Abstract The biosynthesis of acerogenin A was studied by feeding various 14 C-labelled compounds to the young shoots of Acer nikoense . Phenylalanine and cinnamic acid were the best precursors. C-2 of both acetate and malonic acid were efficiently incorporated into acerogenin A, but C-1 of acetate and the methyl carbon of methionine were incorporated very poorly. These results show that acerogenin A is probably biosynthesized via (−)-centrolobol derived from two p -coumarate residues and one malonate.