A pyranocoumarin and two alkaloids (one with antispasmodic effect) from Citrus deliciosa

One pyranocoumarin (xanthyletin, 1) and two acridone alkaloids (2',2'-dimethyl-(pyrano5',6': 3:4)-1,5-dihydroxy, 6-methoxy, 10-methylacridone, 3, and citpressLne-I, 4), were isolated from the roots of Citrus deliciosa Ten (Rutacea). Their structures were elucidated by spectroscopic methods. Reported C-13 NMR assignments of alkaloid 3 have been corrected and those of alkaloid 4 are reported for the first time. Alkaloid 3 was found to have antispasmodic effect on isolated ileum segments excised from male rabbits.