Antioxidative activities of several marine polysaccharides evaluated in a phosphatidylcholine-liposomal suspension and organic solvents

The antioxidative activities of several water-soluble marine polysaccharides. alginate (ALG), alginate sulfate (SALG), propylene glucolalginate sodium sulfate (PSS), propylene glucol mannuronate sulfate (PGMS), the oligosaccharide of chitosan (OLC), N,O-carboxymethyl chitosan (NOCC) and hydroxypropylated chitosan (HPC), were examined in a phosphatidylcholine (PC)-liposomal suspension containing the water-soluble radical emitter, 2,2'-azobis (2-amidinopropane) dihydrochloride. In the suspensions containing OLC and SALG, the initial rates of PC-OOH accumulation were 2.78 x 10(-8) MS-1 and 2.88 x 10(-8) Ms-1, respectively, while all the polysaccharides tested showed antioxidative activity. Liposoluble marine polysaccharides, hexanoyl chitin (HCH) and an N-benzoylhexanoyl chitosan (NBHC) solution, also retarded the hydroperoxide accumulation of methyl linoleate by effectively trapping peroxide radicals in organic solvents when the radical chain reaction had been initiated by 2,2'-azobis (2,4-dimethylvaleronitrile). The kinetic data presented indicate that the alginate and chitin derivatives can be expected to play a role in the antioxidative mechanism of biological systems.