1993 Volume 46 Issue 7 Pages 1063-1068
R1128 A, B, C and D, new non-steroidal estrogen-receptor antagonists, were isolated from the cultured broth of Streptomyces sp. No. 1128. Their structures were elucidated to be l, 3, 6-trihydroxy-8-alkylanthraquinones on the basis of their physico-chemical properties and spectroscopic data.