Effect of Selenium Nanoparticles on Germination of Hordéum Vulgáre Barley Seeds

Within the framework of this study, the effect of nanoparticles of the essential trace element selenium stabilized by Polyvinylpirrolidone (PVP) C15 (8 ± 2 kDa) and ascorbic acid on the germination of barley seeds has been studied. Selenium nanoparticles stabilized by PVP C15 (8 ± 2 kDa) and ascorbic acid, characterized by a spherical shape, monodisperse size distribution, and a diameter of about 70 ± 5 nm, were obtained by the chemical reduction method. The experiment compared the effect of selenium nanoparticles and selenous acid on seed germination. The positive effect of preparation of selenium nanoparticles stabilized by PVP C15 (8 ± 2 kDa) and ascorbic acid on the length of roots and shoots, the number of roots, and the percentage of seed germination has been revealed. It was determined that the highest percentage of Hordeum vulgare L. culture seed germination was achieved using a preparation of selenium nanoparticles stabilized by PVP C15 (8 ± 2 kDa) and ascorbic acid at a concentration of of 4.65 µg/mL. Analysis of the results showed that selenium in the form of nanoparticles has an order of magnitude that is less toxic than in the form of selenous acid. The study of morphological and functional parameters during the germination of Hordeum vulgare L. seeds allowed us to conclude that selenium nanoparticles can be successfully used in agronomy and agriculture to provide plants with the essential microelement selenium, which is necessary for the normal growth and development of crops.

Synthesis of 5-Phenyl-(5,6-Diphenyl-)-2,3-Dihydro-1,2,4-Triazine-3-Thions and Investigation of Their Reactions with 1,2-Dibromoethane

5-Phenyl-(5,6-diphenyl-)-1,2,4-triazine-3(2H)-thions (1,2) were synthesized by condensation of phenylglyoxal monohydrate with thiosemicarbazide and benzyl with thiosemicarbazide hydrochloride, respectively. Phenylglyoxal monohydrate was obtained by oxidation of acetophenone with selenous acid by the Riley reaction, while benzyl (1,2-diphenylethane-1,2-dione) waw obtained by oxidation of (2-hydroxy-1,2-diphenylethanone) benzoin with nitric acid by the known procedure. The compounds 1 and 2 were studied in reactions with 1,2-dibromoethane in various ratios. The interaction of triazinethione 1 with 1,2-dibromoethane in molar ratios of 1:1 and 1:2 led to the formation of a previously unknown 3-[(2-bromoethyl)sulfanyl]-5-phenyl-1,2,4-triazine (3а). Using a double excess of 1,2-dibromoethane increased the yield of compound 3а by 11 %. The interaction of triazinethione 2 with 1,2-dibromoethane in molar ratios 1:1 and 2:1 led to the formation of 3-[(2-bromoethyl)sulfanyl]-5,6-diphenyl-1,2,4-triazine (3b). In the 1H NMR spectra of compounds 3a,b there are signals of aromatic ring protons in the region of 7.23-8.81 ppm, a triplet of protons of the SCH2 group at 3.22 and 4.06 ppm, and a triplet of protons of the CH2Br group at 4.39 and 5.28 ppm. It is of interest that1,2-bis-(5-phenyl-[1,2,4]triazinyl-3-sulfanyl)-ethane is formed in the case of the reaction of compound 1 with 1,2-dibromoethane in the 2:1 ratio of reagents. In the 1H NMR spectra of the latter, in contrast to the spectrum of compound 3a, there is a signal of the S-CH2 group protons, which are equivalent in this structure and form a singlet at 3.79 ppm. Compound 3a was also studied by chromatography-mass spectrometry (direct sample insertion). It should be noted that under the conditions of mass spectrum imaging, the bromine atom is split off and the mass spectrum shows a peak with m/z 216 with an intensity of 38% and no peak of the molecular ion. The peak with the maximum intensity (m/z 116, 100 %) seems to correspond to 4-thia-6,7-diaza-1-azoniumbicyclo[3.2.0]hept-1(5)-ene. Its high intensity is due to the fact that the structure of the 1,2-dihydrotriazetium cation is aromatic.

Selenium supplementation in pediatric patients using parenteral nutrition: Is it time to do something?

Summary Objective: To analyze the nutritional status of selenium and verify the effect of its supplementation in pediatric patients during 14 days of parenteral nutrition (PN). Method: This is a series of cases with patients followed for two weeks while using PN. Data collection was performed at the beginning (T0), in the 7th (T1) and 14th days of PN (T2). The supplemented group received 2 µg/kg/day of selenous acid. Weight and height were measured for nutritional status assessment. Tests requested: plasma selenium, albumin, pre-albumin, C-reactive protein (CRP), total cholesterol and HDL-cholesterol. Results: Fourteen (14) patients with inflammatory process and with low or very low weight for their ages were evaluated. In both groups (with and without supplementation), all patients had low selenium levels. Median plasma selenium concentrations were 17.4 µg/L (T0), 23.0 µg/L (T1) and 20.7 µg/L (T2). Increase and reduction of selenium occurred both in patients with high CRP and in those presenting normalization of this parameter. Conclusion: Lower plasma selenium levels have been detected since the start of the research and supplementation (2 µg/kg/day of selenous acid) was not to enough to approach the reference values.

Synthetic, structural, and computational investigations of N-alkyl benzo-2,1,3-selenadiazolium iodides and their supramolecular aggregates

Alkyl benzo-2,1,3-selenadiazolium cations are conveniently prepared by cyclo-condensation ofN-alkyl-phenylenediamines with selenous acid.