Key indicators
- Single-crystal X-ray study
- T = 173 K
- Mean (C-C) = 0.007 Å
- R factor = 0.079
- wR factor = 0.067
- Data-to-parameter ratio = 8.6
checkCIF/PLATON results
No syntax errors found
Alert level A
PLAT201_ALERT_2_A Isotropic non-H Atoms in Main Residue(s) ..... = 13
| Author Response: Because of the limited numbers of observed reflections. Even
at the low temperature condition (173 K), diffractions from the crystal
of (I) were too weak to collect enough numbers. Therefore only main-cain
|
atoms were refefined anisotropically.
Alert level B
PLAT432_ALERT_2_B Short Inter X...Y Contact O131 .. C136 = 2.91 Ang.
| Author Response: It is attributable to the conformational isomerism of the
five- membered ring (-C131-C133-C134(C136)-C135-N131-) in the Pro
residue.
|
Alert level C
PLAT066_ALERT_1_C Predicted and Reported Transmissions Identical . ?
PLAT220_ALERT_2_C Large Non-Solvent C Ueq(max)/Ueq(min) ... 2.57 Ratio
| Author Response: It is due to the difference of thermal mobility.
The chain end atoms often shows higer U(eq) compared with the atoms
located inside of the chain.
|
PLAT241_ALERT_2_C Check High U(eq) as Compared to Neighbors .... C141
| Author Response: It is due to the difference of thermal mobility.
The chain end atoms often shows higer U(eq) compared with the atoms
located inside of the chain.
|
PLAT242_ALERT_2_C Check Low U(eq) as Compared to Neighbors .... C142
| Author Response: It is due to the low mobility of C142 which is located at
the
pivot position of the phenyl group.
|
PLAT250_ALERT_2_C Large U3/U1 ratio for average U(i,j) tensor .... 2.32
| Author Response: It is due to the thermal mobility of C141 and O141.
Atoms in the chain-end group often show higer U(eq) and larger U3/U1
ratio
compared with the atoms located inside of the chain.
|
PLAT301_ALERT_3_C Main Residue Disorder ......................... 4.00 Perc.
| Author Response: It is due to the conformational isomerism of the
five- membered ring in the Pro residue.
|
PLAT340_ALERT_3_C Low Bond Precision on C-C bonds (x 1000) Ang ... 7
| Author Response: It is attributable to the conformational isomerism
of the five- membered ring in the Pro residue.
|
PLAT713_ALERT_1_C TORSION Unknown or Inconsistent Label .......... C11
H(3) C11 C1 H(9)
PLAT779_ALERT_2_C Suspect or Irrelevant (Bond) Angle in CIF ...... 39.70 Deg.
C134 -C133 -C136 1.555 1.555 1.555
| Author Response: For both C134-C135-C136 and C134-C133-C136
It is attributable to the conformational isomerism of the five-
membered ring in the Pro residue. The explanation has been added into
the text.
|
PLAT779_ALERT_2_C Suspect or Irrelevant (Bond) Angle in CIF ...... 38.10 Deg.
C134 -C135 -C136 1.555 1.555 1.555
| Author Response: For both C134-C135-C136 and C134-C133-C136
It is attributable to the conformational isomerism of the five-
membered ring in the Pro residue. The explanation has been added into
the text.
|
Alert level G
REFLT03_ALERT_4_G Please check that the estimate of the number of Friedel pairs is
correct. If it is not, please give the correct count in the
_publ_section_exptl_refinement section of the submitted CIF.
From the CIF: _diffrn_reflns_theta_max 65.50
From the CIF: _reflns_number_total 1844
Count of symmetry unique reflns 1844
Completeness (_total/calc) 100.00%
TEST3: Check Friedels for noncentro structure
Estimate of Friedel pairs measured 0
Fraction of Friedel pairs measured 0.000
Are heavy atom types Z>Si present no
1 ALERT level A = In general: serious problem
1 ALERT level B = Potentially serious problem
10 ALERT level C = Check and explain
1 ALERT level G = General alerts; check
2 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
8 ALERT type 2 Indicator that the structure model may be wrong or deficient
2 ALERT type 3 Indicator that the structure quality may be low
1 ALERT type 4 Improvement, methodology, query or suggestion
The title peptide, (I), was prepared by conventional liquid-phase peptide synthesis. Crystals of (I) were successfully grown from dimethylformamide-water (Ratio?). Analytical data (1H NMR, ESI-MS and [α]D20) were in accordance with the expected structure; [α]D20 = −163.5° (c 0.1, methanol).
For non-H atoms, refinement was performed with anisotropic displacement parameters for main-chain atoms, and with isotropic refinements for side-chains (Hmb, Ala and Pro) and protecting groups (benzene ring). This is due to the limited numbers of observed reflections. Even with the techniques available, such as a low temperature (173 K), Cu Kα radiation and an area detector, reflections from the crystal of (I) were too weak to collect enough data for anisotropic refinement. H atoms were placed geometrically, except for atoms H1, H17, H18 and H29. How were these H atoms located? They were refined with a riding model and with Uiso(H) = 1.2Uiso of the carrier atom. The absolute stereochemistry of (I) was not established from the diffraction experiment and Friedel pairs were averaged. The absolute configuration was confirmed from the spectroscopic data, αD, of the compound.
Data collection: RAPID-AUTO (Molecular Structure Corporation & Rigaku Corporation, 2003); cell refinement: RAPID-AUTO; data reduction: CrystalStructure (Molecular Structure Corporation & Rigaku Corporation, 2003); program(s) used to solve structure: SIR2002 (Burla et al., 2003); program(s) used to refine structure: CRYSTALS (Watkin et al., 1996); molecular graphics: ORTEP (Johnson, 1965); software used to prepare material for publication: CrystalStructure.
(
S)-2-Hydroxy-3-methylbutanoyl-
L-alanyl-
L-proline benzyl ester
top
Crystal data top
C20H28N2O5 | F(000) = 404.00 |
Mr = 376.45 | Dx = 1.233 Mg m−3 |
Monoclinic, P21 | Melting point: 405 K |
Hall symbol: P 2yb | Cu Kα radiation, λ = 1.5418 Å |
a = 5.8977 (7) Å | Cell parameters from 9297 reflections |
b = 10.1767 (16) Å | θ = 4.3–68.3° |
c = 16.941 (2) Å | µ = 0.73 mm−1 |
β = 94.394 (10)° | T = 173 K |
V = 1013.8 (2) Å3 | Platelet, colourless |
Z = 2 | 0.5 × 0.5 × 0.05 mm |
Data collection top
Rigaku RAXIS-RAPID area-detector diffractometer | 1799 reflections with F2 > 2.0σ(F2) |
Detector resolution: 10.00 pixels mm-1 | Rint = 0.055 |
ω scans | θmax = 65.5° |
Absorption correction: part of the refinement model (ΔF) (DIFABS; Walker & Stuart, 1983) | h = −7→7 |
Tmin = 0.730, Tmax = 0.964 | k = −11→11 |
16496 measured reflections | l = −20→20 |
1844 independent reflections | |
Refinement top
Refinement on F2 | H-atom parameters constrained |
R[F2 > 2σ(F2)] = 0.079 | Chebychev polynomial with 3 parameters (Carruthers & Watkin, 1979),
25758.0000 31369.7000 698.5290 |
wR(F2) = 0.067 | (Δ/σ)max < 0.001 |
S = 1.01 | Δρmax = 0.59 e Å−3 |
1844 reflections | Δρmin = −0.41 e Å−3 |
215 parameters | |
Crystal data top
C20H28N2O5 | V = 1013.8 (2) Å3 |
Mr = 376.45 | Z = 2 |
Monoclinic, P21 | Cu Kα radiation |
a = 5.8977 (7) Å | µ = 0.73 mm−1 |
b = 10.1767 (16) Å | T = 173 K |
c = 16.941 (2) Å | 0.5 × 0.5 × 0.05 mm |
β = 94.394 (10)° | |
Data collection top
Rigaku RAXIS-RAPID area-detector diffractometer | 1844 independent reflections |
Absorption correction: part of the refinement model (ΔF) (DIFABS; Walker & Stuart, 1983) | 1799 reflections with F2 > 2.0σ(F2) |
Tmin = 0.730, Tmax = 0.964 | Rint = 0.055 |
16496 measured reflections | |
Refinement top
R[F2 > 2σ(F2)] = 0.079 | 215 parameters |
wR(F2) = 0.067 | H-atom parameters constrained |
S = 1.01 | Δρmax = 0.59 e Å−3 |
1844 reflections | Δρmin = −0.41 e Å−3 |
Special details top
Refinement. Refinement using all reflections. The weighted R-factor (wR) and goodness of fit (S) are based on F2. R-factor (gt) are based on F. The threshold expression of F2 > 2.0 σ(F2) is used only for calculating R-factor (gt). |
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top | x | y | z | Uiso*/Ueq | Occ. (<1) |
O111 | 1.2011 (4) | 0.4494 (4) | 0.1492 (1) | 0.0451 (9) | |
O112 | 0.6301 (4) | 0.5643 (3) | 0.1351 (1) | 0.0421 (9) | |
O121 | 1.0652 (4) | 0.4970 (3) | 0.3807 (1) | 0.0410 (8) | |
O131 | 0.8572 (7) | 0.3977 (4) | 0.5506 (2) | 0.071 (1) | |
O141 | 1.1124 (5) | 0.5288 (4) | 0.6152 (1) | 0.063 (1) | |
N121 | 0.8717 (5) | 0.4929 (4) | 0.2358 (2) | 0.0335 (9) | |
N131 | 0.7668 (5) | 0.5928 (4) | 0.4335 (2) | 0.037 (1) | |
C111 | 1.0116 (6) | 0.5105 (5) | 0.1059 (2) | 0.036 (1) | |
C112 | 0.8201 (6) | 0.5250 (4) | 0.1615 (2) | 0.031 (1) | |
C113 | 0.9324 (7) | 0.4335 (5) | 0.0314 (2) | 0.038 (1)* | |
C114 | 0.8334 (8) | 0.3002 (5) | 0.0504 (3) | 0.061 (1)* | |
C115 | 1.1248 (7) | 0.4201 (5) | −0.0229 (2) | 0.050 (1)* | |
C121 | 0.7170 (6) | 0.5043 (5) | 0.2988 (2) | 0.033 (1) | |
C122 | 0.8641 (7) | 0.5326 (5) | 0.3744 (2) | 0.033 (1) | |
C123 | 0.5830 (7) | 0.3763 (5) | 0.3073 (2) | 0.044 (1)* | |
C131 | 0.9013 (7) | 0.6217 (5) | 0.5079 (2) | 0.040 (1) | |
C132 | 0.9505 (8) | 0.5009 (6) | 0.5571 (2) | 0.047 (1) | |
C133 | 0.7486 (8) | 0.7148 (5) | 0.5505 (3) | 0.049 (1)* | |
C134 | 0.515 (1) | 0.6737 (8) | 0.5202 (4) | 0.039 (2)* | 0.65 |
C135 | 0.5333 (7) | 0.6451 (5) | 0.4335 (2) | 0.041 (1)* | |
C136 | 0.562 (2) | 0.758 (1) | 0.4954 (8) | 0.038 (3)* | 0.35 |
C141 | 1.1412 (9) | 0.4328 (7) | 0.6778 (2) | 0.081 (2) | |
C142 | 0.9547 (8) | 0.4424 (6) | 0.7335 (3) | 0.051 (1)* | |
C143 | 0.9019 (8) | 0.5591 (5) | 0.7655 (3) | 0.052 (1)* | |
C144 | 0.7294 (8) | 0.5708 (6) | 0.8166 (3) | 0.059 (1)* | |
C145 | 0.6131 (8) | 0.4582 (5) | 0.8358 (3) | 0.058 (1)* | |
C146 | 0.665 (1) | 0.3408 (7) | 0.8058 (3) | 0.075 (2)* | |
C147 | 0.8321 (9) | 0.3297 (6) | 0.7523 (3) | 0.069 (2)* | |
H(1) | 1.3219 | 0.5034 | 0.1382 | 0.054* | |
H(2) | 1.0561 | 0.5957 | 0.0902 | 0.044* | |
H(3) | 0.8156 | 0.4832 | 0.0036 | 0.046* | |
H(4) | 0.7108 | 0.3141 | 0.0827 | 0.073* | |
H(5) | 0.7791 | 0.2564 | 0.0032 | 0.073* | |
H(6) | 0.9464 | 0.2479 | 0.0782 | 0.073* | |
H(7) | 1.2445 | 0.3704 | 0.0033 | 0.060* | |
H(8) | 1.0699 | 0.3761 | −0.0700 | 0.060* | |
H(9) | 1.1801 | 0.5045 | −0.0359 | 0.060* | |
H(10) | 1.0196 | 0.4593 | 0.2498 | 0.040* | |
H(11) | 0.6155 | 0.5756 | 0.2878 | 0.040* | |
H(12) | 0.4876 | 0.3855 | 0.3496 | 0.053* | |
H(13) | 0.4923 | 0.3596 | 0.2595 | 0.053* | |
H(14) | 0.6851 | 0.3052 | 0.3180 | 0.052* | |
H(15) | 0.5158 | 0.7229 | 0.4027 | 0.049* | |
H(16) | 0.4241 | 0.5819 | 0.4143 | 0.050* | |
H(17) | 0.4128 | 0.7488 | 0.5268 | 0.042* | |
H(18) | 0.4812 | 0.5982 | 0.5559 | 0.042* | 0.65 |
H(19) | 0.7704 | 0.7032 | 0.6062 | 0.058* | |
H(20) | 0.7758 | 0.8040 | 0.5377 | 0.058* | |
H(21) | 1.0393 | 0.6642 | 0.4976 | 0.048* | |
H(22) | 1.1347 | 0.3476 | 0.6548 | 0.097* | |
H(23) | 1.2846 | 0.4448 | 0.7064 | 0.097* | |
H(24) | 0.9854 | 0.6352 | 0.7531 | 0.062* | |
H(25) | 0.6922 | 0.6536 | 0.8381 | 0.071* | |
H(26) | 0.4938 | 0.4648 | 0.8702 | 0.070* | |
H(27) | 0.5841 | 0.2653 | 0.8212 | 0.090* | |
H(28) | 0.8657 | 0.2467 | 0.7303 | 0.083* | |
H(29) | 0.5344 | 0.8606 | 0.4799 | 0.042* | 0.35 |
Atomic displacement parameters (Å2) top | U11 | U22 | U33 | U12 | U13 | U23 |
O111 | 0.026 (1) | 0.076 (3) | 0.034 (1) | 0.002 (2) | 0.004 (1) | 0.009 (2) |
O112 | 0.031 (1) | 0.065 (2) | 0.030 (1) | 0.011 (2) | 0.005 (1) | 0.005 (2) |
O121 | 0.029 (1) | 0.059 (2) | 0.034 (1) | 0.012 (2) | 0.002 (1) | −0.005 (2) |
O131 | 0.108 (3) | 0.058 (3) | 0.045 (2) | 0.004 (3) | −0.005 (2) | −0.002 (2) |
O141 | 0.051 (2) | 0.103 (3) | 0.032 (2) | 0.011 (2) | −0.006 (1) | 0.002 (2) |
N121 | 0.026 (2) | 0.053 (3) | 0.023 (1) | 0.003 (2) | 0.008 (1) | −0.001 (2) |
N131 | 0.029 (2) | 0.058 (3) | 0.023 (2) | 0.004 (2) | 0.002 (1) | −0.005 (2) |
C111 | 0.032 (2) | 0.048 (3) | 0.028 (2) | −0.000 (2) | 0.007 (2) | 0.001 (2) |
C112 | 0.034 (2) | 0.031 (3) | 0.030 (2) | −0.003 (2) | 0.006 (2) | 0.003 (2) |
C121 | 0.031 (2) | 0.048 (3) | 0.022 (2) | 0.000 (2) | 0.011 (2) | 0.006 (2) |
C122 | 0.036 (2) | 0.039 (3) | 0.025 (2) | −0.002 (2) | 0.009 (2) | 0.002 (2) |
C131 | 0.030 (2) | 0.061 (4) | 0.027 (2) | −0.008 (2) | 0.003 (2) | −0.006 (2) |
C132 | 0.049 (3) | 0.071 (4) | 0.022 (2) | 0.014 (3) | 0.004 (2) | −0.006 (3) |
C141 | 0.086 (4) | 0.129 (6) | 0.027 (2) | 0.049 (4) | −0.001 (2) | 0.008 (3) |
Geometric parameters (Å, º) top
O111—C111 | 1.431 (5) | C131—C132 | 1.501 (7) |
O111—H(1) | 0.930 | C131—C133 | 1.525 (7) |
O112—C112 | 1.240 (4) | C131—H(21) | 0.950 |
O121—C122 | 1.237 (5) | C133—C134 | 1.490 (8) |
O131—C132 | 1.187 (7) | C133—C136 | 1.449 (13) |
O141—C132 | 1.349 (5) | C133—H(19) | 0.950 |
O141—C141 | 1.442 (7) | C133—H(20) | 0.950 |
N121—C112 | 1.314 (4) | C134—C135 | 1.508 (8) |
N121—C121 | 1.461 (5) | C134—C136 | 1.004 (13) |
N121—H(10) | 0.950 | C134—H(17) | 0.990 |
N131—C122 | 1.340 (5) | C134—H(18) | 1.010 |
N131—C131 | 1.467 (5) | C135—C136 | 1.556 (13) |
N131—C135 | 1.476 (5) | C135—H(15) | 0.950 |
C111—C112 | 1.531 (5) | C135—H(16) | 0.950 |
C111—C113 | 1.529 (5) | C136—H(17) | 1.067 |
C111—H(2) | 0.950 | C136—H(29) | 1.090 |
C113—C114 | 1.521 (7) | C141—C142 | 1.506 (7) |
C113—C115 | 1.521 (6) | C141—H(22) | 0.950 |
C113—H(3) | 0.950 | C141—H(23) | 0.950 |
C114—H(4) | 0.950 | C142—C143 | 1.352 (8) |
C114—H(5) | 0.950 | C142—C147 | 1.406 (8) |
C114—H(6) | 0.950 | C143—C144 | 1.391 (7) |
C115—H(7) | 0.950 | C143—H(24) | 0.950 |
C115—H(8) | 0.950 | C144—C145 | 1.387 (8) |
C115—H(9) | 0.950 | C144—H(25) | 0.950 |
C121—C122 | 1.518 (5) | C145—C146 | 1.342 (8) |
C121—C123 | 1.536 (6) | C145—H(26) | 0.950 |
C121—H(11) | 0.950 | C146—C147 | 1.396 (8) |
C123—H(12) | 0.950 | C146—H(27) | 0.950 |
C123—H(13) | 0.950 | C147—H(28) | 0.950 |
C123—H(14) | 0.950 | | |
| | | |
C111—O111—H(1) | 102.8 | C134—C133—H(20) | 110.9 |
C132—O141—C141 | 115.5 (4) | C134—C133—C131 | 103.0 (4) |
C112—N121—C121 | 124.7 (3) | C136—C133—H(19) | 135.5 |
C112—N121—H(10) | 118.0 | C136—C133—H(20) | 72.5 |
C121—N121—H(10) | 117.4 | C136—C133—C131 | 109.1 (6) |
C122—N131—C131 | 120.0 (3) | H(19)—C133—H(20) | 109.5 |
C122—N131—C135 | 128.2 (3) | H(19)—C133—C131 | 110.6 |
C131—N131—C135 | 111.7 (3) | H(20)—C133—C131 | 111.6 |
C112—C111—C113 | 111.3 (3) | C135—C134—C136 | 73.4 (9) |
C112—C111—H(2) | 108.5 | C135—C134—H(17) | 110.5 |
C112—C111—O111 | 108.1 (3) | C135—C134—H(18) | 118.1 |
C113—C111—H(2) | 108.0 | C135—C134—C133 | 105.0 (5) |
C113—C111—O111 | 112.1 (4) | C136—C134—H(17) | 65.0 |
H(2)—C111—O111 | 108.6 | C136—C134—H(18) | 167.8 |
O112—C112—N121 | 124.2 (3) | H(17)—C134—H(18) | 111.6 |
O112—C112—C111 | 119.9 (3) | H(17)—C134—C133 | 107.5 |
N121—C112—C111 | 115.9 (3) | H(18)—C134—C133 | 103.2 |
C114—C113—C115 | 111.4 (4) | C133—C134—C136 | 68.2 (8) |
C114—C113—H(3) | 107.7 | C136—C135—H(15) | 76.0 |
C114—C113—C111 | 112.3 (3) | C136—C135—H(16) | 140.0 |
C115—C113—H(3) | 107.1 | C136—C135—N131 | 102.3 (5) |
C115—C113—C111 | 110.5 (3) | H(15)—C135—H(16) | 109.5 |
H(3)—C113—C111 | 107.5 | H(15)—C135—N131 | 111.2 |
H(4)—C114—H(5) | 109.5 | H(15)—C135—C134 | 111.3 |
H(4)—C114—H(6) | 109.5 | H(16)—C135—N131 | 111.3 |
H(4)—C114—C113 | 108.1 | H(16)—C135—C134 | 111.6 |
H(5)—C114—H(6) | 109.5 | N131—C135—C134 | 101.8 (4) |
H(5)—C114—C113 | 110.5 | C134—C135—C136 | 38.1 (6) |
H(6)—C114—C113 | 109.8 | H(17)—C136—H(29) | 95.1 |
H(7)—C115—H(8) | 109.5 | H(29)—C136—C133 | 122.4 |
H(7)—C115—H(9) | 109.5 | H(29)—C136—C134 | 152.0 |
H(7)—C115—C113 | 109.1 | H(29)—C136—C135 | 122.4 |
H(8)—C115—H(9) | 109.5 | C133—C136—C134 | 72.1 (9) |
H(8)—C115—C113 | 109.1 | C134—C136—H(17) | 57.0 |
H(9)—C115—C113 | 110.1 | C134—C136—C135 | 68.5 (9) |
C122—C121—C123 | 110.3 (3) | C135—C136—H(17) | 102.9 |
C122—C121—H(11) | 109.4 | C135—C136—C133 | 104.5 (9) |
C122—C121—N121 | 106.4 (3) | C142—C141—H(22) | 108.0 |
C123—C121—H(11) | 110.2 | C142—C141—H(23) | 109.7 |
C123—C121—N121 | 110.8 (4) | C142—C141—O141 | 111.5 (5) |
H(11)—C121—N121 | 109.7 | H(22)—C141—H(23) | 109.5 |
O121—C122—N131 | 122.1 (3) | H(22)—C141—O141 | 108.6 |
O121—C122—C121 | 120.0 (3) | H(23)—C141—O141 | 109.7 |
N131—C122—C121 | 117.8 (3) | C143—C142—C147 | 119.2 (5) |
H(12)—C123—H(13) | 109.5 | C143—C142—C141 | 120.7 (5) |
H(12)—C123—H(14) | 109.5 | C147—C142—C141 | 120.1 (5) |
H(12)—C123—C121 | 109.0 | C144—C143—H(24) | 118.9 |
H(13)—C123—H(14) | 109.5 | C144—C143—C142 | 121.8 (5) |
H(13)—C123—C121 | 109.5 | H(24)—C143—C142 | 119.2 |
H(14)—C123—C121 | 109.9 | C145—C144—H(25) | 120.7 |
C132—C131—C133 | 110.0 (4) | C145—C144—C143 | 118.3 (5) |
C132—C131—H(21) | 110.1 | H(25)—C144—C143 | 121.1 |
C132—C131—N131 | 112.4 (4) | C146—C145—H(26) | 119.6 |
C133—C131—H(21) | 110.5 | C146—C145—C144 | 121.1 (5) |
C133—C131—N131 | 103.3 (3) | H(26)—C145—C144 | 119.3 |
H(21)—C131—N131 | 110.3 | C147—C146—H(27) | 120.3 |
O131—C132—O141 | 123.5 (5) | C147—C146—C145 | 120.7 (6) |
O131—C132—C131 | 127.2 (4) | H(27)—C146—C145 | 119.0 |
O141—C132—C131 | 109.2 (5) | H(28)—C147—C142 | 120.7 |
C134—C133—C136 | 39.7 (6) | H(28)—C147—C146 | 120.4 |
C134—C133—H(19) | 111.0 | C142—C147—C146 | 118.9 (5) |
| | | |
O111—C111—C112—N121 | 6.4 (6) | C136—C133—C134—C135 | 64.8 (5) |
C111—C112—N121—C121 | 177.5 (4) | C136—C133—C134—H(17) | −52.8 |
C112—N121—C121—C122 | −148.9 (4) | C136—C133—C134—H(18) | −170.9 |
N121—C121—C122—N131 | 156.4 (4) | H(19)—C133—C134—C135 | −158.0 |
C121—C122—N131—C131 | 179.7 (4) | H(19)—C133—C134—C136 | 137.2 |
C122—N131—C131—C132 | −73.6 (5) | H(19)—C133—C134—H(17) | 84.7 |
N131—C131—C132—O141 | 167.0 (3) | H(19)—C133—C134—H(18) | −33.7 |
C131—C132—O141—C141 | 166.4 (4) | H(20)—C133—C134—C135 | 80.0 |
C132—O141—C141—C142 | −76.5 (5) | H(20)—C133—C134—C136 | 15.2 |
H(1)—O111—C111—C112 | −131.1 | H(20)—C133—C134—H(17) | −37.6 |
H(1)—O111—C111—C113 | 105.7 | H(20)—C133—C134—H(18) | −155.7 |
H(1)—O111—C111—H(2) | −13.5 | C131—C133—C136—C134 | 87.4 (9) |
C141—O141—C132—C131 | 166.4 (3) | C131—C133—C136—C135 | 26.2 (9) |
C132—O141—C141—H(22) | 42.3 | C131—C133—C136—H(17) | 134.3 |
C132—O141—C141—H(23) | 161.9 | C131—C133—C136—H(29) | −119.2 |
C121—N121—C112—C111 | 177.5 (4) | C134—C133—C136—C135 | −61.3 (8) |
H(10)—N121—C112—O112 | 176.7 | C134—C133—C136—H(17) | 46.8 |
H(10)—N121—C112—C111 | −2.9 | C134—C133—C136—H(29) | 153.3 |
C112—N121—C121—C123 | 91.1 (5) | H(19)—C133—C136—C134 | −64.8 |
C112—N121—C121—H(11) | −30.7 | H(19)—C133—C136—C135 | −126.1 |
H(10)—N121—C121—C122 | 31.4 | H(19)—C133—C136—H(17) | −18.0 |
H(10)—N121—C121—C123 | −88.5 | H(19)—C133—C136—H(29) | 88.5 |
H(10)—N121—C121—H(11) | 149.6 | H(20)—C133—C136—C134 | −165.1 |
C131—N131—C122—O121 | 1.7 (7) | H(20)—C133—C136—C135 | 133.6 |
C135—N131—C122—O121 | 177.4 (4) | H(20)—C133—C136—H(17) | −118.3 |
C135—N131—C122—C121 | −4.6 (7) | H(20)—C133—C136—H(29) | −11.8 |
C122—N131—C131—C133 | 167.9 (4) | C133—C134—C135—N131 | 33.6 (6) |
C122—N131—C131—H(21) | 49.7 | C133—C134—C135—C136 | −61.3 (9) |
C135—N131—C131—C132 | 110.1 (4) | C133—C134—C135—H(15) | −85.0 |
C135—N131—C131—C133 | −8.5 (5) | C133—C134—C135—H(16) | 152.5 |
C135—N131—C131—H(21) | −126.7 | C136—C134—C135—N131 | 94.9 (6) |
C122—N131—C135—C134 | 168.8 (5) | C136—C134—C135—H(15) | −23.7 |
C122—N131—C135—C136 | −152.2 (6) | C136—C134—C135—H(16) | −146.3 |
C122—N131—C135—H(15) | −72.6 | H(17)—C134—C135—N131 | 149.2 |
C122—N131—C135—H(16) | 49.8 | H(17)—C134—C135—C136 | 54.3 |
C131—N131—C135—C134 | −15.2 (5) | H(17)—C134—C135—H(15) | 30.7 |
C131—N131—C135—C136 | 23.8 (7) | H(17)—C134—C135—H(16) | −91.9 |
C131—N131—C135—H(15) | 103.4 | H(18)—C134—C135—N131 | −80.6 |
C131—N131—C135—H(16) | −134.2 | H(18)—C134—C135—C136 | −175.5 |
O111—C111—C112—O112 | −173.2 (4) | H(18)—C134—C135—H(15) | 160.8 |
C113—C111—C112—O112 | −49.6 (6) | H(18)—C134—C135—H(16) | 38.2 |
C113—C111—C112—N121 | 130.0 (4) | C133—C134—C136—C135 | 114.2 (6) |
H(2)—C111—C112—O112 | 69.2 | C133—C134—C136—H(17) | −122.8 |
H(2)—C111—C112—N121 | −111.2 | C133—C134—C136—H(29) | −126.3 |
O111—C111—C113—C114 | 66.5 (4) | C135—C134—C136—C133 | −114.2 (6) |
O111—C111—C113—C115 | −58.6 (5) | C135—C134—C136—H(17) | 122.8 |
O111—C111—C113—H(3) | −175.2 | C135—C134—C136—H(29) | 119.6 |
C112—C111—C113—C114 | −54.8 (5) | H(17)—C134—C136—C133 | 123.0 |
C112—C111—C113—C115 | −179.8 (4) | H(17)—C134—C136—C135 | −122.8 |
C112—C111—C113—H(3) | 63.5 | H(17)—C134—C136—H(29) | −3.3 |
H(2)—C111—C113—C114 | −173.9 | H(18)—C134—C136—C133 | 46.8 |
H(2)—C111—C113—C115 | 61.0 | H(18)—C134—C136—C135 | 159.8 |
H(2)—C111—C113—H(3) | −55.6 | H(18)—C134—C136—H(17) | −77.3 |
C111—C113—C114—H(4) | 57.5 | H(18)—C134—C136—H(29) | −80.7 |
C111—C113—C114—H(5) | 177.2 | C133—C134—H(17)—C136 | 54.8 |
C111—C113—C114—H(6) | −61.9 | C135—C134—H(17)—C136 | −59.3 |
C115—C113—C114—H(4) | −177.9 | H(18)—C134—H(17)—C136 | 167.3 |
C115—C113—C114—H(5) | −58.1 | N131—C135—C136—C133 | −29.8 (8) |
C115—C113—C114—H(6) | 62.7 | N131—C135—C136—C134 | −93.5 (8) |
H(3)—C113—C114—H(4) | −60.8 | N131—C135—C136—H(17) | −139.8 |
H(3)—C113—C114—H(5) | 59.0 | N131—C135—C136—H(29) | 115.5 |
H(3)—C113—C114—H(6) | 179.7 | C134—C135—C136—C133 | 63.7 (8) |
C111—C113—C115—H(7) | 63.4 | C134—C135—C136—H(17) | −46.3 |
C111—C113—C115—H(8) | −177.0 | C134—C135—C136—H(29) | −151.0 |
C111—C113—C115—H(9) | −56.8 | H(15)—C135—C136—C133 | −138.9 |
C114—C113—C115—H(7) | −62.2 | H(15)—C135—C136—C134 | 157.3 |
C114—C113—C115—H(8) | 57.4 | H(15)—C135—C136—H(17) | 111.1 |
C114—C113—C115—H(9) | 177.6 | H(15)—C135—C136—H(29) | 6.3 |
H(3)—C113—C115—H(7) | −179.8 | H(16)—C135—C136—C133 | 117.3 |
H(3)—C113—C115—H(8) | −60.1 | H(16)—C135—C136—C134 | 53.5 |
H(3)—C11—C1—H(9) | 60.0 | H(16)—C135—C136—H(17) | 7.3 |
N121—C121—C122—O121 | −25.5 (6) | H(16)—C135—C136—H(29) | −97.4 |
C123—C121—C122—O121 | 94.7 (5) | C133—C136—H(17)—C134 | −55.9 |
C123—C121—C122—N131 | −83.3 (5) | C135—C136—H(17)—C134 | 53.3 |
H(11)—C121—C122—O121 | −143.9 | H(29)—C136—H(17)—C134 | 178.5 |
H(11)—C121—C122—N131 | 38.0 | O141—C141—C142—C143 | −50.8 (6) |
N121—C121—C123—H(12) | 178.2 | O141—C141—C142—C147 | 128.6 (5) |
N121—C121—C123—H(13) | −62.1 | H(22)—C141—C142—C143 | −170.0 |
N121—C121—C123—H(14) | 58.2 | H(22)—C141—C142—C147 | 9.5 |
C122—C121—C123—H(12) | 60.6 | H(23)—C141—C142—C143 | 70.8 |
C122—C121—C123—H(13) | −179.7 | H(23)—C141—C142—C147 | −109.7 |
C122—C121—C123—H(14) | −59.4 | C141—C142—C143—C144 | 179.5 (4) |
H(11)—C121—C123—H(12) | −60.3 | C141—C142—C143—H(24) | −0.9 |
H(11)—C121—C123—H(13) | 59.4 | C147—C142—C143—C144 | 0.0 (7) |
H(11)—C121—C123—H(14) | 179.7 | C147—C142—C143—H(24) | 179.6 |
N131—C131—C132—O131 | −16.9 (7) | C141—C142—C147—C146 | 178.2 (4) |
C133—C131—C132—O131 | 97.7 (6) | C141—C142—C147—H(28) | 0.2 |
C133—C131—C132—O141 | −78.4 (4) | C143—C142—C147—C146 | −2.3 (7) |
H(21)—C131—C132—O131 | −140.3 | C143—C142—C147—H(28) | 179.7 |
H(21)—C131—C132—O141 | 43.6 | C142—C143—C144—C145 | 1.3 (7) |
N131—C131—C133—C134 | 29.1 (5) | C142—C143—C144—H(25) | −179.0 |
N131—C131—C133—C136 | −11.8 (7) | H(24)—C143—C144—C145 | −178.3 |
N131—C131—C133—H(19) | 147.8 | H(24)—C143—C144—H(25) | 1.4 |
N131—C131—C133—H(20) | −90.0 | C143—C144—C145—C146 | −0.2 (7) |
C132—C131—C133—C134 | −91.1 (5) | C143—C144—C145—H(26) | −179.4 |
C132—C131—C133—C136 | −132.0 (7) | H(25)—C144—C145—C146 | −179.7 |
C132—C131—C133—H(19) | 27.6 | H(25)—C144—C145—H(26) | 0.9 |
C132—C131—C133—H(20) | 149.7 | C144—C145—C146—C147 | −2.1 (8) |
H(21)—C131—C133—C134 | 147.1 | C144—C145—C146—H(27) | 178.5 |
H(21)—C131—C133—C136 | 106.2 | H(26)—C145—C146—C147 | 177.1 |
H(21)—C131—C133—H(19) | −94.2 | H(26)—C145—C146—H(27) | −2.5 |
H(21)—C131—C133—H(20) | 28.0 | C145—C146—C147—C142 | 3.4 (8) |
C131—C133—C134—C135 | −39.5 | C145—C146—C147—H(28) | −178.6 |
C131—C133—C134—C136 | −104.4 (9) | H(27)—C146—C147—C142 | −177.3 |
C131—C133—C134—H(17) | −157.1 | H(27)—C146—C147—H(28) | 0.7 |
C131—C133—C134—H(18) | 84.7 | | |
Hydrogen-bond geometry (Å, º) top
D—H···A | D—H | H···A | D···A | D—H···A |
O111—H1···O112i | 0.93 | 1.93 | 2.814 (4) | 159 |
N121—H10···O111 | 0.95 | 2.08 | 2.562 (3) | 110 |
N121—H10···O121 | 0.95 | 2.25 | 2.628 (4) | 103 |
C134—H17···O131ii | 0.99 | 2.50 | 3.324 (8) | 142 |
C136—H17···O131ii | 1.07 | 2.50 | 2.910 (11) | 102 |
C136—H29···O131ii | 1.09 | 2.36 | 2.910 (11) | 110 |
Symmetry codes: (i) x+1, y, z; (ii) −x+1, y+1/2, −z+1. |
Experimental details
Crystal data |
Chemical formula | C20H28N2O5 |
Mr | 376.45 |
Crystal system, space group | Monoclinic, P21 |
Temperature (K) | 173 |
a, b, c (Å) | 5.8977 (7), 10.1767 (16), 16.941 (2) |
β (°) | 94.394 (10) |
V (Å3) | 1013.8 (2) |
Z | 2 |
Radiation type | Cu Kα |
µ (mm−1) | 0.73 |
Crystal size (mm) | 0.5 × 0.5 × 0.05 |
|
Data collection |
Diffractometer | Rigaku RAXIS-RAPID area-detector diffractometer |
Absorption correction | Part of the refinement model (ΔF) (DIFABS; Walker & Stuart, 1983) |
Tmin, Tmax | 0.730, 0.964 |
No. of measured, independent and observed [F2 > 2.0σ(F2)] reflections | 16496, 1844, 1799 |
Rint | 0.055 |
(sin θ/λ)max (Å−1) | 0.590 |
|
Refinement |
R[F2 > 2σ(F2)], wR(F2), S | 0.079, 0.067, 1.01 |
No. of reflections | 1844 |
No. of parameters | 215 |
No. of restraints | ? |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.59, −0.41 |
Selected torsion angles (º) topO111—C111—C112—N121 | 6.4 (6) | C122—N131—C131—C132 | −73.6 (5) |
C111—C112—N121—C121 | 177.5 (4) | N131—C131—C132—O141 | 167.0 (3) |
C112—N121—C121—C122 | −148.9 (4) | C131—C132—O141—C141 | 166.4 (4) |
N121—C121—C122—N131 | 156.4 (4) | C132—O141—C141—C142 | −76.5 (5) |
C121—C122—N131—C131 | 179.7 (4) | | |
Hydrogen-bond geometry (Å, º) top
D—H···A | D—H | H···A | D···A | D—H···A |
O111—H1···O112i | 0.93 | 1.93 | 2.814 (4) | 159 |
N121—H10···O111 | 0.95 | 2.08 | 2.562 (3) | 110 |
N121—H10···O121 | 0.95 | 2.25 | 2.628 (4) | 103 |
Symmetry code: (i) x+1, y, z. |
The title compound, (I), is a derivative of the –Ala-Pro- sequence, which has been extensively studied in our laboratory (e.g. Oku et al., 2003; Ishiguro et al., 2001; Abe et al., 2001) to make synthetic antigens and enzyme active sites. In this paper, (I) has been prepared as a hydroxy acid analogue of the –Val-Ala-Pro- sequence. Our ongoing studies of depsipetides have shown that these molecules containing hydroxy acid residues often form single crystals suitable for X-ray crystallography (Ohyama et al., 2000, 2001), in contrast with the corresponding amino acid compounds. In this case, a sequence contaning –Val-Ala-Pro-, such as Boc-Val-Ala-Pro-OBzl (Boc is tert-butyloxycarbonyl) gives an oily state at room temperature. To show an example of the excellent crystallinity of hydroxy acid compounds, the crystal structure of (I) has been determined.
The molecular structure of (I) is shown in Fig. 1. The molecule has an extended sheet-like conformation. Disordered atoms (C134 and C136) were observed in the side chain of Pro, due to the conformational isomerism of the five-membered ring in the Pro residue. This side-chain disorder leads to unusual geometerical parameters, such as the close contact between atoms C136 and O131.
No intermolecular NH···O═C hydrogen bonds were observed in the packing structure of (I). As shown in Fig. 2, the molecules are connected together via an –OH···O═C interaction along the a axis, to give an infinite arrangement.
Generally, intermolecular NH···O═C networks connect peptides together into an infinite anti-parallel β sheet aggregation in crystals (e.g. Antolic et al., 1999; Ashida et al., 1981; Cruse et al., 1982). This is an important crystallizing force for short peptide compounds, although no such interactions were observed in the packing of (I).