Salvatore Petruso

Cardopatine and isocardopatine, two novel cyclobutane substances from Cardopatium corymbosum

Abstract Two new natural substances containing a cyclobutane unit, cardopatine and isocardopatine, the trans and cis isomers respectively of 5,5″ (cyclobut-1,2-ylene-diethynylene) bis 2,2′-bithiophene), together with the known α-terthienyl and 5-(but-3-en-1-ynyl)-2,2′-bithienyl, have been isolated from the roots of Cardopatium corymbosum. Evidence is given that the novel cyclobutane substances are not the products of a spontaneous dimerization of a bithienyl monomeric unit. Structure determination and conformational analysis are reported.

Pyrrolomycins as potential anti-staphylococcal biofilms agents

With the goal of discovering new anti-infective agents active against microbial biofilms, this investigation focused on some natural pyrrolomycins, a family of halogenated pyrrole antibiotics. In this study the anti-staphylococcal biofilm activity of pyrrolomycins C, D, F1, F2a, F2b, F3 and of the synthesized related compounds I, II, III were investigated. The susceptibility of six staphylococcal biofilms was determined by methyltiazotetrazolium staining. Most of the compounds were active at concentrations of 1.5 μg ml−1 with significant inhibition percentages. A few of the compounds were active at the lowest screening concentration of 0.045 μg ml−1. The population log reduction of activity against the two best biofilm forming Staphylococcus aureus strains as determined by viable plate counts is also reported. In order to adequately assess the utility of these compounds, their toxicity against human cells was evaluated. It is concluded that pyrrolomycins and synthetic derivatives are promising compounds for developing novel effective chemical countermeasures against staphylococcal biofilms.

Oxidative reactions of polyarylpyrroles. Part 3. Oxidative trimerization of 2,5-diphenylpyrrole

As in the oxidative reaction of 2,3,5-triphenylpyrrole previously studied, the oxidation of 2,5-diphenylpyrrole with potassium dichromate gave the dimer 2,2′,5,5′-tetraphenyl-3,3′-bipyrrole (2) and the related hydroxy-derivative 3-(2,5-diphenylpyrrol-3-yl)-2,5-diphenyl-2H-pyrrol-2-ol (6), together with the tetracyclic compound 1,6a-dihydro-2,5,6a-triphenylbenzo[g]pyrrolo[3.2-e]indole (3), whose formation involves the α-position of the pyrrole nucleus and the α′-phenyl group of the other pyrrole ring. In addition, large amounts of both the trimer 2,3-bis-(2,5-diphenylpyrrol-3-yl)-2,5-diphenyl-2H-pyrrole (4) and the tetracyclic compound 6a,6b-dihydro-1,3,5,6a,6b,8-hexaphenyl-2H-benzo[1,2-c:4,3-b′:5,6-b″]tripyrrole (5) were obtained. The formation of the various products of the oxidation is demonstrated in terms of the intermediate (2).