Synthesis and biological properties of a tryptophan-containing fragment of a myelin protein and its analogs

Summary 1. By the azide condensation of fragments followed by the hydrogenolysis of the completely protected nonapeptides formed, the encephalitogenic nonapeptides with the structure Phe-Ser-Try-Gly-Ala-Glu-Gly-Gln-Arc and two of its analogs — the 6-glycine and 5,6-diglycine compounds, have been synthesized.2. It has been shown that the 6-glycine analog induces EAE, i.e., the side chain in position 6 is not essential for the appearance of EAE activity.3. The absence of an encephalitogenic effect in the 5,6-diglycine analog permits the conclusion that the side chain of the alanine-5 makes a contribution to the induction of the disease.4. The N-acetyl derivative of the encephalitogenic nonapeptide retains a high EAE activity.Institute of Molecular Biology and Genetics, Academy of Sciences of the Ukrainian SSR, Kiev. A. V. Palladin Institute of Biochemistry, Academy of Sciences of the Ukrainian SSR, Kiev. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 507–517, July–August, 1976.     

Phytoecdysones ofSerratula xeranthemoides

Summary Ecdysterone and integristerone A have been isolated from the inflorescences ofSerratula xeranthemoides.The amount of these phytoecdysones in the flower heads increases as the plant ripens, reaching a maximum for ecdysterone in the full-flowering phase and for integristerone A at the end of the flowering phase and the beginning of fruit formation.A. V. Palladin Institute of Biochemistry, Academy of Sciences of the Ukrainian SSR, Kiev. Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 171–174, March–April, 1979.     

Photoproduction of homogeneous chromium(V) compounds in pentanol for targets containing polarized hydrogen nuclei

Measurements have been made on photochemical and subsequent dark reactions with an He-Cd laser (44l nm) with ammonium dichromate solutions in pentanol. Exposing the solution directly in the spectrometer cavity leads to an ESR signal having g = 1.973 characteristic of chromium(V) compounds. The compounds have been examined by ESR and optical spectroscopy. A kinetic analysis is presented. It is suggested that homogeneous Cr(V) compounds are formed. No Cr(III) or other paramagnetic products have been detected. These compounds can be used in polarized nuclear targets.Joint Nuclear Research Institute, Dubna. Pisarzhevskii Physical Chemistry Institute, Academy of Sciences of the Ukrainian SSR, Kiev. Translated from Teoreticheskaya i Éksperimental' naya Khimiya, No. 1, pp. 60–65, January–February, 1991. original article submitted November 17, 1987.     

A new method for the purification and determination of the total alkaloids in a culture of Rauwolfia tissue

Institute of Molecular Biology and Genetics, Academy of Sciences of the Ukrainian SSR, Kiev. Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 148–149, January–February, 1991.     

Synthesis and physicochemical and encephalitogenic properties of analogs of a tryptophan-containing fragment of myelin protein

Summary 1. Analogs of the encephalitogenic nonapeptide with the substitution of glycine in the first and in the first and second positions and also with the deletion of the glutamic acid residue and the insertion of a glycine residue between the fifth and sixth positions have been synthesized.2. An investigation of the encephalitogenic activity of the compounds synthesized has shown the necessity for a hydrophobic N-terminal amino acid, since the replacement of phenylalanine by glycine leads to the inactivation of the compound. A change in the length of the encephalitogenic determinant also leads to the loss of EAE activity.3. The CD spectra of the peptides synthesized are identical in water, a 1% solution of SDS, and an 8 M solution of urea and do not change on heating to 50°C. It is obvious that under the conditions mentioned these compounds do not possess an ordered structure of the -helical type of a structure, and their dichroic absorption is due to the contribution of the aromatic side chains.Institute of Molecular Biology and Genetics, Academy of Sciences of the Ukrainian SSR, Kiev. A. V. Palladin Institute of Biochemistry, Academy of Sciences of the Ukrainian SSR, Kiev. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 842–849, November–December, 1977.     

Application of the chugaev reaction for the quantitative determination of ecdysones

Summary The spectrophotometric characteristics of the products of the Chugaev reaction with ecdysones have been studied. Methods have been proposed for determination of ecdysterone and viticosterone E in an artificial mixture and of ecdysterone in extracts of plant raw material by thin-layer chromatography followed by the Chugaev reaction.A. V. Palladin Institute of Biochemistry, Academy of Sciences of the Ukrainian SSR, Kiev. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 227–230, March–April, 1977.     

Immobilization of the protease ofBacillus mesentericus on Silochromes

The immobilization of the protease ofBacillus mesentericus on Silochrome using cyanuryl chloride, 2,4-toluylene diisocyanate, glutaraldehyde, thionyl chloride, phosphorus tribromide, titanium tetrachloride, and zirconium and hafnium oxychlorides as cross-linking reagents has been studied. The greatest binding and retention of activity were observed with the use of transition-metal salts. A comparison of the properties of the native and immobilized preparations has been made. The stability of the immobilized protease on storage and repeated use has been investigated.Physicochemical Institute, Academy of Sciences of the Ukrainian SSR, Odessa. Institute of Microbiology Academy of Sciences of the Ukrainian SSR, Kiev. Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 104–109, January–February, 1980.     

Determination of the relative reactivities of reactants in competitive heterogeneous-catalytic reactions with irreversible initial steps

A simple method for determining the relative reactivities of the reactants in competitive heterogeneous-catalytic reactions, the initial steps of which are irreversible and include the same number of identical surface intermediates, is proposed.L. V. Pisarzhevskii Institute of Physical Chemistry, Academy of Sciences of the Ukrainian SSR, Kiev.Translated from Teoreticheskaya i Éksperimental'naya Khimiya, Vol. 27, No. 2, pp. 228–230, March–April, 1991. Original article submitted September 3, 1990.     

Electronic structure of lanthanides in orthoborates with various structures

Institute of Chemistry, Ural Branch, Academy of Sciences of the USSR. A. V. Bogatskii Physicochemical Institute, Academy of Sciences of the Ukrainian SSR. Translated from Zhurnal Strukturnoi Khimii, Vol. 32, No. 1, pp. 26–33, January–February, 1991.     

New catalytic reaction: Oxidative condensation of methane to cyclopropane

During the oxidative dimerization of methane on a titanium silicide catalyst, a cyclic hydrocarbon, cyclopropane, was detected in the reaction products together with C₂ and C₃ open-chain hydrocarbons.L. V. Pisarzhevskii Institute of Physical Chemistry, Academy of Sciences of the Ukrainian SSR, Kiev. Translated from Teoreticheskaya i Éksperimental'naya Khimiya, Vol. 27, No. 2, pp. 231–232, March–April, 1991. Original article submitted November 14, 1990.