Strychnan and secoangustilobine A type alkaloids from Alstonia spatulata. Revision of the C-20 configuration of scholaricine.
Tan, Shin-Jowl; Low, Yun-Yee; Choo, Yeun-Mun; Abdullah, Zanariah; Etoh, Tadahiro; Hayashi, Masahiko; Komiyama, Kanki; Kam, Toh-Seok; Journal of natural products 73 (2010) 1891–1897; doi:10.1021/np100552b

data_1502815
_publ_section_title
;
 Strychnan and secoangustilobine A type alkaloids from Alstonia spatulata.
 Revision of the C-20 configuration of scholaricine.
;
_journal_issue                   11
_journal_name_full               'Journal of natural products'
_journal_page_first              1891
_journal_page_last               1897
_journal_paper_doi               10.1021/np100552b
_journal_volume                  73
_journal_year                    2010
_chemical_absolute_configuration syn
_chemical_formula_moiety         '2(C20 H24 N2 O4), C4 H8 O2, H2 O'
_chemical_formula_sum            'C44 H58 N4 O11'
_chemical_formula_weight         818.94
_chemical_name_common            Scholaricine
_space_group_IT_number           19
_symmetry_cell_setting           orthorhombic
_symmetry_space_group_name_Hall  'P 2ac 2ab'
_symmetry_space_group_name_H-M   'P 21 21 21'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL-97
_cell_angle_alpha                90.00
_cell_angle_beta                 90.00
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   10.4901(3)
_cell_length_b                   18.5736(5)
_cell_length_c                   21.1075(5)
_cell_measurement_reflns_used    3615
_cell_measurement_temperature    100(2)
_cell_measurement_theta_max      24.89
_cell_measurement_theta_min      2.22
_cell_volume                     4112.56(19)
_computing_cell_refinement       'SAINT (Bruker, 2007)'
_computing_data_collection       'APEX2 (Bruker, 2007)'
_computing_data_reduction        'SAINT (Bruker, 2007)'
_computing_molecular_graphics    'X-SEED (Barbour, 2001)'
_computing_publication_material
;  
SHELXL-97, enCIFer (Allen et al., 2004),
;
_computing_structure_refinement
;  
SHELXL97 (Sheldrick, 2008), Olex2 (Dolomanov & Puschmann, 2009)
;
_computing_structure_solution    'SHELXS97 (Sheldrick, 2008)'
_diffrn_ambient_temperature      100(2)
_diffrn_measured_fraction_theta_full 1.000
_diffrn_measured_fraction_theta_max 1.000
_diffrn_measurement_device_type  'Bruker APEX-II CCD'
_diffrn_measurement_method       '\w scans'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'fine-focus sealed tube'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.1005
_diffrn_reflns_av_sigmaI/netI    0.0549
_diffrn_reflns_limit_h_max       12
_diffrn_reflns_limit_h_min       -12
_diffrn_reflns_limit_k_max       22
_diffrn_reflns_limit_k_min       -22
_diffrn_reflns_limit_l_max       25
_diffrn_reflns_limit_l_min       -25
_diffrn_reflns_number            31934
_diffrn_reflns_theta_full        25.00
_diffrn_reflns_theta_max         25.00
_diffrn_reflns_theta_min         1.46
_exptl_absorpt_coefficient_mu    0.095
_exptl_absorpt_correction_T_max  0.7461
_exptl_absorpt_correction_T_min  0.6275
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   'SADBS (Bruker, 2006)'
_exptl_crystal_colour            yellow
_exptl_crystal_density_diffrn    1.326
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       block
_exptl_crystal_F_000             1760
_exptl_crystal_size_max          0.301
_exptl_crystal_size_mid          0.282
_exptl_crystal_size_min          0.096
_refine_diff_density_max         0.296
_refine_diff_density_min         -0.634
_refine_diff_density_rms         0.064
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.071
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     545
_refine_ls_number_reflns         4055
_refine_ls_number_restraints     3
_refine_ls_restrained_S_all      1.073
_refine_ls_R_factor_all          0.0839
_refine_ls_R_factor_gt           0.0592
_refine_ls_shift/su_max          0.002
_refine_ls_shift/su_mean         <0.001
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0922P)^2^+2.1355P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1509
_refine_ls_wR_factor_ref         0.1641
_reflns_number_gt                3126
_reflns_number_total             4055
_reflns_threshold_expression     I>2\s(I)
_cod_data_source_file            np100552b_si_003.cif
_cod_data_source_block           tsj_1728_0m
_cod_database_code               1502815