Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S0108270199016029/qb0156sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S0108270199016029/qb0156Isup2.hkl |
CCDC reference: 140864
Taurine was purchased from Sigma. The crystals were obtained by diffusion of 2-propanol into 50 µl of an aqueous solution containing about 2.0 mg of the acid.
The data collection nominally covered over a hemisphere of reciprocal space by a combination of five sets of exposures; two with the detector set at 2θ = 30° and three with 2θ = 55°. Each set had a different ϕ angle for the crystal and each exposure covered 0.6° in ω. The crystal-to-detector distance was 4.97 cm. Coverage of the unique set is over 99% complete to at least 70° in 2θ. H atoms were refined isotropically.
Data collection: SMART (Siemens, 1995); cell refinement: SAINT (Siemens, 1995); data reduction: SAINT (Siemens, 1995); program(s) used to solve structure: SHELXTL (Sheldrick, 1997); program(s) used to refine structure: SHELXTL (Sheldrick, 1997); molecular graphics: SHELXTL (Sheldrick, 1997); software used to prepare material for publication: SHELXTL (Sheldrick, 1997).
C2H7NO3S | F(000) = 264 |
Mr = 125.15 | Dx = 1.730 Mg m−3 |
Monoclinic, P21/c | Mo Kα radiation, λ = 0.71073 Å |
a = 5.2729 (1) Å | Cell parameters from 2830 reflections |
b = 11.6565 (3) Å | θ = 3.5–40.0° |
c = 7.8383 (2) Å | µ = 0.56 mm−1 |
β = 94.011 (1)° | T = 150 K |
V = 480.59 (2) Å3 | Block, colourless |
Z = 4 | 0.60 × 0.45 × 0.40 mm |
Siemens SMART CCD diffractometer | 2891 independent reflections |
Radiation source: fine-focus sealed tube | 2736 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.027 |
Detector resolution: 8.3 pixels mm-1 | θmax = 40.3°, θmin = 3.5° |
Sets of exposures each taken over 0.6° ω rotation scans | h = −9→8 |
Absorption correction: empirical (using intensity measurements) (SADABS; Sheldrick, 1996) | k = −21→20 |
Tmin = 0.755, Tmax = 0.844 | l = −14→13 |
7640 measured reflections |
Refinement on F2 | Secondary atom site location: difference Fourier map |
Least-squares matrix: full | Hydrogen site location: inferred from neighbouring sites |
R[F2 > 2σ(F2)] = 0.026 | H atoms treated by a mixture of independent and constrained refinement |
wR(F2) = 0.075 | w = 1/[σ2(Fo2) + (0.0408P)2 + 0.0602P] where P = (Fo2 + 2Fc2)/3 |
S = 1.13 | (Δ/σ)max = 0.010 |
2891 reflections | Δρmax = 0.53 e Å−3 |
93 parameters | Δρmin = −0.42 e Å−3 |
0 restraints | Extinction correction: SHELXTL, Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4 |
Primary atom site location: structure-invariant direct methods | Extinction coefficient: 0.133 (10) |
C2H7NO3S | V = 480.59 (2) Å3 |
Mr = 125.15 | Z = 4 |
Monoclinic, P21/c | Mo Kα radiation |
a = 5.2729 (1) Å | µ = 0.56 mm−1 |
b = 11.6565 (3) Å | T = 150 K |
c = 7.8383 (2) Å | 0.60 × 0.45 × 0.40 mm |
β = 94.011 (1)° |
Siemens SMART CCD diffractometer | 2891 independent reflections |
Absorption correction: empirical (using intensity measurements) (SADABS; Sheldrick, 1996) | 2736 reflections with I > 2σ(I) |
Tmin = 0.755, Tmax = 0.844 | Rint = 0.027 |
7640 measured reflections |
R[F2 > 2σ(F2)] = 0.026 | 0 restraints |
wR(F2) = 0.075 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.13 | Δρmax = 0.53 e Å−3 |
2891 reflections | Δρmin = −0.42 e Å−3 |
93 parameters |
x | y | z | Uiso*/Ueq | ||
S1 | 0.20206 (2) | 0.349635 (11) | 0.350184 (17) | 0.01098 (5) | |
O1 | 0.34141 (10) | 0.24190 (4) | 0.35347 (7) | 0.01856 (9) | |
O2 | −0.06739 (9) | 0.33817 (4) | 0.29125 (7) | 0.01825 (9) | |
O3 | 0.23035 (9) | 0.41200 (4) | 0.51340 (5) | 0.01480 (8) | |
N1 | 0.26644 (10) | 0.63028 (4) | 0.33278 (6) | 0.01304 (8) | |
H1 | 0.199 (3) | 0.6079 (13) | 0.4132 (18) | 0.029 (3)* | |
H2 | 0.205 (3) | 0.6931 (13) | 0.3125 (19) | 0.026 (3)* | |
H3 | 0.418 (3) | 0.6326 (12) | 0.3580 (18) | 0.025 (3)* | |
C1 | 0.33923 (11) | 0.43962 (5) | 0.19717 (7) | 0.01318 (9) | |
H11 | 0.516 (3) | 0.4464 (12) | 0.2367 (18) | 0.027 (3)* | |
H12 | 0.318 (3) | 0.3986 (11) | 0.0901 (16) | 0.022 (3)* | |
C2 | 0.20939 (11) | 0.55634 (5) | 0.17965 (7) | 0.01411 (9) | |
H21 | 0.266 (3) | 0.5993 (12) | 0.0777 (17) | 0.026 (3)* | |
H22 | 0.037 (3) | 0.5455 (12) | 0.1644 (19) | 0.026 (3)* |
U11 | U22 | U33 | U12 | U13 | U23 | |
S1 | 0.00983 (7) | 0.00924 (7) | 0.01388 (7) | 0.00062 (3) | 0.00088 (4) | −0.00031 (3) |
O1 | 0.0207 (2) | 0.01261 (17) | 0.0228 (2) | 0.00667 (14) | 0.00483 (15) | 0.00220 (14) |
O2 | 0.01131 (18) | 0.01537 (17) | 0.0276 (2) | −0.00261 (13) | −0.00209 (15) | −0.00208 (15) |
O3 | 0.01626 (17) | 0.01562 (17) | 0.01268 (15) | 0.00014 (13) | 0.00207 (12) | −0.00137 (12) |
N1 | 0.01319 (19) | 0.01188 (16) | 0.01416 (17) | 0.00084 (14) | 0.00179 (13) | 0.00057 (13) |
C1 | 0.0136 (2) | 0.01328 (19) | 0.01279 (18) | 0.00019 (15) | 0.00179 (14) | −0.00043 (14) |
C2 | 0.0152 (2) | 0.01305 (19) | 0.01364 (18) | −0.00020 (15) | −0.00212 (15) | 0.00166 (14) |
S1—O1 | 1.4543 (5) | N1—H3 | 0.810 (15) |
S1—O2 | 1.4690 (5) | C1—C2 | 1.5249 (8) |
S1—O3 | 1.4699 (4) | C1—H11 | 0.964 (15) |
S1—C1 | 1.7842 (6) | C1—H12 | 0.966 (13) |
N1—C2 | 1.4911 (7) | C2—H21 | 1.005 (14) |
N1—H1 | 0.790 (15) | C2—H22 | 0.919 (15) |
N1—H2 | 0.812 (15) | ||
O1—S1—O2 | 113.79 (3) | C2—C1—S1 | 112.61 (4) |
O1—S1—O3 | 113.03 (3) | C2—C1—H11 | 111.9 (8) |
O2—S1—O3 | 110.84 (3) | S1—C1—H11 | 105.1 (9) |
O1—S1—C1 | 106.95 (3) | C2—C1—H12 | 109.8 (8) |
O2—S1—C1 | 105.71 (3) | S1—C1—H12 | 105.3 (8) |
O3—S1—C1 | 105.85 (3) | H11—C1—H12 | 111.9 (11) |
C2—N1—H1 | 112.0 (11) | N1—C2—C1 | 112.28 (4) |
C2—N1—H2 | 108.0 (10) | N1—C2—H21 | 107.4 (8) |
H1—N1—H2 | 105.0 (15) | C1—C2—H21 | 111.1 (8) |
C2—N1—H3 | 110.9 (10) | N1—C2—H22 | 109.1 (9) |
H1—N1—H3 | 107.9 (14) | C1—C2—H22 | 108.8 (9) |
H2—N1—H3 | 112.9 (14) | H21—C2—H22 | 108.0 (12) |
O1—S1—C1—C2 | 179.69 (4) | O3—S1—C1—C2 | −59.53 (4) |
O2—S1—C1—C2 | 58.11 (4) | S1—C1—C2—N1 | 70.96 (5) |
D—H···A | D—H | H···A | D···A | D—H···A |
N1—H1···O3 | 0.790 (14) | 2.416 (15) | 2.924 (1) | 123.2 (13) |
N1—H1···O3i | 0.790 (14) | 2.386 (15) | 3.000 (1) | 135.5 (13) |
N1—H1···O2i | 0.790 (14) | 2.543 (14) | 3.218 (1) | 144.3 (14) |
N1—H2···O2ii | 0.812 (15) | 1.991 (15) | 2.789 (1) | 167.1 (15) |
N1—H3···O3iii | 0.811 (15) | 2.112 (14) | 2.879 (1) | 157.8 (14) |
Symmetry codes: (i) −x, −y+1, −z+1; (ii) −x, y+1/2, −z+1/2; (iii) −x+1, −y+1, −z+1. |
Experimental details
Crystal data | |
Chemical formula | C2H7NO3S |
Mr | 125.15 |
Crystal system, space group | Monoclinic, P21/c |
Temperature (K) | 150 |
a, b, c (Å) | 5.2729 (1), 11.6565 (3), 7.8383 (2) |
β (°) | 94.011 (1) |
V (Å3) | 480.59 (2) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 0.56 |
Crystal size (mm) | 0.60 × 0.45 × 0.40 |
Data collection | |
Diffractometer | Siemens SMART CCD diffractometer |
Absorption correction | Empirical (using intensity measurements) (SADABS; Sheldrick, 1996) |
Tmin, Tmax | 0.755, 0.844 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 7640, 2891, 2736 |
Rint | 0.027 |
(sin θ/λ)max (Å−1) | 0.909 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.026, 0.075, 1.13 |
No. of reflections | 2891 |
No. of parameters | 93 |
H-atom treatment | H atoms treated by a mixture of independent and constrained refinement |
Δρmax, Δρmin (e Å−3) | 0.53, −0.42 |
Computer programs: SMART (Siemens, 1995), SAINT (Siemens, 1995), SHELXTL (Sheldrick, 1997).
S1—O1 | 1.4543 (5) | S1—C1 | 1.7842 (6) |
S1—O2 | 1.4690 (5) | N1—C2 | 1.4911 (7) |
S1—O3 | 1.4699 (4) | C1—C2 | 1.5249 (8) |
O1—S1—C1 | 106.95 (3) | C2—C1—S1 | 112.61 (4) |
O2—S1—C1 | 105.71 (3) | N1—C2—C1 | 112.28 (4) |
O3—S1—C1 | 105.85 (3) | ||
O1—S1—C1—C2 | 179.69 (4) | S1—C1—C2—N1 | 70.96 (5) |
D—H···A | D—H | H···A | D···A | D—H···A |
N1—H1···O3 | 0.790 (14) | 2.416 (15) | 2.924 (1) | 123.2 (13) |
N1—H1···O3i | 0.790 (14) | 2.386 (15) | 3.000 (1) | 135.5 (13) |
N1—H1···O2i | 0.790 (14) | 2.543 (14) | 3.218 (1) | 144.3 (14) |
N1—H2···O2ii | 0.812 (15) | 1.991 (15) | 2.789 (1) | 167.1 (15) |
N1—H3···O3iii | 0.811 (15) | 2.112 (14) | 2.879 (1) | 157.8 (14) |
Symmetry codes: (i) −x, −y+1, −z+1; (ii) −x, y+1/2, −z+1/2; (iii) −x+1, −y+1, −z+1. |
Bile acids are conjugated with glycine and taurine, (I), to become more water soluble, which facilitates secretion. This enzymatic activity seems to have a bimodal localization in rat liver with different Kms for glycine and taurine, but competition experiments indicate that the same enzymes are able to catalyse conjugation both with glycine and taurine (Kase & Björkhem, 1989). Furthermore, β-alanine (3-aminopropanoic acid, not to be misinterpreted as a second polymorph of L-alanine) is also a substrate. This makes a structural comparison of these three amino acids interesting. The strucure of taurine was first presented by Okaya (1966). We report here a more accurate low-temperature study.
Glycine has been crystallized in three polymorphic forms, α-glycine (Jönnson & Kvick, 1972), β-glycine (Iitaka, 1960) and γ-glycine (Kvick et al., 1980) with different hydrogen-bond patterns. The structure of α-glycine (Jönnson & Kvick, 1972) is very similar to the structure of β-alanine (Jose & Pant, 1965; Papavinasam et al., 1986) in that amino acid dimers (with centers of symmetry) connected by two hydrogen bonds occur in both structures. The corresponding first-level graph-sets (Etter, 1990; Bernstein et al., 1995) are R22(10) and R22(12), respectively. The conformation at the central C—C bond in β-alanine is gauche [N—C—C—C = 83.2 (2)°, Papavinasam et al., 1986]. A gauche orientation is found also for taurine with N1—C2—C1—S1 = 70.96 (5)°. In addition to a weak intramolecular contact between the amino- and sulfonic acid groups [graph-set S(6)], the hydrogen-bond pattern again incorporates the centrosymmetric R22(12) motif, involving not just one, but two different neighboring molecules resulting in formation of hydrogen-bonded ribbons along the a axis. In summary, the structures of glycine (in the α-modification, Jönnson & Kvick, 1972), β-alanine (Papavinasam et al., 1986) and taurine show several common features. In particular, the tendency of these molecules to form hydrogen-bonded ring systems may be important for substrate specificity when conjugation with bile acids occurs.