Synthesis and Crystal Structure of N-[2-（4-Chlorophenyl）-1-（1-methylcarbamoyl-2-phenyl-ethylcarbamoyl）-3-phenyl-cyclopropyl]-benzamide

N-[2-(4-chlorophenyl)-1-(1-methylcarbamoyl-2-phenyl-ethylcarbamoyl)-3-phenyl-cyclopropyl]benzamide,C33H30ClN3O3,has been synthesized and characterized by IR,1H NMR,13C NMR and single-crystal X-ray diffraction.The crystal is of triclinic,space group P1 with a = 11.646(2),b = 13.795(3),c = 14.559(3),α = 76.422(4),β = 78.028(4),γ = 74.500(4)°,V = 2164.6(7)3,Z = 3,Mr = 552.05,Dc = 1.270 g/cm3,λ = 0.71073 ,μ(MoKα)= 0.171 mm–1,F(000)= 870,the final R = 0.0469 and wR = 0.0805 for 5554 observed reflections with I > 2σ(I).The N–H and oxygen atoms are involved in one-dimensional intermolecular hydrogen bonds,which further stabilize the structure.     

Selective and sensitive determination of peptides using 3,4-dihydroxyphenylacetic acid as a fluorogenic reagent

A novel fluorescence (FL) reaction for N-terminal Gly-containing peptides has been developed using 3,4-dihydroxyphenylacetic acid (3,4-DHPAA). The reaction of the peptides with 3,4-DHPAA was carried out in borate buffer (pH 8.0) in the presence of sodium periodate at 37 °C for 10 min, and the FL was measured with a spectrofluorimeter at the excitation and emission wavelengths of 370 nm and 465 nm, respectively. The 3,4-DHPAA reagent generated particularly strong FL for peptides containing Gly at their N-termini. When various other bio-substances, such as amino acids, sugars, nucleic bases, nucleotides, and proteins, were reacted with 3,4-DHPAA, no FL was observed. Under optimized reaction conditions, the lower detection limit of 0.25 μmol L⁻¹ was obtained for the N-terminal Gly-containing peptides of Gly-Pro (GP) and Gly-Pro-Pro (GPP), which gave 3 times greater FL intensity than that observed for the reagent blank. The proposed reaction with 3,4-DHPAA as a fluorogenic reagent is selective and sensitive for the detection of N-terminal Gly-containing peptides, and therefore, this method could be a useful tool for the determination of these particular oligopeptides.     

Novel immobilized zinc(II) affinity chromatography for phosphopeptides and phosphorylated proteins

Immobilized metal ion affinity chromatography (IMAC) is now a widely accepted technique for the separation of natural or artificial products that is beginning to find industrial applications. Here, we introduce a novel procedure for the separation of phosphopeptides and phosphorylated proteins by immobilized zinc(II) affinity chromatography. The phosphate-binding site of the affinity gel is an alkoxide-bridged dinuclear zinc(II) complex, the 1,3-bis[bis(pyridin-2-ylmethyl)amino]propan-2-olato dizinc(II) complex (Phos-tag), which is linked to a highly cross-linked 4% (w/v) agarose. The affinity gel (Phos-tag agarose) was prepared by the quantitative reaction of N-hydroxysuccinimide-activated Sepharose and a Phos-tag derivative having a 2-aminoethylcarbamoyl group in dry CH3CN. Phosphopeptides were retrieved in a quantitative and highly selective manner by a spin column method using Phos-tag agarose at room temperature. Furthermore, in this study, we demonstrate a simple, rapid, and reusable affinity column chromatography for the separation of phosphorylated proteins such as ovalbumin, alpha(s1)-casein, and beta-casein at physiological pH.     

Fluorescence properties of some 2-(4-amino-substituted-3-nitrophenyl)-3-hydroxyquinolin-4(1H)-ones

2-(4-Amino-substituted-3-nitrophenyl)-3-hydroxyquinolin-4(1H)-ones have been studied to evaluate their fluorescence properties and possible use as molecular fluorescent probes. The amino group was substituted with various alkyl moieties possessing a suitable terminal functional group (such as hydroxy or amino group) that could serve to bind a 3-hydroxyquinolin-4(1H)-one (3HQ) fluorescence label to a biomolecule. Besides simple hydrocarbon chains, ligands containing ethylenoxy units as optimal spacers were also tested. The structure-fluorescence properties and theoretical applicability of the studied molecules are discussed.     

Thermochromism of 1, 4-Bis[2-(4-pyridyl)ethenyl]-benzene Derivatives

Three kinds of thermochromic materials (DC8, DC12, DC16) were synthesized by linking the rigid 1, 4-bis[2-(4-pyridyl)ethenyl]-benzene (bpeb) with different lengths of alkyl chains. They exhibit remarkable fluorescent color changes under the irradiation of 365 nm light with elevating temperature, which is supposed to be caused by the transition between the crystal state and the amorphous state. Interestingly, the DC16 solid also has a photochromic character. It should be noticed that the phase transition temperatures of three materials measured by differential scanning calorimetry are higher than those of the fluorescence color changes during the heating process. Thus, the allochroic effect is attributed to the synergistic effect of both heating and photo-inducement (365 nm). Ethanol can turn the heated powder into the initial crystal again which indicates that their thermochromic behavior is reversible and makes the fluorescence recover.     

A new Tb-selective fluorescent sensor based on 2-(5-(dimethylamino)naphthalen-1-ylsulfonyl)-N-henylhydrazinecarbothioamide

A novel fluorescent chemosensor 2-(5-(dimethylamino)naphthalen-1-ylsulfonyl)-N-phenylhydrazinecarbothioamide (L) has been synthesized, which revealed an emission of 530 nm and when excited at 360 nm. The fluorescent probe undergoes a fluorescent emission intensity quenching upon binding to terbium ions in MeCN solution. The fluorescence quenching of L is attributed to the 1:1 complex formation between L and Tb(III) which has been utilized as the basis for the selective detection of Tb(III). The linear response range covers a concentration range of Tb(III) from 4.0 × 10⁻⁷ to 1.0 × 10⁻⁵ M and the detection limit is 1.4 × 10⁻⁷ M. The association constant of the 1:1 complex formation for L–Tb⁺³ was calculated to be 6.01 × 10⁶ M⁻¹, and the fluorescent probe exhibits high selectivity over other common metal ions mono-, di-, and trivalent cations indicate good selectivity for Tb(III) ions over a large number of interfering cations.     

4,4′-[1,n-亚烷基双[(E)-2-(4-氧苯基)乙烯基]]双吡啶的光化学性质

通过E-[4-[2-(4-羟基苯基)乙烯基]吡啶与1,n-二溴烷烃亲核取代反应合成了4,4′-[1,n-亚烷基双[(E)-2-(4-氧苯基)乙烯基]]双吡啶[n=2(Ia),3(Ib),4(Ic),6(Id)].用元素分析、红外、紫外和质子核磁共振谱鉴定了Ia～Id的结构.将Ia～Id的稀溶液用中压汞灯和低压汞灯交替照射,发现其分子内光环加成反应的存在,并且随着亚烷基碳链的延长,反应速度加快.研究还发现锌离子可以与吡啶环上氮原子发生螯合作用使分子内光环加成反应加快.本文化合物荧光很弱,在较高浓度下有较强分子间激基缔合物荧光.     

4,4’-[1,n-亚烷基双[(E)-2-(4-氧苯基)乙烯基]]双吡啶的光化学性质(英文)

通过E-[4-[2-（4-羟基苯基）乙烯基]吡啶与1,n-二溴烷烃亲核取代反应合成了4,4’-[1,n-亚烷基双[（E）-2-（4-氧苯基）乙烯基]]双吡啶[n=2（Ia）,3（Ib）,4（Ic）,6（Id）].用元素分析、红外、紫外和质子核磁共振谱鉴定了Ia-Id的结构.将Ia-Id的稀溶液用中压汞灯和低压汞灯交替照射,发现其分子内光环加成反应的存在,并且随着亚烷基碳链的延长,反应速度加快.研究还发现锌离子可以与毗陡环上氮原子发生螯合作用使分子内光环加成反应加快.本文化合物荧光很弱,在较高浓度下有较强分子间激基缔合物荧光.     

Synthesis and optical behaviors of 2-(9-phenanthrenyl)-, 2-(9-anthryl)-, and 2-(1-pyrenyl)-1-alkylimidazole homologues

Eight 2-(9-phenanthrenyl)-, 2-(9-anthryl)- and 2-(1-pyrenyl)-1-alkyl-benzimidazole compounds, three 2-(9-anthryl)-1-alkylphenanthroimidazole compounds and five 4,5-diphenyl-1-alkyl-2-(9-anthryl)imidazole compounds were synthesized by alkylation reactions of the corresponding benzimidazole, phenanthroimidazole or imidazole compounds. 2-(10-Bromo-9-anthryl)-1-alkyl-benzimidazole compounds were prepared by bromination reaction of 2-(9-anthryl)-1-alkylbenzimidazole compounds. All the synthesized compounds were characterized by elemental analysis, ¹H NMR, ¹³C NMR, MS or HRMS; their absorption coefficients (), maximum absorption λ_amax, fluorescence emission maximum λ_em, Stokes shifts and fluorescence quantum yields (Φ_F) in ethyl acetate were determined; their fluorescent lifetimes (T₁ and T₂) were measured in ethyl acetate and in solid state, respectively. The crystal structure of 2-(9-anthryl)-1-n-butyl-4,5-diphenylimidazole (12a) was determined to be triclinic, space group P-1 types, using single crystal X-ray crystallography technique. The results showed that these compounds exhibited moderate fluorescence-emission abilities and higher solubility in most organic solvents than their corresponding starting materials. The relationships between the optical behaviors and structures for these compounds were discussed.     

Study on the Surface Photovoltage and Fluorescence Properties of N, N-Bis(4-aminopheny)-1, 4 quinonenediimine Doped with H_4SiW_(12)O_(40)

Polyaniline, especially its acid-dopping composite material, is a kind of important photoelectric material due to its potential application in many fields1~3. However, it seems to be a problem that the polymers exhibit several deficiencies, including chemical and structural imperfections as a result of mislinkage, saturated sites, molecular weight distribution, the presence of the end groups and conformation defects. All of these defects affect the device efficiency and make it difficult to …     

1,3-Dipolar cycloaddition of diazoalkanes onto dimethyl 1-(formylamino)ethylenephosphonate: a new route to 1-aminocyclopropanephosphonic acids and 3-phosphorylated pyrazoles

Diazoalkanes regiospecifically react with dimethyl 1-(formylamino)ethylenephosphonate (1a) to afford 5-substituted dimethyl 3-(formylamino)-4,5-dihydro-3H-pyrazol-3-phosphonates 2 in high yields. Their thermal decomposition followed by hydrolysis provides a straightforward access to 2-substituted 1-aminocyclopropanephosphonic acids 4. Aromatization of 2 under acidic conditions leads to 3-phosphorylated pyrazoles 5.     

A novel method for identification and relative quantification of N-terminal peptides using metal-element-chelated tags coupled with mass spectrometry

By means of the reaction between a DOTA-NHS-ester bifunctional reagent and N-terminal peptides of proteins,and then chelation of lanthanide metal ions as tags,we established a novel method for the identification of N-terminal peptides of proteins and their relative quantification using metal-element-chelated tags coupled with mass spectrometry.The experimental results indicate that metal elements are able to completely label N-terminal peptides at the protein level.The N-terminal peptides are enriched as the peptides digested with trypsin are selectively eliminated by isothiocyanate-coupled silica beads.We successfully identified the N-terminal peptides of 158 proteins of Thermoanaerobacter tengcongensis incubated at 55 and 75°C,among which N-terminal peptides of 24 proteins are partially acetylated.Moreover,metal-element tags with high molecule weights make it convenient for N-terminal peptides consisting of less than 6 amino acids to be identified;these make up 55percent of the identified proteins.Finally,we developed a general approach for the relative quantification of proteins based on N-terminal peptides.We adopted lysozyme and ribonuclease B as model proteins;the correlation coefficients(R2)of the standard curves for the quantitative method were 0.9994 and 0.9997,respectively,with each concentration ratio ranging from0.1 to 10 and both relative standard derivations(RSD)measured at less than 5%.In T.tengcongensis at two incubation temperatures,80 proteins possess quantitative information.In addition,compared with the proteins of T.tengcongensis incubated at 55°C,in T.tengcongensis incubated at 75°C,7 proteins upregulate whereas 16 proteins downregulate,and most differential proteins are related to protein synthesis.     

Synthesis of 4-(1-Adamantyl)- and 4-(1-Adamantylmethyl)-substituted Halothiazoles

1-Adamantyl bromomethyl ketone and 1-adamantylmethyl chloromethyl ketone react with potassium thiocyanate in dimethylformamide to give the corresponding thiocyanatoketones which cyclize under the influence of HCl into 4-(1-adamantyl) and 4(-adamantylmethyl)chlorothiazole respectively. 4-(1-Adamantyl)-2-amino-5-bromothiazole and its N-derivative were synthesized by the reaction of 1-adamantyl dibromomethyl ketone with thioureas and N-substituted thiourea in acetonitrile.     

Crystal structure and characterization of two cadmium(II) coordination polymers with a multidentate N-donor tecton 3-(pyridin-4-yl)-5-(pyrazin-2-yl)-1H-1,2,4-triazole

Two new cadmium(II) complexes [Cd_1.5(L)Cl₂(H₂O)]_{2 n} (1) and [CdL₂] _n (2) with a multidentate N-donor building block 3-(pyridin-4-yl)-5-(pyrazin-2-yl)-1H-1,2,4-triazole (HL) have been prepared and characterized by elemental analysis, infra-red spectra, powder X-ray diffraction (XRD), and single-crystal XRD. 1 is a 2-D layered coordination polymer constructed from linkage of [Cd₃(μ-Cl)₄] trinuclear units with HL spacers, while 2 shows a 2-D layer structure. 3-D supramolecular architectures are further assembled in 1 and 2 via hydrogen-bonding contacts. Both 1 and 2 are thermally stable to 450?°C, and 2 showed strong fluorescent emission bands.     

A new liquid chromatography/mass spectrometry method for 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL) in urine

4‐(Methylnitrosamino)‐1‐(3‐pyridyl)‐1‐butanone (NNK) is a carcinogenic nitrosamine produced upon curing tobacco. It is present in tobacco smoke and undergoes metabolism to 4‐(methylnitrosamino)‐1‐(3‐pyridyl)‐1‐butanol (NNAL) in the lungs. NNAL undergoes further uridine diphosphate glucuronosyltransferase (UGT)‐mediated metabolism to give N‐ and O‐glucuronide metabolites, which together with free (non‐conjugated) NNAL are then excreted in the urine. The ability to conduct validated analyses of free and conjugated NNAL in human urine is important in order to assess inter‐individual differences in lung cancer risk from exposure to cigarette smoke. The use of stable isotope dilution (SID) methodology in combination with liquid chromatography/multiple reaction monitoring/mass spectrometry (LC/MRM‐MS) provides the highest bioanalytical specificity possible for such analyses. We describe a novel derivatization procedure, which results in the formation of a pre‐ionized N‐propyl‐NNAL derivative. The increased LC/MS sensitivity arising from this derivative then makes it possible to analyze free NNAL in only 0.25 mL urine. This substantial reduction in urine volume when compared with other methods that have been developed will help preserve the limited amounts of stored urine samples that are available from on‐going longitudinal biomarker studies. The new high sensitivity SID LC/MRM‐MS assay was employed to determine free and conjugated NNAL concentrations in urine samples from 60 individual disease‐free smokers. Effects of inter‐individual differences in urinary creatinine clearance on NNAL concentrations were then assessed and three metabolizer phenotypes were identified in the 60 subjects from the ratio of urinary NNAL glucuronides/free NNAL. Poor metabolizers (PMs, 14 subjects) with a ratio of NNAL glucuronides/free NNAL <2 (mean = 1.3), intermediate metabolizers (IMs, 36 subjects) with a ratio between 2 and 5 (mean = 3.4), and extensive metabolizers (EMs, 10 subjects) with a ratio >5 (mean = 11.1). Copyright © 2010 John Wiley & Sons, Ltd.     

1-(1-Phthalazinyl)- and 1-(4methoxyphenyl)-6,6dimethyl-4oxo-4,5,6,7-tetrahydroindazole

2-(1-Phthalazinylhydrazino)methylene-(IIIa) or 2-(1-phthalazinylhydrazino)ethylidene-5,5-dimethyl-1,3-cyclohexanediones (IIIb) were prepared from 1-hydrazinophthalazine and 2 formyl- or 2-acetyldimedone. Cyclization of IIIb in the presence ofp- TsOH gave 1-(1-phthalazinyl)3, 6, 6-trimethyl-4-oxo-4, 5, 6, 7-tetrahydroindazole. Reaction of 4-methoxyphenylhydrazine with 2 formyl- and 2-acetyidimedone gave the corresponding 1-(4methoxyphenyl)-4-oxo-4, 5, 6, 7-tetrahydroindazole. In the case of 2 -formyldimedone the intermediate 2-(4methoxyphenylhydrazinomethylene)-5, 5-dimethyl-1,3-cyclohexanedione was isolated.Riga Technological University, Riga LV-1658. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 708–710, May, 1996. Original article submitted December 31, 1995.     

A high-performance liquid chromatographic method for determination of flecainide in human plasma using fluorescence detection

Summary A high performance liquid chromatographic method for the determination of flecainide in serum has been developed. The analysis is performed on a microparticulate silica column. The eluate is monitored by fluorescence detection at an excitation wavelength of 300nm and an emission wavelength of 370nm. No sources of interference were identified and a coefficient of variation of less than 8% was observed on repeated flecainide determinations. The method has a good reproducibility, specificity and accuracy, and can be applied in therapeutic drug monitoring of flecainide in patients.