Seed when castor beans have been ingested by animals. In addition, seeds containing amygdalin—apple, apricot, bitter almond, peach, plum, cherry, quince, and others—when consumed in sufficient amounts, may cause cyanide poisoning. Other seeds that contain poisons include annona, cotton, custard apple, datura, uncooked durian, golden chain, horse-chestnut, larkspur, locoweed, lychee, nectarine, rambutan, rosary pea, sour sop, sugar apple, wisteria, and yew. The seeds of the strychnine tree are also poisonous, containing the poison strychnine. The seeds of many legumes, including the common bean ("Phaseolus vulgaris"), contain proteins called lectins which can cause gastric distress if the beans are eaten without cooking.
Apple reaction of phenolic compounds to o-quinones causing the pigment to turn darker and therefore brown. Ideain (cyanidin 3-O-galactoside) is an anthocyanin, a type of pigment, which is found in some red apple cultivars. Phlorizin is a flavonoid that is found in apple trees, particularly in the leaves, and in only small amounts if at all in other plants, even other species of the genus "Malus" or related plants such as pear trees. Apple seed oil and pectin can be produced. Preliminary research is investigating whether nutrients and/or phytochemicals in apples may be preventive against the risk of some types of