Novel sesquiterpenoids isolated from Chimonanthus praecox and their antibacterial activities.

In the present study, four new sesquiterpenoids, chimonols A-D (compounds 1-4), together with four known compounds (5-8) were isolated from the EtOAc extract of Chimonanthus praecox Link. The structures of these new compounds were elucidated on the basis of spectroscopic techniques (UV, IR, MS, and 1D and 2D NMR), and their absolute configurations were established by comparing experimental and calculated electronic circular dichroism (ECD) spectra. Compounds 1-8 were evaluated for antimicrobial activities and the minimum inhibitory concentrations (MICs) were determined by the broth microdilution method in 96-well culture plates. Compounds 1, 2, and 7 exhibited weak antibacterial effects for S. aureus (ATCC 6538), E. coli (ATCC 11775), and P. aeruginosa (ATCC 10145) with MIC values being 158-249 µg·mL-1. Compounds 3-7 showed activities against C. glabrata (ATCC 2001) and S. aureus (ATCC 43300) with MIC values being 128-197 µg·mL-1. Compounds 1-4 showed activity against S. aureus (ATCC 25923) with MIC values being 162-254 µg·mL-1. The present study provided a basis for future evaluation of these compounds as antibacterial agents.

[The in vitro transport mechanism of bentysrepinine: a novel anti-hepatitis B virus drug candidate].

Bentysrepinine (Y101), a derivative of phenylalanine dipeptide, is a novel drug candidate for the treatment of hepatitis B virus (HBV) infection. Our previous preclinical pharmacokinetic study showed that its in vivo absorption and distribution characteristics were probably related to transmembrane transport after Y101 was administered intragastically in rats. In this study, Caco-2 and MDCK-MDR1 cell models were used to investigate interactions between Y101 and P-gp through the apparent permeation coefficient (P(app)) and efflux ratio (RE); the results showed that Y101 was a substrate of P-gp. In addition, gene-transfected cell models, HEK293-h OATP1B1, HEK293-h OATP2B1 and CHO-PEPT1 were used to evaluate the affinity to OATP1B1, OATP2B1 and PEPT1. The results suggest that Y101 has a weak inhibitory effect on OATP1B1 and OATP2B1, and Y101 may not be substrates of OATP1B1, OATP2B1 or PEPT1. The above results can be used to explain the in vivo absorption and distribution characteristics, and to provide a scientific basis for the further development of Y101.

[Studies on flavonoids from Derris eriocarpa].

Derris eriocarpa, a traditional Chinese medicine belonging to the family of Leguminosae, is widely distributed mainly over Yunnan, Guangxi and Guizhou of China. Modern pharmacological researches on this herb showed that it had extensive bioactivities, such as promoting urination, removing dampness and cough and reducing inspissated mucus and other biological activities. The extensive studies on the chemical constituents of this plant have resulted in the isolation of triterpenoids, steroids, fatty acid and others, but the flavone compounds haven't reported before. In our further research on the ethyl acetate of this plant, nine flavone compounds were obtained by column chromatography on silica gel, Sephadex LH-20, semi-prep HPLC, polyamide column chromatography and recrystallization for separation and purification. The structures were determined on the basis of extensive spectroscopic analysis, including MS, NMR experiments and comparison with spectroscopic data in the literature, respectively, as diosmetin (1), 3, 3'-di-O-methylquercetin (2), afromosin (3), 6, 3'-dihydroxy-7, 4'-dimethoxyisoflavone (4), odoratin (5), 7, 3'-dihydroxy-8, 4'-dimethoxyisoflavone (6), 6, 4'-dihydroxy-7, 3'-dimethoxyisoflavone (7), 5, 7, 4'-trihydroxy-3, 3', 5'-trimethoxyflavone (8), and alpinumisoflavone (9). All these compounds were isolated from Derris eriocarpa How for the first time. And the in vitro assays showed that compound 2 possessed moderate inhibitory activity against human cancer cells K562 and HEL.

A novel franchetine type norditerpenoid isolated from the roots of Aconitum carmichaeli Debx. with potential analgesic activity and less toxicity.

Further investigation on the phytochemistry of the plant Aconitum carmichaeli Debx. led to isolate a new franchetine type C(19)-diterpenoid alkaloid, guiwuline 1. Its structure was established on the basis of the spectroscopic data (1D and 2D NMR, HRESIMS, UV, IR). In mouse hot-plate test and acute toxicity assay, compound 1 exhibited potential analgesic activity (ED(50), 15 mg/kg) and showed little toxicity to mice (LD(50), 500 mg/kg). The results indicate that compound 1 may be used as a lead molecule to develop novel analgesic agents.

[Chemical constituents from rhizome of Daphne papyracea var. crassiuscula].

OBJECTIVE: To study chemical constituents from rhizome of Daphne papyracea var. crassiuscula. METHOD: Ethyl acetate fraction of 75% ethanol extracts from rhizome of D. papyracea var. crassiuscula, and its strucutre was identified by spectral method. RESULT: Nine compounds were separated and identified as daphneticin (1), daphnetin (2), hydrangetin (3), daphnoretin (4), 1-4'-hydroxyphenyl-5-phenyl-2 (E)-en-1-pentanone (5), daphneolon (6), 3beta-O-acetyl-olean-12-en (7), and (+)-usnic acid (8). CONCLUSION: Compounds 1-8 were separated from D. papyracea var. crassiuscula for the first time. Compound 8 was separated from the genus for first time.

[Study on the chemical constituents of Humulus scandens].

OBJECTIVE: To study the chemical constituents of Humulus scandens. METHODS: The compounds were isolated by column chromatography on silica gel and Sephadex LH-20. The structures were identified by means of IR, 1H-NMR,13C-NMR and MS analyses. RESULTS: Seven compounds were isolated and identified as friedelanone (I), cis-asarone (II), epifriedelanol (III), stigmasta-4-ene-3,6-dione (IV), gamma-sitosterol (V), n-hexadecanoic acid (VI), and linoleic acid (VII), respectively. CONCLUSION: All compounds are isolated from this species for the first time and compounds I - V are obtained from this genus for the first time.

[Determination of glycyrrhizic acid in different decoctions of sanaotang by HPLC and comparison with antifugal effects in vitro].

OBJECTIVE: To investigate the contents of glycyrrhizic acid in hejian decoction (mixed the traditional Chinese herbs together, then boiling them with water) and the fenjian decoction (boiling the single traditional Chinese herb with water separately, then mixed the abstracts) of Sanaotang (composed of Ephedra sinica, Prunus armeniaca and Glycyrrhiza uralensis) and to compare with their anti-bacterial activities in vitro. METHOD: A HPLC method was established with a Agilent Zorbax SB-C18 column (4. 6 mm x 250 mm, 5 microm), a mobile phase of acetonitrile-0.2% acetic acid solution (35:65), a flow rate of 1 mL x min(-1) and a detection wavelength of 254 nmn in order to determine the contents of glycyrrhizic acid minimal bacterial inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) antagonized the common bacteria in different decoctions were rieasured in vitro by employing dilution method. RESULT: The average content of glycyrrhizic acid of the hejian decoction was higher than that of the fenjian decoction. The hejian decoction could display the inhibitory bactericidal activity to Aeruginosus bacillus, but the fenjian decoction could not. And to Staphylococcus aureus, the inhibitory bactericidal activity the hejian decoction was slightly stronger than that of the fenjian decoction. CONCLUSION: Comparing with that of the fenjian decoction, the content of glycyrrhizic acid of the hejian decoction was higher and the anti-bacterial activities was stronger.

[Comparative study on transdermal osmosis in vitro of Aconitum brachypodium liniment, gel and patcher].

OBJECTIVE: To study the transdermal osmosis process of Aconitum brachypodum's liniment, gel and patcher to provide basis for selecting dosage form and controlling the quality. METHOD: Taking the cumulate rate of transdermal as index, a imitated Fick's diffusion device was used for the investigating the transdermal osmosis course of the three preparations. The best transdermal mathematics models are obtained and the relations between the transdermal course and the release course are analysed. RESULT: The three preparations have different characteristics of transdermal osmosis course. The liniment meets dynamics 0 order process, the gel and the patcher meet dynamic 0 order process of non-corroded drug system. And the relation is good cubic equation between their transdermal course and release course. CONCLUSION: The transdermal osmosis experiment in vitro for three preparations can provide basis for selecting dosage form and the quality control in future studies.

[Studies on factors influencing on ephedrine contents in Maxing Shigan decoction].

OBJECTIVE: To investigate the factors influencing on the ephedrine contents in different compositions of Maxingshigan decoction. METHOD: Adopt mixed uniform design to dismantle recipes, employ the stepping regression analysis to deal with experimental statistics, use the partial correlational analysis to analyze the correlation coefficients and the results were validated. RESULT: The regressive equation was of significance, that is Y = 4.36719347 + 7.752707437X1 + 1.2557197041X3 (r = 0.85564, P = 0.0189). The main influencing factors on ephedrine content in Maxingshigan decoction were gypsum and amygdalin. The influent factor of amygdalin on ephedrine content had great significance, and gypsum had significance. CONCLUSION: The collective effects of amygdalin and gypsum affect the content of ephedrine in Maxing Shigan decoction which the content-effect relationship was in direct correlation.

[Determination of contents of amygdalin in traditional and granular decoctions of Maxingshigan decoction by HPLC].

OBJECTIVE: To determine the contents of amygdalin in traditional and granular decoctions of Maxingshigan decoction. METHODS: The determination was carried out by HPLC with an ODS column and a mobile phase of water-methanol (23:77) at 215 nm. RESULTS: The content of amygdalin in traditional decoction of Maxingshigan Decoction was 17.74 mg/g and 24.80 mg/g in granular one. CONCLUSION: The content of glycyrrhizic acid in traditional decoction of Maxingshigan decoction is obviously higher than that in granular one.

Terpenoids from the seeds of Artemisia annua.

Fourteen sesquiterpenes, three monoterpenes and one diterpene natural product have been isolated from the seeds of Artemisia annua. The possible biogenesis of some of these natural products are discussed by reference to recently reported experimental results for the autoxidation of dihydroartemisinic acid and other terpenoids from Artemisia annua.

[Measurement of baicalin contents by HPLC].

OBJECTIVE: To compare the contents of baicalin in the raw medical material and the different prepared medical materials of Scutellaria baicalensis. METHOD: The contents of baicalin were determined by HPLC. Chromatographic conditions included Hypersil C18 column and the mobile phase consisting of a mixture of methanol-0.04% phosphoric acid (46:54). Baicalin was detected at 280 nm. The standard curve was linear in the range of 0.0280-4.6700 micrograms with correlation coefficient 1.0000. The average recovery of baicalin was 101.22% with RSD = 2.54% (n = 5). RESULT: The contents of baicalin were 6.80% in raw material, 6.00% and 6.73% in the different prepared medical materials of S. baicalensis respectively. CONCLUSION: The two different kinds of preparing methods can be used to the raw material of S. baicalensis.

[Study on the chemical constituents of the volatile oil from Lysimachia trientaloides Hemsl].

The volatile oil from Lysimachia trientaloides Hemsl. was obtained by steam distillation. The chemical constituents were separated and identified by gas chromatography-mass spectrometry (GC-MS). The relative contents in the volatile oil were determined by peak area normalization. The yield of oil by steam distillation was 0.11%, and 40 chemical constituents were separated and identified. Terpenic series and their oxo-derivatives are major chemical constituents in the oil. The main compounds were patchouli alcohol(22.54%), L-bornyl acetate(16.17%), gamma-gurjunene(3.27%), delta-guaiene(2.62%), nerolidol(2.02%), linalool(1.99%) and palmitic acid(1.96%).