alpha vs of import

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

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

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

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