ent-Pimarane diterpenoids from the aerial parts of Sigesbeckia pubescens and their myocardial protective activity
Li, Wanting; Xia, Guiyang; Xia, Jinyu; Liu, Qiyao; Wu, Xuefen; Zhou, Linnan; Wei, Xiaohong; Xia, Huan; Lin, Sheng; RSC Advances 16 (2026) 17310–17321; doi:10.1039/D5RA09664B

data_7251837
_publ_section_title
;
 ent-Pimarane diterpenoids from the aerial parts of Sigesbeckia pubescens
 and their myocardial protective activity
;
_journal_issue                   19
_journal_name_full               'RSC Advances'
_journal_page_first              17310
_journal_page_last               17321
_journal_paper_doi               10.1039/D5RA09664B
_journal_volume                  16
_journal_year                    2026
_chemical_absolute_configuration ad
_chemical_formula_moiety         'C20 H30 O3, H2 O'
_chemical_formula_sum            'C20 H32 O4'
_chemical_formula_weight         336.45
_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   mixed
_atom_sites_solution_primary     dual
_audit_creation_date             2023-02-14
_audit_creation_method
;
Olex2 1.5-beta
(compiled 2022.04.07 svn.rca3783a0 for OlexSys, GUI svn.r6439)
;
_audit_update_record
;
2025-05-21 deposited with the CCDC.	2026-03-06 downloaded from the CCDC.
;
_cell_angle_alpha                90
_cell_angle_beta                 92.9687(16)
_cell_angle_gamma                90
_cell_formula_units_Z            2
_cell_length_a                   6.84365(12)
_cell_length_b                   11.17471(20)
_cell_length_c                   11.9856(2)
_cell_measurement_reflns_used    6028
_cell_measurement_temperature    169.99(10)
_cell_measurement_theta_max      73.7660
_cell_measurement_theta_min      3.6390
_cell_volume                     915.38(3)
_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    'Olex2 1.5-beta (Dolomanov et al., 2009)'
_computing_publication_material  'Olex2 1.5-beta (Dolomanov et al., 2009)'
_computing_structure_refinement  'SHELXL 2018/3 (Sheldrick, 2015)'
_computing_structure_solution    'SHELXT  (Sheldrick, 2015)'
_diffrn_ambient_environment      N~2~
_diffrn_ambient_temperature      169.99(10)
_diffrn_detector                 'CCD plate'
_diffrn_detector_area_resol_mean 5.2684
_diffrn_detector_type            AtlasS2
_diffrn_measured_fraction_theta_full 0.999
_diffrn_measured_fraction_theta_max 0.980
_diffrn_measurement_details
;
List of Runs (angles in degrees, time in seconds):

  # Type    Start    End  Width  t~exp~   \w     \q     \k     \f   Frames
  1  \w   -115.00 -16.00   1.00    1.00    --  -40.73 -37.00 120.00   99
  2  \w   -113.00 -63.00   1.00    1.00    --  -40.73-142.00 162.00   50
  3  \w    -96.00  -2.00   1.00    1.00    --  -40.73 125.00-180.00   94
  4  \w   -115.00 -16.00   1.00    1.00    --  -40.73 -37.00  30.00   99
  5  \w      1.00  82.00   1.00    1.00    --   40.73 -99.00 -30.00   81
  6  \w    -34.00  65.00   1.00    1.00    --   40.73 -37.00 -30.00   99
  7  \w     79.00 178.00   1.00    1.00    --  107.58  30.00 150.00   99
  8  \w     34.00 122.00   1.00    1.00    --  107.58-125.00-150.00   88
  9  \w     37.00  88.00   1.00    1.00    --  107.58 -45.00  30.00   51
 10  \w     34.00 109.00   1.00    1.00    --  107.58 -94.00  60.00   75
 11  \w     35.00 122.00   1.00    1.00    --  107.58-128.00 -26.00   87
 12  \w     77.00 152.00   1.00    1.00    --  107.58  77.00  60.00   75
 13  \w    152.00 177.00   1.00    1.00    --  107.58 125.00 -30.00   25
 14  \w    116.00 178.00   1.00    1.00    --  107.58  30.00 -30.00   62
 15  \w    127.00 171.00   1.00    1.00    --  107.58 125.00 120.00   44
 16  \w    106.00 155.00   1.00    1.00    --  107.58 125.00  90.00   49
 17  \w     36.00 113.00   1.00    1.00    --  107.58 -45.00 150.00   77
 18  \w     96.00 128.00   1.00    1.00    --  107.58 125.00 150.00   32
;
_diffrn_measurement_device       'four-circle diffractometer'
_diffrn_measurement_device_type  'SuperNova, Dual, Cu at zero, AtlasS2'
_diffrn_measurement_method       '\w scans'
_diffrn_orient_matrix_type
'CrysAlisPro convention (1999,Acta A55,543-557)'
_diffrn_orient_matrix_UB_11      0.0377279000
_diffrn_orient_matrix_UB_12      -0.1351476000
_diffrn_orient_matrix_UB_13      -0.0121759000
_diffrn_orient_matrix_UB_21      -0.2114457000
_diffrn_orient_matrix_UB_22      -0.0262827000
_diffrn_orient_matrix_UB_23      0.0309501000
_diffrn_orient_matrix_UB_31      -0.0684247000
_diffrn_orient_matrix_UB_32      0.0068284000
_diffrn_orient_matrix_UB_33      -0.1243424000
_diffrn_radiation_monochromator  mirror
_diffrn_radiation_probe          x-ray
_diffrn_radiation_type           'Cu K\a'
_diffrn_radiation_wavelength     1.54184
_diffrn_reflns_av_R_equivalents  0.0210
_diffrn_reflns_av_unetI/netI     0.0247
_diffrn_reflns_Laue_measured_fraction_full 0.999
_diffrn_reflns_Laue_measured_fraction_max 0.980
_diffrn_reflns_limit_h_max       8
_diffrn_reflns_limit_h_min       -8
_diffrn_reflns_limit_k_max       13
_diffrn_reflns_limit_k_min       -13
_diffrn_reflns_limit_l_max       9
_diffrn_reflns_limit_l_min       -14
_diffrn_reflns_number            6787
_diffrn_reflns_point_group_measured_fraction_full 0.995
_diffrn_reflns_point_group_measured_fraction_max 0.962
_diffrn_reflns_theta_full        67.684
_diffrn_reflns_theta_max         74.072
_diffrn_reflns_theta_min         3.693
_diffrn_source                   'micro-focus sealed X-ray tube'
_diffrn_source_type              'SuperNova (Cu) X-ray Source'
_exptl_absorpt_coefficient_mu    0.663
_exptl_absorpt_correction_T_max  1.00000
_exptl_absorpt_correction_T_min  0.54944
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details
;
CrysAlisPro 1.171.38.43f (Rigaku Oxford Diffraction, 2015)
Empirical absorption correction using spherical harmonics,
 implemented in SCALE3 ABSPACK scaling algorithm.
;
_exptl_crystal_colour            'light colourless'
_exptl_crystal_density_diffrn    1.221
_exptl_crystal_description       block
_exptl_crystal_F_000             368
_exptl_crystal_size_max          0.15
_exptl_crystal_size_mid          0.12
_exptl_crystal_size_min          0.1
_refine_diff_density_max         0.215
_refine_diff_density_min         -0.128
_refine_diff_density_rms         0.032
_refine_ls_abs_structure_details
;
 Flack x determined using 1597 quotients [(I+)-(I-)]/[(I+)+(I-)]
 (Parsons, Flack and Wagner, Acta Cryst. B69 (2013) 249-259).
;
_refine_ls_abs_structure_Flack   0.10(9)
_refine_ls_extinction_coef       0.022(2)
_refine_ls_extinction_expression Fc^*^=kFc[1+0.001xFc^2^\l^3^/sin(2\q)]^-1/4^
_refine_ls_extinction_method     'SHELXL-2018/3 (Sheldrick 2018)'
_refine_ls_goodness_of_fit_ref   1.003
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     231
_refine_ls_number_reflns         3579
_refine_ls_number_restraints     1
_refine_ls_restrained_S_all      1.003
_refine_ls_R_factor_all          0.0305
_refine_ls_R_factor_gt           0.0299
_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^)+(0.0632P)^2^+0.0291P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0837
_refine_ls_wR_factor_ref         0.0843
_reflns_Friedel_coverage         0.865
_reflns_Friedel_fraction_full    0.990
_reflns_Friedel_fraction_max     0.943
_reflns_number_gt                3526
_reflns_number_total             3579
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            d5ra09664b5.cif
_cod_data_source_block           xjy-31
_cod_database_code               7251837
_shelx_shelxl_version_number     2018/3
_olex2_refinement_description
;
1. Fixed Uiso
 At 1.2 times of:
  All C(H) groups, All C(H,H) groups
 At 1.5 times of:
  All C(H,H,H) groups, All O(H) groups
2.a Free rotating group:
 O4(H4A)
2.b Ternary CH refined with riding coordinates:
 C3(H3A), C5(H5), C14(H14), C15(H15)
2.c Secondary CH2 refined with riding coordinates:
 C1(H1A,H1B), C2(H2A,H2B), C6(H6A,H6B), C12(H12A,H12B), C16(H16A,H16B)
2.d Aromatic/amide H refined with riding coordinates:
 C7(H7), C11(H11)
2.e Idealised Me refined as rotating group:
 C17(H17A,H17B,H17C), C18(H18A,H18B,H18C), C19(H19A,H19B,H19C), C20(H20A,H20B,
 H20C)
2.f Idealised tetrahedral OH refined as rotating group:
 O1(H1), O3(H3)
;
_shelx_res_checksum              15020
_olex2_submission_special_instructions 'No special instructions were received'
_oxdiff_exptl_absorpt_empirical_details
;
Empirical correction (ABSPACK) includes:
- Absorption correction using spherical harmonics
- Frame scaling
;
_oxdiff_exptl_absorpt_empirical_full_max 1.736
_oxdiff_exptl_absorpt_empirical_full_min 0.657