Cytotoxic effects and physicochemical properties of marycin: a new hematoporphyrin derivative

This paper reports some physico-chemical properties and cytotoxic activity of marycin, a new hematoporphyrin derivative. The data show that marycin is a new compound, different from the other porphyrins tested. This product appears to be pure by adsorption or reversed phase thin-layer chromatography and high performance liquid chromatography and has chromatographic behavior different from those of other porphyrins tested. It does not appear to link to some tested metals and has a UV-visible absorbance spectrum different from that of a hematoporphyrin methylester. Furthermore, marycin has cytotoxic activity against K-562, ZR-75, MCF-7, HT-29, LOVO, human tumor cell lines and the MRC-9 human lung embryonic cell line. The new radiometric assay was used for all cell lines. Marycin decreases the growth index, measured by the radiometric assay as 14CO2 production. The cytotoxic activity is dose-dependent. Marycin is active at low doses but the activity varies with the cell line studied. The compound has low toxicity on the normal cell line MRC-9. Marycin is very liposoluble and would be expected to have high affinity and toxicity for tumors. The compound is active without light activation. How marcyin acts is still a matter for speculation.