Dioscorealides and dioscoreanone, novel cytotoxic naphthofuranoxepins, and 1,4-phenanthraquinone from Dioscorea membranacea Pierre.
Itharat, Arunporn; Plubrukarn, Anuchit; Kongsaeree, Palangpon; Bui, Tam; Keawpradub, Niwat; Houghton, Peter J.; Organic letters 5 (2003) 2879–2882; doi:10.1021/ol034926y

data_1507348
_publ_section_title
;
 Dioscorealides and dioscoreanone, novel cytotoxic naphthofuranoxepins,
 and 1,4-phenanthraquinone from Dioscorea membranacea Pierre.
;
_journal_issue                   16
_journal_name_full               'Organic letters'
_journal_page_first              2879
_journal_page_last               2882
_journal_paper_doi               10.1021/ol034926y
_journal_volume                  5
_journal_year                    2003
_chemical_compound_source        'Dioscorea membranacea Pierre'
_chemical_formula_moiety         'C17 H14 O6 '
_chemical_formula_sum            'C17 H14 O6'
_chemical_formula_weight         314.293
_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_primary     direct
_atom_sites_solution_secondary   difmap
_cell_angle_alpha                90.00
_cell_angle_beta                 90.00
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   6.6975(3)
_cell_length_b                   14.1282(13)
_cell_length_c                   15.0059(11)
_cell_measurement_reflns_used    1443
_cell_measurement_temperature    298
_cell_measurement_theta_max      26.373
_cell_measurement_theta_min      2.910
_cell_volume                     1419.91(18)
_computing_cell_refinement       'HKL Scalepack (Otwinowski & Minor 1997)'
_computing_data_collection       KappaCCD
_computing_data_reduction        'Denzo and Scalepak (Otwinowski & Minor, 1997)'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution
'SIR97(Cascarano al.,Acta Cryst.,1996,A52,C-79)'
_diffrn_measured_fraction_theta_full 0.902
_diffrn_measured_fraction_theta_max 0.902
_diffrn_measurement_device       KappaCCD
_diffrn_measurement_method       CCD
_diffrn_orient_matrix_type       X=UH
_diffrn_orient_matrix_UB_11      -0.03456
_diffrn_orient_matrix_UB_12      0.10081
_diffrn_orient_matrix_UB_13      0.10457
_diffrn_orient_matrix_UB_21      0.01425
_diffrn_orient_matrix_UB_22      0.05221
_diffrn_orient_matrix_UB_23      -0.04562
_diffrn_orient_matrix_UB_31      -0.06343
_diffrn_orient_matrix_UB_32      -0.00054
_diffrn_orient_matrix_UB_33      -0.02044
_diffrn_radiation_source         'fine-focus sealed tube'
_diffrn_radiation_type           ' MoK\a'
_diffrn_radiation_wavelength_id  all
_diffrn_reflns_limit_h_max       7
_diffrn_reflns_limit_h_min       -7
_diffrn_reflns_limit_k_max       16
_diffrn_reflns_limit_k_min       -16
_diffrn_reflns_limit_l_max       18
_diffrn_reflns_limit_l_min       -18
_diffrn_reflns_number            2652
_diffrn_reflns_theta_full        26.33
_diffrn_reflns_theta_max         26.33
_diffrn_reflns_theta_min         3.07
_exptl_absorpt_coefficient_mu    0.112
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            Colourless
_exptl_crystal_density_diffrn    1.470
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       prism
_exptl_crystal_size_max          0.20
_exptl_crystal_size_mid          0.20
_exptl_crystal_size_min          0.10
_refine_diff_density_max         0.110
_refine_diff_density_min         -0.119
_refine_diff_density_rms         0.030
_refine_ls_extinction_coef       0.069(10)
_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   1.030
_refine_ls_hydrogen_treatment    refxyz
_refine_ls_matrix_type           full
_refine_ls_number_parameters     209
_refine_ls_number_reflns         2641
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.030
_refine_ls_R_factor_all          0.0463
_refine_ls_R_factor_gt           0.0395
_refine_ls_shift/su_max          0.001
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0592P)^2^+0.2020P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0993
_refine_ls_wR_factor_ref         0.1063
_reflns_number_gt                2389
_reflns_number_total             2641
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            ol034926ysi20030627_114914.cif
_cod_data_source_block           dioscorealide_A
_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 2.4.1 from 2010-06-29.

Automatic conversion script
Id: cif_fix_values 1715 2011-07-08 13:25:40Z adriana 
;
_cod_original_cell_volume        1419.9(2)
_cod_original_sg_symbol_H-M      'P 21 21 21    '
_cod_original_formula_sum        'C17 H14 O6 '
_cod_database_code               1507348