Known as: IRL-1620, l-tryptophan, n-(3-carboxy-1-oxopropyl)-l-alpha-aspartyl-L-alpha-glutamyl-L-alpha-glutamyl-L-alanyl-L-valyl-L-tyrosyl-L-phenylalanyl-L-alanyl-L-histidyl-L-leucyl-L-alpha-aspartyl-L-isoleucyl-L-isoleucyl-fluoro-11beta,16alpha,17,21-tetrahydroxypregna-1,4-diene-3,20-dione cyclic 16,17-acetal with acetone, hemihydrate