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A facile synthetic route of 5-formylporphyrin (2) has been developed. Using pyrrole and pivaldehyde as the starting materials, 2 was obtained through several facile reactions. The synthetic route is easy to perform and can be scaled up, which gives the compound a better application perspective.
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The first synthesis of pillar[7]arene is reported with two methods. Method A: the FeCl3-catalyzed condensation reaction of 1, 4-dimethoxybenzene (1) with paraformaldehyde in CHCl3 gave dimethoxypillar[7]arene (3). Method B: the p-toluenesulfonic acid catalyzed condensation reaction of 2,5-bis(benzyloxymethyl)-1,4-dimethoxybenzene (2) in CH2Cl2 gave compound 3. Demethylation of 3 with BBr3 gave pillar[7]arene (4). The pillar[7]arene might be a perspective macrocyclic host in host-guest chemistry.
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To further explore an efficient modified route for the shift from an antibacterial fluoroquinolone to an antitumor one, mono-Schiff bases 6a-6h related to ciprofloxacin C3 carbonylhydrazone and bis-Schiff bases 4a-4h corresponding to C3/C7 carbonylhydrazone/hydrazone attached on a skeleton of ciprofloquinolone were designed and synthesized, and their in vitro antitumor activity against CHO, HL60, L1210 cells and antibacterial activity against S.aureus and E.coli were also reported.
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A novel and practical synthetic route is presented for the preparation of methyl-(E)-2-(3-(3-(2-(7-chloro-2- quinolinyl)ethenyl)phenyl)-3-oxopropyl)benzoate, the key intermediate of Montelukast, a leukotriene antagonist. The main diarylpropane framework was prepared via a polarity conversation reaction resulting in an acyl anion equivalent followed by a nucleophilic substitution reaction. The overall yield of this approach was 61 %. This method is simple for operation and suitable for industrial production.
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The synthesis and biological evaluation of two series of salicylanilide derivatives on the EGFR and ErbB-2 tyrosine kinases inhibitory activities were conducted. Of the tested compounds those having an additional aryl group substituted on the anilino ring were active on the EGFR tyrosine kinase inhibition (7a−c and 13a, 13c, 13d, 13f). The inhibitory activites were all in the low micromolar or submicromolar range. In addition, compound 13a was found to have dual inhibitory acitivities both on EGFR and ErbB-2 tyrosine kinases (1.654?1.280 and 7.134?1.265 μmol/L).
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The new polydentate mixed-N, P, O chiral ligands have been synthesized by the condensation of bis(o-formylphenyl)- phenylphosphane and R-phenylglycinol in CHCl3，and fully characterized by IR, NMR and EIMS spectra. These ligands were employed with a simple Ni complex Ni(PPhs)2Cl2 in situ as catalytic systems for asymmetric transfer hydrogenation of ketones, and the corresponding optical alcohols were obtained with up to 84 % ee under mild conditions.
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Potassium fluoride doped natural zeolite was found to be an efficient and selective solid base catalyst for 1,4-Michael addition. The catalyst is easily prepared and the workup procedure simplified by simple filtration. All products were obtained in high yields as well as short reaction times.
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A new series of isatin semicarbazide derivatives (7a-7j) were synthesized and characterized by spectroscopic means and elemental analysis. Analgesic and anti-inflammatory screening was performed using tail-flick technique and the carrageenan-induced foot paw edema test respectively. The ulcerogenicity was also determined for all the compounds. Some of the compounds showed moderate enhancement of the activity. Among the synthesized derivatives, compound 7d showed higher analgesic, antiinflammatory and one-third of ulcer index of the reference drug.
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Ligand modification of Ni-based catalysts by coordination of dicyandiamide to Ni metal leads to enhanced selectivity for the selective hydrogenation of halonitroaromatics. The selectivity of above 99.9 % to aromatic haloamines can be achieved at the conversion of 100 %. The results of H2-TPD and FT-IR experiments show that Ni−H+ species possessing the properties of Lewis acid site on the surface of Raney Ni could be responsible for the hydrodehalogenation. When Raney Ni was treated by dicyandiamide, Ni−H+ species interacted with N atom from the dicyandiamide. This interaction was stable even at reaction temperature, which reduced the possibility to form the intermediate state of Ar-Cl--H+Ni−. And then C-Cl bond could not be polarized and activated. The hydrodechlorination process was suppressed effectively.
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A series of novel ?uorinated thieno[2, 3-d]pyrimidine derivatives incorporating 1, 3, 4-thiadiazole were synthesized by a facile microwave-assisted procedure, including the cyclization of 2-aminothiophene-3-carbonitrile with trifluoroacetic acid, chlorination and nucleophilic substitution reaction. This protocol offered such advantages as mild reaction conditions, short reaction time, simple puri?cation and good yields. The structures of the products were characterized by 1H NMR, MS, elemental analysis and X-ray diffraction.
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The reaction of electrochemically generated anthradiquinone as a Michael acceptor with 2-mercaptobenzothiazole and 2-mercaptobenzoxazole, as nucleophiles in ethanol/water mixtures has been studied by means of cyclic voltammetry. Our voltammetric data indicate that produced anthradiquinone participates in Michael addition reaction with nucleophiles and via an ECEC mechanism converts to the new anthraquinonethioether derivatives. Based on an EC mechanism, the observed homogeneous rate constants of the Michael reactions of anthradiquinone with nucleophiles were estimated by comparing the experimental cyclic voltammograms with the digital simulated results.
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In order to develop a novel kidney-targeted drug delivery system, a small molecular carrier (2-deoxy-2-amino diglucose) was synthesized, and then the 2-deoxy-2-aminodiglucose-prednisolone conjugate (DPC) was synthesized to verify the kidney targeting capability of the carrier. Both 2-deoxy-2-aminodiglucose and DPC were confirmed by NMR and MS spectrum. The tissue distribution studies showed that DPC presented an excellent kidney targeting property in vivo, compared with prednisolone group, 4.9-fold of drug concentration in kidney was observed in the DPC group. Thus, it indicated that 2-deoxy-2-amino- diglucose could be a potential carrier for kidney-targeted drug delivery.
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Eight novel 5, 7-disubstituted-2-{5-methyl-3-(4-trifluoromethylphenyl)isoxazol-4-ylcarbonylimino}-2H-1, 2, 4-thiadiazolo[2, 3-a]pyrimidines were synthesized by multi-step reactions in yields 68 % 85 %. Reactions were carried out either by ultrasound irradiation or conventional method, and found it was faster and more efficient under ultrasonic irradiation. Preliminary herbicidal activities against E. crus-galli, D. ciliaris and C. serotinum were also evaluated by flat-utensil method, and the results indicated that the target compounds exhibited significant activities, some were even higher than the control herbicide.
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We have developed an expedient approach, “HOPE” (hybrid orthogonal protocol with ease) stratege for the synthesis of peptidyl N-alkylamides. This new strategy was characterized by following points: incorporating Boc and Fmoc protocols together on Merrifield resin, removal of SPG (side-chain protecting groups) without the damage of linker structure on the resin,and the ammonolysis of linker as the last step could achieve the introducing N-alkylamide structure into C-terminal and releasing product from resin-support simultaneously. In present work, eight peptidylamides with different alkylsubstitution at C-terminal were conveniently synthesized by HOPE strategy.
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An efficient green protocol is described for the preparation of highly functionalized piperidines via a one-pot five-component reaction between aromatic aldehydes, anilines and β–ketoesters in the presence of oxalic acid dihydrate as catalyst in ethanol at ambient temperature. The structure as well as the relative stereochemistry of these compounds was confirmed by single X-ray crystallographic analysis.
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Two new phenylethanoid glycosides, himalosides A (1) and B (2), were isolated from the whole plant of Boschniakia himalaica, together with four known compounds. Their structures were elucidated on the basis of spectral and chemical evidences. Himalosides A (1) and (+)-lariciresinol 4'-O-β-D-glucopyranoside (4) exhibited antibacterial activity with the MIC values at 50 and 25 μg/mL against Staphylococcus aureus and S. epidermidis, respectively.
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Two novel styryllactones, goniodilactone (1) and gonioheptenolactone (2), were isolated from the leaves of Goniothalamus cheliensis Hu. Their structures were determined based on spectroscopic data as well as X-ray crystallography analysis. Compounds 1 and 2 exhibited significant cytotoxicities in a panel of human cancer cells, including DU-145, PC-3, MCF-7, A-549, KB and KBvin, with GI50s in the range of 1.29−4.56 µg/mL.
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Isounonal-7-methyl ether (1) and chinendihydrochalcone (2) together with 8 known compounds were isolated from the stem barks of Desmos chinensis. Their structures were determined on the basis of spectroscopic data. Compound 2 exhibited cytotoxic activity against MOLT-3 cancer cell line (IC50 7.16 µg/mL) and antifungal activity against Pyricularia oryzae and Rhizoctonia solani with MIC values of 15.6 and 31.2 µg/mL, respectively.
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A novel capillary electrophoresis method for simultaneous determination of Cu and Pb has been developed in this paper. Cu(II) and Pb(II) ions were reacted with ABEDTA to form complex to achieve an ideal sensitivity of heavy metal complexes. The digestion solution of Rhizoma coptidis drug sample was purified by neutral Al2O3 column chromatography and the chromatographic behavior of metal–L complexes was investigated. The calibration curve was linear in the range of 5−60 µg/mL for Cu2+ and 5−25 µg/mL for Pb2+ with the correlation coefficients 0.9970 and 0.9972 for each (n = 5). The average recoveries were 86.2 % for Pb and 90.1 % for Cu, while the relative standard deviations were 5.1 % and 3.6 % respectively. The method was successfully applied to determine Cu and Pb in Rhizoma coptidis drug samples.
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The wavelength for the peak of fluorescence emission of thioflavin T (ThT) was changed from 445 nm to 481nm when ThT was added in Aβ solution which indicating the β-sheet structure of Aβ fibril. The significant decrease in the intensity of fluorescence at 481 nm was observed when the baicalein was added in mixed solution of Aβ and ThT, suggesting that the depolymerization of Aβ fibrils happened and there were Aβ fibrils left to react with ThT to keep the initial fluorescence intensity. And the existing Aβ fibrils are disaggregated by baicalein in a time- and dose-dependent manner. AFM images of the morphologies of the Aβ1-42 fibrils obviously changed smaller and more dispersive when baicalein added indicating also the depolymerization of Aβ. The results demonstrate a basis for development of a potential herb drug candidate for the treatment of Alzheimer´s disease (AD).
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The interaction between vinpocetine (VPC) and human serum albumin (HSA) in physiological buffer (pH 7.40) was investigated by fluorescence, FT-IR, UV-vis absorption and molecular modeling. VPC effectively quenched the intrinsic fluorescence of HSA via static quenching. The binding site number n and apparent binding constant Ka, corresponding thermodynamic parameters ΔG, ΔH and ΔS at different temperatures were calculated. The synchronous fluorescence and FT-IR spectra were used to investigate the structural change of HSA molecules with addition of VPC. Molecular modeling indicated that VPC could bind to the site I of HSA and hydrophobic interaction was the major acting force, which was in agreement with the binding mode study.
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An anion exchange resin NDP-5 has been prepared successfully and applied on the selective removal of nitrate from SO42−/NO3− binary co-existence system. The composition and morphology of NDP-5 were confirmed by FT-IR and SEM. The NDP-5 resin exhibits the completely different behavior on the adsorption capacity, adsorption kinetic and the effect of the completing anion in the absence or presence of sulfate, compared to D213. And, the resultants of kinetic are well fitted by the pseudo-first-order and pseudo-second-order models. These results are very important to develop novel resins with great features.
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Simple structural compounds 1 to 3 were synthesized. The presence of Cu2+ resulted in the fluorescence and absorption spectra change of 1 and 2, which indicated that 1 and 2 showed a highly selective response to Cu2+ over other metal ions. However, 3 showed no selectivity for metal ions, which means that the compound could bind with several metal ions, such as, Ni2+, Zn2+, Cd2+, Hg2+, Pb2+, Fe3+, Mg2+, Ca2+, and Co2+, except Cu2+ and Ag+. The different spectral responses were attributed to the difference in binding sites for 1 and 3.
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This study describes a simple, rapid and selective catalytic kinetic spectrophotometric method for the determination of 6-monoacetylmorphine (6-MAM) as major metabolite of heroin in biological samples. The method is based upon the catalytic effect of 6-MAM on the oxidation of Janus Green by bromate in acid media. The reaction was followed spectrophotometrically by measuring the decrease in absorbance of Janus Green at 618 nm. The dependence of sensitivity on the reaction variables was studied. Under optimum conditions, two linear calibration curves over the range 0.1 to 1.0 µg mL-1 and 1.0 to 34.0 µg mL-1 of 6-MAM were obtained. The detection limit was 1.2 × 10-2 µg mL-1 of 6-MAM. The relative standard deviations for six replicate determinations of 0.8 and 5.0 µg mL-1 of 6-MAM were 1.4 and 1.1% respectively. The effect of various species commonly associated with heroin in real samples was also investigated. The proposed method was successfully applied in human urine and serum samples with satisfactory results.
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In this work, the quercetin imprinted core-shell microspheres were prepared using silica surface imprinting technique. A simple sol-gel procedure was used for the synthesis of the imprinted materials with 3-aminopropyltriethoxysilane as functional monomer and tetraethyl orthosilicate as crosslinker. The SEM images indicated that the MIPs shell was successfully grafted onto the silica surface. The characteristics of the molecularly imprinted polymers such as capacity, selectivity and absorption dynamic were investigated by rebinding experiments. The results showed that the prepared MIPs had good imprinting effect and adsorption amount of quercetin.
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Redox active polyelectrolyte-surfactant complexes (PSC) were prepared via the ionic self-assembly of sodium poly(styrenesulfonate) (PSS) and ferrocenyl surfactant, (11-ferrocenylundecyl)trimethylammonium bromide (FTMA) in aquesous solution. The PSS-FTMA complex exhibited an ordered interdigitated monolayer mesomorphous structure with the long period of d = 3.13 nm, and was in the ionic thermotropic liquid crystal SmA state at room temperature. Interestingly, in the solid complex, the ferrocenyl moieties formed H-aggregation showing an increase in the π-π* energy transfer of cyclopentadienes in the ferrocene moieties as known from the blue-shift in the UV spectrum. The complexes showed higher thermal stability compared with their components due to the ionic interaction. The PSS-FTMA film had a good redox reversibility, which promised to be used in electrochemical sensors.
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PbO2/activated carbon (AC) hybrid supercapacitor in H2SO4 with a carbon foam current collector is studied. The PbO2/AC hybrid is designed with electrodeposited PbO2 thin film as positive electrode to match with AC negative electrode. The discharge curve shows capacitive characteristics between 1.88 V and 0.65 V. The hybrid system exhibits excellent energy and power performance, with specific energy of 43.6 Wh/kg at a power density of 654.2 W/kg. The use of carbon foam current collector ensures stability of the PbO2 electrode in H2SO4 environment. After 2600 deep cycles at 15C high rate of charge/discharge, the capacity remains nearly unchanged from its initial value.
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Bovine serum albumin (BSA) was utilized to assemble with the binary complexes of poly(vinylpyrrolidone)-graft- poly(2-dimethylaminoethyl methacrylate) (PVP-g-PDMAEMA)/DNA formed by layer-by-layer electrostatic interactions to screen the residual surface positive charges of complexes. The coating of BSA was able to decrease the zeta potential of binary complexes nearly to electroneutrality without interfering with DNA condensation ability. The ternary complexes of BSA/PVP-g-PDMAEMA/DNA demonstrated lower cytotoxicity compared with the binary complexes and also maintained high gene transfection efficiency in HepG2 cells.
