Some New Alkaloids from Chinese Corydalis Ambigua, Cham. et. Sch. (Yen-Hu-So).

Corydaline, the principal alkaloid of Corydalis roots, was discovered by Wackenroder in the tubers of Corydalis tuberosa. It was subsequently examined by several investigators, but not in a pure state until Dobbie and Lauder analyzed the pure alkaloid and its salts and assigned to it the formula C22H28O4N. Freund and Josephy found that the alkaloid was better represented by the formula C22H27O4N, which is now generally adopted. A dozen other alkaloids were successively isolated from Corydalis cava and other species of Corydalis roots by Dobbie and Lauder, Freund and Josephy, Merck, Gadamer, Spath, Heyl, Makoshi, Asahina, and others, to most of which molecular and constitutional formulae have now been assigned. The Chinese Corydalis tubers, Yen-hu-so, are, according to Matsumura and Stuart,Corydalis ambigua, Cham. et Sch. They are small, firm, brownish-yellow pellets, with a depression on one of the surfaces. To the drug itself, in China, are ascribed tonic diuretic, emmenagogue, deobstruant, astringent, alterative and sedative properties. Its chemical investigation was first carried out by Makoshi, who isolated from it corydaline, dehydro corydaline, Corbulbine, protopine, and 2 other alkaloids, C20H17O4N, a quaernary base and a substance m. p. 197-199°, resembling, but not identical with bulbocapnine. With the object of obtaining some bulbocapnine for certain medical requirements, the writer investigated chemically the Chinese drug Yen-hu-so again and found that is contains more alkaloids than had hitherto been isolated. The basic products, obtained from 16 kg. of crude drug, were divided into 4 fractions A, B, C, D. The fraction B, which is non-phenolic and consists of the largest part, weighing about 20 gm., was first studied, from which 5 alkaloids have been isolated, purified, analyzed and some of their salts prepared.