Synthesis And Characterization Of Novel Cationic Lipids Deriving From Stigmasterol

Amphiphilic cationic lipids are extensively studied because they may be used inthe composition of cationic liposomes as delivery agents of genetic material toeukaryotic cells (transfection), and as antitumor and antiviral agents. A lot ofpreviously reported investigations have demonstrated that the molecular structure ofcationic lipids can influence the transfection efficacies of their cationic liposomes.Cationic lipids are characterized by having a hydrophobic anchor, a linker and a headgroup containing one or more positive charges~[3].Cholesterol is the one among the commonly used domains for preparation ofvarious types of cationic amphiphiles. It is known that cholesterol stabilizes the lipidbilayer, is nontoxic, and a number of cationic cholesterol derivatives have turned outto be efficient in transfection.It is known that phytosterols is better than cholesterol on stabilizing the lipidbilayer. Phytosterols, or plant sterols are interesting class of compounds due to theirapplications and biological active ties. The phytosterols found most frequently innature are stigmasterol,β-sitotanol and campesterol.In this thesis we designed and synthesized a series of novel cationic lipidsderiving from stigmasterol to study the structure and activity relationship betweencationic lipids and thier cationic liposomes.Their structures were characterized by IR, ~1H NMR and MS.