Amyl

The word or root amyl has two meanings, in organic chemistry and biochemistry.^[1]

Biochemistry

In biochemistry, "amyl" means "pertaining to starch", "amylum" being another word for starch. Many terms for moderately complex biological chemicals related to starch contain "amyl", for example:

Amylase
Amylopectin
Amylose
Amyloplast
Amyloid (based on an early mistaken opinion that these structures contained starch)

Note that in this usage, it is a part of the word, and becomes "amylo" when preceding a consonant.

Organic chemistry

In organic chemistry, amyl is the old trivial name for the alkyl substituent and 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:

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" (Latin "amylum"), and was taken from Greek αμυλος = "cake made from fine flour", from α + μυλη = "not mill", the flour not being ground on grindstones as bread flour is, but dried from a pulp of wheat softened with water.^[2]

References