Secoyanhusamine A, an Oxidatively Ring-Opened Isoquinoline Inner Salt From .

Secoyanhusamine A (), a rare rearranged -isoquinoline alkaloid derived from ring oxidative cleavage, was isolated from an aqueous extract of tubers, together with its biosynthetic precursor dehydrocorybulbine (). Secoyanhusamine A () was the first example of a highly oxidized isoquinoline inner salt resulting in a 5-(2-azanylethyl)-2-carboxylate-4-oxo-4-pyran ring system. The biosynthetic pathway of was also postulated. Secoyanhusamine A () exhibited potent inhibition against acetylcholinesterase (AChE) with an IC value of 0.81 ± 0.13 M. Molecular simulation docking demonstrated that created a strong interaction with the Asp-74 residue of AChE attractive charge of the quaternary nitrogen.