The seeds of the Mexican tree Casimiroa edulis Llave et Lex. contain seven substances in addition to the previously isolated casimiroin, casimiroedine, casimirolid, a "yellow phenolic substance" (identified as 9-hydroxy-4-methoxyfurano[3,2-g]benzopyran-7-one), β-sitosterol β-D-glucoside, and β-sitosterol. Of these seven, two were identified as palmitamide and N-benzoyltyramine, whereas the other five appear to be new. Casimiroa edulis Llave et Lex. (Rutaceae) is a tree growing in the temperate region of Mexico and Central America; its fruit, known as "Zapote blanco", is commonly eaten in Mexico and has a pleasant flavour. Since Francisco Hernandez claimed the fruit to induce sleep and the kernels to be a powerful poison, a variety of physiological actions (hypnotic, sedative, hypotensive) have been attributed to the plant. The literature up to 1911 was reviewed by Power and Callan, who conducted the only extensive previous chemical investigation of these seeds and found no foundation for the reported physiological activities. However, reports regarding the hypnotic, sedative, and hypotensive action of the seed persisted, leading to a chemical re-investigation of the alcohol-soluble constituents of the seed (a study of the bark is reported in the following paper). Power and Callan isolated six substances from the fruit: casimiroin, casimiroedine, casimirolid, the "yellow phenolic substance", β-sitosterol β-D-glucoside (then called "ipuranol"), and α-sitosterol. We obtained all of these and found seven further compounds, of which five (zapotin, zapotinin, zapoterin, eduline, and zapotidine) appear to be new and two (palmitamide and N-benzoyltyramine) are known. In view of the extensively described physiological action of tyramine (one of the active principles of ergot), the N-benzoyl derivative of this substance is probably responsible for some of the ascribed activity of the seed.