penicillin G vs benzylpenicillin

penicillin G and benzylpenicillin both are nouns.

Word	Noun	Adjective	Verb	Adverb
penicillin G	Yes	No	No	No
benzylpenicillin	Yes	No	No	No

As nouns, penicillin G and benzylpenicillin are synonyms defined as:

penicillin G and benzylpenicillin: the penicillin that constitutes the principal component of many commercial antibiotics

penicillin G (noun)	benzylpenicillin (noun)
the penicillin that constitutes the principal component of many commercial antibiotics	the penicillin that constitutes the principal component of many commercial antibiotics