Bonducellpins A−D, New Cassane Furanoditerpenes of Caesalpinia bonduc

Four cassane furanoditerpenes, designated bonducellpins A (1), B (2), C (3), and D (4), were isolated from the roots of Caesalpinia bonduc. The 1H- and 13C-NMR spectra of all four compounds were completely assigned by using a combination of 2D NMR experiments, which included COSY, HMQC, HMBC, and NOESY sequences.