Study On The Synthesis Of Novel Pseudoamide-linked Disscharides

Guanidine moiety is an important feature commonly found in many biologically active compounds. Most of the compouds with single or mutiple gunidine functional groups isolated from natural products have a wide range of antiviral and antitumor biological activities or pharmacological uses such as therpy for the hypertension and treatment of diabetes. These guanidine-containing molecules are found to be a critical part of many biological processes and promote the design and synthesis of new drugs. Guanidine-containing sugars and sugar-like molecules have a wide range of biologically important uses such as inhibition of inappropriate mitogenic signaling, therapy for bacterial infections, and inhibition of enzymes。In most of these cases, the guanidino-sugars have been developed to mimic carbohydrate and peptidic molecules. In order to seek compounds which having biological activities, we synthesized a serious of 1→2 connecting disaccharide-guanidine derivatives through using glucosamine as the starting material.The structures of all the synthesized compounds were confirmed by analytical analysis and spectral data (IR, 1HNMR and element analysis). We choose some of them to do biological activities test.The major accomplishments of this treatise1. The nomenclature, preparation, application and pharmacological activity of the guanidine-containing molecules as well as the progress in synthesis of guanidinoglycosides were explicated systematically.2. The nucleophilic addition of glycosyl isothiocyanates with glucosamine gave the key intermediates, peracetylated disaccharide thioureas, then used HgO as desulfurizing agent to give disaccharide carbodiimide, and then reacted with substituted arylamine to get series guanidine-linked disscharides. Some goal compounds were deacetylated in MeOH/MeONa.The major innovations of this treatise1. The key the key intermediates disaccharide-carbodiimide were given through desulfurized disaccharide-thioureas in CH2Cl2 / H2O system. Then, a novel class of trisubstituted disaccharide-guanidines were obtained under mild conditions by nucleophilic addition with substituted arylamine. All compounds haven't been reported in the literatures.2. We choosed a convient method to synthesis disaccharide-guanidine derivatives through analysising the phenomena accured in the reaction by accident. The crystal structure of disaccharide-thioureas and disaccharide-carbodiimide were first reported.3. Comparing the two method of synthesizing disaccharide-guanidine derivatives of using HgO and HgCl2, HgO-CH2Cl2 is more convient and effective in the synthesis of disaccharide-guanidine.