17-Norpimaranes and (9βH)-17-Norpimaranes from the Tuber of Icacina trichantha.
Zhao, Ming; Onakpa, Michael Monday; Chen, Wei-Lun; Santarsiero, Bernard D.; Swanson, Steven M.; Burdette, Joanna E.; Asuzu, Isaac Uzoma; Che, Chun-Tao; Journal of natural products 78 (2015) 789–796; doi:10.1021/np5010328

data_1518868
_publ_section_title
;
 17-Norpimaranes and (9\bH)-17-Norpimaranes from the Tuber of Icacina
 trichantha.
;
_journal_issue                   4
_journal_name_full               'Journal of natural products'
_journal_page_first              789
_journal_page_last               796
_journal_paper_doi               10.1021/np5010328
_journal_volume                  78
_journal_year                    2015
_chemical_formula_sum            'C20 H20 O6'
_chemical_formula_weight         356.36
_space_group_crystal_system      orthorhombic
_space_group_IT_number           19
_space_group_name_Hall           'P 2ac 2ab'
_space_group_name_H-M_alt        'P 21 21 21'
_symmetry_space_group_name_Hall  'P 2ac 2ab'
_symmetry_space_group_name_H-M   'P 21 21 21'
_atom_sites_solution_hydrogens   geom
_audit_creation_method           SHELXL-2013
_cell_angle_alpha                90
_cell_angle_beta                 90
_cell_angle_gamma                90
_cell_formula_units_Z            4
_cell_length_a                   6.2991(2)
_cell_length_b                   10.5035(4)
_cell_length_c                   24.7572(9)
_cell_measurement_temperature    100(2)
_cell_volume                     1638.00(10)
_computing_structure_refinement  'SHELXL-2013 (Sheldrick, 2013)'
_diffrn_ambient_temperature      100(2)
_diffrn_measured_fraction_theta_full 0.996
_diffrn_measured_fraction_theta_max 0.995
_diffrn_radiation_type           CuK\a
_diffrn_radiation_wavelength     1.54178
_diffrn_reflns_av_R_equivalents  0.0286
_diffrn_reflns_av_unetI/netI     0.0165
_diffrn_reflns_Laue_measured_fraction_full 0.996
_diffrn_reflns_Laue_measured_fraction_max 0.995
_diffrn_reflns_limit_h_max       7
_diffrn_reflns_limit_h_min       -7
_diffrn_reflns_limit_k_max       11
_diffrn_reflns_limit_k_min       -12
_diffrn_reflns_limit_l_max       29
_diffrn_reflns_limit_l_min       -25
_diffrn_reflns_number            16634
_diffrn_reflns_point_group_measured_fraction_full 0.994
_diffrn_reflns_point_group_measured_fraction_max 0.993
_diffrn_reflns_theta_full        67.679
_diffrn_reflns_theta_max         68.136
_diffrn_reflns_theta_min         3.570
_exptl_absorpt_coefficient_mu    0.888
_exptl_crystal_density_diffrn    1.445
_exptl_crystal_F_000             752
_exptl_crystal_size_max          0.332
_exptl_crystal_size_mid          0.304
_exptl_crystal_size_min          0.202
_refine_diff_density_max         0.307
_refine_diff_density_min         -0.436
_refine_diff_density_rms         0.094
_refine_ls_abs_structure_details
;
 Flack x determined using 1219 quotients [(I+)-(I-)]/[(I+)+(I-)]
 (Parsons and Flack (2004), Acta Cryst. A60, s61).
;
_refine_ls_abs_structure_Flack   0.00(3)
_refine_ls_extinction_coef       0.064(2)
_refine_ls_extinction_expression Fc^*^=kFc[1+0.001xFc^2^\l^3^/sin(2\q)]^-1/4^
_refine_ls_extinction_method     SHELXL
_refine_ls_goodness_of_fit_ref   1.206
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     239
_refine_ls_number_reflns         2981
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.206
_refine_ls_R_factor_all          0.0331
_refine_ls_R_factor_gt           0.0330
_refine_ls_shift/su_max          0.001
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w=1/[\s^2^(Fo^2^)+(0.0451P)^2^+0.3247P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0787
_refine_ls_wR_factor_ref         0.0788
_reflns_Friedel_coverage         0.699
_reflns_Friedel_fraction_full    0.991
_reflns_Friedel_fraction_max     0.989
_reflns_number_gt                2969
_reflns_number_total             2981
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            np5010328_si_002.cif
_cod_data_source_block           a
_cod_depositor_comments          'Adding full bibliography for 1518868.cif.'
_cod_database_code               1518868
_shelx_estimated_absorpt_t_min   0.757
_shelx_estimated_absorpt_t_max   0.841
_shelxl_version_number           2013-3
_shelx_res_checksum              17445
_shelx_hkl_checksum              68548