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1.
Various novel 10-alkyl-2-deoxo-2-methylthioflavin-5-oxides and their 2-alkylamino derivatives were prepared by facile nitrosative cyclization of 6-(N-alkylanilino)-2-methylthiopyrimidin-4(3H)-ones followed by nucleophilic replacement of the 2-methylthio moiety by different amines, and acidic hydrolysis of the 2-methylthio moiety afforded the corresponding flavin derivatives. 2-Deoxo-2-methylthio-5-deazaalloxazines and 2-deoxo-2-methylthioalloxazine-5-oxides were also prepared by Vilsmeier reaction and by nitrosation of 6-anilino-2-methylthiopyrimidin-4(3H)-ones, respectively. Then, they were subjected to nucleophilic replacement with appropriate amines to produce the corresponding 2-alkylamino derivatives. Regiospecific N(3)-alkylation of 2-deoxo-2-methylthioalloxazine-5-oxides was carried out with various alkylating agents in the usual way. The antitumor activities against CCRF-HSB-2 and KB tumor cells have been investigated in vitro, and many compounds showed promising antitumor activities. Furthermore, AutoDock molecular docking into PTK (PDB: 1t46) has been done for lead optimization of the aforementioned compounds as potential PTK inhibitors. 相似文献
2.
Various novel 5-(monosubstituted amino)-2-deoxo-2-phenyl-5-deazaflavins derivatives have been synthesized by direct coupling of 5-deazaflavins and N-alkyl or aryl amines. The antitumor activities against human tumor cell lines CCRF-HSB-2 and KB cells have been investigated in vitro and many compounds showed promising potential antitumor activities with less cytotoxicities. AutoDock molecular docking into PTK (PDB code: 1t46) has been done for lead optimization of these compounds as potential PTK inhibitors. Some of the synthesized 5-(monosubstituted amino)-2-deoxo-2-phenyl-5-deazaflavins at the 5-position exhibited reasonable binding affinities into PTK with the hydrogen bond through their C(5)-NH moiety. 相似文献
3.
Various novel 10-alkyl-2-deoxo-2-methylthio-5-deazaflavins have been synthesized by reaction of 6-(N-alkylanilino)-2-methylthiopyrimidin-4(3H)-ones with Vilsmeier reagent. The similar 2-(N-substituted amino) derivatives were prepared by nucleophilic replacement reaction of the 2-methylthio moiety by appropriate amines. The 2-oxo derivatives (i.e., 5-deazaflavins) were obtained by acidic hydrolysis of the 2-methylthio derivatives. The antitumor activities against CCRF-HSB-2 and KB cells and the antiviral activities against HSV-1 and HSV-2 have been investigated in vitro, and many compounds showed promising antitumor activities. Furthermore, AutoDock molecular docking into PTK has been done for lead optimization of these compounds as potential PTK inhibitors. Whereas, the designed 2-deoxo-5-deazaflavins connected with amino acids at the 2-position exhibited the good binding affinities into PTK with more hydrogen bonds. 相似文献
4.
Ali HI Tomita K Akaho E Kambara H Miura S Hayakawa H Ashida N Kawashima Y Yamagishi T Ikeya H Yoneda F Nagamatsu T 《Bioorganic & medicinal chemistry》2007,15(1):242-256
Novel 2-deoxo-2-phenyl-5-deazaflavins and 2-deoxo-2-phenylflavin-5-oxides were prepared as a new class of antitumor agents and showed significant antitumor activities against NCI-H 460, HCT 116, A 431, CCRF-HSB-2, andKB cell lines. In vivo investigation, 2-deoxo-10-methyl-2-phenyl-5-deazaflavin exhibited the effective antitumor activity against A 431 human adenocarcinoma cells transplanted subcutaneously into nude mouse. Furthermore, AutoDock study has been done by binding of the flavin analogs into PTK pp60(c-src), where a good correlation between their IC(50) and AutoDock binding free energy was exhibited. In particular, 2-deoxo-2-phenylflavin-5-oxides exhibited the highest potential binding affinity within the binding pocket of PTK. 相似文献
5.
K. Gréen F.A. Kimball B.A. Thronburgh A.J. WickremaSinha 《Prostaglandins & other lipid mediators》1980,20(4):767-780
Comparisons were made of 9-deoxo-16,16-dimethyl-9-methylene-PGE2 levels in plasma determined by three assay methods. Plasma samples from Rhesus monkeys treated with 200 μg/kg 9-deoxo-16,16-dimethyl-9-methylene-PGE2 intravenously were analyzed by radioimmunoassay (RIA) and by high pressure liquid chromatography (HPLC). In a second experiment known amounts of 11β-3H-9-deoxo-16,16-dimethyl-9-methylene-PGE2 were added to human plasma at several concentration levels. The samples were analyzed by RIA, HPLC and gas chromatography-mass spectrometry (GC-MS). A limited number of comparisons have been made between RIA and GC-MS analysis of plasma samples from human subjects treated with 9-deoxo-16, 16-dimethyl-9-methylene-PGE2. The results indicated that the three assay methods generally give comparable estimations of 9-deoxo-16,16-dimethyl-9-methylene-PGE2 content in plasma. 相似文献
6.
A number of 2-hydroxy-6-methyl-7-(arylamino)-1,7-dihydropurin-8-ones have been synthesized. 3-Oxo-2-(arylhydrazono)butyric acid ethyl ester were acetylated and treated with triethyl amine and formamide in presence of 1,4-dioxane to yield N-(5-acetyl-4-ethoxy-2-oxo-2,5-dihydro-imidazol-1-yl)-N-arylacetamide, which on refluxation with urea and freshly prepared sodium ethoxide yielded the title compound. All the newly synthesized compounds have been characterized by spectroscopic and elemental analysis data. The synthesized compounds were screened against a representative panel of susceptible and resistant Gram-positive and Gram-negative bacteria using a standard antibiotic drug purinthol as control. Quantitative structure-activity relationship has also been interpreted in terms of correlation of biological activity with molecular refractive index parameters (M(R)) and Hammett substituent constant (sigma). 相似文献
7.
Raffaele Saladino Veronica Neri Claudia Crestini Giovanna Costanzo Michele Graciotti Ernesto Di Mauro 《Journal of molecular evolution》2010,71(2):100-110
We describe the one-pot synthesis of a large variety of nucleic acid bases and related compounds from formamide in the presence
of zirconium minerals as catalysts. The major products observed are: purine, 2-hydroxy pyrimidine, 5-hydroxy pyrimidine, isocytosine,
adenine, urea, and carbodiimide. The synthesis of low molecular weight amides and carboxylic acid derivatives (intermediates
of extant metabolism) was also observed: glyoxylamide, glycolic-, lactic-, succinic-, oxalic-, fumaric-, and maleic acids.
As the major problem in the origin of informational polymers is the instability of their precursors, we also investigated
the effects of zirconia minerals on the stability of ribooligonucleotides in formamide and in water. The relevance of these
findings with respect to the origin of informational polymers and primordial metabolism is discussed. 相似文献
8.
Five 7beta- and 7alpha-oxygenated obacunone-type limonoids were obtained on reinvestigation of the seeds of Trichilia elegans ssp. elegans: 7-deoxo-7beta-acetoxykihadanins A and B, 7-deoxo-7beta-hydroxykihadanins A and B and 7-deoxo-7alpha-hydroxykihadanin A, the last three being isolated after acetylation procedures as their mono- and/or diacetate derivatives. This is the first report of the natural occurrence of C-7 beta-substituted limonoids without any oxygenated function at C-6. The structures of these compounds have been established on the basis of 1D- and 2D-NMR spectral techniques, ESI-mass spectrum and X-ray crystallographic data. 相似文献
9.
Holla BS Mahalinga M Karthikeyan MS Akberali PM Shetty NS 《Bioorganic & medicinal chemistry》2006,14(6):2040-2047
The reaction of 4-hydrazino-8-(trifluoromethyl)quinoline (2) with ethoxymethylenecyanoacetate afforded ethyl 5-amino-1-[8-(trifluoromethyl)quinolin-4-yl]-1H-pyrazole-4-carboxylate (3) and that with ethoxymethylenemalononitrile afforded 5-amino-1-[8-(trifluoromethyl)quinolin-4-yl]-1H-pyrazole-4-carbonitrile (5). Compounds 3 and 5 were hydrolyzed to get 5-amino-1-[8-(trifluoromethyl)quinolin-4-yl]-1H-pyrazole-4-carboxylic acid and then reacted with acetic anhydride to afford 6-methyl-1-[8-(trifluoromethyl)quinolin-4-yl]pyrazolo[3,4-d]oxazin-4-one (6), which was condensed with different aromatic amines to give a series of 5-substituted 6-methyl-1-[8-(trifluoromethyl)quinolin-4-yl]-1,5-dihydro-4H-pyrazolo[3,4-d]pyrimidin-4-ones (7). Compounds 3 and 5 also reacted with formamide, urea, and thiourea affording the corresponding pyrazolo[3,4-d]pyrimidines (8-13), respectively. Structures of the products have been determined by chemical reactions and spectral studies. All compounds of the series have been screened for their antibacterial and antifungal activity studies. The results are summarized in Tables 1 and 2. 相似文献
10.
Per-O-benzoylated derivatives (amide, methyl ester and glycinamide) of C-(1-azido-1-deoxy-alpha-D-glucopyranosyl)formic acid obtained by azide substitution in the corresponding C-(1-bromo-1-deoxy-beta-D-glucopyranosyl)formic acid derivatives were debenzoylated by the Zemplén-protocol. Per-O-benzoylated C-(1-azido-1-deoxy-alpha-D-glucopyranosyl)formamide was dehydrated by oxalyl chloride-DMF to give the corresponding nitrile, while from its reduction mixture obtained by Raney-nickel or sodium hydrogentelluride C-(1-amino-1-deoxy-beta-D-glucopyranosyl)formamide could be isolated. Acetylation of this amino-amide by Ac2O/Py and subsequent debenzoylation gave C-(1-acetamido-1-deoxy-beta-D-glucopyranosyl)formamide. Applying the same conditions to the crude reduction mixture allowed the alpha-anomer to be isolated as a minor component. An alternative pathway to produce the above beta-anomer appeared in the reaction of C-(1-bromo-1-deoxy-beta-D-glucopyranosyl)formamide with CH3CN in the presence of Ag2CO3 to yield 1-acetamido-2,3,4,6,-tetra-O-benzoyl-1-deoxy-beta-D-glucopyranosyl cyanide, which was hydrated, in the presence of TiCl4, to the formamide. Some of the new compounds were shown to be weak inhibitors of muscle glycogen phosphorylase b. 相似文献
11.
Renu Bhardwaj Sukhbir Kaur Pramodh Kumar Nagar Hardesh Kumar Arora 《Plant Growth Regulation》2007,53(1):1-5
Brassinosteroids play an important role in growth and development of plants. They have been reported universally in all the
plants. The present study deals with the presence of these compounds in immature tea seeds. Five brassinosteroids, i.e. 6-deoxo-28-norcathasterone,
6-deoxo-28-norteasterone, 3-dehydro-6-deoxo-28-norteasterone, 6-deoxo-28-nortyphasterol and 6-deoxo-28-norcastasterone have
been isolated and identified by GC–MS. The identified brassinosteroids and their derivatives are active constituents of late
C-6 oxidation pathway, thereby suggesting the biosynthesis of brassinosteroids in tea seeds by late C-6 oxidation pathway. 相似文献
12.
Leandro R. Soria Nicola Altamura Raúl A. Marinelli 《Biochemical and biophysical research communications》2010,393(2):217-2652
Aquaporin-8 (AQP8) is a membrane channel permeable to water and ammonia. As AQP8 is expressed in the inner mitochondrial membrane of several mammalian tissues, we studied the effect of the AQP8 expression on the mitochondrial transport of ammonia. Recombinant rat AQP8 was expressed in the yeast Saccharomyces cerevisiae. The presence of AQP8 in the inner membrane of yeast mitochondria was demonstrated by subcellular fractionation and immunoblotting analysis. The ammonia transport was determined in isolated mitochondria by stopped flow light scattering using formamide as ammonia analog. We found that the presence of AQP8 increased by threefold mitochondrial formamide transport. AQP8-facilitated mitochondrial formamide transport in rat native tissue was confirmed in liver (a mitochondrial AQP8-expressing tissue) vs. brain (a mitochondrial AQP8 non-expressing tissue). Comparative studies indicated that the AQP8-mediated mitochondrial movement of formamide was markedly higher than that of water. Together, our data suggest that ammonia diffusional transport is a major function for mitochondrial AQP8. 相似文献
13.
The nitrofurans, 2-(2-furyl)-3-(5-nitro-2-furyl)acrylamide (AF-2), N-[4-(5-nitro-2-furyl)-2-thiazolyl]formamide (FANFT), nitrofurantoin, 5-nitro-2-furoic acid, 5-nitro-2-furamidoxime, 5-nitrofurfurylidene diacetate and the urine of rats fed these compounds, were assayed for mutagenic activity in Salmonella typhimurium strains TA100 and TA100FR1. All the nitrofurans were mutagenic in the order: AF-2 and FANFT > nitrofurantoin > 5-nitro-2-furamidoxime > 5-nitrofurfurylidene diacetate > 5-nitro-2-furoic acid. Strain TA100 was more sensitive than TA100FR1 to the mutagenic influence of these nitrofurans. Only the urine of rats fed AF-2, FANFT and nitrofurantoin had mutagenic activity. Again, TA100 was more sensitive than TA100FR1. The mutagenicity of the urine was not increased by treatment with β-glucuronidase. AF-2, 2-amino-4-(5-nitro-2-furyl)thiazole (deformylated product of FANFT) and nitrofurantoin were excreted in the urine of rats fed these compounds; whereas the other nitrofurans were not excreted. 相似文献
14.
A phospholipase A2 isoenzyme provokes lipoxin B formation from endogenous sources of arachidonic acid in porcine leukocytes 总被引:1,自引:0,他引:1
B K Lam C N Serhan B Samuelsson P Y Wong 《Biochemical and biophysical research communications》1987,144(1):123-131
Porcine leukocytes incubated with an isoenzyme of phospholipase A2 (PLA2) (isolated from snake venom) produced several trihydroxytetraene- containing compounds which were derived from endogenous sources of arachidonic acid. The formation of these compounds was dose-dependent with an EC50 of approximately 1.25 X 10(-8) M. At this concentration of the isoenzyme and time of exposure the cells remained viable as determined by the exclusion of trypan blue. The compounds were purified by HPLC and their identities were determined by physical criteria which included U.V. spectrometry, GC/MS and by comparison with both synthetic and authentic materials. The biologically derived compounds proved to be lipoxin B (5S, 14R, 15S-trihydroxy-6, 10, 12-trans-8-cis-eicosatetraenoic acid) and its two structural isomers (8-trans-LXB and 14S-8-trans-LXB). Of interest, only small amounts of lipoxin A and its isomers were found in these incubations. Results of the present study indicate that porcine leukocytes can generate lipoxin B and its isomers from endogenous sources of arachidonic acid. Moreover, they suggest that certain PLA2 isoenzymes may initiate the formation of lipoxins and related compounds. 相似文献
15.
Kametani S Kojima-Yuasa A Kikuzaki H Kennedy DO Honzawa M Matsui-Yuasa I 《Bioscience, biotechnology, and biochemistry》2007,71(5):1220-1229
The constituents of cape aloe were investigated after a preliminary screening of the growth-inhibiting effect on Ehrlich ascites tumor cells (EATC) of several extracts of this plant. Ten compounds were isolated from the dichloromethane (CH(2)Cl(2)) extract that showed the strongest activity, and their structures were elucidated as aloe-emodin (1), p-hydroxybenzaldehyde (2), p-hydroxyacetophenone (3), pyrocatechol (4), 10-oxooctadecanoic acid (5), 10-hydroxyoctadecanoic acid (6), methyl 10-hydroxyoctadecanoate (7), 7-hydroxy-2,5-dimethylchromone (8), furoaloesone (9), and 2-acetonyl-8-(2-furoylmethyl)-7-hydroxy-5-methylchromone (10) based on MS and various NMR spectroscopic techniques. Compounds 2-7 were isolated for the first time from cape aloe. Compounds 4-7 and 10 showed a significant growth-inhibiting effect, and compound 1 exhibited a remarkable synergistic effect on compounds 8-10, which was not observed with the treatment by each compound alone on EATC. These results suggest that the strong growth-inhibiting effect of the CH(2)Cl(2) extract was dependent not on one compound alone, but on the synergistic effect from the combination of compound 1 and the other compounds. 相似文献
16.
Partial Purification and Characterization of Messenger RNA Coding 14-3-2 Protein from Rat Brain 总被引:4,自引:1,他引:3
14-3-2 Protein (neuron-specific enolase) is a neuron-specific protein. Using a reticulocyte lysate cell-free system for translation of 14-3-2 protein mRNA, we have partially purified this mRNA by several procedures, including formamide sucrose density centrifugation, formamide polyacrylamide gel electrophoresis (PAGE) and polyuridylic acid (poly(U))-Sepharose affinity chromatography. Using mRNA obtained by these procedures, we could increase the translation ratio of 14-3-2 protein synthesized/total soluble protein synthesized to 7.31%. The overall purification was 37.8-fold. The size of 14-3-2 protein mRNA appears to be about 19-20S, because translation activity of mRNA obtained by sucrose density gradient centrifugation or formamide PAGE was the most active in this RNA size. 相似文献
17.
Microbial metabolism of the pyridine ring. Metabolic pathways of pyridine biodegradation by soil bacteria. 总被引:13,自引:0,他引:13
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1. Two bacteria, a Bacillus sp. and a Nocardia sp. (strain Z1) were isolated from soil by enrichment with 0.1 percent (v/v) pyridine and grew rapidly on this compound as sole C, N and energy source. The monohydroxypyridines, tetrahydropyridine, piperidine and some other analogues were not utilized for growth or oxidized by washed suspensions of either bacterium. 2. Cell-free extracts were unable to metabolize pyridine even after supplementation with a variety of cofactors or protecting agents. Treatment of cells with toluene led to rapid loss of the ability to oxidize pyridine. 3. In the presence of 10mM-semicarbazide at pH 6.0, Nocardia Z1 accumulated a semialdehyde idenditied as its 2,4-dinitrophenylhydrazone by chromatography, mixed melting point, mass spectrometry and isotope trapping from [2,6(-14)C]pyridine as glutarate semialdehyde. 4. Extracts of this bacterium prepared from cells grown with pyridine or exposed to the gratuitous inducer 2-picoline, contained high activities of a specific glutarate semialdehyde dehydrogenase. 5. Cells grown with pyridine or glutarate also contained a glutaric dialdehyde dehydrogenase, an acyl-CoA synthetase and elevated amounts of isocitrate lyase but no glutaryl-CoA dehydrogenase. 6. Bacillus 4 accumulated in the presence of 10mM-semicarbazide several acidic carbonyl compounds from pyridine among which was succinate semialdehyde. Extracts of this bacillus after growth of the cells with pyridine contained an inducible succinate semialdehyde dehydrogenase in amounts at least 50-fold over those found in succinate-grown cells. 7. Two mutants of this bacillus, selected for their inability to grow on pyridine were deficient in succinate semialdehyde dehydrogenase. 8. In the presence of 0.2mM-KCN, washed suspensions of Bacillus 4 accumulated formate and possibly formamide from pyridine. The use of [14C]pyridine showed that formate was derived from C-2 of the pyridine ring. 9. The organism had a specific formamide amidohydrolase cleaving formamide quantitatively to formate and NH3. 10. Formate was further oxidized by the particle fraction. There was no soluble formate dehydrogenase in extracts. 相似文献
18.
《Biochemical and biophysical research communications》1987,149(3):1063-1069
Arachidonate 12-lipoxygenase purified from porcine leukocytes shows 14R-oxygenase and 14,15-leukotriene A synthase activities with 15-hydroperoxy-arachidonic acid as substrate. The enzyme transformed 5,15-dihydroperoxy-arachidonic acid to several compounds with a conjugated tetraene. A major product was identified as 5S,14R,15S-trihydroperoxy-6,10,12-trans-8-cis-eicosatetraenoic acid, which was reduced to 5S,14R,15S-8-cis-lipoxin B. A requirement of molecular oxygen and the results of H218O experiments suggested that formation of the latter compound was attributed mostly to the 14R-oxygenase activity of the enzyme. There were several other minor products identified as lipoxin A and B isomers. They were produced presumably by hydrolysis of 14,15-epoxy compound formed by the leukotriene A synthase activity of 12-lipoxygenase. 相似文献
19.
20.
Eight limonoids, anthothecanolide (1), 3-O-acetylanthothecanolide (2), 2,3-di-O-acetylanthothecanolide (3), 6R,8alpha-dihydroxycarapin (4), 3beta-acetoxy-3-deoxo-6R-hydroxycarapin (5), methyl angolensate, methyl 6-hydroxyangolensate and khayalactone together with sitosterol glucoside, have been isolated from the extracts of the stem bark of Khaya anthotheca. Compounds 1-4 are described for the first time. Their structures were established by analysis of the high-field NMR and MS data. The structure of compound 4 was confirmed by a single crystal X-ray structure analysis. 相似文献