Solid-state and solution NMR in the quality control of guaco (Mikania glomerata)

Nuclear Magnetic Resonance (NMR) is used worldwide for structural determination, quantification, and quality control assessment. In this work, fresh stems (Figure 1-a), fresh leaves (b), dry leaves (c), and commercial dry leaves (d) were compared using semisolid and solution-state NMR. It was observed that the commercial samples contain only traces of 1,2-benzopirone, the main biomarker of the species. Therefore, NMR can be a fast, simple, and valuable tool for quality control of guaco.