The formation of catechin and procyanidins in cell suspension cultures ofCryptomeria japonica

Cell suspension cultures, as well as green leaves, ofCryptomeria japonica contained catechin, epicatechin, procyanidins B-1, B-3 and B-4, and polymeric procyanidins. Those compounds in the cell culture were found to increase, midway through the logarithmic phase, but the polymerization of procyanidins seems to proceed in the stationary phase. The dosage of 0.3 mMl-2-aminooxy-3-phenylpropionic acid (l-AOPP), an inhibitor of phenylalanine ammonia-lyase (PAL), to the cells caused inhibition of the flavan formation to a large extent without significant reduction of growth rate, as well as a large increase in the phenylalanine content of the cells. PAL activity in the cell cultures increased, immediately after transfer to a fresh medium, showed its maximum (a first peak) during 15 hr and a second small peak of the activity in the midst of the logarithmic phase. 0.3 mMl-AOPP inhibited remarkably a first peak of PAL activity, but a second peak was nearly unaffected. 2 mMl-AOPP inhibited the PAL activity completely.