L-Phenylalanine, (1,3,3a,3b,4,4a,5,7,7a,8,8a,8b-dodecahydro-1,3,5,7- tetraoxo-4,8-ethenopyrrolo[3',4':3,4]cyclobut[1,2-f] isoindole-2,6-diyl)bis(methylene) ester, compd. with D-gluconic acid and sodium chloride (1:2:2) NSC608003