Study of binary systems of β-cyclodextrin with a highly potential anti-mycobacterial drug

The present research paper is dedicated to the obtaining and physicochemical characterization of a highly potential anti-mycobacterial drug candidate with β-cyclodextrin (βCD). The active substance is a 1,3,4-oxadiazole derivative, 2-phenyl-5-{[(2-phenyl-1,3-dioxolan-2-yl)methyl]sulfanyl}-1,3,4-oxadiazole, further named DIOX. DIOX–βCD binary systems were obtained as a physical mixture and a lyophilized product with molar ratio between the main components equal to 1:1 and 1:2. The obtained systems were submitted to physicochemical characterization applying the following instrumental methods: infrared spectrometry, differential scanning calorimetry, and X-ray crystallographic analysis. Besides, a molecular modeling analysis has been performed. The research data suggested certain intermolecular interaction between DIOX and βCD, suggesting formation of a three-molecular inclusion complex DIOX:βCD, including one DIOX molecule and two molecules of βCD. The main parts of the DIOX molecule included in the hydrophobic cavity of the cyclodextrin molecules most probably are dioxolane cycle and two benzene rings.     

A simple model for the band structure and D.C. conductivity of an infinite CO···H?N chain perpendicular to the protein backbone

The¹ Hartree–Fock crystal orbital (CO) method in its linear combination of atomic orbitals form was applied to determine the band structure of histone proteins taking 0.041e charge transfer per nucleotide base from the PO groups of poly(guanilic acid) to the arginine, and lysine side chains in histones (see text). Assuming that there are infinite COs, perpendicular to the main chain, formed by the amide groups of one segment of the protein chain bound together by H‐bonds with the C?O groups of another segment of the chain, we have calculated the band structure. From this, we have determined the mobility using the deformation potential approximation. Multiplying this with the mobile electron concentration due to the charge transfer between the PO groups of DNA and the positive side chains in histones, we have obtained for the direct current (D.C.) electron conductivity σ_fib = 1.07 × 10^?9 Ω^?1 cm for a single fiber and after division by the cross‐section of 9.10 × 10^?16 cm², σ_spec = 1.18 × 10⁶ Ω^?1 cm^?1 for the specific conductivity. © 2008 Wiley Periodicals, Inc. Int J Quantum Chem, 2009     

Rinder-Prothrombin-Pr?parate

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Analyse von biologischem Material

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Eine verbesserte Gradientenelution zur Trennung der Steroid-Konjugate des Schwangerenharns an DEAE-Sephadex

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Hydroxams?uren als colorimetrische Reagentien

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Stereochemistry of cycloadducts from 3,4-dihydro-6,7-dimethoxyisoquinoline ylide and olefins

Cycloaddition of 2-methoxycarbonylmethyl-3,4-dihydro-6,7-dimethoxyisoquinolinium ylide with various E-substituted olefin type dipolarophiles gave products of 10b-H, 1-H, 2-H and 3-H α,α,β,β-relative configuration with one exception. Relative configuration of compounds prepared has been determined by 1D and 2D ¹H and ¹³C nmr techniques. It has also been detected that a triple trans ? cis-1 ? cis-2 conformation equilibrium exists in solution.