Bioactive Sesquiterpenes and Lignans from the Fruits of Xanthium sibiricum.
Shi, Yu-Sheng; Liu, Yun-Bao; Ma, Shuang-Gang; Li, Yong; Qu, Jing; Li, Li; Yuan, Shao-Peng; Hou, Qi; Li, Yu-Huan; Jiang, Jian-Dong; Yu, Shi-Shan; Journal of natural products 78 (2015) 1526–1535; doi:10.1021/np500951s

data_1520671
_publ_section_title
;
 Bioactive Sesquiterpenes and Lignans from the Fruits of Xanthium
 sibiricum.
;
_journal_issue                   7
_journal_name_full               'Journal of natural products'
_journal_page_first              1526
_journal_page_last               1535
_journal_paper_doi               10.1021/np500951s
_journal_volume                  78
_journal_year                    2015
_chemical_formula_sum            'C15 H16 O3'
_chemical_formula_weight         244.28
_space_group_IT_number           92
_symmetry_space_group_name_Hall  'P 4abw 2nw'
_symmetry_space_group_name_H-M   'P 41 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            8
_cell_length_a                   9.6557(17)
_cell_length_b                   9.6557(17)
_cell_length_c                   26.319(4)
_cell_measurement_temperature    293(2)
_cell_volume                     2453.8(7)
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      293(2)
_diffrn_measured_fraction_theta_full 0.999
_diffrn_measured_fraction_theta_max 1.000
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'fine-focus sealed tube'
_diffrn_radiation_type           CuK\a
_diffrn_radiation_wavelength     1.54184
_diffrn_reflns_av_R_equivalents  0.0308
_diffrn_reflns_av_sigmaI/netI    0.0270
_diffrn_reflns_limit_h_max       8
_diffrn_reflns_limit_h_min       -11
_diffrn_reflns_limit_k_max       10
_diffrn_reflns_limit_k_min       -11
_diffrn_reflns_limit_l_max       30
_diffrn_reflns_limit_l_min       -31
_diffrn_reflns_number            9461
_diffrn_reflns_theta_full        68.94
_diffrn_reflns_theta_max         68.94
_diffrn_reflns_theta_min         4.88
_exptl_absorpt_coefficient_mu    0.740
_exptl_absorpt_correction_T_max  0.8970
_exptl_absorpt_correction_T_min  0.6447
_exptl_crystal_density_diffrn    1.322
_exptl_crystal_density_method    'not measured'
_exptl_crystal_F_000             1040
_exptl_crystal_size_max          0.65
_exptl_crystal_size_mid          0.20
_exptl_crystal_size_min          0.15
_refine_diff_density_max         0.172
_refine_diff_density_min         -0.156
_refine_diff_density_rms         0.034
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   0.2(2)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.025
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     165
_refine_ls_number_reflns         2288
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.025
_refine_ls_R_factor_all          0.0358
_refine_ls_R_factor_gt           0.0334
_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^)+(0.0441P)^2^+0.4960P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0821
_refine_ls_wR_factor_ref         0.0839
_reflns_number_gt                2172
_reflns_number_total             2288
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            np500951s_si_002.cif
_cod_data_source_block           exp_1882
_cod_depositor_comments
'Adding full bibliography for 1520671--1520672.cif.'
_cod_database_code               1520671