Synthesis and biological activity of some derivatives of rifamycin P.

A series of derivatives of rifamycin P, an antibiotic produced by fermentation of a mutant strain of Nocardia mediterranea or by chemical modification of rifamycin S, have been prepared. The structures of these compounds were determined by 1H NMR, IR, UV, and LC/MS. Their in vitro and in vivo antibacterial activities in comparison with rifampicin and two other rifamycins under investigation were evaluated. The derivatives were more active than rifamycin P against Mycobacterium avium complex and other slowly and rapidly growing nontuberculous mycobacteria which frequently cause systemic infection in patients with AIDS. 2'-(Diethylamino)rifamycin P (P/DEA) appears suitable for further investigation.

Benzodiazepine receptor ligands. Synthesis and preliminary pharmacological evaluation of 2-aminoalkyl-8-chloro- and 2-aryl-1,2,4-triazolo[3,4-a]phthalazine-3(2H)-ones.

Some 2-aminoalkyl-8-chloro- and 2-aryl-1,2,4-triazolo[3,4-a]-phthalazine-3-(2H)-ones were synthesized and preliminarily tested in vitro and in vivo as potential benzodiazepine-receptor (BZRs) ligands. 2-Aryl-1,2,4-triazolo[3,4-a]-phthalazine-3(2H)-ones displaced in vitro 3H-diazepam (3H-DZ) from rat brain specific binding sites with Ki (nM) comparable to DZ and chlordiazepoxide used as reference compounds. The specific binding of the triazolones of this study was not enhanced in vitro by 4-aminobutyric acid (GABA) and in vivo they did not show any activity in counteracting the pentylenetetrazole (PTZ) induced convulsions (mice). One of these compounds (IV a) antagonized the effects of DZ in the bicuculline (BIC) induced convulsions test (mice) and the DZ induced muscle relaxant effects in the horizontal wire test.

Benzodiazepine receptor ligands. Synthesis and preliminary pharmacological evaluation of some 3,7-disubstituted-4H-[1,2,4]triazino[3,4-a]phthalazines and 3,7-disubstituted-4H-[1,2,4]triazino[3,4-a]phthalazine-4-ones.

Some disubstituted triazinophthalazines and traizinophthalazinones were synthesized and tested in vitro for inhibition of the 3H-diazepam (3H-DZ) specific binding to benzodiazepine receptors (BZRs) in membranes from synaptosomes of rat brain and in vivo for their effects on the conditioned behaviour (rat). These compounds showed Ki values (nM) in the in vitro test ranging from 220 to more than 3000 and some of them had approximate ED50S of 30 mg/kg, i.p. (rat) in the conditioned avoidance behaviour test (CR2).

Benzodiazepine receptor ligands. Synthesis and in vitro binding activity of some 6-substituted-3-aryl-1,2,4-triazolo[3,4-a]phthalazines.

Some 3-aryl-6-hydroxymethyl-1,2,4-triazolo[3,4-a]phthalazines (VI a,b) and 3-aryl-6-(2-hydroxyethyl)-1,2,4-triazolo[3,4-a]phthalazines (XVIII) have been synthesized. From (VI b) some 3-aryl-6-(alkylamino)methyl- and 3-aryl-6-(alkoxy)methyl-1,2,4-triazolo[3,4-a]phthalazines have been prepared and evaluated in vitro for their ability to inhibit selective 3H-diazepam (3H-DZ) binding to benzodiazepine-receptors (BZRs) from homogenates of synaptosomes from rat brains. Several compounds have been shown to displace 3H-DZ from BZRs with Ki (nM) values ranging from 2.2 to 88, comparable to those of the reference drugs including Diazepam.

Benzodiazepine receptor ligands. Synthesis and pharmacological evaluation of 6-aryl-3,8-disubstituted-1,2,4-triazolo[3,4-a]phthalazines.

A series of 6-aryl-3,8-disubstituted-1,2,4-triazolo[3,4-a]phthalazines was synthesised starting from suitable o-benzoylbenzoic acids. The compounds were tested in vitro for inhibition of the specific binding of 3H-Diazepam to benzodiazepine receptors in preparations of membranes from rat brain synaptosomes. None of the compounds was notably active in this test.

6-(Alkylamino)-3-aryl-1,2,4-triazolo[3,4-a]phthalazines. A new class of benzodiazepine receptor ligands.

Some 6-(alkylamino)-3-aryl-1,2,4-triazolo[3,4-a]phthalazines have been shown to displace diazepam from rat brain specific binding sites, in vitro, with Ki (nM) values comparable to those of reference benzodiazepines and to have anticonvulsant (pentylenetetrazole test, mice) and anticonflict activity (Vogel test, rat) in vivo. Separation between the doses causing anticonflict effects (Vogel test, rat) and those impairing motor coordination (rotarod test, rat) has been shown for N,N-bis(2-methoxyethyl)-3-(4-methoxyphenyl)-1,2,4-triazolo[3,4-a] phthalazin-6-amine (80). This compound, unlike diazepam, was inactive in counteracting the strychnine (mouse) and maximal electroshock (mouse) induced convulsions and in the "aggressive monkey" model. These differences from the classical benzodiazepines in the animal tests indicate that 80 may have some selective anxiolytic activity.

Benzodiazepine receptor ligands. Synthesis and preliminary pharmacological evaluation of some 3-aryl-6-thioalkyl-, 3-aryl-6-alkylsulphinyl-, 3-aryl-6-alkylsulphonyl-, and 3-aryl-6-alkoxy-1,2,4-triazolo[3,4-a]phthalazines.

A series of 3-aryl-6-alkoxy- and some 3-aryl-6-thioalkyl-, 3-aryl-6-alkylsulphinyl-, and 3-aryl-6-alkylsulphonyl-1,2,4-triazolo[3,4-a]phthalazines were synthesised and tested for inhibition of the in vitro binding of 3H-Diazepam to benzodiazepine receptors in membranes isolated from rat brain synaptosomes. 6-Alkoxy-3-(4'-methoxy)phenyl-1,2,4-triazolo[3,4-a]phthalazines were more active than or as active as diazepam in the binding assay (Ki nM) but unlike diazepam their binding to the benzodiazepine receptors was not enhanced by 4-aminobutyric acid. These compounds did not antagonize pentylenetetrazole induced convulsions and were inactive in modifying the conditioned behaviour of rats. Compound (II a) counteracted the muscle relaxant effects of diazepam (traction test). These results suggest that (II a) may be a benzodiazepine receptor antagonist.

[Synthesis and pharmacologic activity of derivatives of 3-aminopropiophenone and 3-aminomethylcamphor]. / Sintesi ed attività farmacologica di derivati di 3-aminopropiofenoni e di 3-aminometilcanfore.

As a part of a research on analgesic compounds 0-(4-methoxyphenyl)carbamoyl-3-aminopropiophenone oximes, 0-(4-methoxyphenyl)-carbamoyl-3-aminomethylcamphor oximes and 4-(4-methoxyphenyl)semicarbazones of 3-aminopropiophenones were prepared. The analgesic activity of these compounds was tested and the results of pharmacological screening are discussed.

[Substances with central nervous system activity. Derivatives of octahydro-1,4-dihydroxypyrrolo(1,2-a)pyrazine-6-carboxylic acids]. / Sostanze attive sul sistema nervoso centrale. Derivati di acidi ottaidro-1,4-diossopirrolo[1,2-a]pirazino-6-carbossilici.

Compounds with potential activity on the Central Nervous System were prepared starting either from 2,5-diethoxycarbonylpyrrolidine or from N-benzyloxycarbonyl-2,5-pyrrolidinedicarboxylic acid anhydride. By the Arndt-Eistert reaction it was possible to obtain chain lengthening at position 6. The carboxy group was also successfully reduced to a hydroxymethyl group. The synthetic work was completed with the synthesis of some derivatives having a phenyl ring condensed at position 7 and 8. Some pharmacological data on the Central Nervous System depressant activity of the prepared compounds are also reported.

[Substances with central nervous system activity. Derivatives of 2,3,5,9b-tetrahydro-1,3-dioxo-1H-imidazo[5,1-a]isoindole-5 -carboxylic acid]. / Sostanze attive sul sistema nervoso centrale. Derivati degli acidi 2,3,5,9b-tetraidro-1,3-diosso-1H-imidazo [5,1-a]isoindol-5-carbossilici.

The AA. describe the synthesis of some methyl esters of 2-alkyl or 2-aryl-2,3,5, 9b -tetrahydro-1,3-dioxo-1H-imidazo[5,1-a] isoindol -5-carboxylic acids and of the corresponding acids. From these acids some aliphatic and heterocyclic amides were synthesized. The pharmacological data of these compounds are also reported.

[Derivatives of 2,3,5,6,7,7a-hexahydro-1,3-dioxo-1H-pyrrolo[1,2-c]imidazol -5-carboxylic acids]. / Derivati degli acidi 2,3,5,6,7,7a-esaidro-1,3-dioxo-1H-pirrolo[1,2-]i midazolo-5-carbossilici.

The synthesis of the above-mentioned compounds, starting from the diethyl ester of 2,5-pyrrolidine dicarboxylic acid, is reported. The cis and trans isomers od the 2-phenylsubstituted acid were separated, and the trans form was resolved into the two chiral forms. Some amides were also prepared from these acids. The thio analogs (XIII) and (XVI) and the partially reduced derivatives (XIV) were synthesized. Some amides (VI) showed an interesting anti-anxiety effect in pharmacological models.

[Tricyclic homologs of piperazine. III. Synthesis of 4-substituted hexahydro-1H-2,6-methanopyrrolo[1,2a]pyrazines]. / Omologhi triciclici della piperazina. Nota III (1)--Sintesi di esaidro-1H-2,6-metanopirrolo[1,2-a]pirazine 4-sostituite.

The Authors describe the synthesis of some quaternary salts of the hexahydro-1H-2,6-methanopyrrolo[1,2-a]pyrazines mono or disubstituted at carbon-4. These were obtained directly by cyclization of the corresponding diazabicyclooctanes, by formation of a substituted ethylenic bridge between the two nitrogen atoms. The compounds were pharmacologically screened; the hypothesis of enhancement of curare-like activity in comparison with the unsubstituted derivatives was not confirmed.

[Bicyclic analogs of piperazine. XII. (1) - Synthesis of 3,8-diazabicyclo/3,2,1/octanes as potential antiparkinson agents]. / Analoghi biciclici della piperazina XII (1)-Sintesi di 3,8-diazabiciclo [3,2,1] ottani come potenziali antiparkinsoniani

As a part of research on 3,8-diazabicyclo [3,2,1] octanes, the Authors report on the synthesis of some amides of methyl, phenyl and cyclohexyltropic acid, potentially active as antiparkinson agents. Also reported is the synthesis of some compounds similar to two known drugs, Caramiphene and Cycrimine. These compounds differ from the said drugs in having a 3,8-diazabicyclo [3,2,1] octane as a basic moiety.

[Bicyclic analogs of piperazine. XIII (1). Derivatives of 3,8-diazabicyclo[3.2.1]octane with potential anti-inflammatory activity]. / Analoghi biciclici della piperazina. XIII (1) - Derivati del 3,8-diazabiciclo[3.2.1]ottano a potenziale attività antiinfiammatoria

The Authors describe the synthesis of some 8-acyl-3-methyl-3,8-diazabicyclo[3.2.1]octanes and 3-acyl-8-methyl-3,8-diazabicylo[3.2.1] octanes. The compounds were prepared by acylation of the corresponding methyl derivatives with the purpose of obtaining antiinflammatory compounds. The synthesis of some 3-alkyl-8-propionyl-3,8-diazabicylo[3.2.1]octanes is also described. These compounds were prepared in analogy with some 8-pripionyl-3,8-diazabicyclo[3.2.1]octanes endowed with high analgesic and antiinflammatory activity.