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_7153211
_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         'C25 H34 N2 O5'
_chemical_formula_sum            'C25 H34 N2 O5'
_chemical_formula_weight         442.54
_space_group_IT_number           19
_symmetry_cell_setting           orthorhombic
_symmetry_space_group_name_Hall  'P 2ac 2ab'
_symmetry_space_group_name_H-M   'P 21 21 21'
_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                 90.00
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   7.4115(4)
_cell_length_b                   16.5480(9)
_cell_length_c                   19.3577(11)
_cell_measurement_reflns_used    8545
_cell_measurement_temperature    100(2)
_cell_measurement_theta_max      30.608
_cell_measurement_theta_min      2.437
_cell_volume                     2374.1(2)
_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      100(2)
_diffrn_measured_fraction_theta_full 0.998
_diffrn_measured_fraction_theta_max 0.998
_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  0.0435
_diffrn_reflns_av_sigmaI/netI    0.0384
_diffrn_reflns_limit_h_max       8
_diffrn_reflns_limit_h_min       -8
_diffrn_reflns_limit_k_max       19
_diffrn_reflns_limit_k_min       -19
_diffrn_reflns_limit_l_max       17
_diffrn_reflns_limit_l_min       -23
_diffrn_reflns_number            17494
_diffrn_reflns_theta_full        25.00
_diffrn_reflns_theta_max         25.00
_diffrn_reflns_theta_min         2.10
_exptl_absorpt_coefficient_mu    0.086
_exptl_absorpt_correction_T_max  0.9772
_exptl_absorpt_correction_T_min  0.9486
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   'Bruker's SADABS'
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.238
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       block
_exptl_crystal_F_000             952
_exptl_crystal_size_max          0.62
_exptl_crystal_size_mid          0.59
_exptl_crystal_size_min          0.27
_refine_diff_density_max         0.195
_refine_diff_density_min         -0.227
_refine_diff_density_rms         0.038
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   -0.2(11)
_refine_ls_extinction_coef       0.0049(10)
_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   1.090
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     331
_refine_ls_number_reflns         4176
_refine_ls_number_restraints     1
_refine_ls_restrained_S_all      1.097
_refine_ls_R_factor_all          0.0464
_refine_ls_R_factor_gt           0.0442
_refine_ls_shift/su_max          0.004
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0365P)^2^+1.1915P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1039
_refine_ls_wR_factor_ref         0.1054
_reflns_number_gt                3999
_reflns_number_total             4176
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            c3ob41967c.txt
_cod_data_source_block           9
_cod_original_sg_symbol_H-M      P2(1)2(1)2(1)
_cod_database_code               7153211