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_7155685
_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 O9'
_chemical_formula_weight         506.57
_space_group_crystal_system      monoclinic
_space_group_IT_number           5
_space_group_name_Hall           'C 2y'
_space_group_name_H-M_alt        'C 1 2 1'
_symmetry_space_group_name_Hall  'C 2y'
_symmetry_space_group_name_H-M   'C 1 2 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                90.0
_cell_angle_beta                 99.2221(11)
_cell_angle_gamma                90.0
_cell_formula_units_Z            4
_cell_length_a                   32.2353(3)
_cell_length_b                   7.66968(8)
_cell_length_c                   10.48751(13)
_cell_measurement_reflns_used    15778
_cell_measurement_temperature    100.00(10)
_cell_measurement_theta_max      73.3440
_cell_measurement_theta_min      4.2610
_cell_volume                     2559.36(5)
_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_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      100.00(10)
_diffrn_detector_area_resol_mean 5.2684
_diffrn_measured_fraction_theta_full 0.9996
_diffrn_measured_fraction_theta_max 0.9799
_diffrn_measurement_device_type  'SuperNova, Dual, Cu at zero, AtlasS2'
_diffrn_measurement_method       '\w scans'
_diffrn_radiation_type           CuK\a
_diffrn_radiation_wavelength     1.54178
_diffrn_reflns_av_R_equivalents  0.0245
_diffrn_reflns_av_unetI/netI     0.0294
_diffrn_reflns_Laue_measured_fraction_full 1.000
_diffrn_reflns_Laue_measured_fraction_max 0.991
_diffrn_reflns_limit_h_max       39
_diffrn_reflns_limit_h_min       -37
_diffrn_reflns_limit_k_max       9
_diffrn_reflns_limit_k_min       -9
_diffrn_reflns_limit_l_max       12
_diffrn_reflns_limit_l_min       -13
_diffrn_reflns_number            18236
_diffrn_reflns_point_group_measured_fraction_full 0.997
_diffrn_reflns_point_group_measured_fraction_max 0.980
_diffrn_reflns_theta_full        66.9682
_diffrn_reflns_theta_max         73.6524
_diffrn_reflns_theta_min         4.2708
_diffrn_source                   'micro-focus sealed X-ray tube'
_exptl_absorpt_coefficient_mu    0.811
_exptl_absorpt_correction_T_max  1.00000
_exptl_absorpt_correction_T_min  0.80644
_exptl_absorpt_correction_type   multi-scan
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.315
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       block
_exptl_crystal_F_000             1088
_exptl_crystal_size_max          0.40
_exptl_crystal_size_mid          0.26
_exptl_crystal_size_min          0.21
_refine_diff_density_max         0.790
_refine_diff_density_min         -0.249
_refine_diff_density_rms         0.051
_refine_ls_abs_structure_details
;
 Flack x determined using 2272 quotients [(I+)-(I-)]/[(I+)+(I-)]
 (Parsons, Flack and Wagner, Acta Cryst. B69 (2013) 249-259).
;
_refine_ls_abs_structure_Flack   0.02(4)
_refine_ls_extinction_coef       0.0012(2)
_refine_ls_extinction_expression Fc^*^=kFc[1+0.001xFc^2^\l^3^/sin(2\q)]^-1/4^
_refine_ls_extinction_method     'SHELXL-2016/6 (Sheldrick 2016)'
_refine_ls_goodness_of_fit_ref   1.052
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     335
_refine_ls_number_reflns         5075
_refine_ls_number_restraints     2
_refine_ls_restrained_S_all      6.195
_refine_ls_R_factor_all          0.0382
_refine_ls_R_factor_gt           0.0380
_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^)+(0.0676P)^2^+2.0346P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1093
_refine_ls_wR_factor_ref         0.1097
_reflns_Friedel_coverage         0.833
_reflns_Friedel_fraction_full    0.993
_reflns_Friedel_fraction_max     0.966
_reflns_number_gt                5044
_reflns_number_total             5075
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            c7ob01055a2.cif
_cod_data_source_block           TE-2
_cod_original_cell_volume        2559.37(5)
_cod_database_code               7155685
_shelx_shelxl_version_number     2016/6
_shelx_res_checksum              3119