Synthesis and biological activity of certain amino-derivatives of 5α-steroids

Certain 17β-aminoderivatives of 5α-steroids based on tigogenin were synthesized and their antitumor activity was studied. The structures of the synthesized compounds were confirmed by NMR and IR spectroscopy and mass spectrometry. __________ Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 263–265, May–June, 2006.     

Distinctive features of nonlinear nuclear magnetic resonance

Nonlinear NMR modes are classified and the limits of realization are established for each of them. The unstable behavior of magnetization near the separatrix of relaxationless motion of nonlinear NMR is studied and ways of stabilizing this instability are considered.Tbilisi State University. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 34, No. 7, pp. 731–737, July, 1991.     

Synthesis and antituberculosis activity of certain steroidal derivatives of the 5<Emphasis Type="Italic">α</Emphasis>-series

The antituberculosis activity of several steroidal compounds of various structure was studied. Severa compounds that were active toward M. tuberculosis were found in in vitro tests. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 500–501, September-October, 2008. Original article submitted July 10, 2008.     

Synthesis of 17α-amino-5α-androst-2-ene from epiandrosterone

17α-Amino-5ga-androst-2-ene was synthesized from epiandrosterone via formation of the tosylate followed by nucleophilic substitution by azide and reduction with LiAlH₄. The structures of the products were proved by NMR and IR spectroscopy and mass spectrometry. __________ Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 257–258, May–June, 2006.     

Synthesis and antimycobacterial activity of some steroidal derivatives of tigogenin

Some 5α-type steroidal derivatives of the steroidal sapogenin tigogenin were synthesized. The structures of the synthesized derivatives were characterized by spectral methods and elemental analysis. The antituberculosis activity of the compounds toward Mycobacterium tuberculosis strain H37Rv was studied in vitro (Microplate Alamar Blue Assay) in BACTEC 12B medium and was compared with that of isoniazide. Some of the synthesized compounds exhibited high (92-98%) antimycobacterial activity. Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 332-334, May-June, 2009.