STRUCTURES AND ALLELOPATHIC EFFECTS OF NUPHAR ALKALOIDS - NUPHAROLUTINE AND 6,6'-DIHYDROXYTHIOBINUPHARIDINE

Two of the major Nuphar alkaloids, nupharolutine and 6,6'-dihydroxythi obinupharidine, were isolated from the aquatic perennial herb Nuphar l utea (L.) Sibth. & Sm., yellow water lily. In a lettuce seedling bioas say of the two pure compounds, the former was inactive and the latter was highly inhibitory of radicle elongation at concentrations greater than 2 ppm. Structures and stereochemistry of the two compounds were c onfirmed by DEPT, H-1-H-1 COSY, H-1-C-13 COSY, and H-1-H-1 NOESY exper iments.