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1.
5'-Phosphites (5'-hydrogenphosphonates) of 3'-azido-2'-, 3'-dideoxynucleosides are shown to be effective inhibitors of the human immunodeficiency virus (HIV-1) in MT4 cell culture. 5'-Phosphite of 3'-azido-2', 3'-dideoxythymidine was the most active among these compounds and even a little more active as compared to the well-known anti-AIDS drug 3'-azido-2',3'-dideoxythymidine; at the same time 5'-phosphites of 3'-azido-2',3' -dideoxynucleosides with adenine, guanine and cytosine bases were more active than the corresponding nucleosides. The toxicity of all four phosphites was comparatively low and the equimolar mixture of all four phosphites was 2-3 fold less toxic than each of them separately. Data on the decreased toxicity of the phosphite mixture are explained from the viewpoint of a decreased pool disbalance of natural 2'-deoxynucleoside 5'-triphosphates in cells; a significant pool disbalance is developed in the case of 3'-azido-2',3'-dideoxythymidine action.  相似文献   

2.
4-Schiff base-7-benzyloxy-coumarins 5a(1)-5h(2) and its derivative 6 were designed and synthesized based on the 7-benzyloxy-coumarin structure as novel antioxidants. The in vitro antioxidant activities screening revealed that 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activities of compounds 5b(1), 5d(1), 5f(1), 5f(2), 5g(1) and 5g(2), and 2,2'-azinobis-(3-ethylbenzthiazoline-6-sulfonate) cation (ABTS(+)) radical scavenging activities of compounds 5a(1), 5b(1), 5c(1), 5c(2), 5d(1), 5e(1), 5e(2), 5f(2), 5g(1), 5g(2) and 5h(1) were better than that of the commercial antioxidant butylated hydroxytoluene (BHT), while the superoxide anion radical scavenging activities of 5a(2) and 5g(2) were stronger than that of the commercial antioxidant butylated hydroxyanisole (BHA), and the hydroxyl radical scavenging activity of 5e(1) was much better than that of the common antioxidant ascorbic acid.  相似文献   

3.
The present study investigated the site of action of 5-hydroxytryptamine (5-HT) and pharmacologically characterized the receptors involved in regulating blood glucose levels in the crayfish, Procambarus clarkii. Injection of 5-HT into intact animals increased glucose levels in a dose-dependent manner. In contrast, 5-HT failed to elicit a hyperglycemic response in eyestalk-ablated animals. Effects of several 5-HT receptor agonists and antagonists were examined. 5-CT, oxymetazoline (both 5-HT(1) receptor agonists) and alpha-methyl-5-HT (a 5-HT(2) receptor agonist), but not 1-phenylbiguanide, m-CPBG (both 5-HT(3) receptor agonists), or RS 67333 (a 5-HT(4) receptor agonist), induced hyperglycemic responses in a dose-dependent manner. In addition, 8-OH-DPAT (a 5-HT(1A) receptor agonist), L-694,247 (a 5-HT(1B/1D) receptor agonist), and DOI (a 5-HT(2A) receptor agonist) were effective in significantly increasing the glucose levels, whereas both BW 723C86 (a 5-HT(2B) receptor agonist) and m-CPP (a 5-HT(2C) receptor agonist) were ineffective. Finally, ketanserin (a 5-HT(2A) receptor antagonist), but not p-MPPF (a 5-HT(1A) receptor antagonist), GR 55562 (a 5-HT(1B/1D) receptor antagonist), SB 206553 (a 5-HT(2B/2C) receptor antagonist), or tropisetron (a 5-HT(3) receptor antagonist), was able to block 5-HT-induced hyperglycemia. The combined results support the hypothesis that 5-HT exerts its hyperglycemic effect by enhancing the release of hyperglycemic factor(s) from the eyestalks, and suggest that 5 HT-induced hyperglycemia is mediated by 5-HT(1)- and 5-HT(2)-like receptors.  相似文献   

4.
Whole body exposure to high doses of ionizing radiation is associated with small intestinal and colonic dysfunction, the etiology of which remains unknown. In this study, we investigated the role of both neural and nonneural 5-hydroxytryptamine (5-HT)-mediated pathways in radiation-induced attenuation and recovery of colonic secretory function. Rats were exposed to whole body 10-Gy gamma irradiation, and distal colonic tissues were studied in Ussing chambers 1, 3, and 7 days after exposure. Tissue responses to exogenously added 5-HT (nonneural pathway) and electrical field stimulation (EFS; neural pathway) were performed, and 5-HT receptor subtypes implicated in both responses were determined using three different 5-HT receptor antagonists: methysergide (5-HT(2/1C)), granisetron (5-HT(3)), and SDZ-205,557 (5-HT(4)). Maximal responses to exogenously added 5-HT were decreased at 1 and 3 days and returned to control values at 7 days. Responses to exogenous 5-HT were insensitive to both 5-HT(2/1C) and 5-HT(3) antagonists and to TTX but were totally inhibited by SDZ-205, 557 in both control and irradiated tissues. Responses to EFS were decreased 1 and 3 days after exposure and returned to control values at 7 days. In control tissues and 1 and 3 days after exposure, EFS responses were insensitive to both 5-HT(2/1C) and 5-HT(4) antagonists but reduced by granisetron in control (51%) and at 1 (64%) and 3 days (58%) after exposure. Granisetron was more effective at 7 days (73% inhibition), which was concomitant with the appearance of a 5-HT(4) antagonist-sensitive pathway (40% inhibition). In conclusion, neural and nonneural 5-HT-mediated pathways involve 5-HT(3) and 5-HT(4) receptors, respectively, in control as well as in irradiated tissues 1 and 3 days after exposure. Conversely, the recovery of colonic transport is associated with additional 5-HT(3)-mediated pathways, probably in combination with 5-HT(4) receptors.  相似文献   

5.
Endothelin-1 (ET-1) (10 pmol) microinjected into the superficial layer of superior colliculus induces decreases in blood pressure (control, 108 +/- 5 mmHg, n=6; ET-1, 71 +/- 4 mmHg, n=5). The effects on blood pressure induced by endothelin-1 were significantly (p<0.05) reduced by pre-administration into the superior colliculus of the alpha1-adrenoceptor agonist phenylephrine (1 nmol) (46 +/- 5%, n=5), beta1-adrenoceptor antagonist acebutolol (5 nmol) (51 +/- 6%, n=5) or beta1/beta2-adrenoceptor antagonist propranolol (3.4 nmol) (51 +/- 11%, n=5). In contrast, endothelin-1-induced effects were increased (p<0.05) by microinjections into the superior colliculus of prazosin (2.4 nmol) (49 +/- 7%, n=5), an alpha1-adrenoceptor antagonist; dobutamine (4 nmol) (51 +/- 9%, n=5), a beta1-adrenoceptor agonist or isoprenaline (1 nmol) (49 +/- 6%, n=5), a beta1/beta2-adrenoceptor agonist. No involvement of alpha2- or beta2-adrenoceptors has been detected. Therefore, ET-1 induces decreases in blood pressure with selective involvement of alpha1- and beta1-adrenoceptors.  相似文献   

6.
The microbial transformation of mesterolone (= (1alpha,5alpha,17beta)-17-hydroxy-1-methylandrostan-3-one; 1), by a number of fungi yielded (1alpha,5alpha)-1-methylandrostane-3,17-dione (2), (1alpha,3beta,5alpha,17beta)-1-methylandrostane-3,17-diol (3), (5alpha)-1-methylandrost-1-ene-3,17-dione (4), (1alpha,5alpha,15alpha)-15-hydroxy-1-methylandrostane-3,17-dione (5), (1alpha,5alpha,6alpha,17beta)-6,17-dihydroxy-1-methylandrostan-3-one (6), (1alpha,5alpha,7alpha,17beta)-7,17-dihydroxy-1-methylandrostan-3-one (7), (1alpha,5alpha,11alpha,17beta)-11,17-dihydroxy-1-methylandrostan-3-one (8), (1alpha,5alpha,15alpha, 17beta)15,17-dihydroxy-1-methylandrostan-3-one (9), and (5alpha,15alpha,17beta)-15,17-dihydroxy-1-methylandrost-1-en-3-one (10). Metabolites 5-10 were found to be new compounds. All metabolites, except 2, 3, 6, and 7, exhibited potent anti-inflammatory activity. The structures of these metabolites were characterized on the basis of spectroscopic studies, and the structure of 5 was also determined by single-crystal X-ray-diffraction analysis.  相似文献   

7.
The optically pure enantiomers of the potential atypical antipsychotic agents 5-methoxy-2-[N-(2-benzamidoethyl)-N-n-propylamino]tetralin (5-OMe-BPAT, 5) and 5-methoxy-2-{N-[2-(2,6-dimethoxy)benzamidoethyl]-N-n-propylamino}t etralin [5-OMe-(2,6-di-OMe)-BPAT, 6] were synthesized and evaluated for their in vitro binding affinities at alpha1-, alpha2-, and beta-adrenergic, muscarinic, dopamine D1, D2A, and D3, and serotonin 5-HT1A and 5-HT2 receptors. In addition, their intrinsic efficacies at serotonin 5-HT1A receptors were established in vitro. (S)- and (R)-5 had high affinities for dopamine D2A, D3, and serotonin 5-HT1A receptors, moderate affinities for alpha1-adrenergic and serotonin 5-HT2 receptors, and no affinity (Ki > 1000 nM) for the other receptor subtypes. (S)- and (R)-6 had lower affinities for the dopamine D2A and the serotonin 5-HT1A receptor, compared to (S)- and (R)-5, and hence showed some selectivity for the dopamine D3 receptor. The interactions with the receptors were stereospecific, since the serotonin 5-HT1A receptor preferred the (S)-enantiomers, while the dopamine D2A and D3 receptors preferred the (R)-enantiomers of 5 and 6. The intrinsic efficacies at the serotonin 5-HT1A receptor were established by measuring their ability to inhibit VIP-induced cAMP production in GH4ZD10 cells expressing serotonin 5-HT1A receptors. Both enantiomers of 5 behaved as full serotonin 5-HT1A receptor agonists in this assay, while both enantiomers of 6 behaved as weak partial agonists. The potential antipsychotic properties of (S)- and (R)-5 were evaluated by establishing their ability to inhibit d-amphetamine-induced locomotor activity in rats, while their propensity to induce extrapyramidal side-effects (EPS) in man was evaluated by determining their ability to induce catalepsy in rats. Whereas (R)-5 was capable of blocking d-amphetamine-induced locomotor activity, indicative of dopamine D2 receptor antagonism, (S)-5 even enhanced the effect of d-amphetamine, suggesting that this compound has dopamine D2 receptor-stimulating properties. Since both enantiomers also were devoid of cataleptogenic activity, they are interesting candidates for further exploring the dopamine D2/serotonin 5-HT1A hypothesis of atypical antipsychotic drug action.  相似文献   

8.
The heavy (VH) and light (VL) chain variable regions of the murine anti-human CD20 mAb 1F5 were cloned, and four single-chain Ab (scFv) molecules were constructed using linker peptides of variable lengths to join the VH and VL domains. Three constructs were engineered using linker peptides of 15, 10, and 5 aa residues consisting of (GGGGS)3, (GGGGS)2, and (GGGGS)1 sequences, respectively, whereas the fourth was prepared by joining the VH and VL domains directly. Each construct was fused to a derivative of human IgG1 (hinge plus CH2 plus CH3) to facilitate purification using staphylococcal protein A. The aggregation and CD20 binding properties of these four 1F5 scFv-Ig derivatives produced were investigated. Both size-exclusion HPLC column analysis and Western blots of proteins subjected to nonreducing SDS-PAGE suggested that all four 1F5 scFv-Ig were monomeric with m.w. of approximately 55 kDa. The CD20 binding properties of the four 1F5 scFv-Ig were studied by ELISA and flow cytometry. The 1F5 scFv-Ig with the 5-aa linker (GS1) demonstrated significantly superior binding to CD20-expressing target cells, compared with the other scFv-Ig constructs. Scatchard analysis of the radiolabeled monovalent GS1 scFv-Ig revealed a binding avidity of 1.35 x 108 M-1 compared with an avidity of 7.56 x 108 M-1 for the native bivalent 1F5 Ab. These findings suggest that the GS1 scFv-Ig with a short linker peptide of approximately 5 aa is the best of the engineered constructs for future studies.  相似文献   

9.
5-HT1A knockout (KO) mice display an anxious-like phenotype, whereas 5-HT1B KOs are over-aggressive. To identify serotoninergic correlates of these altered behaviors, autoradiographic measurements of 5-HT1A and 5-HT1B serotonin (5-HT) receptors and transporter (5-HTT) were obtained using the radioligands [3H]8-OH-DPAT, [125I]cyanopindolol and [3H]citalopram, respectively. By comparison to wild-type, density of 5-HT1B receptors was unchanged throughout brain in 5-HT1A KOs, and that of 5-HT1A receptors in 5-HT1B KOs. In contrast, decreases in density of 5-HTT binding were measured in several brain regions of both genotypes. Moreover, 5-HTT binding density was significantly increased in the amygdalo-hippocampal nucleus and ventral hippocampus of the 5-HT1B KOs. Measurements of 5-HT axon length and number of axon varicosities by quantitative 5-HT immunocytochemistry revealed proportional increases in the density of 5-HT innervation in these two regions of 5-HT1B KOs, whereas none of the decreases in 5-HTT binding sites were associated with any such changes. Several conclusions could be drawn from these results: (i) 5-HT1B receptors do not adapt in 5-HT1A KOs, nor do 5-HT1A receptors in 5-HT1B KOs. (ii) 5-HTT is down-regulated in several brain regions of 5-HT1A and 5-HT1B KO mice. (iii) This down-regulation could contribute to the anxious-like phenotype of the 5-HT1A KOs, by reducing 5-HT clearance in several territories of 5-HT innervation. (iv) The 5-HT hyperinnervation in the amygdalo-hippocampal nucleus and ventral hippocampus of 5-HT1B KOs could play a role in their increased aggressiveness, and might also explain their better performance in some cognitive tests. (v) These increases in density of 5-HT innervation provide the first evidence for a negative control of 5-HT neuron growth mediated by 5-HT1B receptors.  相似文献   

10.
In this article, we describe the synthesis of 5-nitro-1-(2-deoxy-alpha-D-erythro-pentofuranosyl)cytosine (4alpha), 5-nitro-1-(2-deoxy-beta-D-erythro-pentofuranosyl)cytosine (4beta), 5-amino-1-(2-deoxy-alpha-D-erythro-pentofuranosyl)cytosine (5alpha), 5-nitro-1-(2-deoxy-beta-D-erythro-pentofuranosyl)cytosine (5beta), 5-nitro-1-(2,3-dideoxy-beta-D-ribofuranosyl)uracil (6beta), 5-amino-1-(2,3-dideoxy-alpha,beta-D-ribofuranosyl)uracil (7), 5-nitro-1-(2,3-dideoxy-alpha,beta-D-ribofuranosyl)cytosine (8) and 5-amino-1-(2,3-dideoxy-beta-D-ribofuranosyl)cytosine (9beta). The prepared compounds were tested for their activity against HIV and HBV viruses, but they did not show significant activity.  相似文献   

11.
12.
Analogues of the 2',5'-linked adenylate trimers monophosphate (p5'A2'p5'A2'p5'A) containing 8-hydroxypropyladenosine, 8-bromoadenosine, and 8-hydroxyadenosine in the first, second, and third nucleotide positions were tested for their ability to bind to and activate RNase L of mouse L cells. p5'AHPr2'p5'AHPr2'p5'AHPr (pAHPr3) (1b) and p5'ABr2'p5'ABr2'p5'ABr (pABr3) (1d) were markedly decreased in ability to bind to the 2-5A dependent endonuclease. On the other hand, analogue of the 2',5'-linked adenylate trimer monophosphate substituted by 8-hydroxyadenosine in the first, second, and third nucleotide position was bound about as well as parent 2-5A [pppA(2'p5'A)2] (p3A3) (1e) to RNase L. Additionally, p5'AOH2'p5'AOH2'p5'AOH (pAOH3) (1c) was as active as parent 2-5A in the rRNA cleavage assay, while pAHPr3 (1b) and pABr3 (1d) were devoid of activity. The 8-substituted analogues of 2-5A were more resistant to the degradation by the (2',5') phosphodiesterase. Finally of particular interest was monophosphate, pAOH3 (1c) which possessed nearly 100% of the translation inhibitory activity of 2-5A triphosphate itself. These results suggest that changes in the base-sugar torsion angles of 2-5A may modulate both binding to and activation of mouse L cell RNase L.  相似文献   

13.
14.
Novel, flexible arylpiperazine gepirone analogs (1a-3a) with a mixed 5-HT1A/5-HT2A receptor profile, low D2 receptor affinity, and agonistic (2a) or partial agonistic (1a, 3a) activity toward 5-HT1A receptor sites were synthesized. Their conformationally restricted counterparts (1b-3b) were selective 5-HT1A ligands (over 5-HT2A and D2 receptors), which turned out to be agonists (2b, 3b), or partial agonist (1b) of 5-HT1A receptors.  相似文献   

15.
The stoichiometry of dioxygen uptake of Co complexes with 4',5'-bis-(5-chloro-2-hydroxyphenylmethylideneimino)benzo-12-crown-4 (1a), 4',5'-bis(2-hydroxyphenylmethylideneimino)benzo-12-crown-4 (1b), 4',5'-bis-(5-methoxy-2-hydroxyphenylmethylideneimino)benzo-12-crown-4 (1c), 4',5'-bis-(5-chloro-2-hydroxyphenylmethylideneimino)benzo-15-crown-5 (2a), 4',5'-bis(2-hydroxyphenylmethylideneimino)benzo-15-crown-5 (2b), 4',5'-bis(5-methoxy-2-hydroxyphenylmethylideneimino)benzo-15-crown-5 (2c) were measured in pyridine solution. The equilibrium constants and thermodynamic parameters (DeltaH0, DeltaS0) of these complexes were calculated. At the same time, their catalytic activities in cyclohexene oxidation to 2-cyclohexen-1-one were examined. The influence of the crown ether ring on the dioxygen affinity of Co complexes at different temperature and the catalytic activities were discussed in comparison with uncrowned analogous complexes.  相似文献   

16.
In different cell systems, the lipido-sterolic extract of Serenoa repens (LSESr, Permixon inhibits both type 1 and type 2 5alpha-reductase activity (5alphaR1 and 5alphaR2). LSESr is mainly constituted of fatty acids (90+/-5%) essentially as free fatty acids (80%). Among these free fatty acids, the main components are oleic and lauric acids which represent 65% and linoleic and myristic acids 15%.To evaluate the inhibitory effect of the different components of LSESr on 5alphaR1 or 5alphaR2 activity, the corresponding type 1 and type 2 human genes have been cloned and expressed in the baculovirus-directed insect cell expression system Sf9. The cells were incubated at pH 5.5 (5alphaR2) and pH 7.4 (5alphaR1) with 1 or 3nM testosterone in presence or absence of various concentrations of LSESr or of its different components. Dihydrotestosterone formation was measured with an automatic system combining HPLC and an on-line radiodetector.The inhibition of 5alphaR1 and 5alphaR2 activity was only observed with free fatty acids: esterified fatty acids, alcohols as well as sterols assayed were inactive. A specificity of the fatty acids in 5alphaR1 or 5alphaR2 inhibition has been found. Long unsaturated chains (oleic and linolenic) were active (IC(50)=4+/-2 and 13+/-3 microg/ml, respectively) on 5alphaR1 but to a much lesser extent (IC(50)>100 and 35+/-21 microg/ml, respectively) on 5alphaR2. Palmitic and stearic acids were inactive on the two isoforms. Lauric acid was active on 5alphaR1 (IC(50)=17+/-3 microg/ml) and 5alphaR2 (IC(50)=19+/-9 microg/ml). The inhibitory activity of myristic acid was evaluated on 5alphaR2 only and found active on this isoform (IC(50)=4+/-2 microg/ml).The dual inhibitory activity of LSESr on 5alpha-reductase type 1 and type 2 can be attributed to its high content in free fatty acids.  相似文献   

17.
The following 1-substituted derivatives of 5-methylphenazine and 5-ethylphenazine were synthesized: 1-(3-carboxypropyloxy)-5-methylphenazine (1B), 1-(3-carboxypropyloxy)-5-ethylphenazine (2B), 1-(3-ethoxycarbonylpropyloxy)-5-ethylphenazine (2C) and 1-[N-(2-aminoethyl)carbamoylpropyloxy]-5-ethylphenazine (2D); their spectra, stability and reactivity as electron mediators were investigated, together with those of 5-methylphenazine (1A) and 5-ethylphenazine (2A). The 1-substituted derivatives are all insensitive to light and the derivatives of 5-ethylphenazine are more stable than those of 5-methylphenazine under neutral and alkaline conditions; 2B is the most stable of all the derivatives. The spectral properties of the decomposed compounds showed that photodecomposition of 1A and 2A is associated with hydroxylation at position 1, alkali decomposition of 1A and 1B with elimination of the 5-methyl group and alkali decomposition of 2A, 2B, and 2D with a ring-opening reaction. The second-order rate constant k1 for the reaction of the phenazine derivatives with NADH was measured under steady-state conditions. The k1 values vary depending on the substituents at positions 1 and 5: the values for 1A, 1B, 2A, 2B, 2C and 2D are 1.83 mM-1 s-1, 3.33 mM-1 s-1, 0.75 mM-1 s-1, 1.42 mM-1 s-1, 1.68 mM-1 s-1 and 2.03 mM-1 s-1, respectively. The rate constants, k2 and k3, for the reactions of the reduced form of 2B with oxygen and with 3-(4',5'-dimethylthiazole-2-yl)-2,5-diphenyltetrazolium ion, respectively, were k2 = 1.21 mM-1 s-1 and k3 = 91 mM-1 s-1. These phenazine derivatives have potential applications in the biochemical field.  相似文献   

18.
Saksena R  Chernyak A  Kovác P 《Carbohydrate research》2008,343(10-11):1693-1706
The title rhamnooligosaccharides [alpha-D-Rhap4NAc-(1-->3)-alpha-D-Rhap4NAc-1-O-(CH(2))(5)COOMe, alpha-D-Rhap4NAc-(1-->3)-alpha-D-Rhap4NAc-(1-->3)-alpha-D-Rhap4NAc-1-O-(CH(2))(5)COOMe, alpha-D-Rhap4NAc-(1-->2)-alpha-D-Rhap4NAc-(1-->3)-alpha-D-Rhap4NAc-(1-->3)-alpha-D-Rhap4NAc-1-O-(CH(2))(5)COOMe, and alpha-D-Rhap4NAc-(1-->3)-alpha-D-Rhap4NAc-(1-->2)-alpha-D-Rhap4NAc-(1-->3)-alpha-D-Rhap4NAc-(1-->3)-alpha-D-Rhap4NAc-1-O-(CH(2))(5)COOMe] were synthesized in a stepwise fashion from 5-methoxycarbonylpentyl 4-azido-4,6-dideoxy-2-O-benzyl-alpha-D-mannopyranoside and orthogonally protected 1-thioglycoside glycosyl donors. The amorphous, final products were fully characterized as corresponding per-O-acetyl derivatives.  相似文献   

19.
Two classes of 5-fluorouracil (5-FU) derivatives were prepared from 1,3-bis(hydroxymethyl)-5-fluorouracil (1). The first group was obtained by the direct esterification of 1 with various acids. The second one was derived by the nucleophilic substitution of N-(chloromethyl)-5-FUs, which were easily prepared by halogenation of 1, with hetero nucleophiles. The antitumor activities of the prepared compounds were examined against Leukemia L1210 and the results were compared with that of 1-hexylcarbamoyl-5-fluorouracil (HCFU, Carmofur).  相似文献   

20.
cis-5(6)Epoxy- and cis-14(15)epoxyeicosatrienoic acid are formed from arachidonic acid by monooxygenases. 5(6)Epoxyeicosatrienoic acid is metabolized by fatty acid cyclooxygenase of ram seminal vesicles and the major products were recently identified as 5(6)epoxy-PGE1 and two stereoisomers of 5-hydroxy-PGI1. The two isomers were likely formed from an unstable intermediate, 5(6)epoxy-PGF1 alpha. The isolation of 5(6)epoxy-PGF1 alpha is described here and 14(15)epoxyeicosatrienoic acid is shown to inhibit fatty acid cyclooxygenase of ram seminal vesicles, albeit less potently than eicosatetraynoic acid (IC50 0.18 and 0.05 mM, respectively).  相似文献   

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