IYOMYCIN, A NEW ANTITUMOR ANTIBIOTIC FROM STREPTOMYCES. V

EXPERIMENTAL TREATMENT OF SARCOMA 180 WITH IYOMYCIN-B₁ COMPLEX AND ITS DERIVATIVES

Abstract

In attempts to reduce the toxicity while maintaining the antitumor activitvy of iyomycin B₁, a variety of complexes and derivatives were prepared and tested.
1. No enhancement of anti-tumor activity was observed with complexes of iyomycin B₁ and human serum albumin prepared at various ratios, and with 6 kinds of metal salts. However, an interesting result was obtained with the magnesium salt of iyomycin B₁.
2. Although the toxicity was reduced in complexes of A and B₁, and in reduced B₁ prepared by the cataltic hydrogenation, their antitumor activities were inferior to that of iyomycin B₁ itself.
3. The acetyl derivative of iyomycin B₁ was found to have lower toxicity and higher antitumor activity than iyomycin B₁ itself. Tumors disappeared entirely in 70% of the mice treated with the derivative from 3 days after the implantation of the tumor.