Amyl

The word or root amyl has two meanings, in organic chemistry and biochemistry.

Biochemistry
In biochemistry, "amyl" means "pertaining to starch". Many moderately complex biological chemicals related to starch contain it, for example:- Note that in this usage, it is a part of the word, and becomes "amylo" when preceding a consonant.
 * amylase
 * amylopectin
 * amylose

Chemistry
In organic chemistry, amyl is the old trivial name for the radical called pentyl under the IUPAC nomenclature: that is, -C5H11. This usage may derive from the presence of amyl alcohol in fusel oil, which is often fermented from starches. In this usage, amyl (normally) remains a separate word and it does not become "amylo-" before a consonant.

Several important amyl/pentyl compounds are still widely known by their older, amyl names, including:
 * amylamine
 * amyl acetate
 * amyl alcohol
 * amyl nitrate
 * amyl nitrite

There are eight possible isomers of amyl; see under pentyl for more information. Frequently chemicals sold commercially as amyl compounds will be a mixture of several isomers.

Slang
"Amyl" is also a slang term for amyl nitrite when used as a recreational drug.

Etymology
"Amyl", used to mean "starch", was taken from Greek αμυλος = "cake made from fine flour", from α + μυλη = "not mill" because the flour used to make an αμυλος was not ground on the same grindstones as ordinary bread flour.