Synonyms: Corynoxan-16-carboxylicacid, 16,17-didehydro-9,17-dimethoxy-2-oxo-, methyl ester, (16E)-; Mitragynineoxindole A (8CI); Spiro[3H-indole-3,1'(5'H)-indolizine]-7'-carboxylic acid,6'-ethyl-1,2,2',3',6',7',8',8'a-octahydro-4-methoxy-a-(methoxymethylene)-2-oxo-, methyl ester, [1'S-[1'a,6'b,7'b(E),8'aa]]-