4 NEW CAFFEIC ACID METABOLITES, YUNNANEIC ACIDS E-H, FROM SALVIA-YUNNANENSIS

Four new caffeic acid metabolites, named yunnaneic acids E-H were isol ated from the root of Salvia yunnanensis. Their structures have been e stablished on the basis of spectroscopic and chemical evidence, Yunnan eic acids E and F are biogenetically derived from yunnaneic acid C, wh ich is a Diels-Alder adduct of rosmarinic acid and caffeic acid, On th e other hand, yunnaneic acids G and H are arylnaphthalene-type lignan esters derived by oxidative coupling between two molecules of rosmarin ic acid, The existence of these compounds indicates that caffeic acid metabolism in S. yunnanensis is more complex than that in S. miltiorrh iza.