Ester vs. amide on folding: a case study with a 2-residue synthetic peptide.
Vijayadas, Kuruppanthara N.; Nair, Roshna V.; Gawade, Rupesh L.; Kotmale, Amol S.; Prabhakaran, Panchami; Gonnade, Rajesh G.; Puranik, Vedavadi G.; Rajamohanan, Pattuparambil R.; Sanjayan, Gangadhar J.; Organic & biomolecular chemistry 11 (2013) 8348–8356; doi:10.1039/c3ob41967c

data_7153203
_publ_section_title
;
 Ester vs. amide on folding: a case study with a 2-residue synthetic
 peptide.
;
_journal_issue                   48
_journal_name_full               'Organic &amp; biomolecular chemistry'
_journal_page_first              8348
_journal_page_last               8356
_journal_paper_doi               10.1039/c3ob41967c
_journal_volume                  11
_journal_year                    2013
_chemical_absolute_configuration syn
_chemical_formula_moiety         'C20 H20 Br N3 O3'
_chemical_formula_sum            'C20 H20 Br N3 O3'
_chemical_formula_weight         430.30
_space_group_IT_number           4
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  'P 2yb'
_symmetry_space_group_name_H-M   'P 1 21 1'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL-97
_cell_angle_alpha                90.00
_cell_angle_beta                 105.5640(10)
_cell_angle_gamma                90.00
_cell_formula_units_Z            2
_cell_length_a                   11.1418(8)
_cell_length_b                   7.1748(5)
_cell_length_c                   12.9148(10)
_cell_measurement_reflns_used    2813
_cell_measurement_temperature    297(2)
_cell_measurement_theta_max      24.75
_cell_measurement_theta_min      2.148
_cell_volume                     994.55(13)
_computing_cell_refinement       'SAINT (Bruker, 2003)'
_computing_data_collection       'SMART (Bruker, 2003)'
_computing_data_reduction        'SAINT (Bruker, 2003)'
_computing_molecular_graphics    'ORTEP-3 (Farrugia, 1997)'
_computing_publication_material  'SHELXTL (Bruker, 2003)'
_computing_structure_refinement  'SHELXL97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS97 (Sheldrick, 1997)'
_diffrn_ambient_temperature      297(2)
_diffrn_measured_fraction_theta_full 0.996
_diffrn_measured_fraction_theta_max 0.996
_diffrn_measurement_device_type  'Bruker Smart Apex'
_diffrn_measurement_method       'Phi and Omega Scan'
_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  0.0173
_diffrn_reflns_av_sigmaI/netI    0.0419
_diffrn_reflns_limit_h_max       10
_diffrn_reflns_limit_h_min       -13
_diffrn_reflns_limit_k_max       8
_diffrn_reflns_limit_k_min       -7
_diffrn_reflns_limit_l_max       15
_diffrn_reflns_limit_l_min       -15
_diffrn_reflns_number            5062
_diffrn_reflns_theta_full        25.00
_diffrn_reflns_theta_max         25.00
_diffrn_reflns_theta_min         1.90
_exptl_absorpt_coefficient_mu    2.091
_exptl_absorpt_correction_T_max  0.7950
_exptl_absorpt_correction_T_min  0.5606
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   'Bruker SADABS'
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.437
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       prism
_exptl_crystal_F_000             440
_exptl_crystal_size_max          0.31
_exptl_crystal_size_mid          0.21
_exptl_crystal_size_min          0.12
_refine_diff_density_max         0.375
_refine_diff_density_min         -0.150
_refine_diff_density_rms         0.042
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   0.008(8)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   0.990
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     245
_refine_ls_number_reflns         2888
_refine_ls_number_restraints     1
_refine_ls_restrained_S_all      0.990
_refine_ls_R_factor_all          0.0325
_refine_ls_R_factor_gt           0.0297
_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^)+(0.0391P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0714
_refine_ls_wR_factor_ref         0.0725
_reflns_number_gt                2627
_reflns_number_total             2888
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            c3ob41967c.txt
_cod_data_source_block           1
_cod_original_sg_symbol_H-M      P2(1)
_cod_database_code               7153203