Synthesis and Antiviral Activity of Modified 5α-Steroids

Chemistry of Natural Compounds -     

Chemical modification of oximes with N-protected amino acids

The modification of oximes, including 5α-steroids, with N-protected amino acids, in solution phase, using benzotriazole methodology is reported.     

Conversion of Epiandrosterone Into 17β-Amino-5α-androstane

A new method for synthesizing 17-amino-5-androstane was developed based on tigogenin. The configuration at C-17 was proved by PMR.     

Formation and properties of composite coatings on aluminum alloys

A study was made into the morphology, composition, and electrochemical and mechanical properties of protective composite coatings on various aluminum alloys, including those doped with Sc, Cu, and Ni. It was established that protective coatings significantly increase the corrosion resistance of the alloys in a 3% NaCl solution. Composite coatings produced by triple dip coating in an superdispersed polytetrafluoroethylene suspension have unique corrosion-resistance properties, reducing the corrosion current density for all the protected alloys to 3.1 × 10^–11–4.0 × 10^–12 A/cm², which is more than three orders of magnitude lower than that for coatings formed by plasma electrolytic oxidation and five orders of magnitude lower than that for alloys without coating.     

Synthesis and antituberculosis activity of several steroids from 3<Emphasis Type="Italic">β</Emphasis>-acetoxy-5<Emphasis Type="Italic">α</Emphasis>-pregn-16-en-20-one

The semicarbazone and isonicotinoylhydrazone of 5α-pregn-2-en-20-one, which was prepared from 3β-acetoxy-5α-pregn-16-en-20-one, were synthesized for the first time. The antituberculosis activity of these and semicarbazones and isonicotinoylhydrazones of saturated, unsaturated, and adamantane-modified ketosteroids synthesized by us earlier was studied in vitro experiments.