Electrical and Dielectric Characteristics of BiSmO3

Physics of the Solid State - The synthesis of the perovskites BiSmO3 was done by the solid-state reaction method. In this communication, the structural and detailed electrical (dielectric,...     

Measurement of the neutrino mass splitting and flavor mixing by MINOS

Measurements of neutrino oscillations using the disappearance of muon neutrinos from the Fermilab NuMI neutrino beam as observed by the two MINOS detectors are reported. New analysis methods have been applied to an enlarged data sample from an exposure of 7.25×10(20) protons on target. A fit to neutrino oscillations yields values of |Δm(2)|=(2.32(-0.08)(+0.12))×10(-3) eV(2) for the atmospheric mass splitting and sin(2)(2θ)>0.90 (90% C.L.) for the mixing angle. Pure neutrino decay and quantum decoherence hypotheses are excluded at 7 and 9 standard deviations, respectively.     

Triterpenoids from plants of the genus Tamarix

The taraxeran-14-ene-type triterpenoids methyl 3-β-al-D-fridoolean-14-en-28-oate (1), 3-α-[3″,4′-dihydroxytrans-cinnamoyl]-oxy-D-fridoolean-14-en-28-oic acid (2), and β-sitosterol (3) were isolated from the aerial part of plants from the genus Tamarix (T. laxa, T. elongata) (Tamaricaceae). The structures of the triterpenoids were proved using spectral data (IR, UV, PMR, ¹³C NMR, 2D NMR ¹H-¹H COSY, HMQC, HMBC, mass). Compound 1 is new and not previously described in the literature. __________ Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 271–273, May–June, 2006.     

Phosphodiesterase‐Inhibiting Glycosides from Symplocos racemosa

Phytochemical investigation of Symplocos racemosa resulted in the isolation of two new glycosides, symploracemoside ( 1 ) and symplomoside ( 2 ), which are structurally related to the reported benzoylsalireposide ( 3 ) and salireposide ( 4 ). The structure elucidation of the isolated compounds was based primarily on 1D‐ and 2D‐NMR analysis, including COSY, NOESY, HMQC, and HMBC correlations. These glycosides showed inhibitory activity against snake‐venom phosphodiesterase I.     

Synthesis and Characterization of Diphenyltin(IV) Dicarboxylates Containing Germanium

Twelve new germanium substituted diphenyltin dipropionates with the general formula (R¹GeCHR²‐CHR³COO)₂SnPh₂ where R¹ = N(CH₂CH₂O)₃, (C₆H₅)₃ and (CH₃C₆H₄)₃, R² = H, CH₃, C₆H₅, p‐CH₃C₆H₄, p‐CH₃OC₆H₄, p‐ClC₆H₄, and R³ = H, CH₃ have been synthesized by the reaction of diphenyltin oxide with a germanium substituted propionic acid. All the compounds were characterized by elemental analysis, IR, multi‐nuclear (¹H, ¹³C, ¹¹⁹Sn) NMR and Mössbauer spectroscopies as well as mass spectrometry. The in vitro antibacterial activity of selected compounds is also reported.     

Phase Transfer Catalysed N-Monoalkylation of Amino Anthraquinones

1-Alkylaminoanthraquinones ( 2 a-f) and 1,4-bisalkylaminoanthraquinones ( 4 a-c) were prepared from aminoanthraquinones ( 1,3 ) by alkylation with alkyl sulphate/alkyl halide in presence of powdered sodium hydroxide, potassium carbonate and phase transfer catalyst.     

Structure determination of bioactive galloyl derivatives by NMR spectroscopy

The investigation of the chemical constituents of Symplocos racemosa Roxb led to the isolation of two new glycosides, symcomoside A (1) and symcomoside B (2), together with one known glycoside, tortoside C (3), which is reported for the first time from this plant. The structures of the new compounds were determined by 1D and 2D homonuclear and heteronuclear NMR spectroscopy, from chemical evidence and by comparison with published data for closely related compounds. Symcomoside B (2) showed potent inhibitory activity against alpha-glucosidase in a concentration-dependent fashion with an IC50 value of 0.733 +/- 0.033 mM whereas symcomoside A (1) showed very weak inhibitory activity against alpha-glucosidase (9.90% in 0.70 mM).