Biotransformation of 2,2,5,7,8-pentamethyl-6-chromanol (vitamin E homologue) was investigated with cultured plant cells of Phytolacca americana, Catharanthus roseus, and Eucalyptus perriniana. The cultured cells of P. americana converted 2,2,5,7,8-pentamethyl-6-chromanol into its beta-glucoside, whereas conversion with C roseus and E. perriniana also afforded the hydrolysis product of beta-glucoside and a new beta-gentiobioside product, i.e., 2,2,5,7,8-pentalamethylchroman-6-yl 6-O-beta-D-Glucopyranosyl-beta-D-glucopyranoside.