heteronuclear multiple bond correlation unclassified drug 9 Article 8 proton nuclear magnetic resonance 7 bark 6 carbon nuclear magnetic resonance 6 drug structure 6 antiinflammatory activity 5 antiinflammatory agent 5 drug isolation 5 plant extract 5 xanthone derivative 5 Clusiaceae 4 Plant Bark 4 controlled study 4 heteronuclear multiple quantum coherence 4 mass spectrometry 4 nonhuman 4 Anti-inflammatory 3 IC50 3 Molecular Structure 3 Nuclear Magnetic Resonance, Biomolecular 3 Xanthones 3 chemical structure 3 chemistry 3 hexane 3 nuclear magnetic resonance spectroscopy 3 plant stem 3 priority journal 3 sitosterol 3