Tannins and Related Compounds. LI.1) Elucidation of the Stereochemistry of the Triphenoyl Moiety in Castalagin and Vescalagin, and Isolation of 1-0-Galloyl Castalagin from Eugenia grandis

Abstract

The chirality of the nonahydroxytriphenoyl group in castalagin (1) and vescalagin (2) was determined to be in the 5,5-series on the basis of circular dichroism analysis. In addition, a new ellagitannin (4) has been isolated from the leaves of Eugenia grandis (Myrtaceae), and the structure was established to be 1-0-galloyl castalagin on the basis of chemical and spectroscopic evidence. © 1987, The Pharmaceutical Society of Japan. All rights reserved.