4,4'-Bismoschamine: biomimetic synthesis and evidence to support structural equivalency to montamine.

The dimeric natural product montamine was originally reported as two N-feruloylserotonin (moschamine) units linked by a nitrogen-nitrogen bond, but our recent synthesis of this symmetrical diacyl hydrazide structure revealed this to be incorrect. We subsequently hypothesized that the moschamine subunits were linked through the indole C4 site and that montamine was structurally identical to 4,4'-bismoschamine, a known natural product present in safflower oil. However, given that authentic samples of both montamine and 4,4'-bismoschamine were unavailable and that the NMR data for the natural products were recorded in different solvents, we were unable to unequivocally prove this hypothesis.