安替比林, Antipyrine

D-精氨酸, D-Arginine

硒化砷, Arsenic(III) selenide

碲化砷(III), Arsenic(III) telluride

DL-天门冬素一水化合物, DL-Asparagine Monohydrate

L-天门冬氨酸, L-Aspartic Acid

L-Aspartic Acid Diethyl Ester Hydrochloride

5-氮杂苯并咪唑, 5-Azabenzimidazole

5-Azaindole

6-氮杂胸腺嘧啶, 6-Azathymine