Amygdalin

Amygdalin (from Ancient Greek: ἀμυγδαλήamygdalē 'almond') is a naturally occurring chemical compound found in many plants, such as the seeds (kernels, pips or stones) of apricots, bitter almonds, apples, peaches, cherries and plums, and in the roots of manioc.

Amygdalin is classified as a cyanogenic glycoside, because each amygdalin molecule includes a nitrile group, which can be released as the toxic cyanide anion. This can occur when exposed to a beta-glucosidase, which cleaves the two glucose residues (or β-D-glucosyls) bound with beta-glycosidic linkages. Eating amygdalin will cause it to release cyanide in the human body, and may lead to cyanide poisoning.

Since the early 1950s, both amygdalin and a chemical derivative named laetrile have been promoted as alternative cancer treatments, often under the misnomervitamin B₁₇ (neither amygdalin nor laetrile is a vitamin). Scientific study has found them to not only be clinically ineffective in treating cancer but also dangerous due to the considerable poisoning risks. The promotion of laetrile to treat cancer has been described in the medical literature as a canonical example of quackery and as "the slickest, most sophisticated, and certainly the most remunerative cancer quack promotion in medical history". Amygdalin has also been examined in the context of traditional Chinese medicine.