THE CHEMISTRY OF COLOR CHANGES IN KIRI WOOD (PAULOWNIA-TOMENTOSA STEUD) .3. A NEW CAFFEIC ACID SUGAR ESTER FROM KIRI WOOD

Regarding the aging and color changes of kiri wood (Paulownia tomentosa Steud.), the ethanolic and methanolic extractives from the wood were examined. A new caffeic acid sugar ester, tomentoside A (4), together with three known esters; namely, acteoside (2), isoacteoside (3), and campneoside I nonaacetate (5), and caffeic acid (1) were isolated. The structure of tomentoside A (4) was identified as 2-oxo-2 (3',4'-dihydroxyphenyl) ethyl-O-alpha-L-rhamnopyranosyl-(1-->3)-4-O -caffeoyl-beta-D-glucopyranoside by spectral analyses.