Synthesis and contractile activity of substituted 1,2,3,4-tetrahydroisoquinolines

A series of different 1-monosubstituted and 1,1-disubstituted 1,2,3,4-tetrahydro-isoquinolines was synthesized in high yields from different ketoamides. We have developed a convenient method for the synthesis of disubstituted derivatives by interaction of ketoamides with organomagnesium compounds, followed by cyclization in the presence of catalytic amounts of p-toluenesulfonic acid (PTSA). A number of substituents at the C-1 in the isoquinoline skeleton were introduced varying either carboxylic acid or organomagnesium compound. Some of the obtained 1,1-dialkyl-1,2,3,4-tetrahydro-isoquinolines possess contractile activity against guinea pig's gastric smooth muscle preparations.     

Probabilistic assessment of biodegradability based on metabolic pathways: CATABOL System

A novel mechanistic modeling approach has been developed that assesses chemical biodegradability in a quantitative manner. It is an expert system predicting biotransformation pathway working together with a probabilistic model that calculates probabilities of the individual transformations. The expert system contains a library of hierarchically ordered individual transformations and matching substructure engine. The hierarchy in the expert system was set according to the descending order of the individual transformation probabilities. The integrated principal catabolic steps are derived from set of metabolic pathways predicted for each chemical from the training set and encompass more than one real biodegradation step to improve the speed of predictions. In the current work, we modeled O 2 yield during OECD 302 C (MITI I) test. MITI-I database of 532 chemicals was used as a training set. To make biodegradability predictions, the model only needs structure of a chemical. The output is given as percentage of theoretical biological oxygen demand (BOD). The model allows for identifying potentially persistent catabolic intermediates and their molar amounts. The data in the training set agreed well with the calculated BODs ( r 2 =0.90) in the entire range i.e. a good fit was observed for readily, intermediate and difficult to degrade chemicals. After introducing 60% ThOD as a cut off value the model predicted correctly 98% ready biodegradable structures and 96% not ready biodegradable structures. Crossvalidation by four times leaving 25% of data resulted in Q 2 =0.88 between observed and predicted values. Presented approach and obtained results were used to develop computer software for biodegradability prediction CATABOL.     

Hydrogen bond and exchange interaction in the (CuSO<Subscript>4</Subscript>)(en)·2H<Subscript>2</Subscript>O and (CuSO<Subscript>4</Subscript>)(en)·2D<Subscript>2</Subscript>O organometallic compounds

The influence of the replacement of hydrogen with deuterium in molecules of water of crystallization in the structure of the (CuSO₄)(en) · 2H₂O and (CuSO₄)(en)·2D₂O organometallic compound molecules on exchange interaction between copper ions was studied. The X-ray structural data and the data on angular anisotropy of the effective g-factor of Cu²⁺ ions in both compounds show that distortions of the initial structure caused by deuteration are minimum. A comparative analysis of the width of the exchange coupled EPR lines of the two compounds is indicative of a decrease in the exchange parameter in the deuterated sample, which substantiates the participation of H-bonds in exchange interactions in the systems studied.     

Stability of the Minimizers of Least Squares with a Non-Convex Regularization. Part II: Global Behavior

We address estimation problems where the sought-after solution is defined as the minimizer of an objective function composed of a quadratic data-fidelity term and a regularization term. We especially focus on non-convex and possibly non-smooth regularization terms because of their ability to yield good estimates. This work is dedicated to the stability of the minimizers of such piecewise C^m, with m ≥ 2, non-convex objective functions. It is composed of two parts. In the previous part of this work we considered general local minimizers. In this part we derive results on global minimizers. We show that the data domain contains an open, dense subset such that for every data point therein, the objective function has a finite number of local minimizers, and a unique global minimizer. It gives rise to a global minimizer function which is C^m-1 everywhere on an open and dense subset of the data domain.     

Investigation of solid sample microhomogeneity by laser microanalysis

Summary The microhomogeneity of the distribution of doped neodymium in YAG:Nd³⁺ single crystals and of impurities in an aluminium alloy standard are studied by means of laser emission microanalysis. The applied statistical methods are briefly described: one-way variance analysis, two-way variance analysis, calculation of regression models of the element concentration distribution in samples, gradient method and cluster analysis.

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Untersuchung der Mikrohomogenität fester Proben durch Laser-Mikroanalyse

     

Spectroscopic Elucidation of the Coordination Ability of 2-Oxo-2H-Chromene-3-Phosphonic Acid with Pt(II)

The coordination ability of 2-oxo-2H-chromene-3-phosphonic acid with Pt(II) both in solution and in solid state is elucidated by means of conventional and linear-polarized IR spectroscopy of oriented colloid suspensions in nematic liquid crystal, ¹H-, ¹³C-, and ³¹P-NMR, UV-Vis spectroscopy, positive and negative mass spectrometry (ESI and FAB), and TGV and DSC methods. A comparison with the spectroscopic data of ammonium salt of 2-oxo-2H-chromene-3-phosphonic acid is carried out as well.     

Synthesis,thermal investigations and kinetic data of Zn(BF<Subscript>4</Subscript>)<Subscript>2</Subscript>·6H<Subscript>2</Subscript>O

The thermal dehydration and decomposition of Zn(BF₄)₂·6H₂O have been studied by TG, DTA and DSC analyses. It is found that the dehydration occurs in two steps. Following the experimental results a thermal decomposition scheme of the compound under investigation is proposed. The enthalpies of dehydration have been determined as well as the formal kinetic parameters are presented.