Isolation and identification of L/D-lactate-conjugated bufadienolides from toad eggs revealing lactate racemization in amphibians
Zhou, Shi-Wen; Zheng, Qingfei; Huang, Xiuyong; Wang, Yong; Luo, Sifan; Jiang, Ren-Wang; Wang, Lei; Ye, Wen-Cai; Tian, Hai-Yan; Org. Biomol. Chem.  (2017) –; doi:10.1039/C7OB01055A

data_7155687
_publ_section_title
;
 Isolation and identification of L/D-lactate-conjugated bufadienolides
 from toad eggs revealing lactate racemization in amphibians
;
_journal_name_full               'Org. Biomol. Chem.'
_journal_paper_doi               10.1039/C7OB01055A
_journal_year                    2017
_chemical_absolute_configuration re
_chemical_formula_sum            'C27 H38 N0 O8'
_chemical_formula_weight         490.57
_space_group_crystal_system      monoclinic
_space_group_IT_number           4
_space_group_name_Hall           'P 2yb'
_space_group_name_H-M_alt        'P 1 21 1'
_symmetry_space_group_name_Hall  'P 2yb'
_symmetry_space_group_name_H-M   'P 1 21 1'
_atom_sites_solution_hydrogens   mixed
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   direct
_audit_creation_method           SHELXL-2016/6
_audit_update_record
;
2017-04-27 deposited with the CCDC.
2017-06-14 downloaded from the CCDC.
;
_cell_angle_alpha                90
_cell_angle_beta                 96.497(3)
_cell_angle_gamma                90
_cell_formula_units_Z            2
_cell_length_a                   9.4990(2)
_cell_length_b                   10.4196(3)
_cell_length_c                   12.8765(5)
_cell_measurement_reflns_used    2161
_cell_measurement_temperature    173(2)
_cell_measurement_theta_max      62.7430
_cell_measurement_theta_min      3.4460
_cell_volume                     1266.28(7)
_computing_cell_refinement       'CrysAlis PRO '
_computing_data_collection       'CrysAlis PRO '
_computing_data_reduction        'CrysAlis PRO '
_computing_molecular_graphics    'XP (Sheldrick, 2008)'
_computing_publication_material  'XP (Sheldrick, 2008)'
_computing_structure_refinement  'SHELXL-2016/6 (Sheldrick, 2016)'
_computing_structure_solution    'SHELXT 2014/5 (Sheldrick, 2014)'
_diffrn_ambient_temperature      173(2)
_diffrn_detector_area_resol_mean 16.0288
_diffrn_measured_fraction_theta_full 0.9679
_diffrn_measured_fraction_theta_max 0.9949
_diffrn_measurement_device_type  'Enhance Ultra (Cu) X-ray Source'
_diffrn_measurement_method       '\w scans'
_diffrn_radiation_type           CuK\a
_diffrn_radiation_wavelength     1.54184
_diffrn_reflns_av_R_equivalents  0.0249
_diffrn_reflns_av_unetI/netI     0.0386
_diffrn_reflns_Laue_measured_fraction_full 0.995
_diffrn_reflns_Laue_measured_fraction_max 0.995
_diffrn_reflns_limit_h_max       10
_diffrn_reflns_limit_h_min       -9
_diffrn_reflns_limit_k_max       11
_diffrn_reflns_limit_k_min       -11
_diffrn_reflns_limit_l_max       14
_diffrn_reflns_limit_l_min       -14
_diffrn_reflns_number            5345
_diffrn_reflns_point_group_measured_fraction_full 0.784
_diffrn_reflns_point_group_measured_fraction_max 0.784
_diffrn_reflns_theta_full        63.5953
_diffrn_reflns_theta_max         62.7167
_diffrn_reflns_theta_min         3.4546
_diffrn_source                   'sealed X-ray tube'
_exptl_absorpt_coefficient_mu    0.771
_exptl_absorpt_correction_T_max  1.00000
_exptl_absorpt_correction_T_min  0.82302
_exptl_absorpt_correction_type   multi-scan
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.287
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       block
_exptl_crystal_F_000             528
_exptl_crystal_size_max          0.38
_exptl_crystal_size_mid          0.29
_exptl_crystal_size_min          0.25
_refine_diff_density_max         0.441
_refine_diff_density_min         -0.215
_refine_diff_density_rms         0.039
_refine_ls_abs_structure_details
;
 Flack x determined using 765 quotients [(I+)-(I-)]/[(I+)+(I-)]
 (Parsons, Flack and Wagner, Acta Cryst. B69 (2013) 249-259).
;
_refine_ls_abs_structure_Flack   -0.02(14)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.006
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     324
_refine_ls_number_reflns         3166
_refine_ls_number_restraints     1
_refine_ls_restrained_S_all      1.006
_refine_ls_R_factor_all          0.0565
_refine_ls_R_factor_gt           0.0452
_refine_ls_shift/su_max          0.000
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w=1/[\s^2^(Fo^2^)+(0.0908P)^2^] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1215
_refine_ls_wR_factor_ref         0.1300
_reflns_Friedel_coverage         0.484
_reflns_Friedel_fraction_full    0.545
_reflns_Friedel_fraction_max     0.545
_reflns_number_gt                2590
_reflns_number_total             3166
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            c7ob01055a2.cif
_cod_data_source_block           TE-5
_cod_database_code               7155687
_shelx_shelxl_version_number     2016/6
_shelx_res_checksum              69609