Cucurbitane triterpenoids from Leucopaxillus gentianeus.
Clericuzio, Marco; Mella, Mariella; Vita-Finzi, Paola; Zema, Michele; Vidari, Giovanni; Journal of natural products 67 (2004) 1823–1828; doi:10.1021/np049883o

data_1506868
_publ_section_title
;
 Cucurbitane triterpenoids from Leucopaxillus gentianeus.
;
_journal_issue                   11
_journal_name_full               'Journal of natural products'
_journal_page_first              1823
_journal_page_last               1828
_journal_paper_doi               10.1021/np049883o
_journal_volume                  67
_journal_year                    2004
_chemical_formula_sum            'C37 H62 O8'
_chemical_formula_weight         634.87
_space_group_IT_number           4
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  'P 2yb'
_symmetry_space_group_name_H-M   'P 1 21 1'
_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                 95.72(3)
_cell_angle_gamma                90.00
_cell_formula_units_Z            2
_cell_length_a                   15.189(5)
_cell_length_b                   7.530(3)
_cell_length_c                   15.593(5)
_cell_measurement_reflns_used    25
_cell_measurement_temperature    293(2)
_cell_measurement_theta_max      9.42
_cell_measurement_theta_min      6.13
_cell_volume                     1774.5(11)
_computing_cell_refinement       'CAD4 Express (Enraf Nonius, 1994)'
_computing_data_collection       'CAD4 Express (Enraf Nonius, 1994)'
_computing_data_reduction        'XCAD4 (Harms & Wocadlo, 1995)'
_computing_molecular_graphics    'Ortep-3 (Farrugia, 1997)'
_computing_publication_material  'WinGX (Farrugia, 1998)'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SIR92 (Altomare et al, 1993)'
_diffrn_ambient_temperature      293(2)
_diffrn_measured_fraction_theta_full 0.999
_diffrn_measured_fraction_theta_max 0.999
_diffrn_measurement_device_type  'Enraf Nonius CAD4'
_diffrn_measurement_method       'non-profiled 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  0.0593
_diffrn_reflns_av_sigmaI/netI    0.1790
_diffrn_reflns_limit_h_max       17
_diffrn_reflns_limit_h_min       -18
_diffrn_reflns_limit_k_max       8
_diffrn_reflns_limit_k_min       -7
_diffrn_reflns_limit_l_max       18
_diffrn_reflns_limit_l_min       -14
_diffrn_reflns_number            5406
_diffrn_reflns_theta_full        24.99
_diffrn_reflns_theta_max         24.99
_diffrn_reflns_theta_min         2.63
_diffrn_standards_decay_%        0
_diffrn_standards_interval_time  240
_diffrn_standards_number         3
_exptl_absorpt_coefficient_mu    0.082
_exptl_absorpt_correction_T_max  0.994
_exptl_absorpt_correction_T_min  0.971
_exptl_absorpt_correction_type   psi-scan
_exptl_absorpt_process_details
;
'North, Philips and Mathews, 1968'
;
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.188
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       prism
_exptl_crystal_F_000             696
_exptl_crystal_size_max          0.35
_exptl_crystal_size_mid          0.32
_exptl_crystal_size_min          0.07
_refine_diff_density_max         0.182
_refine_diff_density_min         -0.215
_refine_diff_density_rms         0.040
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   -3(3)
_refine_ls_extinction_coef       0.0065(16)
_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   0.971
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     416
_refine_ls_number_reflns         3375
_refine_ls_number_restraints     4
_refine_ls_restrained_S_all      0.970
_refine_ls_R_factor_all          0.2180
_refine_ls_R_factor_gt           0.0607
_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^)+(0.0498P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1090
_refine_ls_wR_factor_ref         0.1466
_reflns_number_gt                1362
_reflns_number_total             3375
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            np049883osi20040706_111113.cif
_cod_data_source_block           vida1
_cod_original_cell_volume        1774.6(12)
_cod_original_sg_symbol_H-M      'P 21'
_cod_database_code               1506868