precursor

nouns

a substance from which another substance is formed (especially by a metabolic reaction)
precursor
domain category
the organic chemistry of compounds and processes occurring in organisms; the effort to understand biology within the context of chemistry
biochemistry
is a type of (narrower)
the tangible substance that goes into the makeup of a physical object
"coal is a hard black material"; "wheat is the stuff they use to make bread"
material, stuff
a person who goes before or announces the coming of another
forerunner, precursor
something that precedes and indicates the approach of something or someone
forerunner, harbinger, herald, precursor, predecessor