Iodinated 4,4'-Bipyridines with Antiproliferative Activity Against Melanoma Cell Lines.

In the last decade, biological processes involving halogen bond (HaB) as a leading interaction attracted great interest. However, although bound iodine atoms are considered powerful HaB donors, few iodinated new drugs were reported so far. Recently, iodinated 4,4'-bipyridines showed interesting properties as HaB donors in solution and in the solid state. In this paper, a study on the inhibition activity of seven halogenated 4,4'-bipyridines against malignant melanoma (MM) cell proliferation is described. Explorative dose/response proliferation assays were first performed with three 4,4'-bipyridines by using four MM cell lines and the normal BJ fibroblast cell line as control. Among them, the A375 MM cell line was the most sensitive, as determined by MTT assays, which was selected to evaluate the antiproliferative activity of all 4,4'-bipyridines. Significantly, the presence of an electrophilic iodine impacted the biological activity of the corresponding compounds. The 3,3',5,5'-tetrachloro-2-iodo-4,4'-bipyridine showed significant antiproliferation activity against the A375 cell line, and lower toxicity on BJ fibroblasts. Through in silico studies, the stereoelectronic features of possible sites determining the bioactivity were explored. These results pave the way for the utilization of iodinated 4,4'-bipyridines as templates to design new promising HaB-enabled inhibitors of MM cell proliferation.

Comparison of antibacterial activity of natural and hydroformylated essential oil of Thymus capitatus growing wild in north Sardinia with commercial Thymus essential oils.

Thymus capitatus growing wild in Sardinia showed different essential oil composition if grown surrounding Cagliari than in north Sardinia. Here we verify the composition and antimicrobial activity of the oil to make it suitable for the cosmetic and confectionery industries. With the aim of improving the scent and the antimicrobical activity of T. capitatus essential oil, a hydroformylation reaction was carried out to transform the unsaturated components of the oil into the corresponding aldehydes. The essential oil of T. capitatus exhibited a significant antibacterial activity (MIC 0.125-0.5 mg/mL), and was also found effective on C. albicans (MIC 0.125 mg/mL). After hydroformylation, several new irregular terpenoid aldehydes were detected. The perfume of the new terpenic-like aldehydes is very agreeable and, therefore, the acceptability of the aroma is remarkably improved, but the antimicrobial activity was not increased.

Rosmarinus officinalis L.: chemical modifications of the essential oil and evaluation of antioxidant and antimicrobial activity.

Rosmarinus officinalis essential oil was separated into its hydrocarbon and oxygenated fractions. The major compounds in the hydrocarbon fraction were alpha-pinene (44.2%), camphene (24.5%), and limonene (11.7%), while in the oxygenated fraction they were 1,8-cineole (37.6%), camphor (16.5%), and bornyl acetate (21.4%). The hydrocarbon fraction was submitted to a hydroformylation process and the antioxidant activity of the product was screened by the DPPH and beta-carotene/linoleic acid tests. The hydroformylated fraction maintained the antioxidant activity of the whole oil. The MIC (minimal inhibitory concentration) and the MBC (minimal bactericidal concentration) of the essential oil, hydrocarbon, oxygenated and hydroformylated fractions were also tested on several microorganisms. Aeromonas sobria and Candida strains were the most susceptible micro-organisms. The hydroformylated fraction exhibited a MBC against Candida strains resistant to the other fractions.