Chemical composition,antimicrobial, and lipase enzyme activity of essential oil and solvent extracts from Serapias orientalis subsp. orientalis

The volatile components of essential oil (EO), SPME, and SPME of solvent extracts ( n -hexane, methanol, and water) obtained from fresh Serapias orientalis subsp. orientalis ( Soo ) were analyzed by GC-FID/MS. EO of Soo gave 11 compounds in the percentage of 99.97%; capronaldehyde (37.01%), 2-( E )-hexenal (23.19%), and n -nonanal (19.05%) were found to be major constituents. SPME GC-FID/MS analyses of fresh plant and solvent extracts of Soo revealed 7, 12, 7, and 4 compounds within the range of 99.7% to 99.9%. Limonene (76.5%, 41.7%, and 61.3%) was the major compound in SPMEs of the n -hexane and methanol extracts. α -Methoxy- p -cresol (52.9%) was the main component in its water extract. The antimicrobial activity of EO and the solvent extracts of Soo were screened against 9microorganisms. EO showed the best activity against Mycobacterium smegmatis , with 79.5 µg/mL MIC value. The n -hexane, methanol, and water extracts were the most active against the Staphylococcus aureus within the range of 81.25–125.0 µg/mL (MIC). IC ₅₀ values for the lipase enzyme inhibitory activity of EO and solvent extracts ( n -hexane, methanol, and water) were determined to be 59.87 µg/mL, 64.03 µg/mL, 101.91 µg/mL, and 121.24 µg/mL, respectively.     

Morphology of Composite Films Based on Poly(N-vinylcaprolactam) with Titanium Dioxide Nanoparticles

Crystallography Reports - PVCL25 and PVCL40 films have been synthesized by poly(N-vinylcaprolactam) (PVCL) aqueous solution flow coating and complete desiccation below...     

The Influence of Inorganic and Organic Components of Biofilms with Microscopic Fungi on the Phase Composition and Morphology of Crystallizing Calcium Oxalates

Crystallography Reports - The influence of organic and inorganic components of biofilms with microscopic fungi on the phase composition and morphology of precipitating calcium oxalates has been...     

Structural properties of new spiro-1,3-propanediaminocyclotriphosphazene derivatives

New 1,3-propanediaminocyclotriphosphazene derivatives (7-17) were synthesized from the reactions of spiro-1,3-propanediaminocyclotriphosphazene, N₃P₃Cl₄[NH(CH₂)₃NH] (1) with the cyclopropanemethylamine (2), cyclohexylamine (3), pyrrolidine (4) cyclohexanol (5), cyclopropylmethanol (6). The structures of the novel compounds (7-17) were characterized by elemental analysis, mass spectrometry, ¹H and ³¹P NMR spectroscopy. The molecular structures of 8, 12 and 13 were determined by X-ray crystallography. The structures of all these three compounds are in the monoclinic crystal system; compounds 8 and 12 have the P21/c space group while compound 13 has the P21/n space group. The ring conformation of the cyclotriphosphazene and other external rings were investigated based on the X-ray crystal structures.     

New Effects in the Poly-N-Vinylcaprolactam/Titanium(IV) Oxides Nanocomposite System and Their Nature

Nanocomposites based on poly-N-vinylcaprolactam (PVC), characterized by different drying temperatures of aqueous PVC solution at 25°С (PVC25) and 40°С (PVC40), with titanium(IV) oxide nanoparticles (TONs) (η-phase (TP: TiO_{2 – x} · mH₂O) with a superstructure to the anatase structure and ordered solid solution with partial replacement of oxygen atoms in the η-phase with peroxo group O ₂ ^2– (PP: TiO _x (O₂)_{2 – x} · nH₂O)) have been obtained for the first time and characterized by X-ray diffraction and IR spectroscopy. It is found that a common feature of TP/PVC and PP/PVC obtained by dry mixing and grinding is the decrease in the number of water molecules for TP and PP in the interlayer space of the structure and their attachment to the PVC amide groups; the differences are related to the specificity of PVC behavior in these systems: mechanodestruction of PVC in PP/PVC40 and different numbers of water molecules in PVC25 and PVC40.     

Phase formation and structural changes in the chromium-silicon system exposed to compressed plasma fluxes

The results of the study of structural and phase transformations in the silicon substrate-chromium coating system exposed to compression plasma fluxes with power densities of 0.3–1.2 GW/m² are discussed. The formation of hexagonal chromium disilicide and an amorphous phase, the growth of silicon dendrites, and the appearance of a chromium-enriched near-surface layer are revealed effects. The mechanisms of structural and phase transformations caused by rapid cooling of a mixed melt and concentration overcooling during solidification are analyzed.     

Local atomic environments and magnetic properties of copper binuclear azomethine complexes

Local atom environment in binuclear chelate Cu(II) complexes on the basis of azomethine ligands was investigated by extended X-ray absorption fine structure spectroscopy. The temperature magnetic measurements indicated ferro- or antiferromagnetic exchange in these complexes. A direct correlation between the character of the exchange magnetic interaction and the type of the ligand coordination in these complexes was established.     

Determination of the size of particles of highly dispersed materials by low temperature nitrogen adsorption

The average size of particles of highly dispersed materials (Al₂O₃, TiO₂, Y₂O₃) is calculated from their specific surface areas. The latter is determined with the analysis of sorption capacity of materials with nitrogen at ?196°C in the ranges of relative equilibrium pressures of 0.05–0.35 (the Brunauer-Emmett-Teller method, BET) and 0.4–0.7 (the comparative method). Good agreement is obtained between results produced with the comparative method and familiar methods of analysis such as scanning and transmission electron microscopy and small-angle X-ray scattering.     

Molecular and crystal structure of liquid crystalline p-octyloxyphenyl p′-pentyloxybenzoate

The crystal and molecular structure of p-octyloxyphenyl p′-pentyloxybenzoate C₅H₁₁-O-C₆H₄-C(O)-O-C₆H₄-O-C₈H₁₇, which forms a nematic mesophase upon melting, was determined by X-ray diffraction. There is one system of weak directional intermolecular C-H…π interactions responsible for the formation of the nematic phase in these crystals.     

Method of acoustic sweep monitoring of oceanic inhomogeneities (Review)

Theoretical grounds of the new method of monitoring of the temporal variability of oceanic inhomogeneities, which uses the data on frequency shifts of interference maxima of the sound field, were described. The method is free of limitations on both the resolution of signals coming in individual modes (rays) and the adiabatic approximation underlying the conventional methods of inhomogeneity reconstruction. The monitoring sensitivity was estimated, which allows us to estimate minimum detectable changes in the speed of sound by measurement data on frequency shifts of local maxima. Experimental data on shifts of the frequency spectrum of a broadband low-frequency signal on a stationary path in a shallow sea were presented. On their basis, the possibility of applying this method to diagnose tidal variations was shown. Within a numerical simulation, model reconstruction of the frequency spectrum of background internal waves was considered on the basis of the data on measurements of the spectrum of frequency shifts of the interference maximum. The results of the spectrum reconstruction with and without focusing of the conjugate wave field are presented. The problems of monitoring stability and efficiency with respect to the interference pattern formed by various groups of modes were discussed.