Two novel α-tocopheroids from the aerial roots of Ficus microcarpa

Two novel α-tocopheroids, namely α-tocospiros A (1) and B (2), together with α-tocopherol (3) were isolated from the aerial roots of Ficus microcarpa. Their structures were elucidated by spectral methods. Under basic conditions, compounds 1 and 2 were obtained from α-tocoquinon-2,3-oxide (6a and 6b) via a highly stereoselective nucleophilic addition reaction. Reaction and biotransformation mechanisms of 1 and 2 are proposed.