Formation of 3-amino-2,6,8-trimethyl-10-phenyldeca-4E,6E-dienoic acid from microcystin LR by the treatment with various proteases, and its detection in mouce liver.

Microcystin LR metabolism in mammals was examined. The degradation of microcystin LR by the enzymes, pepsin, trypsin and chymotrypsin, from porcine or human gastrointestinal tract was examined. Microcystin LR was digested by these proteases, but 3-amino-2, 6, 8-trimethyl-10-phenyldeca-4E, 6E-dienoic acid (DmADDA) was not formed from microcystin LR treated with pepsin and chymotrypsin. The formation of DmADDA was detected from microcystin LR treated with trypsin. Furthermore, DmADDA was detected from the male ddY mice liver orally administered microcystin LR.