1-[(Benzofuran-2-yl)phenylmethyl]-triazoles and -tetrazoles - potent competitive inhibitors of aromatase.

The synthesis of a series of novel 1-[(benzofuran-2-yl)phenylmethyl]-triazoles and -tetrazoles is described. The compounds were tested for human placental aromatase inhibition in vitro, using [1beta-3H]-androstenedione as the substrate for the aromatase enzyme, the percentage inhibition and IC50 data is included.     

NVP-DPP728 (1-[[[2-[(5-cyanopyridin-2-yl)amino]ethyl]amino]acetyl]-2-cyano-(S)- pyrrolidine), a slow-binding inhibitor of dipeptidyl peptidase IV.

Inhibition of dipeptidyl peptidase IV (DPP-IV) has been proposed recently as a therapeutic approach to the treatment of type 2 diabetes. N-Substituted-glycyl-2-cyanopyrrolidide compounds, typified by NVP-DPP728 (1-[[[2-[(5-cyanopyridin-2-yl)amino]ethyl]amino]acetyl]-2-cyano-(S )-p yrrolidine), inhibit degradation of glucagon-like peptide-1 (GLP-1) and thereby potentiate insulin release in response to glucose-containing meals. In the present study NVP-DPP728 was found to inhibit human DPP-IV amidolytic activity with a K(i) of 11 nM, a k(on) value of 1.3 x 10(5) M(-)(1) s(-)(1), and a k(off) of 1.3 x 10(-)(3) s(-)(1). Purified bovine kidney DPP-IV bound 1 mol/mol [(14)C]-NVP-DPP728 with high affinity (12 nM K(d)). The dissociation constant, k(off), was 1.0 x 10(-)(3) and 1.6 x 10(-)(3) s(-)(1) in the presence of 0 and 200 microM H-Gly-Pro-AMC, respectively (dissociation t(1/2) approximately 10 min). Through kinetic evaluation of DPP-IV inhibition by the D-antipode, des-cyano, and amide analogues of NVP-DPP728, it was determined that the nitrile functionality at the 2-pyrrolidine position is required, in the L-configuration, for maximal activity (K(i) of 11 nM vs K(i) values of 5.6 to >300 microM for the other analogues tested). Surprisingly, it was found that the D-antipode, despite being approximately 500-fold less potent than NVP-DPP728, displayed identical dissociation kinetics (k(off) of 1.5 x 10(-)(3) s(-)(1)). NVP-DPP728 inhibited DPP-IV in a manner consistent with a two-step inhibition mechanism. Taken together, these data suggest that NVP-DPP728 inhibits DPP-IV through formation of a novel, reversible, nitrile-dependent complex with transition state characteristics.     

Optically active antifungal azoles: synthesis and antifungal activity of (2R,3S)-2-(2,4-difluorophenyl)-3-(5-[2-[4-aryl-piperazin-1-yl]-ethyl]-tetrazol-2-yl/1-yl)-1-[1,2,4]-triazol-1-yl-butan-2-ol

A series of (2R,3S)-2-(2,4-difluorophenyl)-3-(5-[2-[4-aryl-piperazin-1-yl]-ethyl]-tetrazol-2-yl)-1-[1,2,4]-triazol-1-yl-butan-2-ol (11a-n) and (2R,3S)-2-(2,4-difluorophenyl)-3-(5-[2-[4-aryl-piperazin-1-yl]-ethyl]-tetrazole-1-yl)-1-[1,2,4]-triazol-1-yl-butan-2-ol (12a-n) has been synthesized. The antifungal activity of compounds was evaluated by in vitro agar diffusion and broth dilution assay. Compounds 11d and its positional isomer 12d having 3-trifluoromethyl substitution on the phenyl ring of piperazine demonstrated significant antifungal activity against variety of fungal cultures (Candida spp. C. neoformans and Aspergillus spp.). The compound 12d showed MIC value of 0.12 microg/mL for C. albicans, C. albicans V-01-191A-261 (resistant strain); 0.25 microg/mL for C. tropicalis, C. parapsilosis ATCC 22019 and C. krusei and MIC value of 0.5 microg/mL for C. glabrata, C. krusei ATCC 6258, which is comparable to itraconazole and better than fluconazole. Further, compound 11d showed significant activity (MIC; 0.25-0.5 microg/mL) against Candida spp. and strong anticryptococcal activity (MIC; 0.25 microg/mL) against C. neoformans.     

Influence of 1-[(E)-2-(2-methyl-4-nitrophenyl)diaz-1-enyl]pyrrolidine-2-carboxylic acid and diphenyliodonium chloride on ruminal protein metabolism and ruminal microorganisms.

The effects of 1-[(E)-2-(2-methyl-4-nitrophenyl)diaz-1-enyl]pyrrolidine-2-carboxy lic acid (LY29) and diphenyliodonium chloride (DIC) on the degradation of protein to ammonia were determined in a mixed rumen microbial population taken from sheep on a grass hay-concentrate diet. Both compounds decreased NH3 production by inhibiting deamination of amino acids. LY29, but not DIC, inhibited growth of the high-activity ammonia-producing species, Clostridium aminophilum and Clostridium sticklandii.     

Discovery of 1-[4-(N-benzylamino)phenyl]-3-phenylurea derivatives as non-peptidic selective SUMO-sentrin specific protease (SENP)1 inhibitors

We developed 1-[4-(N-benzylamino)phenyl]-3-phenylurea derivative 4 (GN6958) as a non-peptidic selective SUMO-sentrin specific protease (SENP)1 protease inhibitor based on the hypoxia inducible factor (HIF)-1α inhibitor 1 (GN6767). The direct interaction of compound 1 with SENP1 protein in cells was observed by the pull-down experiments using the biotin-tagged compound 2 coated on the streptavidin affinity column. Among the various 1-[4-(N-benzylamino)phenyl]-3-phenylurea derivatives tested, compounds 3 and 4 suppressed HIF-1α accumulation in a concentration-dependent manner without affecting the expression level of tubulin protein in HeLa cells. Both compounds inhibited SENP1 protease activity in a concentration-dependent manner, and compound 4 exhibited more potent inhibition than compound 3. Compound 4 exhibited selective inhibition against SENP1 protease activity without inhibiting other protease enzyme activities in vitro.     

Synthesis and anticonvulsant activity of new 1-[2-oxo-2-(4-phenylpiperazin-1-yl)ethyl]pyrrolidine-2,5-diones

Twenty-two new 1-[2-oxo-2-(4-phenylpiperazin-1-yl)ethyl]pyrrolidine-2,5-diones were synthesized and tested for anticonvulsant activity. Initial anticonvulsant screening was performed using standard maximal electroshock (MES) and subcutaneous pentylenetetrazole (scPTZ) screens in mice. Several compounds were tested additionally in the 6-Hz psychomotor seizure model. The neurotoxicity was determined applying the rotarod test. Excluding one compound, all other molecules were found to be effective in at least one seizure model. The most active were 1-(2-oxo-2-{4-[3-(trifluoromethyl)phenyl]piperazin-1-yl}ethyl)pyrrolidine-2,5-dione (14), 1-{2-[4-(4-chlorophenyl)piperazin-1-yl]-2-oxoethyl}-3-methylpyrrolidine-2,5-dione (17), 1-{2-[4-(4-chlorophenyl)piperazin-1-yl]-2-oxoethyl}-3,3-dimethylpyrrolidine-2,5-dione (23) and 3,3-dimethyl-1-(2-oxo-2-{4-[3-(trifluoromethyl)phenyl]piperazin-1-yl}ethyl)pyrrolidine-2,5-dione (26). These compounds showed high activity in the 6-Hz psychomotor seizure test as well as were active in the maximal electroshock and subcutaneous pentylenetetrazole (14 and 23) screens. Initial SAR studies for anticonvulsant activity have been discussed.     

6-Acylamino-2-[(alkylsulfonyl)oxy]-1H-isoindole-1,3-dione mechanism-based inhibitors of human leukocyte elastase

A study of various 2-[(alkylsulfonyl)oxy]-6-substituted-1H-isoindole-1,3-diones' inhibition of chymotrypsin compared to inhibition of HLE reveals that acylamino substitution in the 6-position increases selectivity and potency of these inhibitors for HLE. The best HLE inhibitor in this series was 6-(methylglutaryl)amino-2-[(ethylsulfonyl)oxy]-1H-isoindole-1,3-di one with a kobs/[I] = 220,000 M(-1) s(-1).     

2-(2-Furanyl)-7-phenyl[1,2,4]triazolo[1,5-c]pyrimidin-5-amine analogs as adenosine A2A antagonists: the successful reduction of hERG activity. Part 2

The structure-activity relationship (SAR) exploration using 2-(2-furanyl)-7-phenyl[1,2,4]triazolo-[1,5-c]pyrimidin-5-amine (1) as a template led to the identification of a novel class of potent and selective adenosine A2A receptor (AR) antagonists. However, these compounds were found to be associated with significant hERG activity. This report discusses the strategy and outcome of an expanded SAR focused on addressing the hERG liability. As a result, compounds 21 and 24 possess excellent in vitro profiles, highly promising in vivo profiles, and acceptable levels of hERG channel inhibition.     

Discovery of (-)-6-[2-[4-(3-fluorophenyl)-4-hydroxy-1-piperidinyl]-1-hydroxyethyl]-3,4-dihydro-2(1H)-quinolinone--a potent NR2B-selective N-methyl D-aspartate (NMDA) antagonist for the treatment of pain

(-)-6-[2-[4-(3-Fluorophenyl)-4-hydroxy-1-piperidinyl]-1-hydroxyethyl]-3,4-dihydro-2(1H)-quinolinone was identified as an orally active NR2B-subunit selective N-methyl-d-aspartate (NMDA) receptor antagonist. It has very high selectivity for NR2B subunits containing NMDA receptors versus the HERG-channel inhibition (therapeutic index=4200 vs NR2B binding IC(50)). This compound has improved pharmacokinetic properties compared to the prototype CP-101,606.     

Inhibition of IKK-2 by 2-[(aminocarbonyl)amino]-5-acetylenyl-3-thiophenecarboxamides

A series of 21 novel 2-[(aminocarbonyl)amino]-5-acetylenyl-3-thiophenecarboxamides were synthesized and evaluated for the inhibition of IKK-2. In spite of their often modest activity on the enzyme, six selected analogs showed significant inhibition of the production of inflammatory cytokine IL-8 in IL-1beta stimulated rheumatoid arthritis-derived synovial fibroblasts, demonstrating their potential usefulness as NF-kappaB regulators.     

Alpha1- and alpha2-adrenoreceptor antagonist profiles of 1- and 2-[omega-(4-arylpiperazin-1-yl)alkyl]-1,2,3-benzotriazoles

A series of pharmacologically interesting 1- and 2-[omega-(4-arylpiperazin-1-yl)alkyl]-1,2,3-benzotriazoles, compounds 1-27, were synthesized (Scheme) and subjected to various biological studies to identify structure-activity relationships (SAR). The new compounds were found to exhibit good non-selective binding affinity towards the alpha1-adrenoreceptor (Table 1). In several cases, high functional antagonism was observed towards the alpha1A-, alpha1B-, and alpha1D-adrenoreceptor subtypes (Table 2). The selectivity for these three subtypes was comparable with or superior to that displayed by the standard drug prazosin. The most-common selectivity rank order was alpha1D > alpha1B > alpha1A, followed by alpha1B > alpha1D > alpha1A. In functional experiments, antagonism towards the alpha2-adrenoreceptor was generally low; however, a few compounds were endowed with significant antagonist properties (pA2 values of up to 7.87).     

Synthesis and antibacterial activity of a novel series of DNA gyrase inhibitors: 5-[(E)-2-arylvinyl]pyrazoles

The 2-arylvinyl moiety in 1-(3-chlorophenyl)-3-(4-piperidyl)-5-[(E)-2-(5-chloro-1H-indol-3-yl)vinyl]pyrazole 2, which has previously shown improved DNA gyrase inhibition and target-related antibacterial activity, was transformed to other groups and the in vitro antibacterial activity of the synthesized compounds was evaluated. Many of the 5-[(E)-2-arylvinyl]pyrazoles synthesized in this study exhibited potent antibacterial activity against quinolone-resistant clinical isolates of gram-positive bacteria with minimal inhibitory concentration values equivalent to those against susceptible strains.     

Synthesis of new 4-[2-(alkylamino) ethylthio]pyrrolo[1,2-a]quinoxaline and 5-[2-(alkylamino) ethylthio]pyrrolo[1,2-a]thieno[3,2-e]pyrazine derivatives, as potential bacterial multidrug resistance pump inhibitors

The synthesis of new 4-[2-(alkylamino)ethylthio]pyrrolo[1,2-a]quinoxaline derivatives la-1 is described in five or six steps starting from various substituted nitroanilines 2a-e. The bioisostere 5-[2-(alkylamino)ethylthio]pyrrolo[1,2- a]thieno[3,2-e]pyrazine 1m was also prepared. The new derivatives were evaluated as efflux pump inhibitors (EPIs) in a model targeting the NorA system of Staphylococcus aureus. The antibiotic susceptibility of two strains overproducing NorA, SA-1199B and SA-1, was determined alone and in combination with the neo-synthesised compounds by the agar diffusion method and MIC determination, in comparison with reserpine and omeprazole taken as reference EPIs. A preliminary structure-activity relationship study firstly allowed to clarify the influence of the substituents at positions 7 and/or 8 of the pyrrolo[1,2-a]quinoxaline nucleus. Methoxy substituted compounds, 1b and 1g, were more potent EPIs than the unsubstituted compounds (1a and 1f), followed by chlorinated derivatives (1c-d and 1h). Moreover, the replacement of the N,N-diethylamino group (compounds 1a-e) by a bioisostere such as pyrrolidine (compounds 1f-h) enhanced the EPI activity, in contrast with the replacement by a piperidine moiety (compounds 1i-k). Finally, the pyrrolo[1,2-a]thieno[3,2-e]pyrazine compound 1m exhibited a higher EPI activity than its pyrrolo[1,2-a]quinoxaline analogue la, opening the way to further pharmacomodulation.     

N-[2-(1-cyclohexenyl)ethyl]-N'-[2-(5-bromopyridyl)]-thiourea and N'-[2-(1-cyclohexenyl)ethyl]-N'-[2-(5-chloropyridyl)]-thiourea as potent inhibitors of multidrug-resistant human immunodeficiency virus-1.

We have replaced the pyridyl ring of trovirdine with an alicyclic cyclohexenyl, adamantyl or cis-myrtanyl ring. Only the cyclohexenyl-containing thiourea compound N-[2-(1-cyclohexenyl)ethyl]-N'-[2-(5-bromopyridyl)]- thiourea (HI-346) (as well as its chlorine-substituted derivative N-[2-(1-cyclohexenyl)ethyl]-N'-[2-(5-chloropyridyl)]- thiourea/HI-445) showed RT inhibitory activity. HI-346 and HI-445 effectively inhibited recombinant RT with better IC50 values than other anti-HIV agents tested. The ranking order of efficacy in cell-free RT inhibition assays was: HI-346 (IC50 = 0.4 microM) > HI-445 (IC50 = 0.5 microM) > trovirdine (IC50 = 0.8 microM) > MKC-442 (IC5 = 0.8 microM) = delavirdine (IC50 = 1.5 microM) > nevirapine (IC50 = 23 microM). In accord with this data, both compounds inhibited the replication of the drug-sensitive HIV-1 strain HTLV(IIIB) with better IC50 values than other anti-HIV agents tested. The ranking order of efficacy in cellular HIV-1 inhibition assays was: HI-445 = HI-346 (IC50 = 3 nM) > MKC-442 (IC50 = 4 nM) = AZT (IC50 = 4 nM) > trovirdine (IC50 = 7 nM) > delavirdine (IC50 = 9 nM) > nevirapine (IC50 = 34 nM). Surprisingly, the lead compounds HI-346 and HI-445 were 3-times more effective against the multidrug resistant HIV-1 strain RT-MDR with a V106A mutation (as well as additional mutations involving the RT residues 74V,41L, and 215Y) than they were against HTLV(IIIB) with wild-type RT. HI-346 and HI-445 were 20-times more potent than trovirdine, 200-times more potent than AZT, 300-times more potent than MKC-442, 400-times more potent than delavirdine, and 5000-times more potent than nevirapine against the multidrug resistant HIV-1 strain RT-MDR. HI-445 was also tested against the RT Y181C mutant A17 strain of HIV-1 and found to be >7-fold more effective than trovirdine and >1,400-fold more effective than nevirapine or delavirdine. Similarly, both HI-346 and HI-445 were more effective than trovirdine, nevirapine, and delavirdine against the problematic NNI-resistant HIV-1 strain A17-variant with both Y181C and K103N mutations in RT, although their activity was markedly reduced against this strain. Neither compound exhibited significant cytotoxicity at effective concentrations (CC50 >100 microM). These findings establish the lead compounds HI-346 and HI-445 as potent inhibitors of drug-sensitive as well as multidrug-resistant stains of HIV-1.     

Synthesis and antimycobacterial activity of some alkyl [5-(nitroaryl)-1,3,4-thiadiazol-2-ylthio]propionates

Two series of 2- and 3-[5-(nitroaryl)-1,3,4-thiadiazol-2-ylthio, sulfinyl and sulfonyl] propionic acid alkyl esters were synthesized and screened for antituberculosis activity against Mycobacterium tuberculosis H37Rv using the BACTEC 460 radiometric system. The MIC values for the compounds showing more than 90% inhibition were determined. The result of comparison between two groups of data exhibited that among the synthesized derivatives, the compound propyl 3-[5-(5-nitrothiophen-2-yl)-1,3,4-thiadiazol-2-ylthio]propionate was the most active one (MIC=1.56 microgml(-1)).     

Designing,synthesis and bioactivities of 4-[3-(4-hydroxyphenyl)-5-aryl-4,5-dihydro-pyrazol-1-yl]benzenesulfonamides

In this study, 4-[3-(4-hydroxyphenyl)-5-aryl-4,5-dihydro-pyrazol-1-yl]benzenesulfonamide (1–9) types compounds were synthesized and their chemical structures were confirmed by ¹H NMR, ¹³C NMR and HRMS spectra. Cytotoxic and carbonic anhydrase (CA) inhibitory effects of the compounds were investigated. Cytotoxicity experiments pointed out that compound 4, (4-[5-(4-chlorophenyl)-3-(4-hydroxyphenyl)-4,5-dihydro-pyrazol-1-yl]benzenesulfonamide), exerting the highest tumor selectivity (TS) and potency selectivity expression (PSE) values, can be considered as a lead compound of this study in terms of development of novel anticancer agents. All synthesized sulfonamides showed a good inhibition profile on hCA IX and XII in the range of 53.5–923?nM and 6.2–95?nM, respectively. These compounds were 2.5–13.4 times more selective for the inhibition of hCA XII versus hCA IX, except compound 2 which had similar inhibitory action towards both isoenzymes.     

Synthesis of 1-/2-substituted-[1,2,3]triazolo[4,5-g]phthalazine-4,9-diones and evaluation of their cytotoxicity and topoisomerase II inhibition

Studies on antitumor heterocyclic quinones containing nitrogens revealed that the number and position of nitrogens on the heterocyclic ring have significance on cytotoxicity of quinones. In our continuous effort to find more cytotoxic quinone compounds, we designed triazolophthalazine analogues in order to introduce more nitrogens on the heterocyclic quinones. 1-/2-Substituted-[1,2,3]triazolo[4,5-g]phthalazine-4,9-diones were synthesized by 1,3-dipolar addition of phthalazine-5,8-dione and 4-methoxybenzyl azide by modification of previously reported method. The cytotoxicity of the synthesized compounds was evaluated by a SRB (sulforhodamine B) assay against nine types of human cancer cell lines and inhibition against topoisomerase II (Topo II) of them was assessed by a decatenation assay. Most of the synthesized compounds showed considerably higher cytotoxicity than that of doxorubicin. Also, topoisomerase II inhibitory activity of the tested compounds was higher than that of etoposide and IC(50) values of the compounds were 19.4-64.5 microM.