Synthesis,antimicrobial, antiquorum-sensing and cytotoxic activities of new series of benzothiazole derivatives

New series of benzothiazole derivatives were designed and synthesized. The newly synthesized compounds were screened for their antibacterial activity against Escherichia coli, Staphylococcus aureus and Bacillus cereus. Compounds 6j and 6o showed the highest activity against E. coli and S. aureus. The antifungal activity of these compounds was also tested against Candida albicans and Aspergillus fumigatus293. Compounds 4c, 4g and 6j exhibited the highest activity against C. albicans. In addition, compounds4 a and 6j displayed promising activity against A. fumigatus 293. The same compounds were examined for their antiquorum-sensing activity against Chromobacterium violaceum ATCC 12472, whereas compounds4 a, 6j and 6p showed moderate activity. The in vitro cytotoxicity testing of the synthesized compounds was performed against cervical cancer(Hela) and kidney fibroblast cancer(COS-7) cell lines. Results indicated that all tested compounds have IC50 values 50 mmol/L against both cell lines. Molecular properties, toxicities, drug-likeness, and drug score profiles of compounds 4a–c, 5a, 6g,h, 6j, 6l, 6o and7 c,d were also assessed.     

Novel synthetic acridine-based derivatives as topoisomerase Ⅰ inhibitors

Novel DNA binding agents against topoisomerases are needed for effective treatment of cancers. A series of new acridine-based derivatives 7a–7d were synthesized and their antiproliferative activity against K562 and HepG-2 cell lines were evaluated. Compound 7c with pyridin-2-yl-methanamino group substituted at the C9 position of acridine showed good antitumor activity against both cell lines. The DNA-binding affinity of compound 7c was evaluated by UV–vis absorption spectra and fluorescence emission spectra. DNA topoisomerase I mediated relaxation of plasmid pBR322 DNA was also tested. Our results suggested that compound 7c with good antitumor activity and topoisomerase I inhibition activity can be developed as a prime candidate for further chemical optimization.     

A Styrylpyrone Dimer from the Bark of Goniothalamus leiocarpus

A dimer of styrylpyrone derivative, leiocarpin E(1), was isolated from the bark of Goniothalamus leiocarpus. Its structures was elucidated by means of spectral and chemical methods. The cytotoxicity of leiocarpin E against HL-60 cells was tested.     

Study on the synthesis and antimicrobial activity of novel cationic porphyrins

A novel series of quaternary ammonium cationic derivatives based on tetrapyridyl-porphyrin was synthesized.All the compounds were evaluated for their in vitro antibacterial activities against S.aureus,E.coli and P.aeruginosa,and antifungal activities against C.albicans,where microorganisms were exposed and unexposed to the irradiation.The results revealed that some of these compounds,especially,3a and 4a displayed satisfactory antibacterial activity against Gram-positive bacteria S.aureus and moderate an...     

A cytotoxic pyrrolidinoindoline diketopiperazine dimer from the algal fungus Eurotium herbariorum HT-2

A new cytotoxic pyrrolidinoindoline diketopiperazine dimer, cristatumin E （1）, was isolated from the fermentation broth of the algal fungus Eurotium herbariorum HT-2 associated with the marine algae, Enteromorpha prolifera. The structure was determined by spectroscopic analyses and Marfey＇s amino acid analysis. Cristatumin E （1） showed cytotoxicity against K562 tumor cell line and antibacterial activity against Enterobacter aerogenes and Escherichia coli with IC50 and MIC values of 8.3, 44.0 and 44.0 μmol/L, respectively.     

Synthesis of 6,8-dichloroquinolones utilizing new method and evaluation of their antibacterial activities

Several 6,8-dichloroquinolone analogues were synthesized from the key intermediate compound of 2,3,4,5-tetrachlorobenzene carbonyl chloride,which was obtained from the starting material of tetrachlorophthalic anhydride.Their in vitro antibacterial activities were evaluated.As a result of this study,compounds 21c and 21d were twofold more potent than ciprofloxacin (CPFX) and norfloxacin (NFLX) against Staphylococcus aureus-9,and with the same potent as CPFX and NFLX while against Escherichia coli-2,but were less potent than references in against Pseudomonas aeruginosa-17.     

Design,synthesis and antitumor activity of 3-substituted quinolone derivatives （Ⅰ）

A series of quinolone derivatives containing benzimidazole, benzoxazole or benzothiazole ring were synthesized. The cytotoxicity of 12 new compounds was evaluated in KB, Be17402, A2780 and HT-29 cell lines. Most of synthesized compounds showed moderate inhibitory activity against cancer cells. The inhibitory activities of 6k, against KB and A2780 tumor ceils are comparable to that of topotecan, one of topoisomerase I inhibitors.     

黄烷类衍生物的合成及其生物活性研究

An efficient and feasible synthetic approach was developed for the synthesis of an array of new flavane derivafives from the substituted benzaldehyde with the reduction of chalcones and subsequent cyclization as the key steps. The purity and structure of the products were confirmed by the elemental analysis and a combination of its IR, ^1H and ^13C NMR, and mass spectra. These synthetic compounds were tested for xanthine oxidase （XO） inhibitions and antifungal actions against Candida albicans, Cryptococcus neoformans, Aspergillus sp. and Trichophyton rubrum. 7-Hydrazinocarbonylmethoxy-4＇-methoxyflavane （9） was found to be the most XO inhibitory with IC50=76.4 μmol/L, and the most potent antifungal compound was 4＇-hydrazinocarbonylmethoxyflavane （12） with minimal inhibition concentration MIC=8 μg/mL against Trichophyton rubrum.     

Lignan glucoside from Sinopodophyllum emodi and its cytotoxic activity

A new lignan glycoside was isolated from the n-butanol extract of the roots and rhizomes of Sinopodophyllum emodi.On the basis of spectral evidences,its structure was established and named as 4,5-didemethylpodophyllotoxin 7’-O-β-D-glucopyranoside. This compound showed cytotoxicity against four human cancer cell lines(Hela,K562,SH-SY5Y and CNE) in vitro.     

Synthesis and structure-activity relationship of rhodomyrtone derivatives as antibacterial agent

To study structure-activity relationship of rhodomyrtone against Gram-positive bacteria,structural modification of rhodo-myrtone was carried out to afford its 10 analogues.All compounds were assayed for their antibacterial potency using broth microdilution method.The results indicated that rhodomyrtone exhibited higher antibacterial activity against all Gram-positive bacteria than its analogues,with the exception of rhodomyrtone 6,8-diacetate(3) and oxime analogues 6 and 7 which demonstrated similar activity as the parent compound against Bacillus subtilis and Staphylococcus epidermidis with minimum inhibitory concentration and minimum bactericidal concentration ranged from 1 to 4μg/mL and 2 to 4μg/mL,respectively.In contrast,all analogues displayed no activity against Acinetobacter baumannii.Hydroxyl and ketone groups of rhodomyrtone were elucidated to be essential for the antibacterial property.     

Euphoractone,a cytotoxic meroterpenoid with an unusual ent-abietane-phloroglucinol skeleton,from Euphorbia fischeriana Steud.

A novel meroterpenoid,euphoractone(1),was isolated from the extracts of the roots of Euphorbia fischeriana Steud.Its structure was determined by spectroscopic methods and X-ray crystallography.1 possesses an unusual ent-abietane-phloroglucinol skeleton.The plausible biosynthetic pathway for 1 was proposed.1 showed inhibitory activities against human lung cancer H23 and H460 cells with the IC₅₀values of 21.07±3.54 and 20.91±4.07 μmol/L.     

DICHLOROETHYL CARBAMOYL ESTER OF DELTA-9-TETRAHYDROCANNABINOL——CHEMICAL SYNTHESIS AND BIOLOGICAL TESTING AND EVALUATION AS A POTENTIALLY SITE-SPECIFIC ANTI-TUMOR AGENT

A novel compound, Delta-9-Tetrahydrocannabinol Nitrogen Mustard (THC-mustard), waschemically synthesized and characterized. The rationale was to target a known anti-tumoragent, nitrogen mustard, to tumor cells with "THC Receptors" and/or "Estrogen Recep-tots", A microtest by vitro bioassay was designed and developed to compare the ID50of the drug in cell culture against various tumor cell types. The ID50's of the THC-mustardwere determined against several tumor cell types in culture, compared with MechlorethamineHCI, Delta-9-Tetrahydrocannabinol (THC), and an equimolar mixture of THC and nitrogennmstard. A preliminary toxicity study by the NCI of the THC-mustard (in vivo) in Swissmale mice bearing the P388 tumor (1 dose × 1day) by the I. P. route was also carried out.A deseription of the rationale, chemical synthesis and characterization, bioassay, and resultsis herewith presented.     

Syntheses and Anti-cancer Activities of Derivatives of Tetrandrine and Fangchinoline

A series of derivatives of tetrandrine and fangchinoline was designed and synthesized to find more active anti-cancer compounds. Their anti-cancer activities were tested against human hcpatocellular carcinoma BEL-7402 and PLC/PRF/5 cells, human lung adenocarcinoma A549 cells as well as human leukaemia K562 cells, and the structure-activity relationship（SAR） was also studied. All the compounds except BI exhibited superior inhibitory ac- tivities against PLC/PRF/5 cells with half maximal inhibitory conccntration（ICs0） values of less than 15 μmol/L, and compounds A2, A4, B2 and B4 showed IC50 values of less than 9 pmol/L. Compounds A2, A6, B2 and B4 showed potent anti-cancer activities against all the tested cells with 1C5o values of less than 10 pmol/L. The results show that terandrine and fangchinoline derivatives are potential suppressors to human cancer.     

Design,Synthesis and Antitumor Activity in vitro of a Series of 3-Arylcoumarins

A new series of 7-substituted 3-arylcoumarins was designed, synthesized and evaluated as novel antitumor agents in vitro. It was found that several compounds of them exhibit activity in vitro against SK-HEP-l（hepatocellular carcinoma）, HepG2（hepatocellular carcinoma） and SGC7901（gastric carcinoma） cell lines to some extent. Moreover, compounds 5a, 5b, 6a and 6b have better activity against HeLa（cervical carcinoma） cell and their half maximal inhibitory concentration（IC50） values are less than 10μmol/L.     

Toxicity （-lgEC50） Measurement of the Fluorobenzene Derivants against Vibrio Qinghaiensis （Q67） and Their 2D,3D-QSAR Study

Toxicities (-lgEC50) of 16 fluorobenzene derivants against vibrio qinghaiensis (Q67) were measured systematically,and their quantum chemistry parameters were calculated at the B3LYP/6-311G** level. Based on the experimental toxicity data and quantum chemistry parameters,2D-QSAR model was proposed,which was validated by variance inflation factors (VIF),t-value and cross-validation method. At the mean time,comparative molecular force field (CoMFA) based on molecular simulation was used to investigate the toxicity of fluorobenzene derivants. Furthermore,the intoxicating mechanism of fluorobenzene derivants was discussed. To our interest,2D-QSAR and CoMFA models exhibit good prediction ability,with which the toxicity of similar compounds can be predicted. Finally,toxicities (-lgEC50) of 12 fluorobenzene derivants against vibrio qinghaiensis (Q67) were predicted with these models.     

Functional Mechanism of Resveratrol in Inhabiting Growth of Cells Is174t and Its Mechanism in Subcutaneously Transplanted Tumor of Nude Mice

To explore the functional mechanism of Resveratrol against colon cancer cells ls174t and the growth of colon cancer tissue of tumor-bearing mice, MTT method was used to observe the functions of resveratrol for inhibition against cells ls174t in vitro. Transmission electron microscope was used to observe the cell apoptosis. FCM assay was performed to measure the change of the cell apoptosis rate and of cell cycle. RT-PCR method was used to detect the expressions of bcl-2 and bax mRNA. Western blot method was used to detect the expressions of bcl-2 and bax protein. Ceils ls174t were transplanted subcutaneously to nude mice to observe the effect of resveratrol on the growth of subcutaneously transplanted tumor, RT-PCR method was used to detect the expressions of bcl-2 and bax mRNA in the tumor tissue. Western blot method was used to detect the expressions of bcl-2 and bax protein in the tumor tissue. Resveratrol has an effect of inhibiting proliferation of cells ls174t in vitro（P〈0.01）. It is able to induce the apoptosis of cells ls174t, causing the decrease in the expression of bcl-2 and the increase in the expression of bax. Resveratrol could inhibit the growth of subcutaneously transplanted tumor of nude mice（P〈0.05）, causing the decrease in the expression of bcl-2 and the increase in the expression of bax. Resveratrol can inhibit the growth of cells 174t and the growth of subcutaneously transplanted tumor. The mechanism is possibly related to the induction of the cell apoptosis and the regulation of bcl-2/bax expression.     

Purification and Crystallization of Flammulin, a Basic Protein with Anti—tumor Activities from Flammulina Velutipes

Flammulin, an anti-tumor protein, was purified from the aqueous extract of basidiomes of Flammulina Velutipes to electrophoretic homogeneity and crystallized by microdialysis against a polyethylene glycol- sodium phosphate buffer. The purified product was found to have marked anti-tumor effects and be able to affect the tumor cells directly.     

Modification of Sugar Chains in Glycoalkaloids and Variation of Anticancer Activity

To study the effect of the sugar chains in glycoalkaloids against cancer cells, 6-O-sulfated solamargine and acid-catalyzed hydrolytic products of α-solamargine and α-solasonine were prepared. The sulfation at O-6 of solamargine was proceeded in five steps. The 6-OH group was first selectively protected with DMT-Cl, and then the secondary hydroxyl groups on the sugar ring were acetylated. After the protective group DMTr was removed, the free 6-OH group was sulfated. Finally, the acetyl groups were removed to give 6-O-sulfated solamargine in a good yield. The hydrolyses of solamargine and solasonine were performed in diluted hydrogen chlorede. Three and two hydrolyzed products were obtained from solamargine and solasonine, respectively. The antiproliferative activities against HCT-8 tumor cells of two glycoalkaloids and their derivaties were examined via a MTT assay. The results show that α-solamargine and α-solasonine exhibit strong cytotoxic activities with an IC50 of 10.63 and 11.97 μmol/L, respectively, wheras their derivaties seem to be less activities.     

Expression of Catalytic Domain of Protein Tyrosine Phosphatase 1B and Preparation of Its Polyclonal Antibody

This study focuses on the expression of human protein tyrosine phosphatase 1B(PTP1B) catalytic domain (△PTP1B) and preparation of polyclonal antibody against △PTP1B. △PTP1B gene was PCR amplified with the cDNA of human PTP1B as the template, and cloned into the pT7 expression vector. The recombinant pT7-△PTP1B was expressed in E. coli Rosetta( DE3 ) host cells and purified. The antiserum was prepared by immunizing rabbit with purified recombinant △PTP1B. The polyclonal antibody against △PTP1B was purified by PVDF immobilized antigen affinity chromatography. △PTP1B was correctly cloned, expressed, and purified as confirmed by PCR, DNA sequence ratio) and 0. 1 ng, respectively. This study provides an important basis for further studying the biological function of PTP1B and its relationship with human diseases.     

Benzofuran-isatin-hydroxylimine/thiosemicarbazide hybrids: Design,synthesis and in vitro anti-mycobacterial activity evaluation

A series of novel benzofuran-isatin-hydroxylimine/-thiosemicarbazide hybrids were designed, synthesized and evaluated for their in vitro anti-TB activities against drug-sensitive MTB H₃₇Rv and MDR-TB isolates as well as cytotoxicity. All benzofuran-isatin-hydroxylimine/-thiosemicarbazide hybrids exhibited considerable in vitro anti-mycobacterial activities against the tested three MTB strains, and all of them also showed acceptable cytotoxicity. The most active hybrid 7f was >4.8 and >51 folds more potent than the first line anti-TB agents RIF and INH against both drug-sensitive MTB H₃₇Rv and MDR-TB isolates, respectively. The results demonstrated the potential utility of benzofuran-isatin-hydroxylimine/-thiosemicarbazide hybrids as anti-TB agents.