1952, with chemical suffix -ine (2) + tetracyclic "containing four fused hydrocarbon rings," from tetra- "four" + cyclic.
Entries linking to tetracycline
-ine 2
word-forming element in chemistry, often interchangeable with -in (2), though modern use distinguishes them; early 19c., from French -ine, the suffix commonly used to form words for derived substances, hence its extended use in chemistry. It was applied unsystematically at first (as in aniline), but now has more restricted use.
The French suffix is from Latin -ina, fem. form of -inus, suffix used to form adjectives from nouns, and thus is identical with -ine (1).
tetra-
before vowels tetr-, word-forming element meaning "four," from Greek tetra-, combining form of tettares (Attic), tessares "the numeral four" (from PIE root *kwetwer- "four").