were identified as three sterols, beta-sitosterol acetate (2), betasitosterol (3), daucosterol (11), eight triterpenoids, squalene (1), ursolic acid (4), ilekudinol A (5), corosolic acid (6), ilekudinol B (7), esculentic acid (8), pomolic acid (9), asiatic acid (10), and one iridoid glycoside, alboside I (12). This is the first report pertaining to the isolation of these compounds from Weigela subsessilis L. H. Bailey. In addition, three compounds 7, 9, and 12 were found to display a strong inhibitory effect on the production of IL-8 in the HT29 cells stimulated by TNF-alpha.

Distribution and contents of phenolic compounds in eighteen Scandinavian berry species

Berries contain a wide range of phenolic compounds in different conjugated forms, a fact that makes their simultaneous analysis a difficult task. In this work, soluble and insoluble phenolic compounds were identified and quantified in 18 species of berries by reversed phase high-performance liquid chromatography combined with diode array detection. The analytical results and literature data were used for the identification of the predominant conjugated hydroxycinnamic acids, flavonol glycosides, and anthocyanins in berries from six families, viz. Grossulariaceae, Ericaceae, Rosaceae, Empetraceae, Elaeagnaceae, and Caprifoliaceae. The study showed distinctive similarities among berry species of the same family in the distribution of conjugated forms of phenolic compounds but differences in chromatographic profiles of conjugates and compositions of aglycones especially in the case of anthocyanins. The chromatographic profiles of chokeberry and the related sweet rowanberry (Rosaceae) were exceptionally similar. These data are informative to studies on the authenticity of berry raw materials as well as to those on the evaluation of berries as sources of phenolic compounds.

Investigation of Pictet-Spengler type reactions of secologanin with histamine and its benzyl derivative

The reaction of secologanin (1) (mainly in its tetraacetylated form 1a) with histamine (2) and its benzyl derivative (2b) was investigated. With the benzylated amine (2b), the main product was the normal, tetraacetylated benzyl derivative of histeloside having the R configuration at the new center of chirality, C-1 (5b), with a small amount of an unidentified minor component (probably the 1S epimer 5a). In a slightly acidic medium, the reaction with histamine (2) gave two products in an approximately 6:4 ratio. The main compound proved to be the normal, tetraacetylated derivative of the lactam histelosamide with R configuration at C-1 (7b), and the minor product was the tetraacetylisohisteloside with S configuration at the same C-1 center (3a). When the reaction was carried out under acid-free conditions, in addition to the epimeric pair of the normal tetraacetylated lactam (7a, 7b) and the tetraacetylisohisteloside with 1S configuration (3a), tetraacetylneohistelosamide (8b) was also isolated, in which the cyclization took place at one of the cyclic nitrogens of the imidazole ring. Probably, this latter compound is an intermediate also in the formation of the normal isomers, but under slightly acidic conditions it rapidly isomerized into the normal alkaloid. The tendencies experienced previously in the tryptamine and dopamine series were observed also in the histamine series; that is, at C-1, the R configuration is favored over the S one, and lactamization is faster in the former than in the latter case. The structure of the products and their stereoschemistry were established by NMR spectroscopy.

Cyclooxygenase inhibitory and antioxidant cyanidin glycosides in cherries and berries

Anthocyanins from tart cherries, Prunus cerasus L. (Rosaceae) cv. Balaton and Montmorency; sweet cherries, Prunus avium L. (Rosaceae); bilberries, Vaccinum myrtillus L. (Ericaceae); blackberries, Rubus sp. (Rosaceae); blueberries var. Jersey, Vaccinium corymbosum L. (Ericaceae); cranberries var. Early Black, Vaccinium macrocarpon Ait. (Ericaceae); elderberries, Sambucus canadensis (Caprifoliaceae); raspberries, Rubus idaeus (Rosaceae); and strawberries var. Honeoye, Fragaria x ananassa Duch. (Rosaceae), were investigated for cyclooxygenase inhibitory and antioxidant activities. The presence and levels of cyanidin-3-glucosylrutinoside 1 and cyanidin-3-rutinoside 2 were determined in the fruits using HPLC. The antioxidant activity of anthocyanins from cherries was comparable to the commercial antioxidants, tert-butylhydroquinone, butylated hydroxytoluene and butylated hydroxyanisole, and superior to vitamin E, at a test concentration of 125 microg/ml. Anthocyanins from raspberries and sweet cherries demonstrated 45% and 47% cyclooxygenase-I and cyclooxygenase-II inhibitory activities, respectively, when assayed at 125 microg/ml. The cyclooxygenase inhibitory activities of anthocyanins from these fruits were comparable to those of ibuprofen and naproxen at 10 microM concentrations. Anthocyanins 1 and 2 are present in both cherries and raspberry. The yields of pure anthocyanins 1 and 2 in 100 g Balaton and Montmorency tart cherries, sweet cherries and raspberries were 21, 16.5; 11, 5; 4.95, 21; and 4.65, 13.5 mg, respectively. Fresh blackberries and strawberries contained only anthocyanin 2 in yields of 24 and 22.5 mg/100 g, respectively. Anthocyanins 1 and 2 were not found in bilberries, blueberries, cranberries or elderberries.

[Preliminary studies on chemotaxonomy of Caprifoliaceae L]

OBJECTIVE

To study the taxonomy of Caprifoliaceae.

METHOD

Using chemotaxonomical methods to discuss the distribution characteristics of chemical constituents in Caprifoliaceae family.

RESULTS

Iridoids and flavonoids were confirmed as the characteristic constituents of Caprifoliaceae family.

CONCLUSION

Though there are great deviations among the genera of Caprifoliaceae family, it is not recommended to separate genus Sambucus and genus Viburnum from Caprifoliaceae family.

[Influence of drug compatibility on extractive retes of chlorogenic acid and isochlorogenic acid in simiaoyonglan tang decoction]

OBJECTIVE

To study the influence of drug compatibility on the extractive rates of chlorogenic acid and isochlorogenic acid in Simiaoyonglan Tang (SMYAT) decoction.

METHOD

The contents of chlorogenic acid and isochlorogenic acid in SMYAT decoction, Flos Lonicerae and Flos Lonicerae in combination with other single drugs were determined by TLC-UV spectrophotometry respectively. The data from this experiment were treated statistically.

RESULTS

The contents of chlorogenic acid in other five prescriptions of different compatibilities decreased markedly in comparison with those in Flos Loniceraés decoction (P < 0.01). The content of isochlorogenic acid in SMYAT decoction as a whole was about the same as thar in Flos Loniceraés decoction, but decreased significantly in other prescriptions of different compatibilities (P < 0.01).

CONCLUSION

Drug compatibility is one of the main causes for changes of chlorogenic acid and isochlorogenic acid contents in SMYAT decoction.