Bonducellpins A−D, New Cassane Furanoditerpenes of Caesalpinia bonduc

Abstract

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.

New Cassane-Type Diterpenes of Caesalpinia crista from Myanmar

“…The 13 C-NMR spectrum of 3 had 24 signals including a carboxyl carbon, two ester carbonyl carbons, four olefinic carbons, four oxygen-substituted carbons, and three aliphatic methylene carbons (Table 1). These spectral data were similar to those of bonducellpin A, 9) except for the presence of a carboxylic acid functionality at C-17 instead of a carbomethoxyl group. Analysis of the COSY, HMQC, HMBC, and ROESY correlations assigned the structure 3 to caesalpinin MH.…”

“…Moreover, the 13 C-NMR spectrum of 1 showed four olefinic carbons (d 150.7, 141.1, 113.9, 108.8) and three oxygen-substituted carbons (d 76.9, 76.8, 73.7) together with three ester carbonyl carbons (d 169.3, 169.3, 174.5). These 1 H-and 13 C-NMR data were similar to those of 7-acetoxybonducellpin C (9), 9) except for the difference in the location of one of the acetyl groups. Analysis of the correlation spectroscopy (COSY) and heteronuclear multiple-quantum coherence (HMQC) spectra indicated downfield shift of H-3 (d 4.95) and upfield shift of H-7 (d 1.72) compared to those of 9 (H-3; d 1.15, H-7; d 5.22).…”

“…The fractions 4 and 5 were further subjected to repeated silica gel column chromatography, followed by normal-and reversed-phase preparative TLC, to afford seven new cassane-type diterpenes, caesalpinins MF-ML (1-7), and a new norcassane-type diterpene, norcaesalpinin MD (8), together with sixteen known diterpenes, 7-acetoxybonducellpin C, 9) caesaldekarin e, 10) caesalmin C, 5) caesalmin G, 5) 2-acetoxycaesaldekarin e, 11) zcaesalpin, 12) caesalpinin D, 4) caesalpinin E, 4) caesalpinin F, 8) caesalpinin H, 8) caesalpinin I, 8) caesalpinin J, 8) caesalpinin K, 8) caesalpinin M, 8) caesalpinin N, 8) and caesalpinin O. 8) Caesalpinin MF (1) 13 C-NMR data were similar to those of 7-acetoxybonducellpin C (9), 9) except for the difference in the location of one of the acetyl groups. Analysis of the correlation spectroscopy (COSY) and heteronuclear multiple-quantum coherence (HMQC) spectra indicated downfield shift of H-3 (d 4.95) and upfield shift of H-7 (d 1.72) compared to those of 9 (H-3; d 1.15, H-7; d 5.22).…”

“…Subfraction 4-1 (250 mg) was further subjected to reversed-phase preparative TLC with MeOH-CH 3 CN-H 2 O (2 : 1 : 1) to give caesalpinin MF (1, 9.0 mg), 2-acetoxycaesaldekarin e (18.2 mg), 11) caesaldekarin e (5.2 mg), 10) caesalmin C (15.7 mg), 5) and z-caesalpin (2.2 mg). 12) Subfraction 4-2 (400 mg) was separated by normal-phase preparative TLC with 2% acetone-CHCl 3 to give norcaesalpinin MD (8, 2.0 mg), 2-acetoxycaesaldekarin e (20.0 mg), 11) caesalpinin D (59.0 mg), 4) caesalpinin E (5.0 mg), 4) 7-acetoxybonducellpin C (3.0 mg), 9) and caesalmin G (3.0 mg). 5) Subfraction 4-3 (350 mg) was subjected to normal-phase preparative TLC with 2% acetone-CHCl 3 to give caesalpinin MG (2, 10.0 mg), caesalpinin MH (3, 7.0 mg), and caesalpinin F (9.0 mg).…”

Constituents of Caesalpinia crista from Indonesia

“…Thus, the presence of a ketone instead of the hydroxyl substituent at C-1 was assumed, which was confirmed by the HMBC correlations of C-1 with H 2 -2, H 2 -3, and H 3 -20 in its HMBC spectrum. The relative stereochemistry of 2 was determined on the basis of coupling constants and the analysis C-NMR spectra of 3 were similar to those of bonducellpin B (12), 14) except for the presence of signals due to an additional acetyl group. The location of the additional acetyl group was determined to be at C-7 from the lowfield shift of H-7 (3: d H 5.32; 12: d H 3.75) and the HMBC correlations (Fig.…”