3H-[1,2]Dithiolo[3,4-b]pyridine-3-thione and its derivatives synthesis and antimicrobial activity.

A series of 2-substituted isothiazolo[5,4-b]pyridine-3(2H)-thiones, isothiazolo[5,4-b]pyridin-3(2H)-ones, N-substituted 2-sulfanylnicotinamides and the corresponding carbothioamide derivatives were synthesized and evaluated for their antimicrobial activity against several strains of Gram+ and Gram- bacteria and fungi. Chemical syntheses were resumed into a comprehensive cyclic route that enables the reversible conversion for each derivative of the series considered. Among the tested compounds the N-(aralkyl)-2-sulfanylnicotinamides show the highest fungitoxicity (MIC = 1.25-5 microg/ml). The best activity towards Gram-positive bacteria was in the range of 2.5-5 microg/ml. Activity against Gram-negative bacteria was generally very poor for all compounds.

Antimicrobial and genotoxic activities of N-hydroxyalkyl-1, 2-benzisothiazol-3(2H)-one carbamic esters.

N-Hydroxyethyl- and N-hydroxypropyl-1,2-benzisothiazol-3(2H)-one carbamic esters were prepared in order to test their activity against representative bacterial and fungal strains. The obtained results were compared with those reported for parent alcohols and some interesting considerations were drawn. None of the studied derivatives possess genotoxic activity in the Bacillus subtilis rec-assay and Salmonella-microsome test.

In vitro anti-Mycobacterium avium activity of N-(2-hydroxyethyl)-1,2-benzisothiazol-3(2H)-one and -thione carbamic esters.

A series of N-(2-hydroxyethyl)-1,2-benzisothiazol-3(2H)-one and -thione carbamic esters have been synthesised and tested against Mycobacterium avium strains. The MIC values determined by the radiometric broth dilution method were between 2 and 8 micrograms/mliters for the benzisothiazolthione derivatives and between 16 and 32 micrograms/mliters or higher for the corresponding benzisothiazolone derivatives.

[Phytotoxic activity of N,N-di-sec-butylbenzamides with alkyl substituents on the aromatic nucleus]. / Sull'attivita fitotossica di N,N-di,sec.butilbenzamidi alchilsostituite al nucleo aromatico.

A new series of N,N-di,sec.butylalkylbenzamides was studied and it was found that some compounds showed particularly interesting selective phytotoxicity comparable with that shown by analogous halogen derivatives.

[Phytotoxic activity of asymmetric N,N-dialkylamides of trisubstituted benzoic acids]. / Attività fitotossica di N,N-dialchilamidi asimmetriche di acidi benzoici trisostituiti.

Asimmetric N,N-dialkylamides of benzoic acids variously trisubstituted on the nucleus were prepared and tested for phytotoxicity in pre- and post-emergence experiments. These amides are characterized by the presence on the amidic N of a sec.butyl or a 1-methylbutyl or a 1-ethylpropyl group and a second alkyl group of varying weight and nature. For reference the Authors prepared and studied 2,3,5-trichlorobenzamides bearing on the N atom a tert.butyl and a second linear C2 leads to C4 alkyl. The substances studied generally proved very active against the weeds tested and showed marked specificity of action towards Setaria and Echinochloa. The compounds proving most active against the weeds were also tested against plants of agricultural interest. In general these asymmetric amides proved more phytotoxic against agrarian species than the corresponding N,N-di,sec.butylamides studied previously.

[Preparation and study of the phytotoxic activity of arylalkylamides. II. N-Phenethylamides]. / Preparazione e studio dell'attività fitotossica di amidi n-aralchilsostituite. Nota II--N-fenetilamidi.

A series of N-phenetylamides was prepared and tested for phytotoxic activity. Comparison with N-benzylamides showed that lengthening the alkyl chain in the aralkylamide residue reduces phytotoxicity and that, also in the case of phenetylamides, phytotoxic activity is not due to inhibition of the Hill reaction.

[2-amino-3,5-dichloro-benzoic acid and 3-amino-2,5-dichloro-benzoic acid derivatives with phytotoxic action]. / Derivati degli acidi 2-amino-3,5-dicloro- e 3-amino-2,5-diclorobenzoici ad attività fitotossica.

Derivatives of 2-amino-3,5-dichloro- and 3-amino-2,5-dichlorobenzoic acids have been prepared in order to extend previous research regarding the phytotoxicity of these two acids and of the corresponding N,N-di,sec.butylamides. The methyl esters of the two acids, the corresponding acids acetylated on the amino group and their respective methyl esters, and the N,N-di,sec.butylamides acetylated or formylated on the amino group were prepared. All these compounds were subjected to pre- and post-emergence tests using seven representative weeds, using doses of 6 kg/ha and, where substances proved active, at lower doses also. The results showed the importance of the N,N-di,sec.butylamide of 2-amino-3,5-dichlorobenzoic acid which, in contrast to the other derivatives tested, shows selective activity. For 3-amino-2,5-dichlorobenzoic acids and the amides tested, it was confirmed that only the acid shows marked generic phytotoxic activity in both pre- and post-emergence tests. It should be noted that the methyl ester of 3-acetylamino-2,5-dichlorobenzoic acid shows selective phytotoxicity activity.

[Preparation and study of phytotoxicity of N-arylalkyl substituted amides. I. Benzylamides]. / Preparazione e studio dell'attività fitotossica di amidi N-aralchilsostituite. Nota I - Benzilamidi.

A series of N-benzyl substituted amides (substances I-CV) have been prepared and tested for phytotoxicity. Preliminary tests were carried out on various common plants using both pre- and post-emergence tests at doses of 6 kg/ha. Further tests using doses of 4 and 2 kg/ha were carried out on the most interesting compounds. Some of the compounds tested showed marked phytotoxic activity. This activity appears clearly different as regards mechanism from that of homologous anilides. The amides studied appear to be quite inactive as inhibitors of the Hill reaction.

[Preparation and study of phytotoxic activity of anilides of the (+/-) hydratropic acid]. / Preparazione e studio dell'attività fitotossica di anilidi dell'ac. (+/-)-idratropico

A series of ((+/-)-hydratropanilides variously substituted in the aniline nucleus (substances I leads to XXXIX) were prepared. The substances were studied for inhibition of the Hill reaction and for phytotoxicity. Comparison of the results of in vitro and in vivo tests did not often show strict correlation of data: in particular it seems probable that in the hydratropanilide series substances active on the isolated chloroplast are hindered in vivo in the absorption and transport phases and thus cannot reach the receptor sites.

Alkylthiophenylureas with phytotoxic activity. / p.alchiltionfeniluree ad attivitá fitotossica

A series of 1-(p.alkylthio)phenylureas variously substituted on the N atom in position 3 (substances I leads to XXXVII) has been prepared and studied for pre- and post-emergence phytotoxicity. Some compounds were found to have high activity; in particular some 1-(p.alkylthio)phenyl-3-dimethylureas showed high activity even at very low doses (2 kg/ha).