Structure requirement of sterol for growth and development

More than 20 analogues of cholesterol, cholesterol esters, cholestenols, and cholestadienols were tested for supporting the growth of the silkworm B. mori in our laboratory [182,183]. 5a-Cholest-7-en-3i8-ol, cholesta-5,7-dien-3 8-ol and 5o-cholest- 

6- en-3 -ol as well as cholesteryl acetate can replace cholesterol as sterol sources for B. mori. Good growth was also obtained with 5a-cholest-14-en- -ol, 5a-cholesta-6,8(14)-dien-3j8-ol, (20 )-cholesta-5,20(22)-dien-3 8-ol, (22 )-cholesta-5,22-dien-3i8-ol, and cholesta-5,25-dien-3 8-ol. Other cholestenols and cholestadienols such as 5a-cholest-14-en-3j8-ol, 5a-cholest-8(14)-en- -ol, 5a-cholesta-7,14-dien- -ol and cholesta-5,23-dien-3j/8-ol were partially effective and the larvae fed on these sterols reached 2nd instars. 5a- and 5 -cholestan-3/8-ols, cholest-4-en- -ol, and cholest-4-en-3-one are unable to support the growth of B. mori. 

---