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Biomedical subjects

S Burnelli

Publications and source records attributed to S Burnelli.

At least 19 recordsLinked to original sources
PubMed2001

Synthesis and antimicrobial activity of new diazoimidazole derivatives containing an N-acylpyrrolidine ring.

A series of 4-diazoimidazole-5-carboxamides bearing in position 2 lipophilic substituents was synthesized and their antimicrobial activity was evaluated in vitro against pathogenic Gram-positive, Gram-negative bacteria and fungi. Some compounds presented antifungal activity, particularly two derivatives (1g and 1h) showed good MIC values (10-50 microg/ml) against both moulds and yeasts.

Anti-Bacterial Agents↗
PubMed1999

Synthesis and antagonistic activity at muscarinic receptor subtypes of some 2-carbonyl derivatives of diphenidol.

A series of 2-carbonyl analogues of the muscarinic antagonist diphenidol bearing 1-substituents of different lipophilic, electronic, and steric properties was synthesized and their affinity for the M2 and M3 muscarinic receptor subtypes was evaluated by functional tests. Two derivatives (2g and 2d) showed an M2-selective profile which was confirmed by functional tests on the M1 and M4 receptors. A possible relationship between M2 selectivity and lipophilicity of the 1-substituent was suggested by structure-activity analysis. This work showed that appropriate structural modification of diphenidol can lead to M2-selective muscarinic antagonists of possible interest in the field of Alzheimer's disease.

Animals↗
PubMed1998

Synthesis, metabolism and structure-mutagenicity relationships of novel 4-nitro-(imidazoles and pyrazoles) in Salmonella typhimurium.

A new series of 4-nitro-(imidazoles and pyrazoles) were synthesized as novel antimycotics and tested for their activation to mutagenic forms using Salmonella typhimurium TA98 and TA100, in the presence and in the absence of metabolic activation. TA100NR, TA100/1,8-DNP6, YG1026 and YG1029 strains were employed to identify a specific metabolic reaction which governs the mutagenic potency. Derivatives in the pyrazole group were generally found to be non mutagenic and active imidazoles were weak-direct-acting mutagens. For most of the compounds the mutagenic responses in TA98 were absent or 12- to 22-fold lower compared to TA100. The presence of a methyl or a benzylic group on the imidazole ring and substituents on the N1 and N3 positions were determinant for mutagenicity. Metabolism by bacterial enzyme systems was important to the expression of genotoxicity. Active compounds showed no mutagenicity toward the strain defective in classical nitroreductase and increased mutagenicity, from 2- to 7-fold depending on the test compound, toward the corresponding overproducing bacteria. On the other hand, compounds displayed reduced mutagenicity to the O-acetyltransferase strain without having increased activity in the corresponding overproducing bacteria, YG1029.

Imidazoles↗
PubMed1995

Nonsteroidal antiinflammatory agents. XXIII. Synthesis and activity of stereomeric (+/-)-erythro- and (+/-)-threo-2-(4-biphenylyl)-3-hydroxy-2-methyl-3-phenyl-propionic acids.

In pursuing our research on the NSAIDs, the diastereomeric (+/-)-erythro- and (+/-)-threo-2-(4-biphenylyl)-3-hydroxy-2-methyl-3-phenyl-propionic acids (4 and 5) were synthesized; the last was also resolved in its optical isomers (6 and 7). The attribution of the relative configuration to 4 and 5 was performed by means of X-ray analysis. The compounds were tested for their antiinflammatory activity. The acid 4, which resulted very interesting, was tested also for analgesic and antipyretic activity, as well as for behavioural effects, gastric tolerability and acute toxicity. On the basis of the obtained data, this compound resulted a very promising one.

Animals↗
PubMed1993

Synthesis of a series of 5-nitro-(benzimidazoles and indoles) as novel antimycotics and evaluation as genotoxins in the Ames test.

Nitrobenzimidazole and nitroindole derivatives, related to oxiconazole and characterized by an oxyiminic function, have been synthesized as novel antimycotics and their mutagenic activity tested in Salmonella typhimurium strains TA100 and TA98 with and without an exogenous metabolizing system. TA98NR and TA98/1,8-DNP6 strains were employed to identify a specific metabolic reaction which governs the mutagenic potency. Active compounds are weak direct-acting mutagens. Only derivatives bearing a nitro group on the phenyl ring linked to the oxyiminic function and lacking halogenated substituents show mutagenic activity. Metabolism by bacterial enzyme systems is important to the expression of genotoxicity. The reductive activation of nitrobenzimidazoles and nitroindoles carried out by the 'classical' nitroreductase of Salmonella, which is defective in TA98NR, is required of mutagenicity. Similarly, the O-acetyltransferase defective in TA98/1,8-DNP6 is required for the efficient production of the ultimate electrophilic nitrogen species, which react with DNA. The role of bacterial metabolism in mutation induction needs careful consideration to assess the potential risk to humans from nitrobenzimidazole and nitroindole antimycotics.

Antifungal Agents↗
PubMed1991

[Non-steroidal anti-inflammatory agents. XXII. Chiral aryl-hydroxy-fluorenylpropionic acids].

As fluorenyl rigid analogues of previous biphenylyl alcanoic acids with very interesting antiinflammatory activity, the 3-(m-tolyl and m-anisyl)-3-hydroxy-3-(2-fluorenyl)-propionic acids have been prepared by means of the Reformatsky reaction and following hydrolysis of the obtained ethyl esters. The preliminary antiinflammatory assay showed that the structural modification inactivates the compounds.

Animals↗
PubMed1988

Nonsteroidal anti-inflammatory agents. Part 17: Stereomeric o-, m-tolyl- and anisyl-biphenylyl-hydroxypropionic acids.

As a part of wider research project on chiral anti-inflammatory arylacanoic acids, the 3-(o- and m-)-(methyl and methoxy)-phenyl-2-biphenylyl-3-hydroxypropionic acids 3a-d were synthesized and resolved in their optically active erythro and threo stereomers, which were submitted to the carrageenan induced rat paw edema test. With respect to the p-isomers, only the threo p-methoxy substitution enhances the anti-inflammatory activity. Some conclusions on structure-activity relationship are discussed.

Animals↗
PubMed1988

[Nonsteroidal anti-inflammatory agents. 19. Synthesis and activity of stereomeric phenylacetic homologues].

The authors synthesized the title compounds as analogues of previously prepared potential antiphlogistic agents. Starting from appropriate carbonyl compound and alpha-metallated phenylacetic acid the diastereomeric racemate pairs were obtained; they were separated, attributed to erythro/threo-configuration by NMR and finally resolved. The potassium salts of the enantiomers were tested for analgesic and antiinflammatory activity, as well as for acute toxicity. Their action in the carrageenan test has been found to be stereoselective, but relatively poor or of briefly lastening.

Analgesics↗
PubMed1985

Nonsteroidal antiinflammatory agents. Part 16: Stereomeric 3-aryl-biphenylyl-hydroxy-propionic acids.

As part of a wider research project on structure-activity relationships of chiral arylalkanoic acids, stereomeric aryl- biphenylyl-hydroxypropionic acids 3a-d have been prepared and their antiinflammatory activity evaluated. Diastereomeric racemic erythro- and threo-acids have been synthesized by reaction of alpha-lithiated biphenylyl-acetic acid salts with the appropriate aldehyde. They were separated, and after attribution of their relative configuration by 1H-NMR analysis, resolved. The antiinflammatory activities of the enantiomeric potassium salts were determined by the carrageenan test.

Animals↗
PubMed1983

[Nonsteroidal anti-inflammatory agents. XIII. 4-Cyclohexylphenylhydroxyalkanoic acids].

The preparation of some homologues of 2-(4-cyclohexylphenyl)-3-hydroxypropionic acid, the separation of the diastereomeric race-mates, their attribution to erythro and threo series, and the optical resolution of the enantiomers are described. The optical antipodes were screened for acute toxicity, as well as for antiinflammatory and analgesic activity.

Animals↗
PubMed1983

[Non-steroidal anti-inflammatory agents. Stereoisomers of homologues of 2-(4-biphenylyl)-3-hydroxypropionic acid. XII].

The synthesis of some homologues of 2-(4-biphenylyl)-3-hydroxypropionic acid, the separation of related diastereoisomers, their attribution to erythro and threo series, and resolution of the optical antipodes are described. The antiinflammatory activity--initially tested by carrageenin assay--proves generally influenced by steric configuration and is interesting for the isohexanoic derivative.

Animals↗