THE CHITOSAN?(FE(II), CO(II), AND CU(II)) COMPLEXES WERE PREPARED BY MIXING CHITOSAN (CHI) POWDER WITH A SALICYLALDEHYDE (SAL, 5-HYDROGEN (?H)) AND THEIR 5-BROMO (?BR), 5-CHLORO (?CL), 5-METHOXY (?OCH3), 5-FLUORO (?F), 5-METHYL (?CH3), AND 5-NITRO (?NO2) DERIVATIVES (GROUPS R) AND MIXING THESE WITH FECL2 AND CUCL2 IN ETHANOL AND WITH CO(CH3COO)2 SOLUTIONS IN BUTANOL AT 80 °C OVER 8 H IN HETEROGENEOUS PHASE, FOLLOWED BY EXTRACTION WITH ETHANOL AND BUTANOL, RESPECTIVELY. THE COMPLEXES WERE CHARACTERIZED BY FTIR AND UV?VIS SPECTROSCOPY, ELEMENTAL ANALYSIS, AND CYCLIC VOLTAMMETRY. A LINEAR CORRELATION BETWEEN THE METAL FORMAL POTENTIAL VERSUS THE HAMMETT PARAMETERS OF THE SUBSTITUENTS WAS OBSERVED. THE ELECTRON-WITHDRAWING GROUPS SHIFT THE REDOX POTENTIAL TO POSITIVE VALUES, AS A RESULT OF LOWERING THE ENERGY OF THE HIGHEST OCCUPIED MOLECULAR ORBITAL. THE FORMAL POTENTIAL WAS USED AS A MEASUREMENT FOR THE DRIVING FORCE OF CHITOSAN COMPLEXES FOR REDOX REACTIONS.

THE EXOPOLYSACCHARIDE (EPS) SEPARATED FROM THE ENTOMOPATHOGENIC FUNGUS METARHIZIUM ANISOPLIAE WAS DETERMINED BY GEL PERMEATION CHROMATOGRAPHY TO BE HOMOGENEOUS. THE HIGH-PERFORMANCE ANION-EXCHANGE CHROMATOGRAPHY WITH PULSED-AMPEROMETRIC DETECTION (HPAE-PAD) SHOWED A CONTENT OF MONOSACCHARIDES D-GALACTOSAMINE AND D-FUCOSE AT A MOLAR RATIO OF ABOUT 2:1. THE RESULTS OBTAINED FROM FOURIER TRANSFORM-INFRARED SPECTROSCOPY (FT-IR) AND SECOND DERIVATIVE FT-IR SPECTRUM CONFIRMED THE PROPOSED STRUCTURE.

SCHIFF DERIVATIVES WERE PREPARED BY THE REACTIONS OF SALICYLALDEHYDE AND ITS DERIVATIVES (5-CHLORO, 5-METHOXY, 5-FLUORO, 5-METHYL, 5-NITRO) WITH THE AMINO GROUP OF CHITOSAN. THE SCHIFF BASES WERE STUDIED BY FOURIER IR SPECTROSCOPY AND BY UV-VISIBLE SPECTROSCOPY. THE CYCLIC VOLTAMMOGRAMS OF THE SCHIFF BASES WERE ANALYZED AND COMPARED TO THOSE OF CHITOSAN AND SALICYLALDEHYDE. THE FORMAL POTENTIAL OF THE CHITOSAN SCHIFF BASE DERIVATIVE CORRELATES WITH THE HAMMETT PARAMETERS. THE OXIDATION POTENTIAL INCREASES AND THE OPTICAL DENSITY DECREASES WITH ENHANCEMENT OF THE ELECTRON-ACCEPTOR PROPERTIES OF THE FUNCTIONAL GROUP R IN THE M-POSITION TO THE -N=CH-GROUP. CHITOSAN (CHI) IS A POLYSACCHARIDE WHOSE CHAINS CONSIST OF RECURRENT UNITS OF ACETAMIDO-2-DEOXY-D-GLUCODE LINKED BY THE 1,4-?-GLYCOSIDE BOND. THIS POLYSACCHARIDE WAS WIDELY STUDIED AS DRUG CARRIER [1, 2], BECAUSE IT IS NONTOXIC, BIODEGRADABLE, AND WELL BIOCOMPATIBLE [3].