Production of hormone B by Achlya heterosexualis.

Sexual morphogenesis in Achlya, a filamentous water mold, is initiated by two hormones. Hormone A, or antheridiol, is a C-29 steroid. Four stereoisomers of antheridiol have been synthesized. The natural one (antheridiol 22S 23R) and its 7-deoxy 7-dihydro form, when added to an aerated culture of hermaphroditic Achlya heterosexualis, stimulated this mold to secrete twice as much hormone B as the untreated control. An unnatural stereoisomer (antheridiol 22R 23S) and fucosterol, however, did not stimulate strain 8-6 in the same way. Methods by which hormone B can be produced in sufficient yield for isolation and characterization are described.