Steroids from Harrisonia abyssinica

in addition to the known sterols and ketosteroids beta-sitosterol (24 alpha -ethylcholest-5-en-3 beta-ol), stigmasterol (24 alpha-ethylcholesta-5,22-di en-3 beta-ol), campesterol (24 alpha-methylcholest-5-en-3 beta-ol), beta-si tostenone (stigmast-4-en-3-one, 24 alpha-ethylcholest-4-en-3-one), stigmast enone (stigmasta-4,22-dien-3-one, 24 alpha-ethylcholesta-4,22-dien-3-one), campestenone (24 alpha-methylcholest-4-en-3-one), and stigmasta-3,5-dien-7- one (24 alpha-ethylcholesta-3,5-dien-7-one), the new steroids stigmasta-3,5 ,22-trien-7-one (24 alpha-ethylcholesta-3,5,22-trien-7-one), and campesta-3 ,5-dien-7-one (24 alpha-methylcholesta-3,5-dien-7-one) were isolated from t he stem bark of Harrisonia abyssinica and identified by NMR and mass spectr ometry.