Carpedilactones A-D, Four New Isomeric Sesquiterpene Lactone Dimers with Potent Cytotoxicity from Carpesium faberi.
Yang, Yong-Xun; Shan, Lei; Liu, Qing-Xin; Shen, Yun-Heng; Zhang, Jian-Ping; Ye, Ji; Xu, Xi-Ke; Li, Hui-Liang; Zhang, Wei-Dong; Organic letters 16 (2014) 4216–4219; doi:10.1021/ol501923k

data_1517267
_publ_section_title
;
 Carpedilactones A-D, Four New Isomeric Sesquiterpene Lactone Dimers with
 Potent Cytotoxicity from Carpesium faberi.
;
_journal_issue                   16
_journal_name_full               'Organic letters'
_journal_page_first              4216
_journal_page_last               4219
_journal_paper_doi               10.1021/ol501923k
_journal_volume                  16
_journal_year                    2014
_chemical_absolute_configuration ad
_chemical_formula_sum            'C30 H38 O6'
_chemical_formula_weight         494.60
_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                   8.46880(10)
_cell_length_b                   9.6160(2)
_cell_length_c                   32.4284(5)
_cell_measurement_reflns_used    8791
_cell_measurement_temperature    140(2)
_cell_measurement_theta_max      68.67
_cell_measurement_theta_min      2.73
_cell_volume                     2640.84(8)
_computing_cell_refinement       'Bruker SAINT'
_computing_data_collection       'Bruker APEX2'
_computing_data_reduction        'Bruker SAINT'
_computing_molecular_graphics    'Bruker SHELXTL'
_computing_publication_material  'Bruker SHELXTL'
_computing_structure_refinement  'SHELXL-2013 (Sheldrick, 2013)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 2008)'
_diffrn_ambient_temperature      140(2)
_diffrn_measured_fraction_theta_full 0.997
_diffrn_measured_fraction_theta_max 0.982
_diffrn_measurement_device_type  'Bruker APEX-II CCD'
_diffrn_measurement_method       '\f and \w scans'
_diffrn_radiation_type           CuK\a
_diffrn_radiation_wavelength     1.54178
_diffrn_reflns_av_R_equivalents  0.0467
_diffrn_reflns_av_unetI/netI     0.0400
_diffrn_reflns_Laue_measured_fraction_full 0.997
_diffrn_reflns_Laue_measured_fraction_max 0.982
_diffrn_reflns_limit_h_max       10
_diffrn_reflns_limit_h_min       -7
_diffrn_reflns_limit_k_max       11
_diffrn_reflns_limit_k_min       -8
_diffrn_reflns_limit_l_max       39
_diffrn_reflns_limit_l_min       -39
_diffrn_reflns_number            17018
_diffrn_reflns_point_group_measured_fraction_full 0.978
_diffrn_reflns_point_group_measured_fraction_max 0.957
_diffrn_reflns_theta_full        67.679
_diffrn_reflns_theta_max         69.724
_diffrn_reflns_theta_min         2.725
_exptl_absorpt_coefficient_mu    0.689
_exptl_absorpt_correction_T_max  0.753
_exptl_absorpt_correction_T_min  0.415
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   sadabs
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.244
_exptl_crystal_description       block
_exptl_crystal_F_000             1064
_exptl_crystal_size_max          0.290
_exptl_crystal_size_mid          0.120
_exptl_crystal_size_min          0.100
_refine_diff_density_max         0.228
_refine_diff_density_min         -0.253
_refine_diff_density_rms         0.051
_refine_ls_abs_structure_details
; 
 Flack x determined using 1867 quotients [(I+)-(I-)]/[(I+)+(I-)] 
 (Parsons and Flack (2004), Acta Cryst. A60, s61). 
;
_refine_ls_abs_structure_Flack   0.00(7)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.023
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     330
_refine_ls_number_reflns         4770
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.023
_refine_ls_R_factor_all          0.0373
_refine_ls_R_factor_gt           0.0366
_refine_ls_shift/su_max          0.018
_refine_ls_shift/su_mean         0.002
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w=1/[\s^2^(Fo^2^)+(0.0578P)^2^+0.4550P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0934
_refine_ls_wR_factor_ref         0.0941
_reflns_Friedel_coverage         0.695
_reflns_Friedel_fraction_full    0.952
_reflns_Friedel_fraction_max     0.923
_reflns_number_gt                4632
_reflns_number_total             4770
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            ol501923k_si_004.cif
_cod_data_source_block           cu_dm14100_0m
_cod_depositor_comments
'Adding full bibliography for 1517265--1517268.cif.'
_cod_database_code               1517267
_shelx_estimated_absorpt_t_min   0.825
_shelx_estimated_absorpt_t_max   0.934
_shelxl_version_number           2013-4
_shelx_res_checksum              7220
_shelx_hkl_checksum              63400