5-aryl-imidazo[2,1-c][1,4]benzodiazepine derivatives as tricyclic constrained analogues of diazepam and Ro5-4864. Synthesis and binding properties at peripheral and central benzodiazepine receptors.

Four series of 5-aryl-imidazo[2,-c][1,4]benzodiazepine derivatives 1a-f, 2a-f, 3a-f, and 4a-f were synthesized and tested for their affinity at both the peripheral and central benzodiazepine receptors. Among the four series, only N-10 and C-11 sites were changed, mainly [N(CH3)-CO], [N=CH], [NH-CO], [NH-CH2], and in each series the halogen site was varied at the positions C-7, C-2', and C-4'. In particular, 10-methyl-benzodiazepinones 1a and 1b were designed as tricyclic constrained analogues of diazepam and Ro5-4864. All the tested compounds did not show significant binding activity at central benzodiazepine receptors, but relatively good PBzR binding affinities were found for 10-methyl-benzodiazepinone 1c and benzodiazepines 2b, c. Benzodiazepinones 3a-f were prepared by cyclization with 1,1'-carbonyldiimidazole of the corresponding 2-(aryl-imidazol-1-yl-methyl)-arylamines, obtained from the suitable (2-amino-aryl)-aryl-methanols with 1,1'-carbonyldiimidazole in different conditions. N-Alkylation of 3a-f to 1a-f was achieved using dimethylformamide-dimethylacetal. Reduction of 3a-f to 4a-f was accomplished with lithium aluminum hydride or borane and oxidation of 4a-f to 2a-f was performed with manganese (IV) oxide.

Synthesis of 11-aryl-5H-imidazo[2,1-c][1,4]benzodiazepines and their benzodiazepine and A1 adenosine binding activity.

In the context of a research program aimed at elucidating the properties of the 5H-imidazo[2,1-c][1.4]benzodiazepine system, a series of 11-aryl-5H-imidazo[2,1-c][1,4]benzodiazepines (3a-i) and their 10,11-dihydro-derivatives (4a-i) has been synthesized. The synthetic strategy includes the preparation of the aryl-[1-(2-nitrobenzyl)-1H-imidazol-2-yl]methanones (5a-i) followed by their reduction and subsequent cyclization. Affinities of compounds 3a-i and 4a-i for central benzodiazepine as well as for adenosine A1-receptors were determined by radioligand binding assays. Among the unsaturated analogues, the highest activity at both receptors is displayed by 1H-(2-thienyl) derivative 3e. The hydrogenated analogues 4a-i do not exhibit considerable binding affinity either for central benzodiazepine or for adenosine A1-receptors.

New structural analogues of Tubulozole induce apoptosis, [Ca2+]i modifications and cytoskeletal disorganization in glial (GL15) and neuronal-like (PC12) cell lines.

The synthesis and the biological activity of (+/-)-cis- and (+/-)-trans-[4-[[2-(1,1'-biphenyl-4-yl)-2-(1H-imidazol-1-ylmethyl)-1, 3-dioxolan-4-yl]methylthio]phenyl]carbamic acid ethyl esters (2a and 2b) are discussed. They were designed as structural analogues of Tubulozole, a synthetic tubulin polymerisation inhibitor with antimitotic properties. Biological tests were carried out on PC12, a neuronal-like cell line derived from rat pheochromocytoma, and on GL15, a cell line derived from human glioblastoma. The exposure (from 5 to 20 h) of GL15 and PC12 cells to different concentrations (0.1-1000 microM; IC50 approximately 1 microM) of 2a or 2b resulted in a drastic decrease in the number of viable cells without an apparent effect on the cell distribution in the various phases of the cell cycle. Compound 2a or 2b (10 microM) induced cell death by activating apoptosis. This was correlated with the activation of an oscillating Ca(2+)-dependent mechanism which increased the intracellular calcium concentration ([Ca2+]i) via Ca(2+)-release from internal stores. Moreover, 2a (10 microM) also induced severe damage of cytoskeletal F-actin filaments after a 5 h incubation in GL15 cells. This was also observed but to a smaller extent, for 2b. Under the same experimental conditions, PC12 cells showed similar actin deregulation.

Design and synthesis of novel [60]fullerene derivatives as potential HIV aspartic protease inhibitors.

[structure] Two water-soluble fullerene derivatives have been computer-designed and synthesized. They may exhibit interesting anti-HIV activity owing to the presence of two ammonium groups strategically located on the spheroid surface.

A new class of antifungal agents. Synthesis and antimycotic activity of disubstituted N-azolylamines.

In this study we extended our exploration of the N-azolylamine moiety for its antifungal activity. We prepared a number of N-azolylamino derivatives. The synthetic sequence includes the preparation of aminoazole Schiff bases, and the reduction and the alkylation of the corresponding secondary amines. The title compounds were evaluated in vitro against several pathogenic fungi responsible for human disease. The most potent antimicrobial compound was the N-(biphenyl-4-yl)methyl-N-(2,4-dichlorophenyl)methyl-1H-imidazol-l-yl amine (21), which was found to be active against yeasts and dermatophytes; its potency and selectivity were comparable to those of miconazole.

Azole antifungal agents related to naftifine and butenafine.

The methyl group of naftifine (1) and butenafine (2) was replaced by an azolic nucleus to obtain the new compounds 3-8 which exhibit the characteristics of both allylamine (or benzylamine) and azole antifungals. The title compounds were evaluated in vitro against several pathogenic fungi responsible for human disease. Among these, compounds 5, 6, and 8 were found to inhibit the growth of dermatophytes with a potency comparable to that of naftifine. The synthetic sequence includes the preparation of aminoazole Schiff bases, reduction, and alkylation of the corresponding secondary amines.

Chemoenzymatic synthesis of chiral biologically active heterocycles.

The chemoenzymatic approach to the preparation of some chiral biologically active heterocycles is discussed. Synthetic strategies took advantage of enantioselective bioconversion processes carried out on suitable reaction intermediates. Reductions of carbonyl compounds catalyzed by different alcohol dehydogenases (TBADH from Thermoanaerobium brockii, 20 beta-HSDH from Streptomyces hydrogenans, beta-HSDH from Pseudomonas testosteroni) allowed the preparation with high enantiomeric purity of the eutomer of broxaterol (a selective beta 2-adrenergic agonist) and six out of the eight muscarine stereoisomers. On the other hand, hydrolyses, catalyzed by lipase PS (from Pseudomonas cepacia), of racemic butyrates were the key step in the synthesis of both the enantiomers of two muscarinic antagonists. Finally, the preparation of acetyl cycloserine antipodes was attained by means of a highly enantioselective hydrolysis catalyzed by lipase from Chromobacterium viscosum.

Sulfone derivatives with anti-HIV activity.

Following the discovery of anti-HIV properties of suramin great efforts were devoted to design novel NNRT agents with the aims to find novel drugs for the clinical therapeutic management of AIDS. Sulfone and sulfonamide derivatives were studied by NCI at Bethesda as potential anti-HIV-1 agents and nitrophenyl phenyl sulfone (NPPS) was selected as lead compound for further investigations. At the same time Merck Laboratories discovered L-737,126, a potent indolyl aryl sulfone with inhibitory activity against reverse transcriptase. These studies stimulated novel search in the sulfone series and both diarylsulfones and cyclic sulfone derivatives were investigated. Our decennial interest in chemotherapeutic agents containing a pyrrole ring pulsed us to synthesize and test as anti-HIV-1 agents a number of pyrryl aryl sulfones (PASs), pyrrolobenzothiadiazepine (PBTDs) and pyrrolobenzothiazepine related sulfones. The new sulfone derivatives inhibit selectively HIV-1 and were inactive against HIV-2. Most of them were as active as, if not more active than, nevirapine.

5H-pyrrolo[1,2-b] [1,2,5]benzothiadiazepines (PBTDs): a novel class of non-nucleoside reverse transcriptase inhibitors.

With the aim of developing novel inhibitors of human immunodeficiency virus, various derivatives (10-17) related to 5H-pyrrolo[1,2-b] [1,2,5]benzothiadiazepine (PBTD) were prepared and tested in vitro. The title tricyclic derivatives were obtained by intramolecular cyclization of the open-chain intermediate arylpyrrylsulfones, followed by N-alkylation at position 10. Among test derivatives some 10-alkyl-5H-pyrrolo[1,2-b] [1,2,5]benzothiadiazepin-11(10H)-one-5,5-dioxides were found to exert potent and specific activity against HIV-1. In particular, 7-chloro derivatives 11i and j showed a potency comparable to that of nevirapine. However, when the chloro atom was shifted to the 8 position, the related products were scarcely active or totally inactive. Replacement of the pyrrole with pyrrolidine led to inactive products and the reduction of SO2 to S strongly diminished the antiviral potency. PBTD derivatives active in cell cultures were also inhibitory to the recombinant HIV-1 RT in enzyme assays, thus allowing the conclusion that PBTDs are a new class of non-nucleoside reverse transcriptase inhibitors (NNRTIs).

Synthesis and anti-HIV activity of 10,11-dihydropyrrolo [1,2-b][1,2,5]benzothiadiazepine-11-acetic acid 5,5-dioxide derivatives and related compounds.

The synthesis and the in vitro anti-HIV-1 activity of novel pyrrolo annulated benzothiadiazepine acetic acids and some related derivatives are reported. The new compounds share chemical features with pyrrolo[1,2-d][1,4]benzodiazepin-6-one 1 and Ro 5-3335 pyrrylbenzodiazepinone 4, two inhibitors of HIV-replication at the level of reverse transcriptase (RT) and transcriptional transactivation by Tat, respectively. Two derivatives, namely methyl 10,11-dihydropyrrolo[1,2-b][1,2,5]benzothiadiazepine-11-acetic-5,5 -dioxide (5a) and 1,12b-dihydro-2H-azeto[2,1-d]pyrrolo[1,2-b][1,2,5]benzoth iadiazepin-2-one 8,8-dioxide (7a), were found to exhibit a significant, although not very potent, activity against human immunodeficiency virus Type 1 (HIV-1).

Antifungal agents. 10. Synthesis and antifungal activities of aryl-(1H-imidazol-1-yl)-(isoquinolin-1-yl) methane derivatives.

Various aryl-(1H-imidazol-1-yl)-(isoquinolin-1-yl)methane derivatives have been synthesized and tested as antifungal agents. The new imidazoles have been obtained by the action of 1,1'-sulfinyldiimidazole on aryl-(isoquinolin-1-yl)carbinols, which have been prepared by standard procedures starting from isoquinoline. Among 44 test derivatives only a few have exhibited some antifungal activity, the most active compound (4e) being twofold less potent than miconazole, ketoconazole and bifonazole, used as standard drugs.

Synthesis of pyrryl aryl sulfones targeted at the HIV-1 reverse transcriptase.

Various aryl 1-pyrryl sulfones were synthesized and tested as inhibitors of HIV-1. 2-Nitrophenyl-2-ethoxycarbonyl-1-pyrryl sulfone, the most active among test derivatives, was selected as lead compound of the aryl pyrryl sulfone series. The in vitro anti-HIV-1 activity and cytotoxicity of 41 compounds is reported. Some structure-activity relationships are discussed also in comparison with the known NPPS (2-nitrophenyl phenyl sulfone).

Antifungal agents. VI. In vitro antifungal activities of halobenzoyl esters of cis- and trans-[2-(1,1'-biphenyl-4-yl)-2-(1H-imidazol-1-ylmethyl)-1,3- dioxolan-4-yl]carbinols.

The synthesis and the in vitro antifungal activities against Candida albicans and Candida spp of a number of halobenzoyl esters of cis- and trans- [2-(1,1'-biphenyl-4-yl)-2-(1H-imidazol-1-ylmethyl)-1,3-dioxolan -4- yl]carbinols is reported. Some new imidazoles were found more active than ketoconazole and sometimes as potent as bifonazole against Candida albicans. All derivatives were found scarcely active against Candida spp.

Antibacterial and antifungal agents. XV. Synthesis and antifungal activity of structural analogues of bifonazole and ketoconazole.

The synthesis and antifungal activities of the cis- and trans-1-acetyl-4-[4-[[2-(1,1'-biphenyl-4-yl)-2-(1H-imidazol-1-ylmethy l)- 1,3-dioxolan-4-yl]-methoxy]phenyl)piperazines 3 and 4 are reported. Stereochemical assignments to diastereomeric pairs of cis/trans isomers were made on the basis of 1H- and 13C-NMR data. Among test derivatives the best activity was shown by the benzoyl esters of the cis- and trans-[2-(1,1'-biphenyl-4-yl)-2-(1H-imidazol-1-ylmethyl)-1,3-di oxolan-4- yl]methanols 9 and 10.

Researches on psychotropic agents. IV. Synthesis and neuropsychopharmacological effects of 1,3,4,14 b-tetrahydro-10-methyl-2H,10H- pyrazino[2,1-d] pyrrolo[1,2-b][1,2,5]benzotriazepine and its derivatives.

The synthesis and neuropsychopharmacological properties of new 1,3,4,14b-tetrahydro-2H,10H-pyrazino [2,1-d] pyrrolo [1,2-b] [1,2,5] benzotriazepine derivatives related to antidepressant agent aptazepine are reported. The new derivatives displayed sedative-miorelaxant activity in mice, but no significant antagonist effect on clonidine blockade of phenylquinone-induced abdominal constriction. Among test compounds 4a, 4l and 4n showed high antinociceptive effect on the hot-plate test and compound 4e protected from death and convulsion all the electroshocked animals.

Researches on antibacterial and antifungal agents, XIV: Thiophene analogues of bifonazole.

Some thiophene analogues of bifonazole have been synthesized by standard procedures and their antifungal activity has been tested against Candida albicans. Among test derivatives biphenyl-4-yl-5-chloro-thien-2-ylimidazol-1-ylmethane and its 5-deschlorothien-2-yl analogue resulted to be the most active. Their antifungal potency was almost comparable to that of control substances, such as miconazole, ketoconazole, and bifonazole. Replacement of benzene by the pyrrole ring in the biphenyl portion retained almost quantitatively the antifungal activity, whereas substitution with other azoles and with nitrogen alicyclic rings led always to less potent derivatives.

Bovine serum amine oxidase: half-site reactivity with phenylhydrazine, semicarbazide, and aromatic hydrazides.

Aromatic hydrazides of the general formula NH2NHCO(CH2)nC6H4R were covalently bound by bovine serum amine oxidase (BSAO), giving rise to optical and CD absorptions at 350-400 nm. Benzohydrazides (n = 0) reacted slowly, in the ratio of one per dimeric protein molecule, like semicarbazide. Phenylacetohydrazides (n = 1) and phenylpropionic hydrazides (n = 2) reacted instead in the ratio of two per dimer, one molecule at a much faster rate than the other. The fast reaction correlated with the loss of enzymatic activity. The contribution to the optical absorbance of either molecule was identical, but only the first one produced a CD band, the wavelength and sign of which were determined by the number n of methylene groups in the hydrazide. In n = 1 and n = 2 compounds, the reaction was faster as the R substituent became more hydrophobic (triazolyl less than imidazolyl less than phenyl), suggesting a specific interaction with the protein matrix. Phenylhydrazine was found to react with the native enzyme in the ratio of only one per protein dimer. However, one phenylhydrazine was also slowly bound by most 1:1 enzyme-hydrazide adducts, with the formation of ternary derivatives. Phenylhydrazine formed the usual intense band at 447 nm with n = 1 and n = 2 hydrazide-BSAO adducts and a weaker, blue-shifted band with the adducts of semicarbazide and of some n = 0 hydrazides. In both cases, the hydrazide absorption band was unaffected. Competition was observed with other benzohydrazides and with the second molecule of n = 1 compounds. A half-site mechanism appears to be operative, the second site being always less reactive than the first. Reactivity and adduct conformation were also affected by N,N-diethyldithiocarbamate, a powerful enzyme inhibitor that binds copper.

Non-steroidal antiinflammatory agents. VII. Synthesis and antiinflammatory activity of 5-methyl-10,11-dihydro-5H-pyrrolo [1,2-b] [1,2,5]benzotriazepine-11-acetic acid and its 10-aroyl derivatives.

The synthesis of 5-methyl-10,11-dihydro-5H-pyrrolo [1,2-b] [1,2,5]benzotriazepine-11-acetic acid and its 10-aroyl derivatives is reported. Compounds were evaluated for antiinflammatory activity by the carrageenin-induced rat paw edema method. Antinociceptic activity was tested by the hot plate and Randall-Selitto tests. General neuropsychopharmacological effects were also screened. All test compounds showed antiinflammatory effect comparable to that of tolmetin.

Researches on antibacterial and antifungal agents, XII: Analogues of bifonazole with two imidazole moieties and related azoles.

Analogues of bifonazole bearing two imidazole rings and other related azoles have been synthesized and tested as antifungal agents against Candida albicans and Candida spp.. Only a slight part of the antifungal power of the parent drug is retained by some derivatives as evinced by the comparison of new compounds with bifonazole, miconazole, and ketoconazole.