Phytotoxic Neocassane Diterpenes from <i>Eragrostis plana</i>.
Klein Hendges, Ana Paula P.; Dos Santos, Elaine Fernanda; Teixeira, Sirlei D.; Santana, Francielli S.; Trezzi, Michelangelo M.; Batista, Andrea N. L.; Batista, Jr, Joao M; de Lima, Vanderlei A.; de Assis Marques, Francisco; Maia, Beatriz Helena L N Sales; Journal of natural products  (2020) –; doi:10.1021/acs.jnatprod.0c00324

data_1559534
_publ_section_title
;
 Phytotoxic Neocassane Diterpenes from <i>Eragrostis plana</i>.
;
_journal_name_full               'Journal of natural products'
_journal_paper_doi               10.1021/acs.jnatprod.0c00324
_journal_year                    2020
_chemical_absolute_configuration rm
_chemical_formula_moiety         'C20 H30 O'
_chemical_formula_structural     C20H30O
_chemical_formula_sum            'C20 H30 O'
_chemical_formula_weight         286.45
_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'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     dual
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL-2018/3
_cell_angle_alpha                90
_cell_angle_beta                 98.210(5)
_cell_angle_gamma                90
_cell_formula_units_Z            2
_cell_length_a                   6.2593(14)
_cell_length_b                   11.449(3)
_cell_length_c                   12.078(3)
_cell_measurement_reflns_used    6027
_cell_measurement_temperature    299(2)
_cell_measurement_theta_max      23.42
_cell_measurement_theta_min      3.28
_cell_volume                     856.7(4)
_computing_cell_refinement       'Bruker SAINT'
_computing_data_collection       'Bruker APEX3 (2015)'
_computing_data_reduction        'Bruker SAINT'
_computing_molecular_graphics    'ORTEP (Johnson, 1976 and Farrugia, 2012)'
_computing_publication_material
'SHELXL-97 (Sheldrick, 2008) and WINGX (Farrugia, 2012)'
_computing_structure_refinement  'SHELXL-2018/3 (Sheldrick, 2015)'
_computing_structure_solution    'SHELXT-2015 (Sheldrick, 2015a)'
_diffrn_ambient_temperature      299(2)
_diffrn_detector_area_resol_mean 10.4167
_diffrn_measured_fraction_theta_full 0.997
_diffrn_measured_fraction_theta_max 0.997
_diffrn_measurement_device_type  'Bruker D8 Venture/Photon 100 CMOS'
_diffrn_measurement_method       '\f and \w scans'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0481
_diffrn_reflns_av_unetI/netI     0.0344
_diffrn_reflns_Laue_measured_fraction_full 0.997
_diffrn_reflns_Laue_measured_fraction_max 0.997
_diffrn_reflns_limit_h_max       7
_diffrn_reflns_limit_h_min       -7
_diffrn_reflns_limit_k_max       13
_diffrn_reflns_limit_k_min       -13
_diffrn_reflns_limit_l_max       14
_diffrn_reflns_limit_l_min       -14
_diffrn_reflns_number            17626
_diffrn_reflns_point_group_measured_fraction_full 0.998
_diffrn_reflns_point_group_measured_fraction_max 0.998
_diffrn_reflns_theta_full        24.498
_diffrn_reflns_theta_max         24.498
_diffrn_reflns_theta_min         3.288
_diffrn_source                   'fine-focus sealed tube'
_exptl_absorpt_coefficient_mu    0.066
_exptl_absorpt_correction_T_max  0.7455
_exptl_absorpt_correction_T_min  0.6747
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details
;
SADABS-2012/1 - Bruker AXS area detector scaling and absorption correction 
;
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.110
_exptl_crystal_description       parallelepiped
_exptl_crystal_F_000             316
_exptl_crystal_size_max          0.452
_exptl_crystal_size_mid          0.415
_exptl_crystal_size_min          0.070
_refine_diff_density_max         0.316
_refine_diff_density_min         -0.190
_refine_diff_density_rms         0.059
_refine_ls_abs_structure_details
;
 Flack x determined using 922 quotients [(I+)-(I-)]/[(I+)+(I-)]
 (Parsons, Flack and Wagner, Acta Cryst. B69 (2013) 249-259).
;
_refine_ls_abs_structure_Flack   0.7(10)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.189
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     195
_refine_ls_number_reflns         2850
_refine_ls_number_restraints     1
_refine_ls_restrained_S_all      1.189
_refine_ls_R_factor_all          0.0992
_refine_ls_R_factor_gt           0.0839
_refine_ls_shift/su_max          0.004
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w=1/[\s^2^(Fo^2^)+(0.1920P)^2^+0.1695P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.2781
_refine_ls_wR_factor_ref         0.2904
_reflns_Friedel_coverage         0.895
_reflns_Friedel_fraction_full    0.998
_reflns_Friedel_fraction_max     0.998
_reflns_number_gt                2309
_reflns_number_total             2850
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            np0c00324_si_002.cif
_cod_data_source_block           shelx
_cod_original_cell_volume        856.6(3)
_cod_original_sg_symbol_H-M      'P 21'
_cod_database_code               1559534
_shelx_shelxl_version_number     2018/3
_shelx_estimated_absorpt_t_min   0.971
_shelx_estimated_absorpt_t_max   0.995
_shelx_res_checksum              81916
_shelx_hkl_checksum              66699