Potential of pyrazolooxadiazinone derivatives as serine protease inhibitors.

As a part of an investigation on molecular hybrids as new serine protease inhibitors, the pyrazolo [4,3-c][1,2,5]oxadiazin-3(5H)-one ring system was selected as a model of potential mechanism-based inhibitors. Due to the inherent reactivity of this system an optimal balance between susceptibility to nucleophilic attack and stability in solvents was sought prior to development as therapeutic agents. Substitutions on N5 and C7 of the supporting pyrazole ring with either aliphatic or aromatic groups (compounds 2 a-m) and the replacement of the carbonyl oxygen on the reactive oxadiazinone ring with sulfur (compounds 3a,i) were explored. Two members (2i and 2k) of this class of inhibitors displayed time-dependent inhibition of HLE suggesting mechanism-based inhibition. The observation that HLE generated a product(s) from compound 2i which displayed an identical UV-Visible spectrum to that observed during non-enzymatic hydrolysis further supports this proposal. FlexX-based docking of these compounds into a model of the human leukocyte elastase (HLE) active site produced a molecular model of the inhibitor-enzyme interaction.

6-Alkyl and 6-arylcarbamoyloximino pyrazolo[3,4-b][1,4]diazepines as potential fungicidal, insecticidal and herbicidal agents.

A series of 6-alkyl and 6-arylcarbamoyloximinopyrazolo[3,4-b][1,4]diazepines was prepared and evaluated for fungicidal, insecticidal and herbicidal activity. No one compound showed a general effect but individual compounds exhibited specific activities.

Pyrazolo[3,4-d][1,2,3]triazole-1-carboxamides and 5-alkylaminopyrazolo[3,4-d]oxazoles: synthesis and evaluation of the in vitro antifungal activity.

A series of N-alkyl-N'-(4-diazo-5-pyrazolyl)-ureas (4) was thermally and photochemically converted into pyrazolo [3,4-d][1,2,3]triazole derivatives (5,6) and 5-alkylaminopyrazolo[3,4-d]oxazoles (7) respectively. The products were tested for in vitro antifungal activity against Fusarium culmorum, Botrytis cinerea, Phoma betae, Pythium ultimum, Sclerotinia minor and Rhizoctonia solani. The MIC and ED50 values of compound (6) against some of the test fungi were comparable to those of the reference fungicides iprodione and mancozeb.

4-Diazo-5-alkylsulphonamidopyrazoles: synthesis and evaluation of biological activity.

A series of 4-diazo-5-alkylsulphonamidopyrazoles (5) was prepared and tested for antitumor, antiviral and antimicrobial activity. Compounds (5a) and (5b) showed a selective, although not very potent cytostatic activity against L1210 and a human T lymphoblastoid cell line (C8166). Compounds (5a) and (5d-h) showed a selective anti-coxsackie B1 virus activity, whereas 5b was also endowed with some activity against Bacillus subtilis.

Synthesis and antifungal activity of 4-thiazol-2-yl-5-aminopyrazoles and 4-aminopyrazolo [3,4-c] isothiazoles.

Starting from 4-thiocarbamoyl-5-aminopyrazoles (I), the AA could prepare two series of products: 4-thiazol-2-yl-5-aminopyrazoles (II) and 4-aminopyrazolo [3,4-c] isothiazoles (III). The screening for in vitro antifungal activity evidenced that compounds (III) are effective in controlling most examined fungi; in particular 1-phenyl-3-methyl-4-aminopyrazolo [3,4-c] isothiazole (III a) at the concentration of 20 p.p.m. completely inhibited the growth of Pythium ultimum and Corticium solani, responsible for the collar rot of the beet.

Synthesis and anti-inflammatory and analgesic activities of 3-methyl-N-phenyl-1H-pyrazol-5-ylcarboxamides.

The anti-inflammatory and analgesic activities of a series of 3-methyl-N-phenyl-1H-pyrazol-5-ylcarboxamides were investigated and compared with flufenamic acid. The compounds were synthesized by condensation of diketopiperazines 2 with the appropriate aniline. The pharmacological tests showed that some compounds have good anti-inflammatory activity in rat paw edema induced by carrageenin and low toxicity.

[Amides of amino acids and peptides as antifungal agents]. / Ammidi di amminoacidi e peptidi come antifungini.

The synthesis of pyrazolyl-amides of aminoacids and peptides is described. The chemicals were tested for antifungal activity against wheat powdery mildew (Erysiphe graminis DC.), cucumber powdery mildew (Erysiphe cichoracearum DC.), wheat brown rust (Puccinia recondita Rob. ex Desm. f. sp. tritici Erikss et Henn.), celery leaf spot (Septoria Apii Briosi ed Cav. Chest.) and collar rot (Rhizoctonia solani Kuhn). Some of these compounds showed antifungal activity.

[Derivatives of 4-nitroso-aminopyrazole as antifungal agents]. / Derivati del 4-nitroso-5-amminopirazolo come antifungini.

The synthesis of 4-nitroso-5-amminopyrazoles and of 4-nitroso-5-pyrazolylurethans and -ureas is described. The chemicals were tested for antifungal activity against Erysiphe graminis, Erysiphe cichoracearum, Puccinia recondita, Septoria apii and Rhizoctonia solani. A number of the described compounds showed some antifungal activity.

Antifungal properties of some pyrazolyl-alkyl-sulfides. Electron microscopic evidence in two dermatophytes and Candida albicans.

Four 5-amino-4-alkylthio-pyrazoles were synthesized and their antifungal activity was evaluated in vitro in Trichophyton mentagrophytes, Microsporum cookei and Candida albicans. The compounds slightly influenced the growth kinetics of the yeast, but at concentrations ranging from 20 to 40 micrograms/ml completely prevented the mycelial growth of the two dermatophytes cultivated on Sabouraud's agar medium. An electron microscopic study, undertaken by using the most active compound, showed that in C. albicans mitochondria were the only cell targets affected whereas in the dermatophytes cell wall, plasmalemma and the main cytoplasmic organelles were damaged in various degrees. Since the most remarkable alterations were connected with membrane abnormalities, the cytological changes observed were tentatively interpreted as a consequence of the compound intrusion into the lipid bilayer of the membranes, since the drug is lipophilic in nature.

Carboxyl activation in peptide synthesis using 4-oximino-pyrazol-5-ones.

4-Oximino-pyrazol-5-ones 2a, b and their esters with N-protected amino acids 3a, b have been studied for carboxyl activation in peptide synthesis. 2a, b and 3a, b appear to be diastereoisomeric mixtures whose configurations have been assigned on the basis of spectroscopic and X-ray data. Some peptides obtained using these pyrazolone derivatives are reported: no racemization was noted by the Weigand test.

[Synthesis and anti-fungal activity of 5-aminopyrazole derivatives]. / Sintesi ed attività antifungina di derivati del 5-aminopirazolo.

4-Thiocyanato-5-amino or acylaminopyrazoles were prepared and their antifungal activity was tested against Candida albicans and Trichophyton mentagrophytes: the 4-thiocyanato-5-aminopyrazoles were the most effective in both tests.

On the fungitoxicity of some new thiocyanatopyrazole derivatives: electron microscopical study in Trichophyton mentagrophytes.

Four thiocyanatopyrazole derivatives were synthesized and their fungistatic activity was demonstrated in vitro against a number of dermatophytic fungi. In Trichophyton mentagrophytes, the most active compound induced as unusual increase of the plasma membrane with production of intra and extracytoplasmic complexes, a deterioration of nuclear and mitochondrial membranes and a formation of autophagic-like vacuoles. Plasmolysis, accompanied by an almost complete disorganization of cytoplasmic structures, seemed to be the final event. A possible mechanism of action of the compounds were discussed.

[Esters and amides of salicyloylamino acids]. / Esteri ed ammidi di saliciloilamminoacidi

N-Salicyloylamino acids, esters and amides have been prepared by the usual condensation methods and also by methods which may demonstrate 2-(o-hydroxyphenyl)oxazoline-5-ones as possible reaction intermediates. Some derivatives display pharmacological activities.