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_7155686
_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_formula_sum            'C27 H36 O8'
_chemical_formula_weight         488.56
_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   geom
_audit_creation_method           SHELXL-2014/7
_audit_update_record
;
2017-04-27 deposited with the CCDC.
2017-06-14 downloaded from the CCDC.
;
_cell_angle_alpha                90
_cell_angle_beta                 91.2643(9)
_cell_angle_gamma                90
_cell_formula_units_Z            2
_cell_length_a                   6.26417(6)
_cell_length_b                   18.04765(14)
_cell_length_c                   10.53779(10)
_cell_measurement_reflns_used    7920
_cell_measurement_temperature    293(2)
_cell_measurement_theta_max      73.4900
_cell_measurement_theta_min      4.8470
_cell_volume                     1191.045(19)
_computing_cell_refinement       'CrysAlisPro 1.171.38.43f (Rigaku OD, 2015)'
_computing_data_collection       'CrysAlisPro 1.171.38.43f (Rigaku OD, 2015)'
_computing_data_reduction        'CrysAlisPro 1.171.38.43f (Rigaku OD, 2015)'
_computing_structure_refinement  'SHELXL-2014/7 (Sheldrick, 2014)'
_diffrn_ambient_temperature      293(2)
_diffrn_detector_area_resol_mean 5.2684
_diffrn_measured_fraction_theta_full 0.998
_diffrn_measured_fraction_theta_max 0.982
_diffrn_measurement_device_type  'SuperNova, Dual, Cu at zero, AtlasS2'
_diffrn_measurement_method       '\w scans'
_diffrn_radiation_type           CuK\a
_diffrn_radiation_wavelength     1.54184
_diffrn_reflns_av_R_equivalents  0.0191
_diffrn_reflns_av_unetI/netI     0.0233
_diffrn_reflns_Laue_measured_fraction_full 0.998
_diffrn_reflns_Laue_measured_fraction_max 0.982
_diffrn_reflns_limit_h_max       5
_diffrn_reflns_limit_h_min       -7
_diffrn_reflns_limit_k_max       22
_diffrn_reflns_limit_k_min       -22
_diffrn_reflns_limit_l_max       12
_diffrn_reflns_limit_l_min       -12
_diffrn_reflns_number            10324
_diffrn_reflns_point_group_measured_fraction_full 0.978
_diffrn_reflns_point_group_measured_fraction_max 0.944
_diffrn_reflns_theta_full        67.684
_diffrn_reflns_theta_max         73.630
_diffrn_reflns_theta_min         4.196
_exptl_absorpt_coefficient_mu    0.820
_exptl_absorpt_correction_T_max  1.00000
_exptl_absorpt_correction_T_min  0.91008
_exptl_absorpt_correction_type   multi-scan
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.362
_exptl_crystal_description       blocks
_exptl_crystal_F_000             524
_exptl_crystal_size_max          0.41
_exptl_crystal_size_mid          0.32
_exptl_crystal_size_min          0.20
_refine_diff_density_max         0.198
_refine_diff_density_min         -0.141
_refine_diff_density_rms         0.030
_refine_ls_abs_structure_details
;
 Flack x determined using 2014 quotients [(I+)-(I-)]/[(I+)+(I-)]
 (Parsons, Flack and Wagner, Acta Cryst. B69 (2013) 249-259).
;
_refine_ls_abs_structure_Flack   0.01(5)
_refine_ls_extinction_coef       0.0015(4)
_refine_ls_extinction_expression Fc^*^=kFc[1+0.001xFc^2^\l^3^/sin(2\q)]^-1/4^
_refine_ls_extinction_method     'SHELXL-2014/7 (Sheldrick 2014'
_refine_ls_goodness_of_fit_ref   1.028
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     323
_refine_ls_number_reflns         4548
_refine_ls_number_restraints     1
_refine_ls_restrained_S_all      1.028
_refine_ls_R_factor_all          0.0260
_refine_ls_R_factor_gt           0.0255
_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^)+(0.0346P)^2^+0.1883P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0647
_refine_ls_wR_factor_ref         0.0652
_reflns_Friedel_coverage         0.861
_reflns_Friedel_fraction_full    0.956
_reflns_Friedel_fraction_max     0.903
_reflns_number_gt                4480
_reflns_number_total             4548
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            c7ob01055a2.cif
_cod_data_source_block           compd1
_cod_original_cell_volume        1191.043(19)
_cod_database_code               7155686
_shelx_shelxl_version_number     2014/7
_shelx_res_checksum              7569