Qin Cai-qin

A new cross-linked quaternized-chitosan resin as the support of borohydride reducing agent

A new cross-linked resin was prepared by an inverse emulsion method under the protection of amino group. The resin reacted with glycidyl trimethylammonium chloride to form the quaternary ammonium ion resin, whose chloride was exchanged with potassium borohydride to get the borohydride exchange resin (CBER). CBER was used as a new polymer-supported reducing agent for the reduction of carbonyl compounds to corresponding alcohols, and exhibited a relatively high chemoselectivity and possessed the advantage of easy work-up.

Effect of Molecular Weight and Structure on Antitumor Activity of Oxidized Chitosan

Various low molecular weight chitosans were prepared by oxidative degradation with H2O2, and characterized by IR,13C-NMR and gel permeation chromatography. Their carboxylic contents increased with decrease in molecular weight (Mw). The antitumor test of the samples against sarcoma 180 tumors suggested that the water-soluble chitosan with higherMw have higher inhibitory ratioin vivo. The introduction of carboxylic group is advantage to water-solubility of chitosan, but more acidic groups might decrease the function of amino groups of chitosan against sarcoma 180 tumor.