LETTERS TO THE EDITOR

Cytotoxic Steroids with Antiestrogenic Activity of the 11α-Acyloxyestra-1,3,5(10)- Triene Series

L. E. Golubovskaya a , Z. S. Smirnova b , V. N. Tolkachev b , and V. M. Rzheznikov a #

# Phone/fax: +7 (495) 324-9605; e-mail: sterlabenc@mtu-net.ru

a Endocrinology Research Center , Russian Academy of Medical Sciences , ul. Dmitriya Ul'yanova 11, Moscow , 117036 Russia

b Blokhin Cancer Research Center , Russian Academy of Medical Sciences, Kashirskoe sh . 24, Moscow , 115478 Russia

Received June 24, 2005; in final form, October 25, 2005

Abstract: Esterification of 3-hydroxyl group in 11α-acyloxyestra-1,3,5(10)-trienes with p-[bis(2-chloroethyl)amino]phenylacetic acid led to antitumor steroids displaying antiestrogenic and cytotoxic activities. Our substances exhibit their activities on the model of murine mammary adenocarcinoma Ca-755, with inhibition of the tumor growth being 9499%. A new approach was used for the 11α-hydroxylation of estra-1,3,5(10)-trienes.

Key words: antiestrogen , antitumor steroid, cytostatic, synthesis

Russian Journal of Bioorganic Chemistry 2006, 32 (2):201-203