Response of Achyla ambisexualis e87 to the Hormone Antheridiol and Certain Other Steroids

Abstract

SUMMARY: Of 53 steroids tested for their ability to induce the formation of antheridial branches in the water mould Achlya ambisexualis Raper, strain e87,34 were inactive, including 18 steroids having hormonal activity in mammals and six related to antheridiol, a C-29 steroid controlling the formation of antheridia in Achlya. The C-22, C-23 stereoisomers of antheridiol and two intermediates in its synthesis had about 10−3 to 10−6 the activity of antheridiol. Certain modifications in the side chain of antheridiol resulted in a loss of activity.