Novel lignan-based compounds via click chemistry: paulownin isolation, structural modifications and cytotoxic activity evaluations

Paulownin, a natural compound obtained from the tree Tecoma stans var. stans, was chemically modified by alkylation of its hydroxyl position. Thirteen novel lignans derivatives synthesized via a copper-catalyzed cycloaddition (CuAAC), known as click reaction, using different organic azides and lignan terminal alkyne. Characterization by mass spectrometry, NMR (1H and 13C) and infrared spectroscopy.