Composition #1: TINTO, WF., REYNOLDS, WF., SEAFORTH, CE., MOHAMMED, S., MAXWELL, A. NEW BITTER SAPONINS FROM THE BARK OF COLUBRINA-ELLIPTICA - H-1 AND C-13 ASSIGNMENTS BY 2D NMR-SPECTROSCOPY. MAGNETIC RESONANCE IN CHEMISTRY, 1993, vol. 31, no. 9, p. 859–864. DOI: 10.1002/mrc.1260310913.
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