Tadaaki Nishihama

Bitter principles of Picrasma ailanthoides planchon. Nigakilactones A, B, C, D, E and F

Abstract Five new crystalline bitter principles were isolated from the stem-chips of Picrasma ailanthoides Planchon (Simaroubaceae). Structures of nigakilactones A, B, C, E and F were shown to be II, III, IV, V and VI, respectively. A sixth constituent, nigakilactone D, was proved to be identical with quassin (I).

Bitter principles of Picrasma ailanthoides Planchon : Nigakihemiacetals A, B and C, and nigakilactones G, H and I

Abstract Three new crystalline bitter principles, nigakihemiacetal A (I), nigakihemiacetal C (IIIa) and nigakilactone H (V), have been isolated from the stem-chips of Picrasma ailanthoides Planchon (Simaroubaceae), and their structures determined. The other three bitter constituents, nigakihemiacetal B, nigakilactone G and nigakilactone I proved to be identical with neoquassin (II), picrasin A (IVa) and picrasin B (VI), respectively.