Synthesis Of Lactosylguanidines And Thioglycosides

Recently, many important advances have occured in the field of guanidines due to their remarkable biological and pharmacological activities such as antiviral activities against herpes simplex virus, antifungal activities, antihypertensive activities, antimalarial activities, antibacterial activities and anti-inflammatory activities. Moreover, guanidines bearing thiazolyl moiety are reported to exhibit antimicrobial, anticancer activities and so on. Some guanidines bearing thiazolyl and glycosyl moiety are reported to serve as HIV-1 protease and HIV-1 reverse transcriptase inhibitors and NO synthase inhibitors. Therefore, the goal of our work is to research the function of the glycosyl moiety, so we synthesized a series of novel N-alkyl/aryl-N′-(4/6-substituted benzothiazol-2-yl)-N′′-peracetylated lactosyl guanidines and then reacted in the solution of CH₃ONa/CH₃OH, the deacetylated lactosyl guanidines were obtained.Thioglycosides have found their place in carbohydrate chemistry and carbohydrate biology as an important tool. Their lasting popularity stems from a combination of relative ease of synthesis, stability, compatibility with numerous protection and deprotection steps, and very versatile. Moreover, they are more resistant to cleavage by glycosidases than the naturally occurring O-glycosides. So such compounds have been exploited as glycosyl donors and modest competitive inhibitors of glycosidases. The structures of all the synthesized compounds were confirmed by IR, MS, ¹H NMR spectral date and elemental analysis.The major works of this thesis:1. Lactosylthiourea were obtained by the reaction of 2-amino-4/6-substituted benzothiazoles with lactosylisothocyantes, desulfurization of the resulting thiourea with HgCl₂ in the presence of amines gave a series of novel glucosylguanidines, then deacetylated in the solution of CH₃ONa/CH₃OH.2. By the reaction of chloroacetyl chloride and 2-amino-substituted benzothiazoles or 2-amino-substituted phenylthiazoles, a series of 2-chloro-N-(2-thiazolyl)acetamides were obtained. Then reacted with glycosyl thiols, a series of novel thioglycosides were produced.The Innovations of the Thesis:1 A series of novel N-alkyl/aryl-N′-(4/6-substituted benzothiazol-2-yl)-N′′-peracetylated lactosyl guanidines were synthesized. Particularly, the conditions of turning sec-amines into guanidines were investigated. The deacetylated lactosyl guanidines were obtained in the solution of CH₃ONa/CH₃OH. 2 A series of novel thioglycosides were obtained by S_N2 displacement reactions of 2-chloro-N-(2-thiazolyl)acetamides and glycosyl thiols triumphantly. And they may be provided with some biological activities.