Protopine has antiplatelet effects,which is due to inhibition on thromboxane formation and phosphoinositides breakdown and then lead to the decrease of intracellular calcium concentration.

Suc-Leu-Tyr-AMC is a fluorescent substrate for calpain I and II, papain (another cysteine protease), and is used to measure the chymotrypsin-like peptidase activity of the 20S proteasome (excitation max: 360 nm; emission max: 460 nm). Suc-Leu-Tyr-AMC can also be cleaved by the Ti protease from E. coli.

邻苯二酚及其磺酸经常存在于许多哺乳动物的尿液中。水果和蔬菜中天然存在少量儿茶酚以及多酚氧化酶。将酶与底物混合并暴露于氧气（如切土豆或苹果时），无色儿茶酚氧化成红棕色苯醌衍生物。