PRESENCE OF 1-HYDROXYPYRENE CONJUGATES IN WOODY PLANT-LEAVES AND SEASONAL-CHANGES IN THEIR CONCENTRATIONS

beta-O-Glucoside and beta-O-glucuronide conjugates of 1-hydroxypyrene (OHPy) were found in the leaves of four kinds of woody plant; cherry, maple, ginkgo, and camphor. The conjugates were quantified by measurin g OHPy liberated from the water-soluble fraction of leaves treated wit h beta-O-glucosidase and beta-O-glucuronidase. Concentrations of beta- O-glucuronide and beta-O-glucoside ranged from 0 to 358 and from 0 to 129 pmol/g of fresh leaves, respectively, in monthly measurement over a period of 1 year. The amounts of glucuronide conjugates were greater than those of glucoside conjugates in most plants examined. Both conj ugates were detected at the highest concentrations in summer to autumn . For most plants, the total amounts of the conjugates were greater th an that of free OHPy in the leaves in all seasons, and the differences reached 30-fold in maple leaves in September. From these results, the source of the OHPy conjugates in leaves and their implications are di scussed.