References
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- General Experimental Procedures. All the mps were obtained on a Koffler apparatus which was uncorrected. IR spectral data were measured on a Perkin-Elmer 577 or Bio-Rad FTS-135 spectrometer with KBr pellets. NMR spectra were recorded on a Bruker AM-400 or DRX-500 instrument with TMS as internal standard and pyridine-d 5 as solvent. 1H-NMR, 1H-1H COSY spectra were recorded at 400.13 or 500.13 MHz; 13C-NMR and DEPT spectra were recorded at 100.6 or 125.8 MHz. 13C-NMR assignments were determined by 13C-1H COSY and HMQC spectra. the HREIMS and FIMS data were carried out on a VG Auto Spec-3000 spectrometer
- Properties of 1: C22H32O5 (HREIMS found 376.2236, calc. 376.2250); colorless prisms, m.p. 199.2–200.6 °C; [α]D 22: +26.42° (CHCl3, c=0.27); UV (CHCl3) δmax : no absorption; IR vmax : 3365 (s), 2945 (s), 2920 (s), 2860 (s), 1725 (s), 1690 (s), 1430 (m), 1380 (s), 1230 (s), 1175 (s), 1105 (s), 1045 (s), 980 (s), 825 (m) cm−1; EIMS m/z (rel. int. %): 376 [M]+ (49), 333 (32), 316 (56), 298 (26), 288 (9), 273 (28), 219 (100), 201 (31); 1H-NMR δ: 6.35 (1H, d, J=5.8 Hz, H-1α-OH), 4.32 (1H, dd, J=5.8 and 3.0 Hz, H-1β), 2.22 (2H, t, J=3.0 Hz, H2-2α and 2β), 4.83 (1H, t, J=3.0 Hz, H-3α), 2.96 (1H, s, H-5β), 1.83 (1H, d, J=11.0 Hz, H-7β), 1.38 (1H, d, J=11.0 Hz, H-7α), 2.55 (1H, br d, J=3.4 H-9β), 5.71 (1H, t, J=3.4 Hz, H-11α), 1.94 (1H, dt, J=11.8 and 3.4 Hz, H-12α), 1.27 (1H, m, H-12β), 2.13 (1H, overlapped, H-13α), 2.15 (1H, overlapped, H-14β), 2.09 (1H, overlapped, H-14α), 2.75 (1H, d, J=13.3 Hz, H-15α), 2.10 (1H, d, J=13.3 Hz, H-15β), 1.38 (3H, s, Me-17), 1.08 (3H, s, Me-18), 1.50 (3H, s, Me-19), 1.34 (3H, s, Me-20), 2.00 (3H, s, Ac). 13C-NMR δ: 14.5 (C-20), 20.9 (AcO), 22.4 (C-19), 23.4 (C-17), 27.0 (C-18), 33.0 (C-2), 35.9 (C-4), 40.3 (C-14), 44.6 (C-12), 46.1 (C-13), 48.3 (C-8), 48.7 (C-10), 53.5 (C-15), 57.7 (C-7), 59.8 (C-9), 60.6 (C-5), 74.3 (C-1), 79.3 (C-3), 79.4 (C-11), 85.1 (C-16), 170.3 (AcO), 210.2 (C-6)
- Properties of 2: C26H36O8 (HREIMS found 476.2410, calc. 476.2393); colorless cubes, m.p. 94.7 −96.1 °C; [α]D 22: −94.88° (CHCl3, c=0.47); UV (CHCl3) δmax: 240 nm (log ν 3.91); IR vmax : 3473 (or m), 2945 (m), 2881 (m), 1734 (s), 1647 (m), 1456 (m), 1435 (m), 1372 (s), 1258 (s), 1240 (s), 1035 (s), 963 (m) cm−1; EIMS m/z (rel. int. %): 476 [M]+ (14), 433 (52), 416 (61), 373 (9), 356 (42), 331 (23), 313 (78), 296 (100), 278 (24), 253 (20), 241 (26), 200 (60); 1H-NMR δ: 4.31 (1H, d, J=10.0 Hz, H-1β), 5.68 (1H, dd, J=10.0 and 2.4 Hz, H-2α), 5.37 (1H, d, J=2.4 Hz, H-3α), 1.61 (1H, dd, J=11.7 and 2.8 Hz, H-5β), 1.49 (1H, br d, J=11.7 Hz, H-6β), 1.33 (1H, overlapped, H-6α), 2.20 (1H, overlapped, H-7β), 1.39 (1H, overlapped, H-7α), 2.11 (1H, br s, H-9β), 6.94 (1H, t, J=2.7 Hz, H-11α), 2.07 (2H, overlapped, H2-12β and 12α), 2.91 (1H, br d, J=3.0 Hz, H-13α), 2.38 (1H, d, J=12.1 Hz, H-14β), 1.34 (1H, overlapped, H-14α), 5.97 (1H, s, H-17a), 5.18 (1H, s, H-17b), 0.84 (3H, s, Me-18), 0.95 (3H, s, Me-19), 1.36 (3H, s, Me-20), 2.04, 1.86, 1.73 (each 3H, 3xAc). 13C-NMR δ: 15.7 (C-20), 18.2 (C-6), 20.6 (AcO), 20.9 (AcO), 21.3 (AcO), 21.4 (C-19), 28.1 (C-18), 34.6 (C-7), 37.1 (C-14), 37.3 (C-13), 37.6 (C-4), 38.1 (C-12), 45.3 (C-10), 49.0 (C-5), 51.1 (C-8), 60.4 (C-9), 71.5 (C-11), 72.7 (C-2), 76.7 (C-1), 77.9 (C-3), 111.9 (C-17), 151.3 (C-16), 169.5 (AcO), 170.7 (AcO), 170.8 (AcO), 208.4 (C-15)