(3α,16α)-Eburnamenine-14-carboxylic Acid Methyl Ester; 1H-Indolo[3,2,1-de]pyrido[3,2,1-ij][1,5]naphthyridine, eburnamenine-14-carboxylic acid deriv.; (+)-Apovincamine; (+)-cis-Apovincamine; Methyl (3α,16α)-eburnamenine-14-carboxylate; USP Vinpocetine Related Compound B; (methyl (13aS,13bS)-13a-ethyl-9-methoxy-2,3,5,6,13a,13b-hexahydro-1H-indolo[3,2,1-de]-pyrido[3,2,1-ij][1,5]naphthyridine-12-carboxylate