Structure and absolute configuration of helosides A and B, new saponins from Chamaelirium luteum.
Challinor, Victoria L.; Stuthe, Julia M. U.; Bernhardt, Paul V.; Lehmann, Reginald P.; Kitching, William; De Voss, James J.; Journal of natural products 74 (2011) 1557–1560; doi:10.1021/np200100a

data_1501821
_publ_section_title
;
 Structure and absolute configuration of helosides A and B, new saponins
 from Chamaelirium luteum.
;
_journal_issue                   7
_journal_name_full               'Journal of natural products'
_journal_page_first              1557
_journal_page_last               1560
_journal_paper_doi               10.1021/np200100a
_journal_volume                  74
_journal_year                    2011
_chemical_absolute_configuration ad
_chemical_compound_source        'synthesis as described'
_chemical_formula_moiety         '(C27 H46 O5), 0.5(C H4 O)'
_chemical_formula_sum            'C27.5 H48 O5.5'
_chemical_formula_weight         466.66
_space_group_IT_number           19
_symmetry_cell_setting           orthorhombic
_symmetry_Int_Tables_number      19
_symmetry_space_group_name_Hall  'P 2ac 2ab'
_symmetry_space_group_name_H-M   'P 21 21 21'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_conform_dict_location     ftp://ftp.iucr.org/pub/cif_core.dic
_audit_conform_dict_name         cif_core.dic
_audit_conform_dict_version      2.3
_audit_creation_date             2010-04-20T14:33:32-00:00
_audit_creation_method           'WinGX routine CIF_UPDATE'
_cell_angle_alpha                90
_cell_angle_beta                 90
_cell_angle_gamma                90
_cell_formula_units_Z            4
_cell_length_a                   6.10590(10)
_cell_length_b                   12.3606(2)
_cell_length_c                   34.9384(6)
_cell_measurement_reflns_used    16195
_cell_measurement_temperature    293(2)
_cell_measurement_theta_max      60.4386
_cell_measurement_theta_min      3.5709
_cell_measurement_wavelength     1.5418
_cell_volume                     2636.89(8)
_computing_molecular_graphics    'Ortep-3 for Windows (Farrugia, 1997)'
_computing_publication_material  'WinGX publication routines (Farrugia, 1999)'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-86 (Sheldrick, 1986)'
_diffrn_ambient_temperature      293(2)
_diffrn_measured_fraction_theta_full 0.999
_diffrn_measured_fraction_theta_max 0.999
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_probe          x-ray
_diffrn_radiation_type           CuK\a
_diffrn_radiation_wavelength     1.54184
_diffrn_reflns_av_R_equivalents  0.029
_diffrn_reflns_av_unetI/netI     0.0158
_diffrn_reflns_limit_h_max       6
_diffrn_reflns_limit_h_min       -6
_diffrn_reflns_limit_k_max       13
_diffrn_reflns_limit_k_min       -13
_diffrn_reflns_limit_l_max       39
_diffrn_reflns_limit_l_min       -39
_diffrn_reflns_number            35496
_diffrn_reflns_theta_full        60.53
_diffrn_reflns_theta_max         60.53
_diffrn_reflns_theta_min         3.79
_exptl_absorpt_coefficient_mu    0.633
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.175
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       prism
_exptl_crystal_F_000             1028
_exptl_crystal_size_max          0.2
_exptl_crystal_size_mid          0.2
_exptl_crystal_size_min          0.08
_refine_diff_density_max         0.739
_refine_diff_density_min         -0.269
_refine_diff_density_rms         0.066
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   -0.1(4)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.04
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     312
_refine_ls_number_reflns         3965
_refine_ls_number_restraints     2
_refine_ls_restrained_S_all      1.042
_refine_ls_R_factor_all          0.0637
_refine_ls_R_factor_gt           0.0593
_refine_ls_shift/su_max          0
_refine_ls_shift/su_mean         0
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.1599P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1813
_refine_ls_wR_factor_ref         0.1866
_reflns_number_gt                3522
_reflns_number_total             3965
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            np200100a_si_002.cif
_cod_data_source_block           379vc1
_cod_database_code               1501821