Polysaccharide-mediated synthesis of melanins from serotonin and other 5-hydroxy indoles

AIM: As a continuation of our research on the melanin formation from catecholamines, we studied the polysaccharide-mediated oxidation of serotonin and other 5-hydroxy indoles into melanin-like materials. As for the catecholamines, we observed that many polysaccharides promote the oxidation of such compounds, particularly in the presence of Cu(2+). METHODOLOGY: The reactions were monitored using reverse phase-HPLC and size-exclusion chromatography techniques. Melanin-like materials were purified through dialysis and characterized using UV-Vis and Fourier transform IR spectroscopic techniques. RESULTS: One such material, synthesized from chondroitin sulfate type A and serotonin in the presence of Cu(2+) was found to affect the release of IL-1β and IL-6 cytokines from immune cells.