Synthesis, characterization, physical and biological properties of some cholesterol derivatives

Abstract

A series of new cholesterol derivatives have been prepared via Mitsunobu reaction. The reaction was monitored by thin-layer chromatography (TLC) technique. All new compounds were characterized by melting points, elemental analysis, FT-IR, 1 H, 13 C and 2D-NMR spectroscopy. The antibacterial and antifungal activity of these derivatives was also determined. The phase transitions of the prepared derivatives were measured with the aid of differential scanning calorimetry. The textures of the mesophases have been determined with a hot stage equipped polarizing microscope, also the electrical conductivity of the solutions of these liquid crystals measured by electrical conductivity meter. The analysis showed that these prepared derivatives were liquid crystals.

Synthesis, Identification and Biological Activity of Some New Chalcone derivatives from 8-Chlorotheophylline

“…8-CTh was a starting material for the synthesis of new chalcone compound over a reaction with (P-amino acetophenone) scheme 1. The appearance of stretching band of secondary aromatic amine (NH) at (3361) cm -1 and disappearance of C-Cl of 8-CTh at (760) cm -1 , and showed-1 H-NMR spectrum for N-H 14.54 (s, br,1H, NH), are attributed to the formation amine compound. 13 C-NMR spectrum for 24.6 (Me), 113.9 (C2´+ 6´ ), 127.3 (C4´), 131 (C3´+5´), 143.8 (C1´ ) 16 . The reaction of S1 compond with different aromatic aldehydes in the presence NaOH to formation chalcone in scheme 2 showed appearance of the band 1516, 1589 17 .…”