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1.
Ten dioxide species derived from N,N′-bis(alkylmethyl)-1,2-ethanediamine and N,N′-bis(alkylmethyl)-1,2-propanediamine were
tested for their activity withStaphylococcus aureus, Escherichia coli andCandida albicans. A relation between the length of the alkylchain, and/or the molecule asymmetry, and the antimicrobial activity was found.
Part V of the series Amine Oxides; part IV: Mlynarciket al.: Folia Microbiol.
24, 188 (1979). 相似文献
2.
《Inorganica chimica acta》1987,131(1):95-99
The platinum(II) complexes of the formula [Pt(DCHEDA)X2], where DCHEDA is N,N′-dicyclohexylethylenediamine and X− is CL−, Br−, I−, 0.5C2O42− (oxalate), 0.5C3H2O42− (malonate), 0.5C9H4O62− (4-carboxyphthalate), 0.5S2O32− or 0.5SO42−, have been synthesized and characterized by UVVis, IR, and 1H NMR spectral techniques. All the above complexes are non-electrolytes in DMF/H2O, except the sulphate complex which becomes a 1:1 electrolyte after incubation for 24 h at 28 °C. The halide complexes were also studied by X-ray photoelectron spectroscopy and these data suggest that there is π-bonding from platinum to halide in these complexes. The oxalate, malonate and sulphate bind in their complexes as bidentate ligands to platinum through two oxygen atoms whereas the thiosulphate in its complex binds as a bidentate ligand to platinum through one oxygen atom and one sulphur atom. 相似文献
3.
Hultsch C Bergmann R Pawelke B Pietzsch J Wuest F Johannsen B Henle T 《Amino acids》2005,29(4):405-413
Summary. Isopeptide bonds between the ɛ-amino group of lysine and the γ-carboxamide group of glutamine are formed during strong heating
of pure proteins or, more important, by enzymatic reaction mediated by transglutaminases. Despite the wide use of a microbial
transglutaminase in food biotechnology, up to now little is known about the metabolic fate of the isopeptide Nɛ-(γ-glutamyl)-L-lysine. In the present study, N-succinimidyl-4-[18F]fluorobenzoate was used to modify Nɛ-(γ-glutamyl)-L-lysine at each of its two α-amino groups, resulting in the 4-[18F]fluorobenzoylated derivatives, for which biodistribution, catabolism, and elimination were investigated in male Wistar rats.
A significant different biochemical behavior of the two labelled isopeptides was observed in terms of in vitro stability, in vivo metabolism as well as biodistribution. The results suggest that the metabolic fate of isopeptides is likely to be dependent
on how they are reabsorbed – free or peptide bound. 相似文献
4.
Mazur L. Kozioł A. E. Rzeszotarska B. Masiukiewicz E. 《International journal of peptide research and therapeutics》2002,9(6):255-260
Summary The solid-state conformation of the first N-protected ornithine derivative has been established by X-ray analysis. The hydrochloride
of Nα-(9-fluorenyl)methoxycarbonyl-l-ornithine crystallises as diethyl ether solvate. The backbone (ω0 ϕ, ψ χ1) torsion angles are (174.9°,–84.0°, 145.9°,–171.0°). The conformation of the urethane amide bonds istrans. The ornithine aliphatic side chain adopts preferred fully extended conformation which is stabilised by the hydrogen bonding
of the-NH
3
+
group to the diethyl ether molecule, carboxyl group and Cl− anions. 相似文献
5.
David F. Ewing Robert W. Humblet Graham Mackenzie 《Nucleosides, nucleotides & nucleic acids》2013,32(6):1305-1316
Abstract The conformation of deoxyribosides derived from N1 and N3 substitution of the aglycone ethyl 5-aminoimidazole-4-carboxylate (AICE) has been determined by 1H and 13C NMR spectroscopy. The deoxyribose ring shows considerable variation in the form and population of the contributing N and S conformers but the syn/anti ratio is similar to that in the purine analogues. 相似文献
6.
Martens-Lobenhoffer J Rodionov RN Drust A Bode-Böger SM 《Analytical biochemistry》2011,419(2):234-240
Nitric oxide is an ubiquitary cell signaling substance. Its enzymatic production rate by nitric oxide synthase is regulated by the concentrations of the substrate L-arginine and the competitive inhibitor asymmetric dimethylarginine (ADMA). A newly recognized elimination pathway for ADMA is the transamination to α-keto-δ-(N(G),N(G)-dimethylguanidino)valeric acid (DMGV) by the enzyme alanine-glyoxylate aminotransferase 2 (AGXT2). This pathway has been proven to be relevant for nitric oxide regulation, but up to now no method exists for the determination of DMGV in biological fluids. We have developed a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the quantification of DMGV. D(6)-DMGV was used as internal standard. Samples were purified online by column switching, and separation was achieved on a porous graphitic carbon column. The calibration was linear over ranges of 10 to 200 nmol/L for plasma and 0.1 to 20 μmol/L for urine. The intra- and interday accuracies and precisions in plasma and urine were better than 10%. In plasma samples, DMGV was present in concentrations between 19.1 and 77.5 nmol/L. In urine samples, concentrations between 0.0114 and 1.03 μmol/mmol creatinine were found. This method can be used as a tool for the scientific investigation of the ADMA conversion to DMGV via the enzyme AGXT2. 相似文献
7.
Satoshi Matsubara Satoshi Shiojiri Tozo Fujii Nobuo Ogawa Kikuko Imamura Kagari Yamagishi Koichi Koshimizu 《Phytochemistry》1977,16(7):933-937
(R)-(+)- and (S)-(?)-dihydrozeatins [(R)-(+)- and (S)-(?)-6-(4-hydroxy-3-methylbutylamino)purines, 1a and 1b] and their ribosides {(?)-6-[(R)-4-hydroxy-3-methylbutylamino]- and (?)-6-[(S)-4-hydroxy-3-methyl-butylamino]-9-β-D-ribofuranosylpurines, 3a and 3b} were synthesized and tested for their cytokinin activity by four bioassay systems, the growth of tobacco callus, the seed germination of lettuce, the fr. wt increase of excised radish cotyledons and the retardation of chlorophyll degradation in radish cotyledons. In tobacco callus bioassay, 1a was more active than 1b. The ribosides 3a and 3b were not less active than their corresponding aglycones 1a and 1b. In other bioassays used the activity followed the order: 1a >3a >1b >3b. In tobacco callus bioassay and lettuce seed germination, trans-zeatin [6-(4-hydroxy-3-methylbut-trans-2-enylamino)purine] showed stronger cytokinin activity than 1a. 相似文献
8.
The structure of N i -( N '-Sulfodiaminophosphinyl)- l -ornithine (PSOrn) in complex with the enzyme ornithine transcarbamoylase (OTCase) was recently characterised by Langley et al. [D.B. Langley, M.D. Templeton, B.A. Fields, R.E. Mitchell and C.A. Collyer, J. Biol. Chem., 275 (2000) 20012] using X-ray diffraction techniques. In this work, the interaction of PSOrn with the arginine residues of OTCase is modelled using density functional theory, with an emphasis on characterising the mechanism of binding between PSOrn, an inhibitor, and the enzyme. For the purposes of this study, the interaction of PSO, an analogue of PSOrn (obtained by replacing a (CH 2 ) 3 CH( CO 2 m )( NH 3 + ) side chain by methyl) with one and two arginine (Arg) molecules are investigated. The PSO > (Arg) 2 trimer is found to be strongly bound, by ~171 kJ mol m 1 , due to the presence of four hydrogen bonds in addition to a large ionic interaction between a dinegative PSO 2 m and protonated arginines. The computed geometry is consistent with the X-ray structure and the large binding energy is consistent with the observation that PSOrn is a powerful inhibitor. Furthermore, in agreement with the proposals of Langley et al. , the most stable bound form of PSO is found to be an imino type tautomer. The population analyses that were carried out on PSO suggest that PN, PO, SN and SO bonds, as in a range of other systems, are generally either single or semipolar bonds. 相似文献
9.
Synthetic 2′-hydroxy-3,4′,6′-trimethoxy-4-benzyloxychalcone (I) affords (±)-7,3′-di-O-methyleriodictyol (II) and 7,3′-di-O-methylluteolin (or velutin, VII) identical with natural samples. Similarly synthetic 2′-hydroxy-4,4′,6′-trimethoxy-3-benzyloxychalcone (X) gives natural (±)-7,4′-di-O-methyleriodictyol (XI) and 7,4′-di-O-methylluteolin (or pilloin, IX). However, attempts to partially etherify II with one mole of prenyl bromide to obtain the natural prenyl ether failed; only the corresponding diprenyloxychalcone (IV) was obtained. 相似文献
10.
1-[(4-Methylphenyl)oxy]pyrrolidine-2,5-dione and 1-[(4-methylphenyl)oxy]piperidine-2,6-dione react in a Lossen-type reaction with primary alcohols in the presence of triethylamine to furnish corresponding N α-urethane-protected β-alanine and γ-aminopropionic acid (GABA), respectively, with excellent yields and purities, in an essentially “one-pot” procedure. 相似文献
11.
12.
Larry D. Barnes Michael N. Guy Glenda M. Roberson Richard W. Osgood 《Archives of biochemistry and biophysics》1982,214(1):239-247
A fluorescent analog of angiotensin II was synthesized by reacting fluorescein 5′-isothiocyanate with (Asp1, Ile5)-angiotensin II. Nα-(N-Fluoresceinthiocarbamoyl)-(Asp1, Ile5)-angiotensin II was purified by chromatography on DEAE-cellulose and Sephadex G-25. Analysis of the analog by thin-layer chromatography, thin-layer electrophoresis, and reversed-phase high-performance liquid chromatography indicated that the analog was free of angiotensin II and fluorescein 5′-isothiocyanate. N-Terminal sequence analysis demonstrated that fluorescein 5′-isothiocyanate reacted with the N-terminal aspartic acid residue of angiotensin II. Nα-(N-Fluoresceinthiocarbamoyl)-(Asp1, Ile5)-angiotensin II has an absorption maximum at 492 nm, and the value of the molar extinction coefficient, ?, is 7.7 × 104m?1 cm?1. The fluorescence emission maximum occurs at 520 nm. Infusion of the analog (0.69 μg/min/kg body wt) directly into the renal artery of an anesthetized rat reduced the blood flow by 12 to 27% within 2 min. Infusion of angiotensin II (0.48 μg/min/kg body wt) reduced renal arterial blood flow by 35 to 53% within 2 min. Saralasin, a partial agonist and antagonist of angiotensin II, inhibited the biologic effect of the fluorescent analog and angiotensin II by 75 and 70%, respectively. The purity, spectral properties, and in vivo biologic activity of Nα-(N-fluoresceinthiocarbamoyl)-(Asp1, Ile5)-angiotensin II indicate that this analog should facilitate characterization of angiotensin II receptors. 相似文献
13.
Takuro Kisaki Masanao Ihida Einosuke Tamaki 《Bioscience, biotechnology, and biochemistry》2013,77(7):719-728
Nicotine-N′-oxide (II) was purified to give a crystalline form which has m.p. 170~171°C, and . The reaction of nicotine-N′-oxide with acetic anhydride afforded a good yield of 1′-(3-pyridyl)-4′-(N′-acetylmethylamino)-l′-propanone (V) which was hydrolyzed to give pseudoöxynicotine (III). Nicotine-N′-oxide (II) either with acetyl chloride or with benzoyl chloride, under similar conditions, furnished pseudoöxynicotine (III) without giving the corresponding acyl compound as an intermediate. 2′-Methyl-6′-(3-pyridyl)-tetrahydro-l′,2′-oxazine (XII) rearranged from nicotine-N′-oxide reacted neither with acetic anhydride nor acetyl chloride. Reduction of the oxime (IV) of pseudoöxynicotine dihydrochloride gave dl-l′-amino-l′-(3-pyridyl)-4′-methyl-aminobutane (VII) as a main product. The hydrazone (VIII) of pseudoöxynicotine dihydrochloride subjected to a modification of the Wolf-Kischner reaction, was reduced to yield dihydrometanicotine (IX). The pyrolysis of N′-methylmyosmine (IV) gave N′-methylnicotinamide (XI) and nicotyrine (X) in low yields. The presence of N′-methylmyosmine in the autoxidation mixture of nicotine was also established. Oxidation of nornicotine (XIV) with hydrogen peroxide furnished myosmine-N′-oxide (XV) whose identity was established by its chemical and physical properties. This oxide, on pyrolysis, gave nornicotyrine (XVII) and myosmine (XVI). 相似文献
14.
Keith R. Barnard Robert W. Gable A. G. Wedd 《Journal of biological inorganic chemistry》1997,2(5):623-633
Synthesis of complexes cis,cis-WVOXL (X=Cl, NCS), cis,trans-WVOXL (X=Cl, OPh, SPh) and cis,trans-WVIE2L (E2=O2, OS, S2) of the title ligand LH2 are reported. cis,cis-WVOCIL crystallises in space group P21/c with a=13.6541(9) Å, b=7.1555(11) Å, c=18.198(2) Å, β=95.294(6)°, V=1770.4(3) Å3 and Z=4 while the cis,trans isomer crystallises in space group P21/n with a=10.361(3) Å, b=14.141(4) Å, c=12.213(5) Å, β=102.56(3)°, V=1747(2) Å3 and Z=4. cis,trans-WVIS2L crystallises in space group P21/n with a=10.645(2) Å, b=13.929(2) Å, c=12.189(2) Å, β=103.14(2)°, V=1760(1) Å3 and Z=4. A short CH3···Cl distance of 3.067(7) Å and an acute OWCl angle of 94.1(2)° are seen in cis,cis-WVOClL, which converts to the cis,trans form on heating in MeCN. The latter isomer features a CH3···Cl distance of 3.38(2) Å and an OWCl angle of 105.1(8)°. Electrochemical and EPR data are reported. In particular, cis,trans-WVIE2L may be reduced to [WVE2L]–. EPR properties of these anions and those of complexes WVOXL are discussed in the context of WV centres in tungsten enzymes. 相似文献
15.
《Nucleosides, nucleotides & nucleic acids》2013,32(1-2):227-237
The regioselective synthesis of 4‐nitroindazole N 1‐ and N 2‐(β‐d‐ribonucleosides) (8, 9, 1b and 2b) is described. The N 1‐regioisomers are formed under thermodynamic control of the glycosylation reaction [fusion reaction or Silyl Hilbert‐Johnson glycosylation for 48 h (66%)], while the kinetic control (Silyl Hilbert‐Johnson glycosylation for 5 h) afforded only the N 2‐isomer (64%). The structures of the nucleosides 1b and 2b were assigned by single crystal X‐ray analyses. The 4‐amino‐N 1‐(β‐d‐ribofuranosyl)‐1H‐indazole (3b) was obtained from the nitro nucleoside 1b by catalytic hydrogenation. Compound 3b shows fluorescence while the 4‐nitroindazole nucleosides 1b and 2b do not possess this property. 相似文献
16.
In vivo investigations have confirmed the beneficial effects of hydrophilic, cationic Mn(III) porphyrin-based catalytic antioxidants in different models of oxidative stress. Using a cell culture model of rat mixed neuronal/glial cells, this study investigated the effect of MnTnOct-2-PyP5+ on oxygen and glucose deprivation (OGD)-induced cell death as compared to the effects of widely studied hydrophilic analogues MnTE-2-PyP5+ and MnTDE-2-ImP5+ and a standard compound, dizocilpine (MK-801). It was hypothesized that the octylpyridylporphyrin, MnTnOct-2-PyP5+, a lipophilic but equally potent antioxidant as the other two porphyrins, would be more efficacious in reducing OGD-induced cell death due to its higher bioavailability. Cell death was evaluated at 24 h using lactate dehydrogenase (LDH) release and propidium iodide staining. At concentrations from 3–100 µm, all three porphyrins reduced cell death as compared to cultures exposed to OGD alone, the effects depending upon the concentrations and type of treatment. To assess the effect of lipophilicity the additional experiments were performed using submicromolar concentrations of MnTnOct-2-PyP5+ in an organotypic hippocampal slice model of OGD with propidium iodide and Sytox staining. When compared to oxygen and glucose deprivation alone, concentrations of MnTnOct-2-PyP5+ as low as 0.01 µm significantly (p<0.001; power 1.0) reduced neuronal cells similar to control. This is the first in vitro study on the mammalian cells which indicates that MnTnOct-2-PyP5+ is up to 3000-fold more efficacious than equally potent hydrophilic analogues, due entirely to its increased bioavailability. Such remarkable increase in efficacy parallels 5.7-orders of magnitude increase in lipophilicity of MnTnOct-2-PyP5+ (log P=?0.77) when compared to MnTE-2-PyP5+ (log Pow=?6.43), Pow being partition coefficient between n-octanol and water. 相似文献
17.
Abstract Nitration of benzimidazole leads to the formation of the two isomeric 5,6- and 4,6(5,7)-dinitrobenzimidazoles, which may be isolated by fractional crystallization. The chloromercury salts of these were employed to synthesize the corresponding 1-β-D-ribofuranosides, unequivocally characterized by 1H NMR spectroscopy. Reference is made to the biological significance of these results. 相似文献
18.
《Inorganica chimica acta》2006,359(7):2271-2274
Two dinuclear nickel(II) complexes, [Ni2(L-Et)(N3)(H2O)3](NO3)2 · 2H2O (1) and [Ni2(L-Et)(μ-1,3-N3)(H2O)2](NO3)2 · 4H2O (2) containing (HL-Et = N,N,N′,N′-tetrakis[(1-ethyl-2-benzimidazolyl)methyl]-2-hydroxy-1,3-diaminopropane), have been synthesized and characterized by their IR and UV–Vis spectra and magnetic susceptibilities. The crystal structures of [Ni2(L-Et)(N3)(H2O)3](NO3)2 · CH3OH (1′) and [Ni2(L-Et)(μ-1,3-N3)(H2O)2](NO3)2 · 2C2H5OH (2′) similar to 1 and 2 were determined by X-ray crystallography. In 1′, the two nickel(II) ions are bridged by only an alkoxo group of L-Et−, while an azido and an alkoxo connect two nickel(II) ions in 2′. Magnetic susceptibility measurements (2–300 K) showed a weak ferromagnetic exchange coupling between the two nickel(II) ions (2J = 10.1 cm−1) for 1. On the other hand, antiferromagnetic interactions were observed for 2 (2J = −15.8 cm−1). 相似文献
19.
A.K. Banerjee B.J. Broughton T.S. Burton M.P.L. Caton A.J. Christmas E.C.J. Coffee K. Crowshaw M.A. Heazell K.A.J. Stuttle G.L. Watkins 《Prostaglandins & other lipid mediators》1978,16(4):541-554
The synthesis and gastrointestinal pharmacology of some 11-deoxyprostaglandin E1 analogues are described with results analysed for selectivity from side effects. 11-Deoxygenation reduced potency relative to PGE2 but, as has been reported for natural PGs, 15- or 16-methyl analogues were more potent than the unsubstituted parent compound in the order 16-methyl > 15-methyl > 16, 16-dimethyl. The results suggest that a complex interaction between C-15 and C-16 in methyl analogues affects their profile of activity, but that none of the modifications studied conferred a substantial potency or selectivity advantage over PGE2. 相似文献
20.
Emanuela Berrino Murat Bozdag Sonia Del Prete Fatmah A. S. Alasmary Linah S. Alqahtani Zeid AlOthman 《Journal of enzyme inhibition and medicinal chemistry》2018,33(1):1194-1198
The inhibition of α-, β-, γ-, and δ-class carbonic anhydrases (CAs, EC 4.2.1.1) from bacteria (Vibrio cholerae and Porphyromonas gingivalis) and diatoms (Thalassiosira weissflogii) with a panel of N’-aryl-N-hydroxy-ureas is reported. The α-/β-CAs from V. cholerae (VchCAα and VchCAβ) were effectively inhibited by some of these derivatives, with KIs in the range of 97.5?nM – 7.26?µM and 52.5?nM – 1.81?µM, respectively, whereas the γ-class enzyme VchCAγ was less sensitive to inhibition (KIs of 4.75 – 8.87?µM). The β-CA from the pathogenic bacterium Porphyromonas gingivalis (PgiCAβ) was not inhibited by these compounds (KIs?>?10?µM) whereas the corresponding γ-class enzyme (PgiCAγ) was effectively inhibited (KIs of 59.8?nM – 6.42?µM). The δ-CA from the diatom Thalassiosira weissflogii (TweCAδ) showed effective inhibition with these derivatives (KIs of 33.3?nM – 8.74?µM). As most of these N-hydroxyureas are also ineffective as inhibitors of the human (h) widespread isoforms hCA I and II (KIs?>?10?µM), this class of derivatives may lead to the development of CA inhibitors selective for bacterial/diatom enzymes over their human counterparts and thus to anti-infectives or agents with environmental applications. 相似文献