Controlling the intrachain segregation on a single DNA molecule

Intrachain segregation in single DNA molecules induced by quaternary ammonium dications was studied. By means of fluorescent and electron microscopy, it was found that variations in the chemical structure of condensing agents provide one with the opportunity to control the average amount of intrachain segregation centers on the DNA single chain. The manner of interaction between the diammonium molecules was considered to be the key factor for controlling the morphology of the partially collapsed DNA molecules.     

Flavonoid glycosides from Aconitum baicalense

Two known flavonoids, the 7-O-α-L-rhamnopyranosides of kaempferol and of quercetin, and also the new acylated glycoside quercetin 3-O-[O-(6-caffeoyl-β-D-glucopyranosyl)-(1→2)-β-D-glucopyranoside 7-O-α-L-rhamnopyranoside (czekanoside A) have been isolated from the epigeal part ofAconitum baicalense Turcz, ex Rapaics (A. Czekanovskyi Steinb.). Their structures have been demonstrated by the methods of IR, UV,¹H, and¹³C NMR spectroscopies and FAB mass spectrometry and also with the aid of acid hydrolysis.     

Chemical and x-ray structural investigation of a new diterpene lactone betolide

A crystalline substance with the composition C₂₀H₂₄O₅ has been isolated from the roots of common betony. The spatial structure of this new diterpene lactone, betolide, has been established from the results of UV, IR, NMR, and¹³C NMR spectral and x-ray structural investigations — 13-formyl-14-hydroxy-(2-hydroxy-5-oxotetrahydrofuro) [3,4:11,12]-^8,10,12-podocarpane, the first representative of new tetracyclic diterpenes the lactone ring of which is formed with the participation of a hydroxyl of a geminal diol. The stability of a lactone ring of this type and a high reactivity of the semiacetal hydroxyl have been shown.Institute of Chemical Sciences, Kazakhstan SSR Academy of Sciences, Alma-Ata. Division of the Institute of Chemical Physics, USSR Academy of Sciences, Chernogolovka. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 811–817, November–December, 1987.     

Question of the reverse polarization of triple bonds

Irkutsk State University. Translated from Zhurnal Strukturnoi Khimii, Vol 32, No. 1, pp. 73–79, January–February, 1991.     

Acid-base properties of poly(1-vinylazoles) in aqueous solution

The interaction of poly(1-vinylimidazole) and poly(1-vinyl-1,2,4-triazole) with HCl and alkalies in aqueous and water-salt solutions was investigated by potentiometric titration, viscosimetry, ¹H and ¹³C NMR, and UV spectroscopy. The effect of the nature and concentration of low-molecular counterions was found. The interaction of poly(1-vinylazoles) with the acid results in the protonation of the azole cycle. The interaction of poly(1-vinylazoles) with alkalies is stipulated by the capability of the pyridine N atom of forming a coordination bond with the metal ion and that of the unsaturated pi-system of the heterocycle of coordinating with the anions.     

Oxidation of soap chips and antioxidative stabilization with phenolic inhibitors

The initiation of free radicals and oxidizability of soap chips were studied by the methods of inhibited and initiated oxidation. A scheme accounting for the effect of phenolic inhibitors (with Ionol and 2-ethylhexyl gallate as examples) was suggested. The kinetic parameters of the main reactions determining the inhibiting activity of these additives were found.     

Searches for the pentaquark states Ξ(1860)0 and Ξ(1860)−− in neutron-carbon interactions via the EXCHARM experiment

Results of searches for the pentaquark states Ξ(1860)⁰ and Ξ(1860)^?? in neutron-carbon interactions at an average neutron energy of about 51 GeV via the EXCHARM experiment are presented. No such states are found in the Ξ^? π ⁺ and Ξ^? π ^? effective-mass spectra examined in this study. Upper limits on the cross sections for Ξ(1860)⁰ and Ξ(1860)^?? production are estimated.     

Study of a three-dimensional turbulent boundary layer with allowance for coupled heat transfer

Translated from Zhurnal Prikladnoi Mekhaniki i Tekhnicheskoi Fiziki, No. 3, pp. 118–124, May–June, 1989.