5-Di-(2'-tetrahydropyranyl)secalonic acid D as a new antibiotic derivative with anticancer activity.

A pyranyl derivative was chemically synthesized from secalonic acid D, an antibiotic obtained from culture filtrates of Penicillium oxalium, and its anticancer activity towards a highly antigenic rat bladder cancer, BC-47, implanted into inbred ACI/N rat was studied. The anticancer effect of the drug was similar to that of adriamycin. Delayed initiation of treatment, starting 5 days after the cancer implantation, was more effective than treatment starting from day 1. In addition, it was less effective in an immunodeficient host subsequently implanted with BC-47. This compound is thought to retard the cancer cell growth until the appearance of tumor immunity in the host.