of import vs alpha

of import is not a noun while alpha is a noun.

Word	Noun	Adjective	Verb	Adverb
of import	No	Yes	No	No
alpha	Yes	Yes	No	No

of import (noun)	alpha (noun)
	the 1st letter of the Greek alphabet
	the beginning of a series or sequence

of import (adjective)	alpha (adjective)
of great significance or value	early testing stage of a software or hardware product
	first in order of importance