European Pharmacopoeia (EP) Reference Standard Synonym(s): Ethyl (12 RS ,13a RS ,13b RS )-13a-ethyl-2,3,5,6,12,13,13a,13b-octahydro-1 H -indolo[3,2,1-de]pyrido[3,2,1- ij ][1,5]naphthyridine-12-carboxylate; Dihydrovinpocetine Empirical Formula: C22H28N2O2...