Unsaturated Keto and Exomethylene Pyranonucleoside Analogues of Thymine and Uracil Exhibit Potent Antioxidant Properties

Nucleoside analogues play an important role in the development of antitumor and antiviral agents. Specific sugar modified pyranonucleosides, like the keto and exocyclic methylene nucleosides, have been studied for their biological properties, but there is little information regarding their antioxidant activity. The present study reports the antioxidant activity of a series of α,β-unsaturated 2’- or 4’ - keto and exomethylene 5’-hydroxymethyl-lacking pyranonucleosides. The antioxidant activity was evaluated using an in vitro assay which is based on the capacity to protect DNA strand scission induced by peroxyl radicals (ROO?). The majority of the tested nucleoside analogues exhibit potent antioxidant properties against ROO? radicals. We conclude that the presence of a carbon-carbon double bond at α,β-disposition to exomethylene group at position 2 of the sugar moiety and the substitution of thymine with uracil improves the antioxidant capacity of these analogues.

Study of Initial Adhesion of a Bacterium to Different Support Materials before and after Conditioning Film of Olive Oil-Mill Wastewater

To improve the start-up speed and efficiency of bioreactors, biofilm technology is sometimes used. This technology uses various types of materials to facilitate the adhesion of microorganisms. In this study, the surface characteristics of inert substrates and substrates after olive oil-mill wastewater (OMWW) conditioning film were evaluated to understand the impact of OMWW on adhesion as well as the most suitable material to optimize bacterial adhesion. Three common substrates made of different polymers were tested for bacterial adhesion before and after treatment with OMWW: PP (polypropylene), PET (Polyethylene terephthalate), and PVC (polyvinyl chloride). The surfaces’ physicochemical characteristics were studied by measuring the contact angle for the studied bacteria strain and the supports, before and after treatment with OMWW. Results of initial adhesion tests for untreated and treated supports showed differences in how bacterial cells adhered to substrates. Before treatment with OMWW, PVC and then PP showed a significant adhesion capacity, double that of PET [PVC: 1.58 × 105 CFU/cm2, PP: 1.48 × 105 CFU/cm2 and PET: 0.72 × 105 CFU/cm2]. After treatment with OMWW, initial bacterial adhesion increased by 106 (from 105 CFU/cm2 for untreated supports to 1011 CFU/cm2 for treated supports), and PET followed by PP demonstrated the highest adhesion capacity, 2 and 1.7 times more than PVC, respectively [PET: 1.39 × 1011 CFU/cm2, PP: 1.15 × 1011 CFU/cm2 and PVC: 0.67 × 1011 CFU/cm2]. OMWW conditioning film affects the physicochemical characteristics of plastic supports, especially the donor electron character, and improves the initial adhesion of bacteria to substrates (105 to 1011 CFU/cm2). Therefore, surfaces’ physicochemical characteristics were important in the initial adhesion of the bacteria onto the support before and after treatment.

In vitro simulation studies of silica deposition induced by lignin from rice

To reveal the possible mechanism of silica deposition in higher plants, lignin was isolated from rice straw following a modified method to conduct a simulation experiment in vitro. UV and infrared absorption spectra showed that the substance had the unique characteristics of pure lignin. The presence of silicon in the precipitation was revealed by TEM (transmission electron microscopy) with EDXA (energy dispersive X-ray analysis) device. It was found that in the borax solution where lignin precipi-tation occurred silica-lignin co-precipitation was produced but not in the DMSO solution where lignin was broken into its com-position compounds and did not precipitate. This means that it is macromolecular lignin itself but not its compounds that could induce silica deposition in higher plants.

Study of Antimicrobial Activity of Medications for Wound Treatment

This paper presents data on the study of antimicrobial activity of 16 medications used for wound treatment. Antimicrobial activity of medications has been studied by well diffusion method on standard microorganism test strains： S. aureus ATCC 25923, E. coli ATCC 25922, P. aeruginosa ATCC 27853, P. vulgaris ATCC 4636, B. subtilis ATCC 6633, and C. albicans ATCC 885/653. Integrated indexes of antimicrobial activity of medications using vector theory have been calculated, which allowed to place most active of them in the order of descending activity： Levomecolum A = 2.73, r2 = 0.82; Levosin A = 2.41, r2 = 0.83; Synthomycinum A = 2.33, r2 = 0.97; Methyluracilum cum myramistino A = 2.31, r2 = 0.83; Oflocainum-Darnitsa A = 2.25, 1-2 = 0.97; and Betadine A = 2.03, r2 = 0.97. The mean of integrated indexes of antimicrobial activity and the square of the correlation coefficient for the group of these medications are as follows： A = 2.02, and r2 = 0.91. Comparison of mean values of integrated indexes of antimicrobial activity of medicines for wound treatment with those of water-alcohol extracts from plant raw material containing alkaloids, tannins, hydroquinone, naphthoquinones, anthraquinones, and phenols has shown to be promising of further development of domestic agents having antimicrobial activity based on water-alcohol extracts from plant raw material.