Investigating the elemental composition of a soil-plant system, based on the example of Lonicera caerulea

The concentration of 26 elements in the leaves of blue honeysuckle is reliably measured via SR XRF. The overall content of K and Zn, the concentration of their mobile forms in soils, and their accumulation in the leaves of plants are associated by a positive correlation. The accumulation of elements in the leaves of plants remains relatively stable against a background of a high level of variation in the concentrations of macro- and microelements in the soils of the Altai. Lonicera caerulea is an accumulator of Zn and Cu.     

Synthetic approach to preparation of indole derivatives fused with a bicyclo[3.3.1]nonane framework

Starting with Δ¹⁵-17-ketosteroids, applying Normant reaction with allylmagnesium bromide and anionic Cope rearrangement of the formed allyl alcohol, 15α-derivatives of androstane series were prepared. The latter were brought into Wittig reaction with an ylide generated from ethyltriphenylphosphonium bromide, and the product was subjected to ene reaction to provide 15α-substituted pregnanes.     

Vinyl diazophosphonates as precursors to quaternary substituted indolines and cyclopentenes

Vinyl diazophosphonates can be stereoselectively synthesized and, depending upon their substitution pattern, undergo intramolecular C-H insertion reactions or sulfonium ylide rearrangements when exposed to Rh(2)(OAc)(4).     

Improvement of ways to obtain ethidium bromide and synthesis of ethidium ethyl sulfate,a new fluorescent dye for detection of nucleic acids

Two methods for synthesis of ethidium bromide, a fluorescent dye widely used in molecular biology, were improved. An analog of ethidium bromide, ethidium ethyl sulfate, was synthesized.     

D2-symmetric dirhodium catalyst derived from a 1,2,2-triarylcyclopropanecarboxylate ligand: design, synthesis and application

Dirhodium tetrakis-(R)-(1-(4-bromophenyl)-2,2-diphenylcyclopropanecarboxylate) (Rh(2)(R-BTPCP)(4)) was found to be an effective chiral catalyst for enantioselective reactions of aryl- and styryldiazoacetates. Highly enantioselective cyclopropanations, tandem cyclopropanation/Cope rearrangements and a combined C-H functionalization/Cope rearrangement were achieved using Rh(2)(R-BTPCP)(4) as catalyst. The advantages of Rh(2)(R-BTPCP)(4) include its ease of synthesis, its tolerance to the size of the ester group in the styryldiazoacetates, and its compatibility with dichloromethane as solvent. Computational studies suggest that the catalyst adopts a D(2)-symmetric arrangement, but when the carbenoid binds to the catalyst, two of the p-bromophenyl groups on the ligands rotate outward to make room for the carbenoid and the approach of the substrate to the carbenoid.     

Synthesis and structure of amino acid-derived benziodazoles: new hypervalent iodine heterocycles

New N-functionalized benziodazoles were prepared by the peracetic oxidation of 2-iodobenzamides derived from alanine or valine. X-ray crystal structural analysis of two benziodazole-based phenyliodonium derivatives provides insight into facile interchange between benziodazoles and iminium benziodoxoles under acidic or basic conditions. [reaction: see text]     

Biodegradation of polyhydroxyalkanoates (PHAs) in tropical coastal waters and identification of PHA-degrading bacteria

Biodegradability patterns of two PHAs: a polymer of 3-hydroxybutyric acid (3-PHB) and a copolymer of 3-hydroxybutyric and 3-hydroxyvaleric acids (3-PHB/3-PHV) containing 11 mol% of hydroxyvalerate, were studied in the tropical marine environment, in the South China Sea (Nha Trang, Vietnam). No significant differences have been observed between degradation rates of 3-PHB and 3-PHB/3-PHV specimens; it has been found that under study conditions, biodegradation is rather influenced by the shape of the polymer item and the preparation technique than by the chemical composition of the polymer. Biodegradation rates of polymer films in seawater have been found to be higher than those of compacted pellets. As 3-PHB and 3-PHB/3-PHV are degraded and the specimens lose their mass, molecular weight of both polymers is decreased, i.e. polymer chains get destroyed. The polydispersity index of the PHAs grows significantly. However, the degree of crystallinity of both PHAs remains unchanged, i.e. the amorphous phase and the crystalline one are equally disintegrated. PHA-degrading microorganisms were isolated using the clear-zone technique, by inoculating the isolates onto mineral agar that contained PHA as sole carbon source. Based on the 16S rRNA analysis, the PHA-degrading strains were identified as Enterobacter sp. (four strains), Bacillus sp. and Gracilibacillus sp.     

SR XRF Analysis for studying plants in an area of geological heterogeneity

X-ray fluorescence analysis using synchrotron radiation is applied to determine the elemental composition in the leaves of Pentaphylloides fruticosa (L.) O.Schwarz (bush cinquefoil) and Lonicera caerulea subsp. altaica ((Pall.) Gladkova) (blue honeysuckle) growing in a geologically active area. It is found that in the studied period, the total content of microelements increases in the Pentaphylloides fruticosa leaves in the area of geological heterogeneity than that in the control one, and on the contrary, it decreases in Lonicera caerulea. The relationship between Fe/Mn, Ca/Sr, Cu/Zn, and K/Rb ratios and the geochemical and geophysical features of the environment and element accumulation by different types of plants is established. It is noted that two types of bushes under study react differently to changes in the geochemical and geophysical characteristics of the environment.