Investigation of the globulins of cotton seeds VIII. Chymotryptic hydrolysis of the 7S-globulin. Isolation and purification of a chymotryptic peptide

Summary From a chymotryptic hydrolyzate of the CM-7S-globulin of cotton seeds we have isolated and characterized in relation to amino-acid composition and N-terminal amino acids 65 homogeneous peptides, 38 of which contain arginine or lysine residues and are overlapping.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 560–566, July–August, 1977.     

Heteromolecular insertion of EtNCX (X = O, S) and RCN (R = CH3, C6H5) into tungsten hexachloride

The interactions of tungsten hexachloride with EtNCX (X = O, S) and RCN (R = CH₃, C₆H₅) were studied. In the case of E = CH₃, heterocumulenes are inserted at the W-Cl bond, while in the case of R = C₆H₅, they were inserted at a multiple tungsten-nitrogen bond of an intermediate imido complex [WCl₄(NCPh)(CNCl₂Ph)]. The IR, MALDI TOFF mass spectroscopy, and elemental analysis data confirmed that these interactions yielded the products of heteromolecular insertion, namely, [WCl₄{(EtNCO)₂(MeCN)Cl}], [WCl₄(EtNCS)₂(MeCN)Cl], [WCl₄N(CCl₂Ph)C(=NEt)O}], and WCl₄N(CCl₂Ph)C(=NEt)S}], whose compositions and structures were determined by the nature of the organic nitrile radical.     

Imidazo[1,2-α]quinoxaline and its transformations

7-Substituted imidazo [1,2-a]quinoxalines were synthesized. Transformations of compounds of this series — quaternization, reduction to 4,5-dihydro derivatives, and behavior toward oxidizing agents — were studied.See [1] for communication I.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1558–1560, November, 1972.     

Study of acid-modified aluminum oxides produced by centrifugal thermal activation in dehydration of ethanol

Possibility of using products formed in centrifugal thermal activation of hydrargillite to obtain alumina catalysts washed to remove admixtures of alkali metals was considered. A comparison of the physicochemical and catalytic properties of the samples demonstrated that washing with water is more favorable than that with nitric acid; the catalytic activity and acid-base properties of the catalyst surface are determined not only by the content of Na, but also by the whole set of catalyst preparation conditions. The most active of the samples obtained in the study has acidity close to that of industrial aluminum oxide produced by the reprecipitation method, but surpasses it in activity: at 370°C, the total yield of ethylene and diethyl ether reaches a value of 88.8 mol %, which is 4% higher than that for the reference sample.     

Pericyclic reactions in the synthesis of new 5-aryl-5,6-dihydroquinolino[2,1-b]quinazolin-12-ones

1. Download high-res image (52KB)
2. Download full-size image

     

Temperature dynamics of triglycine sulfate domain structure according to atomic force microscopy and dielectric spectroscopy data

A hydrogen-containing ferroelectric triglycine sulfate (TGS) was comprehensively studied with an atomic force microscopy (AFM) and dielectric spectroscopy. The domain structure dynamics was in situ investigated with piezoresponse force microscopy (PFM) during heating and cooling the TGS crystal near phase transition. Relaxation dependencies of domain boundaries general perimeter and domain dimensions were obtained. TGS dielectric spectra measured at the frequency range from 10 to 10¹¹ Hz were analyzed on basis of significant contribution of conductivity into the dielectric response of ferroelectrics and a good agreement with the experimental data was received. It allows us to obtain more information about temperature dynamics of the domain structure.     

X-ray spectroscopy of thermally distorted electronic states in crystals

A new type of x-ray spectroscopy is proposed which can detect the thermal-motion-induced distortions of atomic electronic states in crystals. It is shown that those distortions can cause extra Bragg reflections (so-called forbidden reflections) and that their intensity should grow with increasing temperature. The reason is that the thermal displacements, which change the symmetry of atomic environment, can modify the tensor amplitude of x-ray resonant scattering. In the first approximation, the structure factor of extra reflections is proportional to the reflection vector H and to the mean-square thermal displacement for optical phonons. It is demonstrated that the forbidden resonant reflections, observed recently in Ge, could be caused by the thermal motion. Pis’ma Zh. éksp. Teor. Fiz. 69, No. 12, 885–889 (25 June 1999) Published in English in the original Russian journal. Edited by Steve Torstveit.     

Vladimir Evgen’evich Dmitrienko (On the occasion of his 60th birthday)

Crystallography Reports -