The present disclosure is generally directed to neuroactive enantiomeric 15-, 16- and 17-substituted steroids with additional optional substituents at carbons 3, 4, 6, 7, 10 and 13, and pharmaceutically acceptable salts thereof, for use as, for example, modulators for GABA type-A receptors. The present disclosure is further directed to pharmaceutical compositions comprising such compounds.

(3,9,10,13,14,17,20S,22E)-Ergosta-5,7,22-trien-3-ol. A method for preparing the same by drying a fruiting body of Cordyceps militaris, grinding the fruiting body to yield ultrafine powders; boiling and extracting the ultrafine powders, centrifuging and collecting a precipitate. A method for treating a tumor by administering to a patient in need of treating a tumor (3,9,10,13,14,17,20S,22E)-ergosta-5,7,22-trien-3-ol.

The invention discloses an improved process for production of vitamin D3 from 7-dehydrocholesterol (7-DHC) and to a simple process for recovery unreacted 7-DHC for further reuse. The invention further describes a process for isolation and purification of Vitamin D3.