1.14.17.1 0.37 - hydroquinone pH: 4.9 438609 1.14.17.1 1.05 - hydroquinone pH: 5.9 438609 1.14.17.1 0.015 - beta-ethynytyramine R,S-1 438613 1.14.17.1 0.208 - beta-ethynytyramine S-1 438613 1.14.17.1 0.057 - beta-ethynytyramine S-1, in the presence of ascorbate 438613