Computerized technique for the analysis of weak signals in UV Raman scattering from biological molecules

Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 54, No. 5, pp. 717–724, May, 1991.     

Difference in the reaction course in the reactions of nitrosyl chloride with the aminals of N-methylimida-zolidine and N-methylperhydro-1,3-diazine

Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 6, pp. 1465–1466, June, 1991.     

Surface-enhanced Raman scattering spectroscopy of topotecan-DNA complexes: Binding to DNA induces topotecan dimerization

The interaction of topotecan (TPT), antitumor inhibitor of human DNA topoisomerase I, with calf thymus DNA was studied by surface-enhanced Raman scattering (SERS) spectroscopy. The SERS spectra of TPT are found to depend on its concentration in solution, which is associated with the dimerization of TPT. The spectral signatures of dimerization are identified. It is shown that binding to DNA induces the formation of TPT dimers. The formation of DNA-TPT-TPT-DNA complexes is considered as one of the possible mechanisms of human DNA topoisomerase I inhibition.     

A chemical study of the roots ofFerula kopetdagensis

Summary Ferukrin and the new natural compound acetylferukrin C₂₆H₃₄O₆ have been isolated from the roots ofFerula kopetdagensis.The absolute configuration of ferukrin has been established on the basis of the results of a study of chemical and spectral characteristics and also by means of a passage to farnesiferol A.It has been shown that it is an epimer of deacetylkellerin at C₆.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 17–21, January–February, 1979.     

Spectrochemical properties of some explosives in the vapor state

The FTIR spectra of 1,3,5-trinitro-1,3,5-triazacyclohexane (RDX) and pentaerythritol tetranitrate (PETN) in the vapor phase over wide frequency (3500–500 cm^?1) and temperature ranges (293–383 K) is experimentally studied and the assignment of the observed vibrational bands is performed. To clarify the nature of the physicochemical processes that occur during the heating and evaporation of RDX and PETN and to detect and identify their characteristic components, the mass spectra and sub-THz spectra of these explosives are studied. To obtain spectroscopic information, special experimental techniques for recording of IR, sub-THz, and mass spectra of vapors of explosives and for preparation of high-purity RDX and PETN samples (with a main substance content of >99.7%) are developed based on modern methods of synthesis and purification.