Synthesis and Identification of a New Steroid, 24-Ethyl-5α-cholest-24(28)Z-en-3-one in the Seeds of Foxtail Millet

Study was made to determine the structures of three minor 5α-steroidal 3-ones detected in the seeds of (oxtail millet (Setaria italica Beauv.). For this purpose, 24-ethyl-5α-cholest-24(28)Z-en-3-one and its carbon-carbon double bond isomers were synthesized from isofucosterol. Based on direct GCMS comparison with the synthetic samples, one steroid was found here for the first time to have the structure, 24-ethyl-5α-cholest-24(28)Z-en-3-one. Two other minor steroids were identified as 24ξ-ethyl-5α-cholesta-7,22E-dien-3-one and 24ξ-ethyl-5α-cholest-7-en-3-one.