The US pharmacopeia of 1870 lists amygdalin,…

The US pharmacopeia of 1870 lists amygdalin, a glycoside initially isolated from the seeds of the tree Prunus dulcis, also known as bitter almonds, by Pierre-Jean Robiquet and Antoine Boutron-Charlard, in 1830, and subsequently investigated by Liebig and Wöhler in 1830.

Several other related species in the genus of Prunus, including apricot (Prunus armeniaca) and black cherry (Prunus serotina), also contain amygdalin.

The FDA Grandfather Clause will later prevent the FDA from claiming jurisdiction over laetrile, or “Vitamin B17”, a modified form of amygdalin that, from the 1950s, will be promoted under the names laetrile as a cancer cure.

In reality, neither amygdalin nor any derivative such as laetrile is in any sense a vitamin.

Studies have found such compounds to be dangerously toxic as well as being clinically ineffective in the treatment of cancer.

Taken by mouth they are potentially lethal because certain enzymes (in particular, glucosidases that occur in the gut and in various kinds of seeds, edible or inedible) act on them to produce cyanide.

The promotion of laetrile to treat cancer will be described in the medical literature as a canonical example of quackery.