(N,N-diethylamino)alkoxy derivatives of phenanthrolines asDNA binding agents

The interaction of the tricyclic angular azaaromatic system having positive charged side chains withDNA, influence of molecular structure of the ligand on the mode of noncovalent binding, and stability of the complex formed were established. Several (N,N-diethylamino)alkoxy derivatives of 1,7-, 1,8-, 1,10- and 4,7-phenanthroline in the protonated form were used as ligand. The electronic and steric factors were shown as responsible for the electrostatic and intercalative interactions of the ligand withDNA. The syntheses of (N,N-diethylamino)alkoxy derivatives from parent phenanthrolines were elaborated.

---

(N,N-Diethylamino)alkoxy-phenanthrolinverbindungen als DNA Bindungsagentien

Zusammenfassung Die Wechselwirkung von trizyklischen, azaaromatischen Systemen mit positiver Ladung an Seitenketten mitDNA, der Einfluß der molekularen Struktur des Liganden bei nonkovalenter Bindung und die Stabilität des gebildeten Komplexes wurde bestimmt. Als Liganden wurden mehrere (N,N-diethylamino)alkoxy-Verbindungen von 1,7-, 1,8-, 1,10- und 4,7-Phenanthrolin in protonierter Form benutzt. Es wurde gezeigt, daß die elektronischen und sterischen Faktoren für elektrostatische und intercalative Wechselwirkungen des Ligand undDNA verantwortlich sind. Es wurden Synthesen von (N,N-diethylamino)alkoxy-phenanthrolinen aus entsprechenden Chlorverbindungen ausgearbeitet.

     

An efficient route to 4-(substituted benzyl)piperidines

A novel approach to 4-(substituted benzyl)piperidines has been developed. The key steps involve the cyclization of imines bearing an allylsilane in the side-chain followed by the palladium-catalyzed cross-coupling of the resulting 4-methylenepiperidine with organoboronic acids under an atmosphere of oxygen.     

Thermal behavior of α-(Cu–Al–Ag) alloys

Thermal behavior of α-(Cu–Al–Ag) alloys, i.e. alloys with composition less than about 8.5 mass% Al, was studied using differential scanning calorimetry (DSC), differential thermal analysis (DTA), scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDX) and X-ray diffractometry (XRD). The results indicated that the presence of silver introduces new thermal events ascribed to the formation of a silver-rich phase and, after addition higher amounts than 8 mass% Ag to the Cu–8 mass% Al alloy it is possible to observe the formation of the γ₁ phase (Al₄Cu₉), which is only observed in alloys containing minimum of 9 mass% Al. These results may be attributed to some Ag characteristics and its interaction with Cu and Al.     

HPTLC-densitometric method of determination of oleanolic acid in the Lamii albi flos

HPTLC combined with densitometric method was used to determine the content of oleanolic acid in acetone extract from the Lamii albi flos L. The plant extract was separated on Si 60 HPTLC plates and determined with the use of two densitometric methods: measurement of fluorescence and absorbance. The content of oleanolic acid was statistically calculated. In a measurement of absorbance in 1 g of the dry Lamii albi flos L. 1458 microg of oleanolic acid was determined (0.147%). In a fluorescence method in 1 g of the plant material 1516 microg of oleanolic acid was determined (0.149%).     

Magnesium selective electrodes for blood serum studies and water hardness measurement

Magnesium selective ionophores are described which induce a rejection of Na⁺ and K⁺ in solvent polymeric membranes by factors of up to 6300 and 5000, respectively. Depending on the membrane composition, ion selective electrodes may be obtained with equal selectivity for Mg²⁺ and Ca²⁺ as well as sensors with a discrimination of Ca²⁺ by a factor up to 8. Sensors of the type described are candidates for water hardness determination as well as for an Mg²⁺ assay in blood by chemometric procedures.On leave from the Chemistry Department, University of Warsaw, ul. L. Pasteura 1, PL-02-093 Warsaw, PolandOn leave from the Shanghai University of Technology, 149 Yanchang Road, Shanghai, People's Republic of China     

Polarizable continuum model study of solvent effects on electronic circular dichroism parameters

We present an implementation of the polarizable continuum model for the calculation of solvent effects on electronic circular dichroism spectra. The computational model used is density functional theory in the length-gauge formulation, and gauge-origin independence is ensured through the use of London atomic orbitals. Results of calculations carried out for methyloxirane and bicyclic ketones, camphor, norcamphor, norbornenone, and fenchone are presented, and the theoretically obtained solvent effects are compared with experimental observations.     

Synthesis and spectroscopic characterization of palladium(II) complexes with 6,8-dimethylimidazo[1,5- a ]-1,3,5-triazin-4( 3H )-one and 6,8-dimethyl-2-thioxo-2,3-dihydroimidazo-[1,5- a ]-1,3,5-triazin-4( 1H )-one

The preparation and spectroscopic study (¹H, ¹³C, ¹⁵NNMR, ¹³CP MAS NMR, IR) of new Pd^II complexes with 6,8-dimethylimidazo[1,5-a]-1,3,5-triazin-4(3H)-one (6,8-DiMe-4-O-IMT) (1) and 6,8-dimethyl-2-thioxo-2,3-dihydroimidazo[1,5-a]-1,3,5-triazin-4(1H)-one (6,8-DiMe-4-O-2-S-IMT) (2) is reported. The spectroscopic data indicate a square planar geometry with two N(7) bonded heterocycles and two cis-chloride anions. The final product of the thermal decomposition of cis-PdCl₂(6,8-DiMe-4-O-IMT)₂ (3) is metallic Pd, whereas for cis-PdCl₂(6,8-DiMe-4-O-2-S-IMT)₂ (4) it is metallic Pd plus C.     

Highly selective synthesis of 1-(silyl)-1-(boryl)ethenes via a ruthenium-catalyzed silylative coupling reaction

An efficient silylative coupling of trisubstituted vinylsilanes with dialkoxy(vinyl)boranes is described. Under optimum conditions the reaction offers a selective route to 1-(silyl)-1-(boryl)ethenes, which are potentially attractive intermediates in organic synthesis     

Spectroscopic methods of studying enzyme action in wool fibre

Enzymes may be used to develop an environmentally friendly alternative to the conventional polluting technologies in textile finishing. The action of the unlabeled and fluorescent labeled proteolytic enzymes subtilisin and trypsin on wool was examined. Scanning electron micrographs and a diffusion study, based on fluorescence microscopy, localized the enzymatic attack on the fiber. A kinetic study was carried out by monitoring the amino acid content of the treatment liquor. Enzymatic action is not confined to the fiber surface. To limit attack to the surface and reduce wool damage new treatment methods such as enzyme immobilization onto a solid carrier must be investigated.     

Synthesis and Reactivity of 2,2,4,4–Tetrakis(tri–tert–butoxysilanethiolato)–1,3,2,4–dithiadistannetane – Crystal and Molecular Structures of Two Polymorphic Forms

The title compound, [Sn(μ–S){SSi(O^tBu)₃}₂]₂ ( 1 ), containing four–coordinated tin(IV), crystallizes in two polymorphic modifications. The orthorhombic 1a –form has been obtained in the reaction of (^tBuO)₃SiSH and Et₃N with SnCl₂, whereas the triclinic 1b –form in the reaction with SnCl₄ as substrate. The crystal and molecular structures of both polymorphs ( 1a as a redetermination) have been determined by a single–crystal X–ray diffraction study at room temperature. The title compound was shown to react with ammonia and ammonia complexes of some d–block metal cations giving products of Sn–S bond cleavage.