Dextran, carbamate derivatives

Dextran carbamate derivatives. Activation of dextran with 4-nitro-phenyl chloroformate and subsequent reaction with amines leads to the formation of the corresponding carbamate derivatives 2-Hydroxypro-pylamine was selected as a model for amine type drugs. 

Carbamate derivatives (Table 1) of cellulose, chitin, amylose, amylopectin, and dextran were prepared using the isocyanates described in Part A of the Experimental Section. Amylose, amylopectin, dextran, and cellulose were obtained from Polysciences, Inc. and used without further purification. Chitin, obtained from Eastman Kodak, was decalcified and deproteinated by the method reported by Haye r prior to use. 

Figure 8. Enzymatic degradation of dextran and carbamate derivatives of dextran by dextranase. Degree of modification (%) ...

Btich investigated the activities, following intraperitoneal injection, of a series Of 3-phenylpropyl carbamate derivatives on formalin, dextran and... 

Biich investigated the activities, following intraperitoneal injection, of a series of 3-phenylpropyl carbamate derivatives on formalin, dextran and 5-hydroxytryptamine oedema in the rat-paw. All compounds showed antiinflammatory activity and all apart from one were more active than meprobamate. Further experiments demonstrated that one of these, 3-phenylpropyl carbamate itself (phenprobamate, proformiphen, Gamaquil, MH 532), Ph(CH2)8-0 CO-NHg, a central muscle relaxant with analgesic and antipyretic properties, possesses anti-inflammatory effects comparable to those of phenylbutazone . In doses of 160 mg/kg orally, this compound does not delay the appearance of ultra-violet erythema in the guinea-pig. 

Table I lists physical data for a number of the carbamate and ester derivatives of cellulose, chitin, amylose, amylopectin, and dextran synthesized as described in the Experimental Section. The solubility of the polysaccharide starting materials as well as that of the produced derivatives allows for macromolecular characterization through techniques including UV, NMR, IR, high pressure liquid chromatography, etc.

More often, carbamates of dextran are prepared by one-step conversion of the polysaccharide with isocyanates or isothiocyanates. This path is especially useful for the conjugation of fluorescent dyes. Fluorescent-marked dextrans are commercial products today. Fluorescent dextran derivatives with different molecular weights and substituents are available as invaluable tracers for studies on microcirculation and vascular permeability in health and disease [8]. Fluorescein isothiocyanate (FITC) dextran (actually the thiocarba-mate) has been well established in this area of research since the 1970s [358]. The isothiocyanate of fluorescein is covalently bound to dextran leading to... 

By varying the amount of chloroformste added per gram dextran different degrees of activation and derivatives of variable carbamate content could be prepared. In the NMR spectrum of the reaction product (IX) the methyl protons of the 2-hydroxy propyl radicals show up as a doublet at 6 = 1,3 ppm. From the integration values of the NMR signals the degree of modification was calculated. 

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