Carotenoids are a group of yellow, brown to reddish pigments. These are of two types - carotenes and xanthophylls, and serve as accessory photosynthetic pigments. Abrin and ricin are natural protein toxins isolated from plant seeds i.e., they are phytotoxins. Concanavalin A is a lectin (carbohydratebinding protein) originally extracted from the jack-bean, Canavalia ensiformis. Morphine and codeine are the alkaloids derived from opium, and are called as opioid narcotics.