Reversal of H-bonding direction by N-sulfonation in a synthetic reverse-turn peptide motif.
Vijayadas, Kuruppanthara N.; Kotmale, Amol S.; Thorat, Shridhar H.; Gonnade, Rajesh G.; Nair, Roshna V.; Rajamohanan, Pattuparambil R.; Sanjayan, Gangadhar J.; Organic & biomolecular chemistry 13 (2015) 3064–3069; doi:10.1039/c4ob02438a

data_7154290
_publ_section_title
;
 Reversal of H-bonding direction by N-sulfonation in a synthetic
 reverse-turn peptide motif.
;
_journal_issue                   10
_journal_name_full               'Organic &amp; biomolecular chemistry'
_journal_page_first              3064
_journal_page_last               3069
_journal_paper_doi               10.1039/c4ob02438a
_journal_volume                  13
_journal_year                    2015
_chemical_absolute_configuration rmad
_chemical_formula_moiety         'C21 H32 N4 O6 S2'
_chemical_formula_sum            'C21 H32 N4 O6 S2'
_chemical_formula_weight         500.63
_space_group_IT_number           5
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  'C 2y'
_symmetry_space_group_name_H-M   'C 1 2 1'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL-97
_audit_update_record
;
2014-09-27 deposited with the CCDC.
2015-01-13 downloaded from the CCDC.
;
_cell_angle_alpha                90.00
_cell_angle_beta                 93.118(5)
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   18.6244(11)
_cell_length_b                   8.4267(4)
_cell_length_c                   16.0611(8)
_cell_measurement_reflns_used    7309
_cell_measurement_temperature    297(2)
_cell_measurement_theta_max      25.49
_cell_measurement_theta_min      2.19
_cell_volume                     2516.9(2)
_computing_cell_refinement       'Bruker SAINT'
_computing_data_collection       'Bruker APEX2'
_computing_data_reduction        'Bruker SAINT'
_computing_molecular_graphics    'Bruker SHELXTL'
_computing_publication_material  'Bruker SHELXTL'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 2008)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 2008)'
_diffrn_ambient_temperature      297(2)
_diffrn_measured_fraction_theta_full 1.000
_diffrn_measured_fraction_theta_max 1.000
_diffrn_measurement_device       'Bruker APEX-II CCD'
_diffrn_measurement_device_type  'CCD Area Detector'
_diffrn_measurement_method       '\f and \w scans'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'fine-focus sealed tube'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0553
_diffrn_reflns_av_sigmaI/netI    0.0453
_diffrn_reflns_limit_h_max       21
_diffrn_reflns_limit_h_min       -22
_diffrn_reflns_limit_k_max       10
_diffrn_reflns_limit_k_min       -10
_diffrn_reflns_limit_l_max       19
_diffrn_reflns_limit_l_min       -19
_diffrn_reflns_number            17277
_diffrn_reflns_theta_full        25.00
_diffrn_reflns_theta_max         25.00
_diffrn_reflns_theta_min         2.19
_exptl_absorpt_coefficient_mu    0.254
_exptl_absorpt_correction_T_max  0.9677
_exptl_absorpt_correction_T_min  0.8547
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   'Bruker SADABS'
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.321
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       needle
_exptl_crystal_F_000             1064
_exptl_crystal_recrystallization_method
'Re-crystallisation from solvent: Ethyl Acetate - Petroleum Ether'
_exptl_crystal_size_max          0.64
_exptl_crystal_size_mid          0.19
_exptl_crystal_size_min          0.13
_refine_diff_density_max         0.330
_refine_diff_density_min         -0.175
_refine_diff_density_rms         0.037
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   0.00(8)
_refine_ls_extinction_coef       0.0050(6)
_refine_ls_extinction_expression Fc^*^=kFc[1+0.001xFc^2^\l^3^/sin(2\q)]^-1/4^
_refine_ls_extinction_method     SHELXL
_refine_ls_goodness_of_fit_ref   1.039
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     310
_refine_ls_number_reflns         4429
_refine_ls_number_restraints     1
_refine_ls_restrained_S_all      1.039
_refine_ls_R_factor_all          0.0474
_refine_ls_R_factor_gt           0.0430
_refine_ls_shift/su_max          0.001
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0555P)^2^+1.3256P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1128
_refine_ls_wR_factor_ref         0.1171
_reflns_number_gt                4052
_reflns_number_total             4429
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            c4ob02438a2.cif
_cod_data_source_block           2
_cod_depositor_comments
'Adding full bibliography for 7154289--7154295.cif.'
_cod_original_sg_symbol_H-M      C2
_cod_database_code               7154290