Ergotaman bearing hydroxy, isopropyl, and 2-methylpropyl groups at the 12', 2' and 5' positions, respectively, and oxo groups at positions 3', 6', and 18. It is a natural ergot alkaloid. Ergocryptine discussed in the literature prior to 1967, when beta-ergocryptine was separated from alpha-ergocryptine, is now referred to as alpha-ergocryptine.