ent-kaurane and ent-pimarane diterpenoids from Siegesbeckia pubescens.
Wang, Rui; Chen, Wen-Hao; Shi, Yan-Ping; Journal of natural products 73 (2010) 17–21; doi:10.1021/np9005579

data_1502826
_publ_section_title
;
 ent-kaurane and ent-pimarane diterpenoids from Siegesbeckia pubescens.
;
_journal_issue                   1
_journal_name_full               'Journal of natural products'
_journal_page_first              17
_journal_page_last               21
_journal_paper_doi               10.1021/np9005579
_journal_volume                  73
_journal_year                    2010
_chemical_formula_sum            'C26 H40 O6'
_chemical_formula_weight         448.58
_space_group_IT_number           18
_symmetry_cell_setting           orthorhombic
_symmetry_space_group_name_Hall  'P 2 2ab'
_symmetry_space_group_name_H-M   'P 21 21 2'
_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                   21.962(3)
_cell_length_b                   7.6252(11)
_cell_length_c                   15.114(2)
_cell_measurement_reflns_used    2683
_cell_measurement_temperature    273(2)
_cell_measurement_theta_max      19.82
_cell_measurement_theta_min      2.83
_cell_volume                     2531.1(6)
_computing_cell_refinement       'Bruker SMART'
_computing_data_collection       'Bruker SMART'
_computing_data_reduction        'Bruker SAINT'
_computing_molecular_graphics    'Bruker SHELXTL'
_computing_publication_material  'Bruker SHELXTL'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      273(2)
_diffrn_measured_fraction_theta_full 0.996
_diffrn_measured_fraction_theta_max 0.996
_diffrn_measurement_device_type  'CCD area detector'
_diffrn_measurement_method       'phi and omega 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  0.0333
_diffrn_reflns_av_sigmaI/netI    0.0287
_diffrn_reflns_limit_h_max       23
_diffrn_reflns_limit_h_min       -23
_diffrn_reflns_limit_k_max       8
_diffrn_reflns_limit_k_min       -8
_diffrn_reflns_limit_l_max       12
_diffrn_reflns_limit_l_min       -15
_diffrn_reflns_number            10228
_diffrn_reflns_theta_full        22.09
_diffrn_reflns_theta_max         22.09
_diffrn_reflns_theta_min         1.64
_exptl_absorpt_coefficient_mu    0.082
_exptl_absorpt_correction_T_max  0.9853
_exptl_absorpt_correction_T_min  0.9782
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   SADABS
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.177
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       block
_exptl_crystal_F_000             976
_exptl_crystal_size_max          0.27
_exptl_crystal_size_mid          0.24
_exptl_crystal_size_min          0.19
_refine_diff_density_max         0.205
_refine_diff_density_min         -0.171
_refine_diff_density_rms         0.038
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   -0.1(19)
_refine_ls_extinction_coef       0.0074(14)
_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   1.069
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     299
_refine_ls_number_reflns         3131
_refine_ls_number_restraints     1
_refine_ls_restrained_S_all      1.075
_refine_ls_R_factor_all          0.0598
_refine_ls_R_factor_gt           0.0493
_refine_ls_shift/su_max          0.000
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0721P)^2^+0.5975P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1278
_refine_ls_wR_factor_ref         0.1361
_reflns_number_gt                2659
_reflns_number_total             3131
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            np9005579_si_004.cif
_cod_data_source_block           p212121
_cod_depositor_comments
;
The following automatic conversions were performed:

'_symmetry_cell_setting' value 'Orthorhombic' changed to
'orthorhombic' according to
/home/saulius/struct/CIF-dictionaries/cif_core.dic dictionary named
'cif_core.dic' version 2.4.2 from 2011-04-26.

Automatic conversion script
Id: cif_fix_values 1715 2011-07-08 13:25:40Z adriana 
;
_cod_original_cell_volume        2531.0(6)
_cod_original_sg_symbol_H-M      P2(1)2(1)2
_cod_database_code               1502826