C–C Bond Cleavage in the Late-Stage Biosynthesis of Huperzine Alkaloids Occurs via Enzymatic Retro-Aza-Prins Reaction - Stefan E. Payer; Mario Prejanò; Philipp Kögl; Tamara Reiter; Eva-Maria Pferschy-Wenzig; Fahmi Himo; Wolfgang Kroutil (Journal of the American Chemical Society, 2025)