Design,synthesis, and pharmacological evaluation of 2-(4-sulfonylphenyl)-2-[(E)-pyrrolidin-1-ylimino]-N-thiazoleacetamides as glucokinase activators

This paper presents the synthesis and glucokinase activity of novel hydrazone derivatives. The 2-(4-cyclopropylsulfonylphenyl)-2-[(E)-pyrrolidin-1-ylimino]-acetamide derivatives 5a–5h presented the in vitro glucokinase activities and in vivo blood glucose-lowering effects in mice. Particularly, 5h showed an oral hypoglycemic effect in rats at 1 mg/kg. These hydrazone derivatives are a potential new class of glucokinase activators for the treatment of type 2 diabetes.     

Design, synthesis, and pharmacological evaluation of benzamide derivatives as glucokinase activators

A series of benzamide derivatives were assembled by using the privileged-fragment-merging (PFM) strategy and their SAR studies as glucokinase activators were described. Compounds 5 and 16b were identified having a suitable balance of potency and activation profile. They showed EC(50) values of 28.3 and 44.8 nM, and activation folds of 2.4 and 2.2, respectively. However, both compounds displayed a minor reduction in plasma glucose levels on imprinting control region (ICR) mice. Unfavorable pharmacokinetic profiles (PK) were also observed on these two compounds.     

Design, synthesis, and preliminary in vitro and in vivo pharmacological evaluation of 2-{4-[4-(2,5-disubstituted thiazol-4-yl)phenylethyl]piperazin-1-yl}-1,8-naphthyridine-3-carbonitriles as atypical antipsychotic agents

A series of 2-{4-[4-(2,5-disubstituted thiazolyl)phenylethyl] piperazin-1-yl}-1,8-naphthyridine-3-carbonitriles were synthesized in an effort to prepare novel atypical antipsychotic agents. The compounds were synthesized either by microwave irradiation technique or by conventional synthesis and were characterized by spectral data (IR, (1)H NMR, and MS) and the purity was ascertained by microanalysis. The D(2) and 5-HT(2A) affinity of the synthesized compounds was screened in vitro by radioligand displacement assays on membrane homogenates isolated from rat striatum and rat cortex, respectively. Furthermore, all the synthesized compounds were screened for their in vivo pharmacological activity in Swiss albino mice. The D(2) antagonism studies were performed using climbing mouse assay model and 5-HT(2A) antagonism studies were performed using quipazine-induced head twitches in mice. It was observed that none of the new chemical entities exhibited catalepsy and 10f is the most active among the synthesized compounds with 5-HT(2A)/D(2) ratio of 1.1286 although the standard drug risperidone exhibited 5-HT(2A)/D(2) ratio of 1.0989.     

Design,synthesis, and preliminary in vitro and in vivo pharmacological evaluation of 2-{4-[4-(2,5-disubstituted thiazol-4-yl)phenylethyl]piperazin-1-yl}-1,8-naphthyridine-3-carbonitriles as atypical antipsychotic agents

A series of 2-{4-[4-(2,5-disubstituted thiazolyl)phenylethyl] piperazin-1-yl}-1,8-naphthyridine-3-carbonitriles were synthesized in an effort to prepare novel atypical antipsychotic agents. The compounds were synthesized either by microwave irradiation technique or by conventional synthesis and were characterized by spectral data (IR, ¹H NMR, and MS) and the purity was ascertained by microanalysis. The D₂ and 5-HT_2A affinity of the synthesized compounds was screened in vitro by radioligand displacement assays on membrane homogenates isolated from rat striatum and rat cortex, respectively. Furthermore, all the synthesized compounds were screened for their in vivo pharmacological activity in Swiss albino mice. The D₂ antagonism studies were performed using climbing mouse assay model and 5-HT_2A antagonism studies were performed using quipazine-induced head twitches in mice. It was observed that none of the new chemical entities exhibited catalepsy and 10f is the most active among the synthesized compounds with 5-HT_2A/D₂ ratio of 1.1286 although the standard drug risperidone exhibited 5-HT_2A/D₂ ratio of 1.0989.     

Design,synthesis and biological evaluation of 4,5-dibromo-N-(thiazol-2-yl)-1H-pyrrole-2-carboxamide derivatives as novel DNA gyrase inhibitors

Development of novel DNA gyrase B inhibitors is an important field of antibacterial drug discovery whose aim is to introduce a more effective representative of this mechanistic class into the clinic. In the present study, two new series of Escherichia coli DNA gyrase inhibitors bearing the 4,5-dibromopyrrolamide moiety have been designed and synthesized. 4,5,6,7-Tetrahydrobenzo[1,2-d]thiazole-2,6-diamine derivatives inhibited E. coli DNA gyrase in the submicromolar to low micromolar range (IC₅₀ values between 0.891 and 10.4 μM). Their “ring-opened” analogues, based on the 2-(2-aminothiazol-4-yl)acetic acid scaffold, displayed weaker DNA gyrase inhibition with IC₅₀ values between 15.9 and 169 μM. Molecular docking experiments were conducted to study the binding modes of inhibitors.     

Synthesis, pharmacological evaluation and docking studies of N-(benzo[d]thiazol-2-yl)-2-(piperazin-1-yl)acetamide analogs as COX-2 inhibitors

The existing NSAIDs having number of toxicities emphasises the need for discovery of new non-toxic anti-inflammatory agents. In this Letter, we present the simple two step chemical synthesis, in vivo pharmacological screening and docking study of few N-(benzo[d]thiazol-2-yl)-2-(piperazin-1-yl)acetamide analogs. Different amino benzothiazoles were chloroacetylated and further reacted with substituted piperazines in presence of a base to get N-(benzo[d]thiazol-2-yl)-2-(piperazin-1-yl)acetamide analogs (A1-C4). These compounds were evaluated for anti-inflammatory activity by carragenan induced paw oedema method. Promising compounds were screened for toxicity by evaluating the ulcerogenic potential. Molecular docking experiments were carried out against COX-2 enzyme using Surflex-Dock GeomX programme of Sybyl software on Dell T-1500 workstation to confirm the mechanism of action of active compounds among the series. In silico study reveal the binding interactions of N-(benzo[d]thiazol-2-yl)-2-(piperazin-1-yl)acetamide analogs with COX-2 protein and is in agreement with the in vivo anti-inflammatory activity.     

Design,synthesis, and evaluation of N-(4-(4-phenyl piperazin-1-yl)butyl)-4-(thiophen-3-yl)benzamides as selective dopamine D3 receptor ligands

As part of our on-going effort to explore the role of dopamine receptors in drug addiction and identify potential novel therapies for this condition, we have a identified a series of N-(4-(4-phenyl piperazin-1-yl)butyl)-4-(thiophen-3-yl)benzamide D₃ ligands. Members of this class are highly selective for D₃ versus D₂, and we have identified two compounds (13g and 13r) whose rat in vivo IV pharmacokinetic properties that indicate that they are suitable for assessment in in vivo efficacy models of substance use disorders.     

Synthesis and preliminary pharmacological evaluation of N-2-(4-(4-(2-substitutedthiazol-4-yl) piperazin-1-yl)-2-oxoethyl)acetamides as novel atypical antipsychotic agents

A series of N-2-(4-(4-(2-substitutedthiazol-4-yl) piperazin-1-yl)-2-oxoethyl)acetamides were synthesized in an effort to prepare novel atypical antipsychotic agents. The compounds were synthesized by either microwave irradiation technique or by conventional synthesis and were characterized by spectral data (IR, (1)H NMR, and MS) and the purity was ascertained by microanalysis. All the synthesized compounds were screened for their in vivo pharmacological activity in Swiss albino mice. D(2) antagonism studies were performed using climbing mouse assay model and 5-HT(2A) antagonism studies were performed using quipazine induced head twitches in mice. It was observed that none of the new chemical entities exhibited catalepsy. AG 3 was found to be the most active compound.     

N-Benzyl-N-(tetrahydro-2H-pyran-4-yl)pyrrolidin-3-amines as selective dual serotonin/noradrenaline reuptake inhibitors

A series of N-benzyl-N-(tetrahydro-2H-pyran-4-yl)pyrrolidin-3-amine monoamine reuptake inhibitors are described. Selective dual 5-HT and NA reuptake inhibition was achieved, and analogues with weak CYP2D6 inhibition, good human in vitro metabolic stability and wide ligand selectivity, such as 12b, were identified.     

Discovery,synthesis and molecular substantiation of N-(benzo[d]thiazol-2-yl)-2-hydroxyquinoline-4-carboxamides as anticancer agents

The effort was taken to develop a series of benzothiazole and quinoline fused bioactive compounds obtained through a four-step synthetic route using a range of substituted acetoacetanilides. Achieved N-(benzo[d]thiazol-2-yl)-2-hydroxyquinoline-4-carboxamides (6a-l) were produced up to 96% of yield while the eco-friendly p-TSA used as a catalyst. Further, the anticancer activity of these compounds was determined using a range of cancer cell lines starting from MCF-7 (Breast cancer), HCT-116 (Colon cancer), PC-3 & LNCaP (Prostate) and SK-HEP-1 (Liver cancer). Present study compounds were also testified for antioxidant properties prior to anticancer studies since the Reactive Oxygen Species (ROS) being vital in cancer development. To determine the cell membrane stability effects of the compounds, human red blood cells (HRBC) based membrane protection assay was determined. In the results, compounds 6a-l were able to produce a dominated result values over PC3 cell lines (Prostate cancer) than the other cell lines used in this study. Since the connectivity of human germ cell alkaline phosphatase (hGC-ALP) in the development of prostate cancer is known, the most active compounds were evaluated for the hGC-ALP inhibition in order to ensure a mechanism of anticancer action of these compounds. The mode of interaction and binding affinity of these compounds was also investigated by a molecular docking study. In the results, 6d, 6i, 6k, and 6l were found with least IC₅₀ values <0.075 µM and highest relative activity of 92%, 90%, and 96% respectively. The need for further animal model evaluation and pre-clinical studies recognized.     

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, spectral analysis and in vitro microbiological evaluation of novel ethyl 4-(naphthalen-2-yl)-2-oxo-6-arylcyclohex-3-enecarboxylates and 4,5-dihydro-6-(napthalen-2-yl)-4-aryl-2H-indazol-3-ols

A series of ethyl 4-(naphthalen-2-yl)-2-oxo-6-arylcyclohex-3-enecarboxylates 8-14 and 4,5-dihydro-6-(naphthalen-2-yl)-4-aryl-2H-indazol-3-ols 15-21 were synthesised and characterised by their spectroscopic data. In vitro microbiological evaluations were carried out for all the newly synthesised compounds 8-21 against clinically isolated bacterial and fungal strains. Compounds 9, 12 and 20 against Staphylococcus aureus, 10, 12, 20 against β-haemolytic streptococcus, 11, 17 against Bacillus subtilis, 12, 16 and 20 against Vibreo cholerae, 13, 16 against Escherichia coli, 13, 16, 18, 19 against Salmonella typhii, 12, 18 against Shigella flexneri, 10 against Salmonella typhii, 10, 13, 17, 18 against Aspergillus flavus, 12, 17, 21 against Aspergillus niger, 12, 15, 17, 18, 20 against Mucor, Rhizopus and Microsporeum gypsuem exhibit potent antimicrobial activity.     

Synthesis and antileishmanial evaluation of 1-aryl-4-(4,5-dihydro-1H-imidazol-2-yl)-1H-pyrazole derivatives

A series of 1-aryl-4-(4,5-dihydro-1H-imidazol-2-yl)-1H-pyrazoles (4a–g) and 5-amino-1-aryl-4-(4,5-dihydro-1H-imidazol-2-yl)-1H-pyrazoles (5a–g) were synthesized and evaluated in vitro against three Leishmania species: L. amazonensis, L. braziliensis and L. infantum (L. chagasi syn.). The cytotoxicity was assessed. Among the derivatives examined, six compounds emerged as the most active on promastigotes forms of L. amazonensis with IC₅₀ values ranging from 15 to 60 μM. The reference drug pentamidine presented IC₅₀ = 10 μM. However, these new compounds were less cytotoxic than pentamidine. Based on these results, the more promising derivative 5d was tested further in vivo. This compound showed inhibition of the progression of cutaneous lesions in CBA mice infected with L. amazonensis relative to an untreated control.     

Synthesis and pharmacological evaluation of a novel series of 3-aryl-2-(2-substituted-4-methylthiazole-5-yl)thiazolidin-4-one as possible anti-inflammatory and antimicrobial agents

A new series of 3-aryl-2-(2-aryl/benzyl-4-methylthiazole-5-yl)thiazolidin-4-one was synthesized by condensation of 2-aryl/benzyl-4-methylthiazole-5-carbaldehyde, aromatic amines and thioglycolic acid in toluene. All the synthesized compounds are characterized by IR, NMR and elemental or mass analysis. Sixteen out of the newly synthesized compounds were screened for in vivo anti-inflammatory activity using carrageenan-induced rat paw edema method. Some of the synthesized compounds exhibited good anti-inflammatory activity compared with indomethacin. The synthesized compounds were also evaluated for their in vitro antimicrobial activity. Some of the compounds showed mild antibacterial activity while most of the compounds showed good antifungal activity.     

N-Methyl-3-(tetrahydro-2H-pyran-4-yl)-2,3,4,9-tetrahydro-1H-carbazole-6-carboxamides as a novel class of cannabinoid receptors agonists with low CNS penetration

Cannabinoid CB(1) receptor agonists exhibit potent analgesic effects in rodents and humans, but their clinical utility as analgesic drugs is often limited by centrally mediated side effects. We report herein the preparation of N-methyl-3-(tetrahydro-2H-pyran-4-yl)-2,3,4,9-tetrahydro-1H-carbazole-6-carboxamides as a novel class of hCB(1)/hCB(2) dual agonists with attractive physicochemical properties. More specifically, (R)-N,9-dimethyl-N-(4-(methylamino)-4-oxobutyl)-3-(tetrahydro-2H-pyran-4-yl)-2,3,4,9-tetrahydro-1H-carbazole-6-carboxamide, displayed an extremely low level of CNS penetration (Rat Cbr/Cplasma=0.005 or 0.5%) and was devoid of CNS side effects during pharmaco-dynamic testing.     

Discovery,synthesis and characterization of a series of (1-alkyl-3-methyl-1H-pyrazol-5-yl)-2-(5-aryl-2H-tetrazol-2-yl)acetamides as novel GIRK1/2 potassium channel activators

The present study describes the discovery and characterization of a series of 5-aryl-2H-tetrazol-3-ylacetamides as G protein-gated inwardly-rectifying potassium (GIRK) channels activators. Working from an initial hit discovered during a high-throughput screening campaign, we identified a tetrazole scaffold that shifts away from the previously reported urea-based scaffolds while remaining effective GIRK1/2 channel activators. In addition, we evaluated the compounds in Tier 1 DMPK assays and have identified a (3-methyl-1H-pyrazol-1-yl)tetrahydrothiophene-1,1-dioxide head group that imparts interesting and unexpected microsomal stability compared to previously-reported pyrazole head groups.     

Design,synthesis, and evaluation of novel 4-amino-2-(4-benzylpiperazin-1-yl)methylbenzonitrile compounds as Zika inhibitors

The prevalence of Zika virus (ZIKV) has become widespread in recent years. ZIKV infection is associated with severe congenital CNS malformations in both newborns and adults. However, neither vaccines nor therapeutics are available to control ZIKV infection until now. We started by hit screening our in-house small molecule library, then designed, synthesized, and evaluated a new class of 1, 4-bibenzylsubstituted piperazine derivatives for their cytopathic effect (CPE) protection effect in a ZIKV-infected Vero E6 cellular assay. A preliminary structure–activity relationship study identified five novel 4-amino-2-(4-benzylpiperazin-1-yl)methylbenzonitrile analogs with obvious CPE reduction effects against ZIKV at micromolar concentrations. Moreover, compound 3p exerted a significant antiviral effect on both Zika RNA replication and virus protein expression in a dose-dependent manner at low micromolar concentrations. This study demonstrated the potential of a novel 4-amino-2-(4-benzylpiperazin-1-yl)methylbenzonitrile scaffold for the development of anti-ZIKV candidates.     

An efficient one-pot synthesis and photoinduced DNA cleavage studies of 2-chloro-3-(5-aryl-4,5-dihydroisoxazol-3-yl)quinolines

4,5-Dihydroisoxazoles continue to attract considerable interest due to their wide spread biological activities. Here, we identify an efficient protocol for the preparation of 4,5-dihydroisoxazoles (2-isaxazolines) (4a–g) from quinolinyl chalcones. The nucleolytic activities of synthesized compounds were investigated by agarose gel electrophoresis. All these compounds were showed the remarkable DNA cleavage activity (concentration dependent) with pUC19 DNA at 365 nm UV light. The DNA cleavage activity was significantly enhanced by the presence of iminyl and carboxy radicals of DIQ.     

3-(2-Benzyloxyphenyl)isoxazoles and isoxazolines: synthesis and evaluation as CFTR activators

A novel class of activators for chloride conductance in the cystic fibrosis transmembrane conductance regulator (CFTR) protein has been identified. These 3-(2-benzyloxyphenyl)isoxazoles and 3-(2-benzyloxyphenyl)isoxazolines were synthesized employing the 1,3-dipolar cycloaddition of nitrile oxides with various alkene and alkyne dipolarophiles. Utilizing a fluorescence cell-based assay of halide transport, the best compounds increased CFTR-dependent chloride transport with half-maximal stimulation at 20-50 microM.     

N-(pyrimidin-4-yl) and N-(pyridin-2-yl) phenylalanine derivatives as VLA-4 integrin antagonists

The SAR studies to optimise both potency and rate of clearance in the rat for a series of pyrimidine and pyridine based VLA-4 antagonists are described.