Okay so the short answer is – YES IT IS HIGHLY TOXIC DON’T EAT IT OR YOU WILL MOST LIKELY DIE.
The long answer goes as follows..many cyanides are highly toxic because the cyanide anion is an inhibitor of the enzyme cytochrome c oxidase (also known as aa3) in the fourth complex of the electron transport chain. This “electron transport chain” is in the membrane of the mitochondria of eukaryotic cells. Eukaryotic cells are (for the sake of this example) cells like yours i.e. your cells. The mitochondria is the place where all the energy for your cells is made. There is one in every cell!
So …cyanide attaches to the iron within the aa3 protein. The binding of cyanide to this cytochrome protein prevents transport of electrons from cytochrome c oxidase to oxygen. As a result, the electron transport chain is disrupted (broken), meaning that the cell can no longer produce ATP for energy in the normal way. Some of our tissues depend VERY HIGHLY on this energy – like out heart and central nervous system so they are not happy when this happens…why cyanides cause death.
The most hazardous compound is hydrogen cyanide, which, because it is a gas at room temperatures and pressure, can be inhaled (breathed in).