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_7251839
_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 H34 O3'
_chemical_formula_sum            'C20 H34 O3'
_chemical_formula_weight         322.47
_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             2023-01-11
_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                 99.615(3)
_cell_angle_gamma                90
_cell_formula_units_Z            2
_cell_length_a                   11.2450(3)
_cell_length_b                   7.2402(2)
_cell_length_c                   11.5790(3)
_cell_measurement_reflns_used    5494
_cell_measurement_temperature    170.00(10)
_cell_measurement_theta_max      73.7280
_cell_measurement_theta_min      3.8390
_cell_volume                     929.47(4)
_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      170.00(10)
_diffrn_detector                 'CCD plate'
_diffrn_detector_area_resol_mean 5.2684
_diffrn_detector_type            AtlasS2
_diffrn_measured_fraction_theta_full 1.000
_diffrn_measured_fraction_theta_max 0.986
_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     36.00  82.00   1.00    1.00    --   40.92 -99.00   0.00   46
  2  \w     43.00  69.00   1.00    1.00    --  107.58-112.00 -20.00   26
  3  \w     64.00 136.00   1.00    1.00    --  107.58 -30.00 -60.00   72
  4  \w     82.00 178.00   1.00    1.00    --  107.58  45.00 -60.00   96
  5  \w    121.00 178.00   1.00    1.00    --  107.58 125.00-150.00   57
  6  \w     42.00 133.00   1.00    1.00    --  107.58 -30.00 120.00   91
  7  \w     35.00 103.00   1.00    1.00    --  107.58 -94.00 150.00   68
  8  \w    -64.00  31.00   1.00    1.00    --  -40.92  37.00-150.00   95
  9  \w   -109.00 -16.00   1.00    1.00    --  -40.92 -57.00-120.00   93
 10  \w    -47.00 -20.00   1.00    1.00    --  -41.23 -37.00  60.00   27
 11  \w   -101.00 -18.00   1.00    1.00    --  -41.23 -57.00   0.00   83
 12  \w    -42.00 -12.00   1.00    1.00    --  -41.23 -77.00  60.00   30
 13  \w     37.00  66.00   1.00    1.00    --   41.23-125.00 -60.00   29
 14  \w     78.00 104.00   1.00    1.00    --  107.58  77.00 120.00   26
 15  \w     75.00 100.00   1.00    1.00    --  107.58  77.00  60.00   25
 16  \w     78.00 116.00   1.00    1.00    --  107.58  61.00  60.00   38
 17  \w    111.00 137.00   1.00    1.00    --  107.58  61.00  30.00   26
 18  \w     76.00 102.00   1.00    1.00    --  107.58  77.00   0.00   26
 19  \w     78.00 104.00   1.00    1.00    --  107.58  61.00  90.00   26
 20  \w     81.00 107.00   1.00    1.00    --  107.58  61.00 120.00   26
 21  \w     79.00 110.00   1.00    1.00    --  107.58  61.00  30.00   31
 22  \w     75.00 119.00   1.00    1.00    --  107.58  77.00  30.00   44
 23  \w     78.00 137.00   1.00    1.00    --  107.58  61.00   0.00   59
 24  \w     85.00 116.00   1.00    1.00    --  107.58  45.00  30.00   31
 25  \w     75.00 101.00   1.00    1.00    --  107.58  77.00  90.00   26
 26  \w     83.00 117.00   1.00    1.00    --  107.58  45.00 150.00   34
 27  \w    132.00 174.00   1.00    1.00    --  107.58  61.00  60.00   42
 28  \w     78.00 123.00   1.00    1.00    --  107.58  61.00 150.00   45
 29  \w     99.00 124.00   1.00    1.00    --  107.58 125.00-150.00   25
 30  \w     83.00 108.00   1.00    1.00    --  107.58  45.00  90.00   25
 31  \w     84.00 110.00   1.00    1.00    --  107.58  30.00 120.00   26
 32  \w     85.00 111.00   1.00    1.00    --  107.58  45.00 120.00   26
;
_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      -0.0820977000
_diffrn_orient_matrix_UB_12      -0.0181945000
_diffrn_orient_matrix_UB_13      -0.1201067000
_diffrn_orient_matrix_UB_21      0.1100890000
_diffrn_orient_matrix_UB_22      -0.0540176000
_diffrn_orient_matrix_UB_23      -0.0560617000
_diffrn_orient_matrix_UB_31      -0.0216576000
_diffrn_orient_matrix_UB_32      -0.2048558000
_diffrn_orient_matrix_UB_33      0.0254277000
_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  0.0258
_diffrn_reflns_av_unetI/netI     0.0273
_diffrn_reflns_Laue_measured_fraction_full 1.000
_diffrn_reflns_Laue_measured_fraction_max 0.986
_diffrn_reflns_limit_h_max       14
_diffrn_reflns_limit_h_min       -13
_diffrn_reflns_limit_k_max       8
_diffrn_reflns_limit_k_min       -8
_diffrn_reflns_limit_l_max       14
_diffrn_reflns_limit_l_min       -13
_diffrn_reflns_number            7872
_diffrn_reflns_point_group_measured_fraction_full 0.953
_diffrn_reflns_point_group_measured_fraction_max 0.925
_diffrn_reflns_theta_full        67.684
_diffrn_reflns_theta_max         73.780
_diffrn_reflns_theta_min         3.872
_diffrn_source                   'micro-focus sealed X-ray tube'
_diffrn_source_type              'SuperNova (Cu) X-ray Source'
_exptl_absorpt_coefficient_mu    0.588
_exptl_absorpt_correction_T_max  1.00000
_exptl_absorpt_correction_T_min  0.80269
_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    1.152
_exptl_crystal_description       block
_exptl_crystal_F_000             356
_exptl_crystal_size_max          0.14
_exptl_crystal_size_mid          0.12
_exptl_crystal_size_min          0.11
_refine_diff_density_max         0.135
_refine_diff_density_min         -0.183
_refine_diff_density_rms         0.040
_refine_ls_abs_structure_details
;
 Flack x determined using 1393 quotients [(I+)-(I-)]/[(I+)+(I-)]
 (Parsons, Flack and Wagner, Acta Cryst. B69 (2013) 249-259).
;
_refine_ls_abs_structure_Flack   -0.01(10)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.064
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     220
_refine_ls_number_reflns         3472
_refine_ls_number_restraints     1
_refine_ls_restrained_S_all      1.063
_refine_ls_R_factor_all          0.0346
_refine_ls_R_factor_gt           0.0338
_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^)+(0.0499P)^2^+0.0737P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0849
_refine_ls_wR_factor_ref         0.0859
_reflns_Friedel_coverage         0.732
_reflns_Friedel_fraction_full    0.896
_reflns_Friedel_fraction_max     0.853
_reflns_number_gt                3384
_reflns_number_total             3472
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            d5ra09664b5.cif
_cod_data_source_block           57-1
_cod_original_cell_volume        929.48(5)
_cod_database_code               7251839
_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 Ternary CH refined with riding coordinates:
 C2(H2A), C5(H5), C9(H9)
2.b Secondary CH2 refined with riding coordinates:
 C1(H1A,H1B), C3(H3A,H3B), C6(H6A,H6B), C7(H7A,H7B), C11(H11A,H11B), C12(H12A,
 H12B), C15(H15A,H15B), C16(H16A,H16B), C19(H19A,H19B)
2.c Aromatic/amide H refined with riding coordinates:
 C14(H14)
2.d Idealised Me refined as rotating group:
 C17(H17A,H17B,H17C), C18(H18A,H18B,H18C), C20(H20A,H20B,H20C)
2.e Idealised tetrahedral OH refined as rotating group:
 O2(H2)
;
_shelx_res_checksum              79197
_olex2_date_sample_data_collection 2023-01-11
_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 1.365
_oxdiff_exptl_absorpt_empirical_full_min 0.678