AN INVESTIGATION OF THE ANTITUMOR PEPTIDOGLYCAN FRACTION FROM SQUID INK

Squid ink, which has little commercial use and is usually discarded, w as extracted using a Tris-HCl buffer (pH 6.8). The extract was fractio nated using DEAE Sephacel ion-exchange chromatography and Sephacryl S- 300 gel filtration to give a peptidoglycan fraction which exhibited st rong antitumor activity against Meth-A fibrosarcoma in BALB/c mice fol lowing intraperitoneal administration. The fraction was composed of 7. 8% peptide, 57% polysaccharide and 30% pigment. The polysaccharide com ponent had a unique structure with equimolar ratios of GlcA, GalNAc an d Fuc. Since the fraction has no direct cytotoxic effect on Meth-A cel ls, inhibition of tumor growth may be due to stimulation of host-media ted responses.