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Background & Aims: Thyroid hormones elicit many cellular and metabolic effects in various organs. Most of these actions, including mitogenesis, are mediated by the thyroid hormone 3,5,3'-triiodo-l-thyronine (T3) nuclear receptors (TRs). They are transcription factors, expressed as different isoforms encoded by the TRalpha and TRbeta genes. Here, experiments were performed to determine whether (i) T3-induces hepatocyte proliferation in mouse liver and pancreas, and, (ii) which TR isoform, is responsible for its mitogenic effect., Methods: Cell proliferation was measured by bromodeoxyuridine (BrdU) incorporation after T3 or the TRbeta agonist GC-1 in liver and pancreas of CD-1, C57BL, or TRalpha(0/0) mice. Cell cycle-associated proteins were measured by Western blot., Results: T3 added to the diet at a concentration of 4 mg/kg caused a striking increase in BrdU incorporation in mouse hepatocytes. Increased BrdU incorporation was associated with enhanced protein levels of cyclin D1 and PCNA and decreased levels of p27. Treatment with GC-1, a selective agonist of the TRbeta isoform, also induced a strong mitogenic response of mouse hepatocytes and pancreatic acinar cells which was similar to that elicited by T3. Finally, treatment with T3 of mice TRalpha(0/0) induced a proliferative response in the liver and pancreas, similar to that of their wild type counterpart., Conclusions: These results demonstrate that T3 is a powerful inducer of cell proliferation in mouse liver and suggest that the beta-isoform is responsible for the hepatomitogenic activity of T3. The same isoform seems to also mediate the proliferation of mouse pancreatic acinar cells., (Copyright © 2010 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.)

The synthesis and anticancer activity of 2-arylamino-6-trifluoromethyl-3-(hydrazonocarbonyl)pyridines is described. The new trifluoromethylpyridine derivatives were evaluated for their anticancer activity toward human cancer cell lines by the National Cancer Institute (NCI). Most of them had excellent growth inhibition activity, having GI(50) values in the low micromolar to nanomolar concentration range. The most potent 2,6-dichlorobenzaldehydehydrazone 29 inhibited the growth of all tested cancer cell lines with nanomolar potency, and did not show animal toxicity. Hydrazone 29 has been selected by the Biological Evaluation Committee of NCI for testing in vivo Hollow Fiber Assay.

The synthesis and antifungal activity of 2-acylhydrazino-5-arylpyrroles 21-62 are described. Pyrrole derivatives 21-62 were evaluated for their antifungal activity towards Candida albicans ATCC 10231 and three Candida non-albicans isolated from clinical specimens. Most of them showed very good antifungal activities against Candidae, having MIC values in the 0.39-3.12 microg/mL range and enhanced inhibition potency as compared to that of fluconazole. In addition, some of the most active compounds were tested for cytotoxic activities against breast (MCF-7), lung (H-460), and central nervous system (SF-268) human cancer cell lines with the NCI anticancer drug screen. The activity of pyrroles described in this paper, along with the low toxicity, shows promise for the future development of non-toxic new antimycotic agents. The relationship between functional group variation and biological activity of the evaluated compounds is also discussed.

Nonalcoholic fatty liver disease is the most common noninfectious liver disease in clinical practice, and there is an increasing need for new therapeutic approaches for the treatment of this liver disease. Here, we examined the effect of the thyroid hormone triiodothyronine (T3) and the agonist of the thyroid hormone receptor beta isoform (TRbeta), GC-1, on fatty liver and steatohepatitis induced in rodents by a choline-methionine deficient (CMD) diet. Male Fischer 344 rats fed a CMD diet for 1 wk developed a marked fatty liver and mild hepatitis. Concurrent administration of T3 resulted in a complete prevention of the fatty change associated with increased fatty acid mitochondrial and peroxisomal beta-oxidation. To investigate whether T3 could also reverse fully established fatty liver, rats were fed a CMD diet for 10 wk and then cofed T3 for 1 wk. Coadministration of T3 resulted in a complete regression of liver steatosis associated with a decrease of lipid peroxidation, cyclooxygenase-2 expression, and activation of phospho-STAT3 and phospho-SAPK/JNK. Finally, additional experiments showed that GC-1, which has no significant side effects on heart rate, prevented and reverted CMD-induced fat accumulation, and ameliorated steatohepatitis. These results indicate that TR agonists have the potential to inhibit or reverse hepatic steatosis induced by a nutritional model.

The synthesis and antitumoral activity of ester and amide derivatives of 2-arylamino-6-trifluoromethyl-3-pyridinecarboxylic acids 8-58 is described. Trifluoromethylpyridine derivatives 8-58 were evaluated for their anticancer activity toward human tumoral cell lines by the National Cancer Institute (NCI). Most of them possess encouraging anticancer activity, having GI(50) values in the low micromolar to nanomolar concentration range. The 3,4,5-trimethoxyphenylamide 44 was the most active, and it is now under review by NCI Biological Evaluation Committee for possible further studies.

A series of new 1,4-diarylimidazol-2(3H)-one derivatives and their 2-thione analogues has been prepared and evaluated in vitro for antitumor activity against the NCI human cancer cell panel. Compounds bearing a 3,4,5-trimethoxyphenyl ring linked to either N-1 or C-4 position of the imidazole core demonstrated an interesting profile of cytotoxicity with preferential activity against leukemic cell lines. Compound 13 exhibited a potent antitumor activity against MOLT-4 (GI(50)=20 nM) and SR (GI(50)=32 nM) cell lines.

There is evidence in the literature that the nonsteroidal anti-inflammatory drugs indomethacin and ibuprofen can interact with the cannabinoid system both in vitro and in vivo. In the present study, a series of analogues of ibuprofen and indomethacin have been investigated with respect to their ability to inhibit fatty acid amide hydrolase, the enzyme responsible for the hydrolysis of the endogenous cannabinoid anandamide. Of the fourteen compounds tested, the 6-methyl-pyridin-2-yl analogue of ibuprofen ("ibu-am5") was selected for further study. This compound inhibited rat brain anandamide hydrolysis in a non-competitive manner, with IC50 values of 4.7 and 2.5 microM being found at pH 6 and 8, respectively. By comparison, the IC50 values for ibuprofen were 130 and 750 microM at pH 6 and 8, respectively. There was no measurable N-acylethanolamine hydrolyzing acid amidase activity in rat brain membrane preparations. In intact C6 glioma cells, ibu-am5 inhibited the hydrolysis of anandamide with an IC50 value of 1.2 microM. There was little difference in the potencies of ibu-am5 and ibuprofen towards cyclooxygenase-1 and -2 enzymes, and neither compound inhibited the activity of monoacylglycerol lipase. Ibu-am5 inhibited the binding of [3H]-CP55,940 to rat brain CB1 and human CB2 cannabinoid receptors more potently than ibuprofen, but the increase in potency was less than the corresponding increase in potency seen for inhibition of FAAH activity. It is concluded that ibu-am5 is an analogue of ibuprofen with a greater potency towards fatty acid amide hydrolase but with a similar cyclooxygenase inhibitory profile, and may be useful for the study of the therapeutic potential of combined fatty acid amide hydrolase-cyclooxygenase inhibitors.

A new series of 2-amino-4-aryl-6-dialkylamino-3,5-dicyanopyridines, 20-47, were synthesized in satisfactory overall yield, through a simple synthetic strategy using 3-amino-3-(dialkylamino)-propenenitriles 1 and 2 as key intermediates. 3,5-Dicyanopyridine derivatives 20-47 were evaluated for their in vitro anticancer activity toward cell lines of nine different types of human cancers. Some of the newly prepared compounds demonstrated inhibitory effects on the growth of a wide range of cancer cell lines generally at 10(-6) M level and in some cases at 10(-8) M concentration.

The complexation of VO(2+) ion by ten acetamidrazone and 2-phenylacetamidrazone derivatives (L) was studied. Sixteen novel VO(2+) complexes were synthesised and characterised through the combined application of analytical and spectroscopic (EPR (electron paramagnetic resonance), FT-IR and diffuse reflectance electronic absorption) techniques. Eight are 1:2 species of composition [VOL(2)]SO(4) x xH(2)O and eight are 1:1 species with formula [VOL(SO(4))](n) x xH(2)O. The experimental data suggest a bidentate coordination mode for L with the donor set formed by the imine nitrogen and the carbonyl oxygen. EPR spectra indicate a square-pyramidal geometry for the 1:1 complexes and a penta-coordinated geometry intermediate between the square-pyramid and the trigonal-bipyramid for the 1:2 species. The hyperfine coupling constant along z axis, A(z), of the 1:2 complexes exhibits a marked reduction with respect to the predicted value (approximately 148x10(-4)cm(-1) vs. approximately 170x10(-4)cm(-1)). IR spectroscopic evidence supports the presence of sulphate as a counter-ion in the 1:2, and as a bridging bidentate ligand in the 1:1 complexes. Insulin-mimetic tests on modified fibroblasts, based on a modified MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazoliumbromide) assay, performed on three of the bis-chelated and eight of the mono-chelated derivatives, indicate that they are biologically active. The similar hydro/lipophilicity and the lack of ligand substituents recognizable by cell membrane receptors prevent substantial differentiation in the insulin-mimetic action.

A new series of 2-amino-6-(2-alkyl or arylidenehydrazinyl)-4-(dialkylamino)pyrimidine-5-carbonitriles, 5-24, were synthesized in satisfactory overall yield, using 2-amino-4-(dialkylamino)-6-hydrazino-5-pyrimidinecarbonitriles 3, 4, as key intermediates, by applying classical synthetic methods to construct the hydrazone moiety at C-6 of the pyrimidine ring. Hydrazinopyrimidine derivatives 5-24 were evaluated for their in vitro anticancer activity toward cell lines of nine different types of human cancers. Some of the newly prepared compounds demonstrated inhibitory effects on the growth of a wide range of cancer cell lines generally at 10(-5)M level and in some cases at 10(-7)M concentrations.

The regioselectivity of coupling phenyl isocyanate to 3-(2-acylhydrazino)-3-aminopropenenitriles and ethyl 3-(2-acylhydrazino)-3-aminopropenoates as simple access to aminopyrazole derivatives, endowed with potential antitumoral activity, is reported. 3-(2-Acylhydrazino)-3-aminopropenenitriles react with phenyl isocyanate to afford 3-amino-3-(2-acylhydrazino)-2-phenylaminocarbonyl-2-propenenitriles. These key intermediates were cyclized into 3,5-diaminopyrazole-4-carboxamide derivatives. Preliminary results of poor antiproliferative activities of these compounds are also reported.

The synthesis and anticancer activity of new compounds designed on the anthranilic acid scaffold are reported. The antiproliferative activity was assayed by the National Cancer Institute in established in vitro and in vivo anticancer experimental models. Structural variations based on the flufenamic acid motif afforded a series of (hetero)aryl esters of N-(2-(trifluoromethyl)pyridin-4-yl)anthranilic acid, which showed in vitro growth inhibitory properties against human tumor cell lines in nanomolar to low micromolar concentrations. The pyridinyl ester 25 exhibited very potent in vitro antiproliferative efficacy, with a chemosensitive profile showing a number of GI(50) values at concentrations lower than 10(-7) M in the full panel of human tumor cell lines. Compound 25 was also tested in vivo as a potential anticancer agent in the hollow fiber assay and in human tumor xenografts, showing moderate inhibitory properties. Analysis of biological activities and the COMPARE procedure was utilized to support putative biochemical mechanisms implicated with the antiproliferative activity.

A new series of 2,6-dibenzylamino-3,5-dicyanopyridines were synthesized and evaluated for their in vitro anticancer activity toward cell lines of nine different types of human cancer. Some of newly prepared compounds demonstrated remarkable anticancer activity against most of the tested subpanel tumor cell lines.

H-Dmt-d-Arg-Phe-Lys-NH(2) ([Dmt(1)]DALDA) binds with high affinity and selectivity to the mu opioid receptor and is a potent and long-acting analgesic. Substitution of d-Arg in position 2 with Tic and masking of the lysine amine side chain by Z protection and of the C-terminal carboxylic function instead of the amide function transform a potent and selective mu agonist into a potent and selective delta antagonist H-Dmt-Tic-Phe-Lys(Z)-OH. Such a delta antagonist could be used as a pharmacological tool.

The antimycobacterial activities of two new S-alkylisothiosemicarbazone derivatives (1i and 1f) against 32 Mycobacterium avium isolates were investigated. The minimum inhibitory concentrations (MICs) were significantly lower than those of rifampicin and other reference drugs. The two derivatives also showed excellent intracellular activity against M. avium residing in the macrophage-like J774 cells. Interestingly, the combination of subinhibitory concentrations of 1i and rifabutin or rifampicin induced a potent synergistic effect, as determined by the fractional inhibitory concentration indexes (FICIs) ranging between 0.103 and 0.412. Such synergistic effect resulted in a 81-fold and 139-fold reduction of the MICs of rifabutin and rifampicin, respectively. Enhancement of intracellular activity of rifabutin by the S-alkylisothiosemicarbazone derivative 1i was also observed. Results indicate that S-alkylisothiosemicarbazones can be useful in the therapy and prophylaxis of M. avium infections and can represent a template for the development of novel antimycobacterial drugs. Furthermore, as a consequence of their ability to enhance the activity of rifamycins, a reduction of drug interactions following the co-administration of protease inhibitors could be achieved by lower doses of rifampicin and rifabutin.

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.

A new series of 2-arylamino-6-trifluoromethyl-3-carboxylic acid derivatives was synthesized and assayed in vivo for their analgesic properties by means of writhing test in rats. When compared to aspirin, ibuprofen and flufenamic acid some of the new compounds exhibited a comparable or improved analgesic activity and a lower ulcerogenic effect.

A series of amides of ibuprofen with heteroaromatic amines was synthesized and assayed in vivo for their analgesic properties by means of writhing test in rats. When compared to parent ibuprofen some of the new amides exhibited a comparable or improved analgesic activity and a lower ulcerogenic effect.

A new series of N-phenylpyrrolecarbothioamides were obtained from base catalyzed intramolecular cyclization of 3-amino-3-(alkyl or arylamino)propenethioamides. Pyrrole derivatives were evaluated for their in vitro anticancer activity toward cell lines of nine different types of human cancer. Some of newly prepared compounds demonstrated inhibitory effects on the growth of a wide range of cancer cell lines generally at 10(-6) M level and in some case at 10(-8) M concentrations.

Bis(pyridyl)methane derivatives 5-40 were obtained from the reaction of 4-hydroxy-2-pyridones 3 and 4 with aldehydes. Compounds 5-40 were evaluated for cytotoxic activity against a panel of 60 human cancer cell lines by the National Cancer Institute and some of them demonstrated inhibitory effects on the growth of a wide range of cancer cell lines generally at 10(-5) M level and in some case at 10(-7) M concentrations., (Copyright 2002 Editions scienctifiques et médicales Elsevier SAS)

A new series of S-alkylisothiosemicarbazones of 3- and 4-pyridincarboxaldehyde and 4-fluoro- and 4-trifluoromethylbenzaldehyde was synthesized and evaluated for biological activity against various Mycobacterium strains. Inhibitory activity against Mycobacterium tuberculosis H37Rv ATCC 27294 and INH-R ATCC 35822 was compared with activity against clinical isolated Mycobacteria as well as against MOTT. Some of newly prepared compounds showed best inhibitory values against clinical isolated Mycobacteria, besides to low citotoxicity values.

The activities of six derivatives of a new class of isonicotinoylhydrazones were investigated in vitro against Mycobacterium tuberculosis H37Rv ATCC 27294, isoniazid-resistant M. tuberculosis ATCC 35822, rifampicin-resistant ATCC 35838, pyrazinamide-resistant ATCC 35828, streptomycin-resistant ATCC 35820 and 16 clinical isolates of M. tuberculosis. Several compounds showed interesting antimycobacterial activity against both ATCC strains and clinical isolates, but were less active against isoniazid-resistant M. tuberculosis. Combinations of five isonicotinoylhydrazone derivatives and rifampicin, ethambutol, para-aminosalicylic acid, isoniazid and clofazimine were also investigated against M. tuberculosis H37Rv ATCC 27294 and against ATCC drug-resistant strains. Addition of sub-MICs of some isonicotinoylhydrazone derivatives resulted in a four- to 16-fold reduction in MICs of ethambutol, para-aminosalicylic acid and rifampicin with fractional inhibitory concentrations (FICs) ranging between 0.17 and 0.37, suggesting a synergic interaction against M. tuberculosis H37Rv. Increased activity was also observed with other combinations (FICs 0.53-0.75), including isoniazid, and a synergic interaction between one of the isonicotinoylhydrazone derivatives and isoniazid (FIC 0.26) was shown against isoniazid-resistant M. tuberculosis ATCC 35822, whereas no effects were observed on combining the isonicotinoylhydrazones with clofazimine. The ability of isonicotinoylhydrazones to inhibit specifically the growth of M. tuberculosis, the high selectivity index and their ability to enhance the activity of standard antituberculous drugs in vitro indicate that they may serve as promising lead compounds for future drug development for the treatment of M. tuberculosis infections.

A series of 6-thioxopyrimidines (5, 6), their 6-oxo- analogs (11-14), and pyrimidine-2,4-diones (20-26), were synthesized and evaluated for their antitumoral activity against 60 tumoral cell lines. The activity of propenethioamide (3, 4) and propeneamide (7-10 and 15-19) intermediates is also reported. Among the tested compounds the thioxopyrimidine 5c, bearing an N'-benzyl group, showed the best cytostatic activity. Furthermore, high selectivity and cytotoxic activity on the HOP-92 cell line of non-small cell lung cancer was exhibited by 3-amino-2-[(methylamino)thioxamethyl]-3-pyrrolidino-2-propenenitrile (3a).

4-(2-Pyridinylamino)-1,1,1-trifluoro-3-penten-2-ones 3, obtained from the reaction of commercially available 2-aminopyridine derivatives and 4-methoxy-1,1,1-trifluoro-3-penten-2-one 2, were converted to 6-(dimethylamino)-4-(2-pyridinylamino)-3,5-hexadien-2-ones 4 by treatment with dimethylformamide dimethyl acetal. Azannulation of hexadienones 4 afforded 4-(2-pyridinylamino)-2-trifluoromethylpyridines 5 and 2-(trifluoroacetylmethylene)pyrido[1,2-a]pyrimidines 6, classes of compounds particularly interesting from a chemical and biological point of view.

4-hydroxy-2-pyridone derivatives 2 were prepared by reaction of 3-amino-3-dialkylaminopropenoates with bis(2,4, 6-trichlorophenyl)malonate. These compounds were further reacted with a set of aldehydes to give bis(pyridyl)methanes 3 and 4. The newly synthesized compounds 2, 3 and 4 were evaluated in vitro as antitumour agents against 60 human tumour cell lines. Some derivatives exhibit tumour growth inhibition activity. In particular, derivative 4g, the most active of the series, possesses significant activity on all cell lines at concentrations ranging from 1 x 10(-6) to 1 x 10(-5) M.

A convenient and simple synthesis of some new thioxopyrimidines was developed starting from 3-amino-3-(dialkylamino)propenethioamide derivatives. The prepared compounds were assayed in vitro for antimicrobial activity and found practically inactive.

The 3,5-diaminoisothiazole derivatives 23-42 were synthesized in excellent yields by oxidative cyclization of 3-amino-3-(dialkylamino)propenethioamide derivatives. These intermediates and the isothiazole derivatives were tested in vitro for their antimicrobial activity.

The synthesis of new 5-aryl-3-ethoxycarbonyl-2-piperazinopyrrole derivatives is reported. The new compounds were tested in vitro for their antimicrobial activity. Compound 11 was the most active against the Gram-positive microorganisms.

Several new 1-acylamino-2-alkyl-4-arylimidazoles were synthesized. The compounds were obtained by reaction of N1-acylacetamidrazones and alpha-bromoketones. The antimicrobial activity of the prepared compounds was tested.

The microbiological activity of a series of isothiosemicarbazones is reported. The experimental data relating to the microbiological screening show an interesting antibacterial activity associated to a good antifungal activity.

The synthesis of some 5-substituted 2-amino-3-cyano (and 3-carboethoxy)pyrroles is described starting from the cyano- and carboethoxyacetomidines and the alpha-halogeno ketones. The compounds tested in vitro as antimicrobial agents did not show any significative activity.

A new series of 1-arylideneamino-2-mercaptoimidazole derivatives obtained by condensation of 1-amino-2-mercaptoimidazole derivatives with variously substituted aromatic aldehydes is described. Investigation of their antimicrobial properties showed a good antibacterial activity for some of the tested compounds on some gram-positive micro-organisms.

A series of 2-(2'-acylhydrazino)-3-ethoxycarbonyl-3-aryl (or alkyl)-pyrrole derivatives was synthesized and submitted to in vitro microbiological screening. Most derivatives showed considerable antibacterial and antifungal activities.

A new series of pyrrole derivatives obtained by heterocyclization of N1-aryliden-3-ethoxycarbonyl (or cyano) acetamidrazones with alpha-bromoketones was described. The in vitro microbiological investigation showed that none of the 2-arylidenhydrazinopyrrole derivatives presented any noteworthy activity.

The synthesis of 3-ethoxycarbonyl-5-aryl-pyrrole derivatives with an arylpiperazine group in position 2 is described. The in vitro biological investigation showed that compound (XVIII) had considerable antibacterial activity against gram-positive microorganisms and antifungal activity against Candida rugosa, while the other compounds did not show any significative activity.

The synthesis and microbiological activities of 1-arylideneaminoimidazole derivatives are reported. Antimicrobial data show that some of the tested imidazoles exhibited an interesting activity on Candida albicans.