共查询到20条相似文献,搜索用时 31 毫秒
1.
Qingyi Chu Bradford T. Evans Michael G. Zeece 《Journal of chromatography. B, Analytical technologies in the biomedical and life sciences》1997,692(2):1271
The phenylthiohydantoin (PTH) derivatives of 3- and 4-hydroxyproline (Hyp) were separated using micellar electrokinetic capillary electrophoresis (MEKC). The separation protocol was also used to determine Hyp content of bovine skeletal perimysial collagen preparations and whole muscle samples. Amino acids from hydrolyzed tissues were labeled using a two step procedure that involved initial reaction with o-phthalaldehyde (OPA) to modify primary amines followed by their precipitation under acidic conditions. In the second step, imino acids were reacted with phenyl isothiocyanate (PITC). This labeling method was rapid and the Hyp values determined in these biological samples were found to be in close agreement with conventional methods and other published reports. 相似文献
2.
Nonradioactive labeling of synthetic oligonucleotide probes with terminal deoxynucleotidyl transferase 总被引:5,自引:0,他引:5
Synthetic oligonucleotides were tailed at the 3' end using terminal deoxynucleotidyl transferase. Nucleotide triphosphates with free primary amines at the end of side chains were compared for their tailing efficiency and/or detection sensitivity, using biotin-11-dUTP as a reference. Free primary amines were tagged with activated biotin or fluorescein isothiocyanate. The probes were then detected with either streptavidin-alkaline phosphatase complex or anti-fluorescein antibodies and alkaline phosphatase-conjugated secondary antibodies. Tailing conditions were optimized and the probes were tested for detection of Escherichia coli ST1a enterotoxin DNA and rotavirus RNA. 相似文献
3.
Esteves-Souza A Pissinate K Nascimento Mda G Grynberg NF Echevarria A 《Bioorganic & medicinal chemistry》2006,14(2):492-499
A new series of N-3,3-diphenylpropyl-N-(p-X-benzyl)-N'-phenylureas (5a-g) and thioureas (6a-g) were synthesized by the reaction of secondary amines and phenyl isocyanate or isothiocyanate. The cytotoxic effects of the urea and thiourea derivatives were evaluated by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay against Ehrlich carcinoma and K562 human leukemia cells. Moreover, the activity of compounds in the inhibition of DNA topoisomerases I and II-alpha was tested. The results indicated that the compounds presented important and promising antiproliferative action. 相似文献
4.
Mirkhani V Tangestaninejad S Moghadam M Moghbel M 《Bioorganic & medicinal chemistry》2004,12(17):4673-4677
Rapid and efficient oxidation of primary aromatic amines was investigated. Mn(III)-salophen catalyst can catalyze the oxidation of primary aromatic amines to azo derivatives with sodium periodate. The ability of various Schiff base complexes in this oxidation system was also investigated. 相似文献
5.
C G Hammar 《Biomedical mass spectrometry》1978,5(1):25-28
A generally applicable silylation method for beta-hydroxylated primary, secondary, tertiary and even quaternary amines is presented. These aminoalcohols form 6-membered heterocycles under the influence of a reagent mixture consisting of 1,3-bis-(chloromethyl)-1,1,3,3-tetramethyldisilazane and chloromethyldimethyl-chlorosilane. Examples of analogue ring closures with a gamma-hydroxyamine and an alpha-amino acid are also given. The formation of the derivatives and their properties, are discussed, mainly from the viewpoint mass spectrometry. 相似文献
6.
The muscarinic antagonists pirenzepine and telenzepine were derivatized as alkylamino derivatives at a site on the molecules corresponding to a region of bulk tolerance in receptor binding. The distal primary amino groups were coupled to the cross-linking reagent meta-phenylene diisothiocyanate, resulting in two isothiocyanate derivatives that were found to inhibit muscarinic receptors irreversibly and in a dose-dependent fashion. Preincubation of rat forebrain membranes with an isothiocyanate derivative followed by radioligand binding using [3H]N-methylscopolamine diminished the Bmax value, but did not affect the Kd value. The receptor binding site was not restored upon repeated washing, indicating that irreversible inhibition had occurred. IC50 values for the irreversible inhibition at rat forebrain muscarinic receptors were 0.15 nM and 0.19 nM, for derivatives of pirenzepine and telenzepine, respectively. The isothiocyanate derivative of pirenzepine was non-selective as an irreversible muscarinic inhibitor, and the corresponding derivative prepared from telenzepine was 5-fold selective for forebrain (mainly m1) vs. heart (m2) muscarinic receptors. 相似文献
7.
Toyohiro Shirahama Tamotsu Furumai Masanori Okanishi 《Bioscience, biotechnology, and biochemistry》2013,77(5):1271-1273
The racemization of optically active imidazoline derivatives catalyzed by amines and alcohols was investigated. The racemization was effected by the catalysis of primary and secondary amines, but not by tertiary amines. In t-BuOH, imidazolines were racemized much more slowly than in primary alcohols. The mechanism through a pseudo-six-membered cyclic transition state was proposed for the racemization. 相似文献
8.
Despite the quinone-dependent copper amine oxidases being described as having the ability to metabolize unbranched primary amines to the corresponding aldehydes, we previously showed that the secondary amines 3-pyrrolines are metabolized as mechanism-based inactivators of bovine plasma amine oxidase (BPAO), and that the 3-(3-nitro-4-methoxyphenyl)-substituted analog was a particularly potent and efficient inactivator. We now show that additional 3-aryl-3-pyrrolines containing highly electron-withdrawing aryl groups (pyridyl, quinolyl, isoquinolyl, and pentafluorophenyl) are some of the most potent inactivators of BPAO reported to date. We also provide mass spectroscopic confirmation of the proposed mechanism of inhibition involving pyrrolylation of the active-site cofactor, through identification by MALDI-TOF and LC-ESI-MS/MS of the (3-arylpyrrol-1-yl)resorcinol derivatives of the cofactor-containing thermolytic peptides. 相似文献
9.
Efficient nitrogen alkylation of various primary and secondary amines, including cyclic, heterocyclic and alkaloid type amines, with a sugar oxetane 3,5-anhydro-1,2-O-cyclohexylidene-alpha-D-xylofuranose is described. As a result, 5-amino-5-deoxy derivatives of xylofuranose were obtained in good yields. 相似文献
10.
Silvano De Bernardo Manfred Weigele Voldemar Toome Karin Manhart Willy Leimgruber Peter Böhlen Stanley Stein Sidney Udenfriend 《Archives of biochemistry and biophysics》1974,163(1):390-399
Fluorescamine is a useful reagent for the fluorometric assay of primary amines. The extent of the reaction between fluorescamine and primary amines, as well as the fluorescence intensities of the resulting fluorophors depend on pH, solvent composition and reagent concentration. Optimum values for these variables further depend on the amine under study. The influence of these parameters on the fluorogenic reaction of representative amines, and on their fluorophoric derivatives has been investigated, and the results are reported here. 相似文献
11.
《Bioorganic & medicinal chemistry》2020,28(1):115185
Novel isothiocyanate derivatives were synthesized starting from noscapine, bile acids, amino acids, and some aromatic compounds. Antiparasitic activities of the synthesized derivatives were tested against four unicellular protozoa, i.e., Trypanosoma brucei rhodesiense, T. cruzi, Leishmania donovani, and Plasmodium falciparum. Interestingly, seven isothiocyanate analogues displayed promising antiparasitic activity against Leishmania donovani with IC50 values between 0.4 and 1.0 µM and selectivity index (SI) ranged from 7.8 to 18.4, comparable to the standard drug miltefosine (IC50 = 0.7 μM). Compound 7h demonstrated the best antileishmanial activity with an IC50 value of 0.4 µM. Seven products exhibited inhibition activity against T. brucei rhodesiense with IC50s below 2.0 μM and SI between 2.7 and 29.3. Four primary amine derivatives of noscapine and five isothiocyanate derivatives exhibited antiplasmodial activity with IC50s in the range of 1.1–2.7 µM and SI values between 1.1 and 14.5. The isothiocyanate derivative 7c showed against T. cruzi with an IC50 value of 1.9 µM and SI 4. Molecular docking and ADMET studies were performed to investigate the interaction between active ligands and T. brucei trypanothione reductase active site. The docking studies showed significant binding affinity of noscapine derivatives to enzyme active site and good compatibility with experimental data. 相似文献
12.
Ingrid Rolle Heinz-Erich HobucherHelmut Kneifel Bernd PascholdCarl Johannes Soeder 《Analytical biochemistry》1977
Scenedesmus acutus contains about 10 major amines and at least 20 other amines which are present in very small quantities. The following amines were identified by mass spectrometry after separation of the trifluoroacetyl derivatives by gas-liquid chromatography and of the dansyl 2 derivatives by thin-layer chromatography: methylamine, dimethylamine, ethylamine, ethanolamine, putrescine, cadaverine, spermidine, N-(3-aminopropyl)-1,3-diaminopropane, N-(4-aminobutyl)-1,4-diaminobutane, 2-phenylethylamine, tyramine, piperazine, adenine, and γ-butyrolactam. The methods applied for the analyses of these amines are described and discussed. 相似文献
13.
Several 17 β-carboxamide derivatives of natural and fluorinated glucocorticoids have been synthesized. The 17 β-carboxylic derivatives were obtained by periodic acid oxidation of their side chains. They were then activated by N-hydroxybenzotriazole (HOBT) and coupled to several primary amines. Using this method eleven 17 β-carboxamide derivatives have been prepared in good yields. 相似文献
14.
Bis(tetra-O-acetyl-beta-D-glucopyranosyl)disulfide reacts, under silver ion activation, with primary and secondary aliphatic as well as aromatic amines to furnish the title compounds in moderate to good yields. The same derivatives could also be obtained from (tetra-O-acetyl)-beta-D-glucopyranosyl methanethiolsulfonate 1 by nucleophilic substitution with amines. It was shown that the polarization of the S-S-bond in 1 is enhanced by Ag+ so as to allow reaction with sterically hindered amines as well. 相似文献
15.
M J López-Zabalza S Sanz A Iriarte N López-Moratalla E Santiago 《Comparative biochemistry and physiology. B, Comparative biochemistry》1990,96(1):101-105
1. Pyridoxal-5'-phosphate (PLP), a marker of primary amines, bound covalently to S-1 in an approximate ratio of 1:1. PLP was localized within the tryptic 25,000 mol. wt fragment. 2. Fluorescein isothiocyanate (FITC), which is known to bind covalently to primary amino groups located at nucleotide binding sites, readily bound to S-1 in a 2:1 ratio. FITC was localized within the 20,000 and 50,000 mol. wt tryptic peptides, in a ratio of 1:1 in each one. 3. These results are consistent with the existence of nucleotide binding sites on myosin different from those of the catalytic sites. 相似文献
16.
The new field of functional glycomics encompasses information about both glycan structure and recognition by carbohydrate-binding proteins (CBPs) and is now being explored through glycan array technology. Glycan array construction, however, is limited by the complexity of efficiently generating derivatives of free, reducing glycans with primary amines for conjugation. Here we describe a straightforward method to derivatize glycans with 2,6-diaminopyridine (DAP) to generate fluorescently labeled glycans (glycan-DAP conjugates or GDAPs) that contain a primary amine for further conjugation. We converted a wide variety of glycans, including milk sugars, N-glycans, glycosaminoglycans and chitin-derived glycans, to GDAPs, as verified by HPLC and mass spectrometry. We covalently conjugated GDAPs to N-hydroxysuccinimide (NHS)-activated glass slides, maleimide-activated protein, carboxylated microspheres and NHS-biotin to provide quantifiable fluorescent derivatives. All types of conjugated glycans were well-recognized by appropriate CBPs. Thus, GDAP derivatives provide versatile new tools for biologists to quantify and covalently capture minute quantities of glycans for exploring their structures and functions and generating new glycan arrays from naturally occurring glycans. 相似文献
17.
Kazuhiro Imai Peter Böhlen Stanley Stein Sidney Udenfriend 《Archives of biochemistry and biophysics》1974,161(1):161-163
Amino acids, peptides, catecholamines, and polyamines were reacted with fluorescamine and subjected to thin-layer chromatography. These fluorescamine derivatives of primary amines were detectable at levels below 100 pmoles. Methods of preparation and chromatography of these fluorophors are presented. 相似文献
18.
Kumar Parai M Panda G Srivastava K Kumar Puri S 《Bioorganic & medicinal chemistry letters》2008,18(2):776-781
A new series of benzene and isoquinoline sulfonamide derivatives were synthesized by nucleophilic displacement reaction on benzene and isoquinoline sulfonyl chlorides by substituted amines (primary and secondary). The title compounds were evaluated for antimalarial activity against Plasmodium falciparum in vitro and showed MIC in the range of 2-50 microg/mL. 相似文献
19.
20.
Reductive amination of 5-formyl-3',5'-di-O-acetyl-2'-deoxyuridine with primary amines and sodium triacetoxyborohydride (NaBH(OAc)(3)) afforded novel enamine derivatives of 5,6-dihydro-2'-deoxyuridine as a result of unexpected 1,4-conjugate reduction of intermediate Schiff bases in addition to the secondary amine derivatives of 2'-deoxyuridine, typical 1,2-reduction products. 相似文献