Studies on iridoid-related compounds. V. Antitumor activity of iridoid dervs. periodate oxidation products.

In the course of a modification study of iridoid glucosides to investigate their antitumor and antimicrobial activity, we found that about all metaperiodate oxidation products of iridoid glucosides which had no antitumor activity showed potent activity against the leukemia P388 in mice. They were found to be more active than the corresponding aglycones obtained by enzymic hydrolysis of iridoid glucosides. Among them, periodate oxidation product of sweroside showed the most potent activity, of which the maximum total/control (T/C) value was 198% at 200 mg/kg.