5-((1H-pyrazol-4-yl)methylene)-2-thioxothiazolidin-4-one inhibitors of ADAMTS-5

A series of 5-((1H-pyrazol-4-yl)methylene)-2-thioxothiazolidin-4-one inhibitors of ADAMTS-5 (aggrecanase-2) is described. These compounds show microM functional inhibition of ADAMTS-5, and represent a new class of agents with the potential of inhibiting degradation of aggrecan, a major component of cartilage which is lost in osteoporosis. Compound 12 is noteworthy in that it has an ADAMTS-5 IC50: 1.1 microM and shows >40-fold functional selectivity over ADAMTS-4 (aggrecanase-1).     

Synthesis, cytotoxicity, and anti-inflammatory evaluation of 2-(furan-2-yl)-4-(phenoxy)quinoline derivatives. Part 4

A number of 2-(furan-2-yl)-4-phenoxyquinoline derivatives have been synthesized and evaluated for anti-inflammatory evaluation. 4-[(2-Furan-2-yl)quinolin-4-yloxy]benzaldehyde (8), with an IC(50) value of 5.0 microM against beta-glucuronidase release, was more potent than its tricyclic furo[2,3-b]quinoline isomer 3a (>30 microM), its 4'-COMe counterpart 7 (7.5 microM), and its oxime derivative 13a (11.4 microM) and methyloxime derivative 13b (>30 microM). For the inhibition of lysozyme release, however, oxime derivative 12a (8.9 microM) and methyloxime derivative 12b (10.4 microM) are more potent than their ketone precursor 7 and their respective tricyclic furo[2,3-b]quinoline counterparts 4a and 4b. Among them, 4-[4-[(2-furan-2-yl)-quinolin-4-yloxy]phenyl]but-3-en-2-one (10) is the most active against lysozyme release with an IC(50) value of 4.6 microM, while 8 is the most active against beta-glucuronidase release with an IC(50) value of 5.0 microM. (E)-1-[3-[(2-Furan-2-yl)quinolin-4-yloxy]phenyl] ethanone oxime (11a) is capable of inhibiting both lysozyme and beta-glucuronidase release with IC(50) values of 7.1 and 9.5 microM, respectively. For the inhibition of TNF-alpha formation, 1-[3-[(2-furan-2-yl)quinolin-4-yloxy]phenyl]ethanone (6) is the most potent with an IC(50) value of 2.3 microM which is more potent than genistein (9.1 microM). For the inhibitory activity of fMLP-induced superoxide anion generation, 11a (2.7 microM), 11b (2.8 microM), and 13b (2.2 microM) are three of the most active. None of above compounds exhibited significant cytotoxicity.     

Synthesis of tyrosinase inhibitory (4-oxo-4H-pyran-2-yl)acrylic acid ester derivatives

Melanogenesis is a physiological process that results in the production of melanin pigment. However, excessive accumulations of epidermal pigmentation can cause various hyperpigmentary disorders such as, melasma and age spots. Kojic acid and hydroxylated cinnamic acid derivatives are known to inhibit tyrosinase, a key component of melanin biosynthesis. Pyronyl-acrylic acid esters 3a–i, which share structural features of kojic acid and hydroxylated cinnamic acid, were prepared and their abilities to inhibit tyrosinase and melanin production were evaluated. Of the esters synthesized, 3e and 3h, which derived from diethylene glycol moieties were found to inhibit melanin production by ca. 20% at 20 μg/ml, whereas kojic acid at 200 μg/ml inhibited melanin production by 15.8%.     

Synthesis,molecular modeling and biological evaluation of N-benzylidene-2-((5-(pyridin-4-yl)-1,3,4-oxadiazol-2-yl)thio)acetohydrazide derivatives as potential anticancer agents

A series of new 1,3,4-oxadiazole derivatives (6a–6x) containing pyridine and acylhydrazone moieties were synthesized and developed as potential telomerase inhibitors. The bioassay tests demonstrated that compounds 6n, 6o, 6q, 6s and 6t exhibited significant broad-spectrum anticancer activity with IC₅₀ range from 0.76 to 9.59 μM against the four cancer cell lines (HEPG2, MCF7, SW1116 and BGC823). Moreover, all the title compounds were assayed for telomerase inhibition using the TRAP-PCR-ELISA assay. Compound 6s showed the highest anticancer activity with IC₅₀ of 0.76–1.54 μM against the tested cancer cell lines and exhibited the most potent telomerase inhibitory activity with IC₅₀ of 1.18 ± 0.14 μM. The docking simulation was carried out to investigate a possible binding mode of compound 6s into the active site of telomerase (pdb. 3DU6) while the QSAR model was built to check the previous work as well as to introduce new directions.     

Synthesis and cytotoxic evaluation of certain 4-(phenylamino)furo[2,3-b]quinoline and 2-(furan-2-yl)-4-(phenylamino)quinoline derivatives

Certain 4-(phenylamino)furo[2,3-b]quinoline and 2-(furan-2-yl)-4-(phenylamino)quinoline derivatives were synthesized and evaluated in vitro against the full panel of NCIs 60 cancer cell lines. The preliminary results indicated these tricyclic 4-(phenylamino)furo[2,3-b]quinolines were more cytotoxic than their corresponding 2-(furan-2-yl)-4-(phenylamino)quinoline isomers. For the 4-(phenylamino)furo[2,3-b]quinolines, compounds 2a and 3d are two of the most potent with a mean GI50 value of 0.025 microM in each case. Inactivity of 2b and 2c (positional isomers of 2a) indicated that both electronic environment, and the distance between intercalating pharmacophore and H-bond-donating MeO group are important. For the 2-(furan-2-yl)-4-(phenylamino)quinoline isomers, compound 12 (a mean GI50 of 4.36 microM), which bears a para-COMe substituent, is more active than its meta-substituted counterpart 13 (10.5 microM). However, the electron-donating MeO substituent is preferred at the meta-position, and the cytotoxicity for the meta-substituted derivatives decreased in the order: MeO derivative 14b (3.05 microM) > oxime 16 (6.85 microM) > ketone 13 (10.5 microM) > methyl oxime 18 (20.6 microM).     

Synthesis of new N-(2-(trifluoromethyl)pyridin-4-yl)anthranilic acid derivatives and their evaluation as anticancer agents

The N-(2-(trifluoromethyl)pyridin-4-yl)anthranilic acid 6 and a series of its ester and amide derivatives were synthesized and evaluated for their in vitro cytotoxic activity against human cancer cells. Ester derivatives 13 and 18 exhibited potent growth inhibitory activity with GI(50) values at nanomolar concentrations. Among amide derivatives, N-anthraniloylglycinate 19 shown moderate inhibitory activity in the full panel cancer cell line screening.     

Synthesis of trans-L/D-2-(tert-butoxycarbonyl-aminomethyl)-4-(thymin-1-yl) pyrrolidin-1-yl acetic acid

To delineate the binding preferences of stereochemically divergent pyrrolidine PNAs, synthesis of all four diastreomeric monomers of I and the systematic complexation studies of the resultant PNAs with complementary DNA/RNA is essential. We herein report the synthesis of trans-L/D-2-(tert-butoxycarbonyl-aminomethyl)-4-(thymin-1-yl) pyrrolidin-1-yl acetic acids I, their incorporation in PNA oligomers and DNA binding studies will be presented.     

Synthesis, antitubercular and antimicrobial evaluation of 3-(4-chlorophenyl)-4-substituted pyrazole derivatives

As a part of our research to develop novel antitubercular and antimicrobial agents, a series of 3-(4-chlorophenyl)-4-substituted pyrazoles have been synthesised. These compounds were tested for antitubercular activity in vitro against Mycobacterium tuberculosis H37Rv strain using the BACTEC 460 radiometric system, antifungal activity against a pathogenic strain of fungi and antibacterial activity against gram-positive and gram-negative organisms. Among them tested, many compounds showed good to excellent antimicrobial and antitubercular activity. The results suggest that hydrazones, 2-azetidinones and 4-thiazolidinones bearing a core pyrazole scaffold would be potent antimicrobial and antitubercular agents.     

Design,synthesis and anti-HIV-1 RT evaluation of 2-(benzyl(4-chlorophenyl)amino)-1-(piperazin-1-yl)ethanone derivatives

In this study, using molecular hybridization approach, fourteen novel 2-(benzyl(4-chlorophenyl)amino)-1-(piperazin-1-yl)ethanone derivatives (7a–n) were designed as inhibitor of HIV-1 RT. The binding affinity of the designed compounds with HIV-1 RT as well as their drug-likeness behavior was predicted using in-silico studies. All the designed compounds were synthesized, characterized and in-vitro evaluated for HIV-1 RT inhibitory activity, in which tested compounds displayed significant to weak potency against the selected target. Moreover, best active compounds of the series, 7k and 7m inhibited the activity of RT with IC₅₀ values 14.18 and 12.26 μM respectively. Structure Activity Relationship (SAR) studies were also performed in order to predict the influence of substitution pattern on the RT inhibitory potency. Anti-HIV-1 and cytotoxicity studies of best five RT inhibitor (7a, 7d, 7k, 7L and 7m) revealed that, except compound 7d other compounds retained significant anti-HIV-1 potency with good safety index. Best scoring pose of compound 7m was analysed in order to predict its putative binding mode with wild HIV-1 RT.     

3-[2-Amino-2-imidazolin-4(5)-yl]alanine (enduracididine) and 2-[2-amino-2-imidazolin-4(5)-yl] acetic acid in seeds of Lonchocarpus sericeus

3-[2-Amino-2-imidazolin-4(5)-yl]alanine (enduracididine) and 2-[2-amino-2-imidazolin-4(5)-yl] acetic acid have been isolated from seeds of Lonchocarpus sericeus. The concentration of each compound was ca 0.5 % of the fresh seed weight.     

New antiprotozoal agents: Synthesis and biological evaluation of different 4-(7-chloroquinolin-4-yl) piperazin-1-yl)pyrrolidin-2-yl)methanone derivatives

In an endeavor to develop efficacious antiprotozoal agents 4-(7-chloroquinolin-4-yl) piperazin-1-yl)pyrrolidin-2-yl)methanone derivatives (5–14) were synthesized, characterized and biologically evaluated for antiprotozoal activity. The compounds were screened in vitro against the HM1: IMSS strain of Entamoeba histolytica and NF54 chloroquine-sensitive strain of Plasmodium falciparum. Among the synthesized compounds six exhibited promising antiamoebic activity with IC₅₀ values (0.14–1.26 μM) lower than the standard drug metronidazole (IC₅₀ 1.80 μM). All nine compounds exhibited antimalarial activity (IC₅₀ range: 1.42–19.62 μM), while maintaining a favorable safety profile to host red blood cells. All the compounds were less effective as an antimalarial and more toxic (IC₅₀ range: 14.67–81.24 μM) than quinine (IC₅₀: 275.6 ± 16.46 μM) against the human kidney epithelial cells. None of the compounds exhibited any inhibitory effect on the viability of Anopheles arabiensis mosquito larvae.     

Synthesis of novel 5-(3-alkylquinolin-2-yl)-3-aryl isoxazole derivatives and their cytotoxic activity

The propargyl alcohol on reaction with aldoxime and NaOCl in DCM gave exclusively (3-arylisoxazol-5-yl) methanol 1. The compound 1 was oxidized to an aldehyde 2 followed by reaction with aniline resulted in Schiff’s base 3. The compounds 3 were further reacted with various aldehydes having α-hydrogen using molecular iodine as catalyst and which yielded 5-(3-alkylquinolin-2-yl)-3-aryl isoxazole derivatives 4. All the final compounds 4 were screened against four human cancer cell lines (A549, COLO 205, MDA-MB 231 and PC-3) and among these compounds 4n showed potent cytotoxicity against all the cell lines at IC₅₀ values of <12 μM.     

Synthesis of 3',5'-cyclic diguanylic acid (cdiGMP) using 1-(4-chlorophenyl)-4-ethoxypiperidin-4-yl as a protecting group for 2'-hydroxy functions of ribonucleosides

We herein report a convenient synthesis of 3',5'-cyclic diguanylic acid via the modified H-phosphonate approach. The 1-(4-chlorophenyl)-4-ethoxypiperidin-4-yl (Cpep) group was used as protecting group for the 2'-hydroxy functions of ribonucleosides. Complete unblocking of the fully protected 3',5'-cyclic diguanylic acid gave cdiGMP as a homogeneous compound in an excellent yield.     

Discovery of 2-(4-((1H-1,2,4-triazol-1-yl)methyl)-5-(4-bromophenyl)-1-(2-chlorophenyl)-1H-pyrazol-3-yl)-5-tert-butyl-1,3,4-thiadiazole (GCC2680) as a potent,selective and orally efficacious cannabinoid-1 receptor antagonist

Structure–activity relationship studies in a series of diarylpyrazolyl thiadiazoles identified cannabinoid-1 receptor antagonists with excellent potency and selectivity. Based on its exceptional in vivo efficacy in animal models and its favorable pharmacokinetic and toxicological profiles, 2-(4-((1H-1,2,4-triazol-1-yl)methyl)-5-(4-bromophenyl)-1-(2-chlorophenyl)-1H-pyrazol-3-yl)-5-tert-butyl-1,3,4-thiadiazole (GCC2680) was selected as a preclinical candidate for the treatment of obesity.     

Synthesis and evaluation of 4-(2-hydroxypropyl)piperazin-1-yl) derivatives as Hsp90 inhibitors

We previously reported 4-(3-((6-bromonaphthalen-2-yl)oxy)-2-hydroxypropyl)-N,N-dimethylpiperazine-1-sulfonamide (1) as a novel heat shock protein 90 inhibitor with moderate activity. In our ongoing efforts for the discovery of Hsp90 modulators we undertake structural investigations on 1. Series of the titled compound were designed, synthesized and evaluated. We have found that compounds with a hydroxyl group at C-4 of the aryl ring on the piperazine moiety possess Hsp90 inhibition properties. Compound 6f with improved activity could be further developed and optimized as Hsp90 inhibitor.     

Synthesis of isonicotinic acid N'-arylidene-N-[2-oxo-2-(4-aryl-piperazin-1-yl)-ethyl]-hydrazides as antituberculosis agents

A new series of antituberculosis agents 6-9 was designed, synthesized and evaluated for antituberculosis activity against Mycobacterium tuberculosis H37Rv and clinical isolates in an agar dilution method. Compound 9h showed comparable in vitro activity (MIC) to isoniazid against M. tuberculosis H37Rv and clinical isolates (sensitive strains) and superior activity against resistant strains of M. tuberculosis.     

Novel substituted (Z)-5-((N-benzyl-1H-indol-3-yl)methylene)imidazolidine-2,4-diones and 5-((N-benzyl-1H-indol-3-yl)methylene)pyrimidine-2,4,6(1H,3H,5H)-triones as potent radio-sensitizing agents

A series of (Z)-5-((N-benzyl-1H-indol-3-yl)methylene)imidazolidine-2,4-dione (9a–9m) and 5-((N-benzyl-1H-indol-3-yl)methylene)pyrimidine-2,4,6(1H,3H,5H)-trione (10a–10i) derivatives that incorporate a variety of aromatic substituents in both the indole and N-benzyl moieties have been synthesized. These analogs were evaluated for their radiosensitization activity against the HT-29 cell line. Three analogs, 10a, 10b, and 10c were identified as the most potent radiosensitizing agents.     

Synthesis, hypolipidemic and hypoglycemic activity of some novel 2-(4-(2-substituted aminothiazole-4-yl) phenoxy)-2-methyl propanoic acid derivatives

An improved synthetic protocol for a novel series of 2-(4-(2-substituted aminothiazole-4-yl) phenoxy)-2-methyl propanoic acid derivatives has been developed using different methods of synthesis. The synthesized compounds are evaluated for their hypolipidemic and hypoglycemic activity by high fat diet induced hyperlipidemia and hyperglycemia in Sprague-Dawley rats.     

A novel bioactive nanoparticle synthesized by conjugation of 3-chloropropyl trimethoxy silane functionalized Fe3O4 and 1-((3-(4-chlorophenyl)-1-phenyl-1H-pyrazol-4-yl)methylene)-2-(4-phenylthiazol-2-yl) hydrazine: assessment on anti-cancer against gastric AGS cancer cells

Molecular Biology Reports - Gastric cancer is one of the common types of cancer around the world which has few therapeutic options. Nitrogen heterocyclic derivatives such as thiazoles are used as...