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.

A novel synthesized 3', 5'-diprenylated chalcone mediates the proliferation of human leukemia cells by regulating apoptosis and autophagy pathways.

Leukemia is a hematologic malignancy with poor prognosis in humans and chemotherapy is the main strategy for treating leukemia patients. Novel drugs with better selectivity and lower toxicity are required for the treatment of patients. A novel 3',5'-diprenylated chalcone, (E)-1-(2-hydroxy-4-methoxy-3,5-diprenyl) phenyl-3-(3- pyridinyl)-propene-1-one (C10) is a potential new anti-leukemia agent. In this study, we investigated the molecular mechanisms of the anti-leukemia effects of C10 on different leukemia cells in vitro. C10 showed strong inhibition of proliferation of the human erythroleukemia cell line HEL and human myeloid leukemia cell line K562, and several cell and flow cytometer assays showed that inhibition by C10 was due to the regulation of gene expression or phosphorylation in the apoptosis and autophagy pathways. The results showed that C10 regulated the expression of Bax, c-Myc, Bcl-2, P38/AMPK and ERK 1/2, activated the expression of Caspase-3, -8, and PARP at the protein level in the apoptosis pathway of the two leukemia cell types, and inhibited the expression of erythroleukemia carcinogene Fli-1 in the human erythroleukemia cell line HEL. Additionally,treatment with the compound induced a time-dependent increase in expression of LC 3A/B via inhibiting the AKT-mTOR pathway, which is associated with cell autophagy. Taken together, the above results suggest that the novel synthesized 3',5'-diprenylated chalcone can prevent the growth of leukemia cells by inducing apoptosis and autophagy.

Novel 3',5'-diprenylated chalcones inhibited the proliferation of cancer cells in vitro by inducing cell apoptosis and arresting cell cycle phase.

A double Claisen rearrangements synthetic strategy was established for the total synthesis of 4,4'-dimethyl medicagenin (compound 6c). A series of its analogs also were prepared, including two novel 3',5'-diprenylated chalcones, in which ring B was replaced by azaheterocycle. The structures of the twenty-two newly synthesized compounds were confirmed by 1H NMR, 13C NMR and ESI-MS. In vitro, the cytotoxicity of the target compounds was evaluated using cancer cells. Noticeably, compound 10 exhibited broad-spectrum cytotoxicity on PC3 prostate cancer cells, MDA-MB-231 breast cancer cells (MDA), HEL and K562 erythroleukemia cells with IC50 values of 2.92, 3.14, 1.85 and 2.64 µM, respectively. Further studies indicated that compound 10 induced apoptosis and arrested the cell cycle phase of the above mentioned four cancer cell lines. By contrast, compound 6g selectively displayed potent inhibitory activity against the proliferation of HEL cells with an IC50 value of 4.35 µM. Compound 6g slightly induced apoptosis and arrested cell cycle phase of HEL cells. Preliminary structure-activity relationship studies indicated that, in all cancer cell lines evaluated, the 3-pyridinyl group was essential for cytotoxicity.

Metabolite identification of bentysrepinine (Y101), a novel anti-HBV agent in rats using a five-step strategy based on a combined workflow with two different platforms of liquid chromatography-tandem mass spectrometry.

Bentysrepinine (Y101), a derivative of repensine (a compound isolated from Dichondrarepens Forst), is a novel phenyalanine dipeptide inhibiting DNA-HBV and cccDNA activities and is currently under development for the treatment of hepatitis B virus (HBV)-infected hepatitis. Our previous study implied that there might be an existence of extensive metabolism of Y101 in rats. Therefore, it is necessary to perform metabolic profiling study to further evaluate its safety and drug-like properties. In this study, the metabolism of Y101 in rats was investigated by a convincible five-step strategy to characterize metabolites in plasma and that excreted into urine, bile and feces. The five-step strategy was realized by using an combined workflow on two different MS platforms, including various scan modes of liquid chromatography with hybrid quadruple-linear ion trap mass spectrometry (LC-QTRAP-MS/MS) and various post-acquiring data mining tools of liquid chromatography-quadrupole time-of-flight tandem mass spectrometry (LC-QTOF-MS/MS). QTOF MS/MS was employed as a powerful complementary tool to enable high confidence of metabolites identification using its functions of accurate MS and MS/MS fragmentation. As a result, a total of 30 metabolites were detected, including 25 phase I and 5 phase II metabolites. Among them, four primary metabolites (M6-M9) were further identified by comparing with the authentic standards chemically synthesized. The possible metabolic pathways of Y101 in rats were proposed to be amide hydrolysis, monohydroxylation, dihydroxylation, N-oxidation, demethylation, methylation, glucosidation and glucuronidation. This is the first study of the metabolism of Y101 in rats. The five-step strategy was successfully used to systematically characterize metabolites of Y101 in rats, and it would be generally applied for metabolite identification of new drug candidate.

Synthesis and Biological Evaluation of Matijin-Su Derivatives as Potential Antihepatitis B Virus and Anticancer Agents.

A series of Matijin-Su (MTS, (2S)-2-{[(2S)-2-benzamido-3-phenylpropanoyl]amino}-3-phenylpropyl acetate) derivatives were synthesized and evaluated for their anti-HBV and cytotoxic activities in vitro. Six compounds (4g, 4j, 5c, 5g, 5h and 5i) showed significant inhibition against HBV DNA replication with the IC50 values in range of 2.18 - 8.55 µm, which were much lower than that of positive control lamivudine (IC50 82.42 µm). In particular, compounds 5h (IC50 2.18 µm; SI 151.59) and 5j (IC50 5.65 µm; SI 51.16) displayed relatively low cytotoxicities, resulting in high SI values. Notably, besides the anti-HBV DNA replication activity, compound 4j also exhibited more potent in vitro cytotoxic activity than 5-fluorouracil in two hepatocellular carcinoma cell (HCC) lines (QGY-7701 and SMMC-7721), indicating that 4j may be a promising lead for the exploration of drugs with dual therapeutic effects on HBV infection and HBV-induced HCC.

[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.

Synthesis and anti-tumor activity evaluation of Matijin-Su derivatives.

A series of Matijin-Su (MTS, N-(N-benzoyl-l-phenylalanyl)-O-acetyl-l-phenylalanol) derivatives was synthesized and evaluated for their anti-tumor activities in hepatocellular carcinoma cells. The IC50 of compounds 1, 3, 4, 11, 13 were less than 20µM, and compound 1 and 3 showed an IC50 value of less than 9µM. Expansion inhibition could be found significantly in compound 1 and 3-treated human hepatoma cell HepG2 and PLC/PRF/5, while both compounds exhibit lower toxicity to human hepatocyte cell line L-02. Compound 1 and 3 could induce cell cycle arrest at G1/S phase. This may be attributed to increase level of intracellular reactive oxygen species (ROS). Up-regulation of p38 MAPK activity in responding the ROS stabilize p53 and activate p21 transcription, the critical regulatory in G1/S checkpoint. Observations in this study shed light on the potential of MTS derivatives compound 1 and 3 as novel suppressors to human liver cancer.

Vulgarisin A, a new diterpenoid with a rare 5/6/4/5 ring skeleton from the Chinese medicinal plant Prunella vulgaris.

Vulgarisin A (1), a new diterpenoid with an unprecedented 5/6/4/5 fused tetracyclic ring skeleton, has been isolated from the medicinal plant Prunella vulgaris Linn. Its structure was characterized by extensive spectroscopic methods, and the absolute configuration was secured by single crystal X-ray diffraction analysis. Compound 1 showed weak cytotoxicity against human lung carcinoma A549 cells with an IC50 value of 57.0 µM.

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.

Synthesis and biological evaluation of Matijing-Su derivatives as potent anti-HBV agents.

A series of Matijing-Su (MTS, N-(N-benzoyl-l-phenylalanyl)-O-acetyl-L-phenylalanol) derivatives were synthesized and evaluated for their anti-hepatitis B virus (HBV) activity in 2.2.15 cells. The IC(50) of compounds 14a (0.71 µM), 13c (2.85 µM), 13b (4.37 µM), etc. and the selective index of 13g (161.01), 13c (90.45), 13a (85.09) etc. of the inhibition on the replication of HBV DNA were better than those of the positive control lamivudine (IC(50): 82.42 µM, SI: 41.59). Compounds 13o, 13p, and 16a also exhibited significant anti-HBV activity.

Fangchinoline induces autophagic cell death via p53/sestrin2/AMPK signalling in human hepatocellular carcinoma cells.

BACKGROUND AND PURPOSE: Fangchinoline is a novel anti-tumour agent with little known of its cellular and molecular mechanisms of action. Here we have investigated the mode of cell death induced by fangchinoline and its underlying mechanism in two human hepatocellular carcinoma cell lines, HepG2 and PLC/PRF/5. EXPERIMENTAL APPROACH: Apoptosis and autophagy were monitored in fangchinoline-treated HepG2 and PLC/PRF/5 cells by histological methods. The signal transduction pathways involved in activation of autophagy were examined, using immunoblotting, real-time PCR and siRNA techniques. KEY RESULTS: Fangchinoline did not induce apoptosis in HepG2 and PLC/PRF/5 cells but triggered, dose-dependently, autophagy, an alternative mode of cell death which may contribute to fangchinoline's anti-tumour action. Nuclear translocation of p53 was involved in induction of autophagy by fangchinoline, followed by selective transactivation of the autophagy-related gene sestrin2 and initiation of the autophagic process. Signalling by the AMP-activated protein kinase was also involved as a downstream target of sestrin2 and induced mTOR-independent autophagic cell death in both cell lines. siRNA for Atg 5 or pharmacological block of p53 abolished fangchinoline-induced autophagy and inhibition of autophagy switched cell death to apoptosis in these cells, suggesting that cell death is irreversible once autophagy is induced by fangchinoline. CONCLUSIONS AND IMPLICATIONS: Fangchinoline is a highly specific agent inducing autophagic cell death in hepatocellular carcinoma cells with a novel mechanism, which elucidates the potential of fangchinoline to potentiate programmed cell death in cancer cells.

Aporphine alkaloids from the roots of Stephania viridiflavens.

Further investigation on the phytochemistry of the medicinal plant Stephania viridiflavens led to the isolation of a new naturally occurring aporphine alkaloid, (+)-6R, 6aS-isocorydine N(beta)-oxide (1), together with three known aporphine alkaloids: (+)-6R, 6aS-corydine N(beta)-oxide (2), (+)-N-methyl-laurotetanine (3) and (+)-stepharine (4). The structure and stereochemistry of 1 were determined on the basis of spectroscopic methods and confirmed by synthesis. Alkaloids 2-4 were isolated for the first time from this species.

[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.

Synthesis and anti-hepatitis B virus activities of Matijing-Su derivatives.

A series of derivatives of Matijing-Su (MTS, N-(N-benzoyl-L-phenylalanyl)-O-acetyl-L-phenylalanol) was synthesized and evaluated for their anti-hepatitis B virus (HBV) activities in 2.2.15 cells. The IC(50) of compounds 9c (1.40 microM), 9g (2.33 microM) and 9n (2.36 microM), etc. and the selective index of 9n (45.93) of the inhibition on the replication of HBV DNA were higher than those of the positive control lamivudine [41.59, (IC(50): 82.42 microM)]. Compounds 11d, 12a and 12e also exhibited significant anti-HBV activities.

A novel iridoid from Torricellia angulata var intermedia.

A new iridoid, named torricellate, was isolated from root bark of Torricellia angulata var intermedia, a Chinese folk medicinal plant used to treat bone fracture, tonsillitis and asthma. Its structure was elucidated by NMR, MS, IR and UV, and confirmed by X-ray diffraction studies.

Diastereoselective synthesis of aminobacteriohopanetetrol, a biomarker for methanotrophic bacteria: confirmation of the absolute configuration.

A short and convenient strategy was developed for the first stereoselective chemical synthesis of aminobacteriohopanetetrol (= (1R,2R,3S,4S)-5-amino-1-[(22R)-hopan-30-yl]pentane-1,2,3,4-tetrol; 1), a typical biomarker for methanotrophic bacteria. Comparison of the NMR spectra of the synthetic and natural (peracetylated) product enabled us to unambiguously corroborate the absolute configuration of the functionalized pentyl side chain of 1.

[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.