Source : Webster's Revised Unabridged Dictionary (1913)

Alkaloid \Al"ka*loid\ ([a^]l"k[.a]*loid), Alkaloidal
\Al`ka*loid"al\ ([a^]l`k[.a]*loid"al), a. [Alkali + -oid: cf. F.
   alcalo["i]de.]
   Pertaining to, resembling, or containing, alkali.

Source : WordNet®

alkaloidal
     adj : pertaining to or consisting of alkaloids