Fumariaflorine ethyl ester (22) has been isolated from the work-up of the alkaloids of Fumaria parviflora. Since ethyl esters are unknown among alkaloids and since ethyl alcohol was used during the isolation process, the true alkaloid is most probably fumariflorine (23). Fumariflorine may be considered the first representative of a new but small group of isoquinoline alkaloids, namely the O-(β-dimethylaminoethyl)benzoic acids, which originate from the breakdown of phthalideisoquinolines. Another new alkaloid of F. parviflora is the glycosidic spirobenzylisoquinoline parviflorine (30) which corresponds to (+)-parfumine-β-D-glucoside and whose acid hydrolysis yields (+)-parfumine (14) and D-glucose. Dihydroparfumine (17) corresponds in all respects to the alkaloid fumaritine and shows a cd curve with a positive Davydov split, pointing to the absolute configuration indicated. This same absolute configuration is prevalent among naturally occurring spirobenzylisoquinolines. A third new alkaloid found is the phthalideisoquinoline base fumaramidine (21).