Electronic Supplementary Material (ESI) for ChemComm. This journal is The Royal Society of Chemistry 2015 Supramolecular chemical shift reagents inducing conformational transition: NMR analysis of carbohydrate homooligomer mixtures Sophie R. Beeren* a and Sebastian Meier* b Supporting Information Contents S1 Materials S1 S2 NMR spectroscopy S3 S1 Materials Glucose, maltose, maltotriose, maltotetraose, maltopentaose, maltohexaose, 8-hydroxypyrene- 1,3,6-trisulfonic acid trisodium salt (HPTS) and sodium dodecyl sulfate (SDS) were obtained from Sigma Aldrich. Maltoheptaose and maltooctaose were obtained from Carbosynth (Compton, UK). D 2 O was purchased from Cambridge Isotope Laboratories, (Andover, MA, USA). HPTS-C 16, HPTS-C 12, HPTS-C 8 and HPTS-C 4 were synthesized as described previously. 1,2 The maltooligosaccharide mixture was prepared by fractional precipitation of a starch digest with ethanol as described previously. 3 The distribution of maltooligosaccharides in the mixture was determined using UPLC/MS analysis following fluorescence labelling at the reducing end with 2-aminobenzamide as described previously. 2 S1
DP 5 DP 10 DP 15 DP 20 Figure S1. Fluorescence chromatogram showing UPLC analysis of the α(1-4) glucan mixture used in this work. S2
S2 NMR spectroscopy 1 H- 13 C HSQC NMR spectra were recorded on an 800 MHz Bruker (Fällanden, Switzerland) Avance spectrometer equipped with a 5 mm TCI z-gradient CryoProbe and an 18.7 T magnet (Oxford Magnet Technology, Oxford, UK) and processed with Topspin 3.0 (Bruker) using extensive zero filling in both dimension, no linear prediction and mild resolution enhancement in the 13 C dimension. Sensitivity enhanced 1 H- 13 C HSQC spectra were acquired with narrow spectral width in the indirect dimension using the standard Bruker pulse sequence (hsqcetgpsi). Specifically: For analysis of the α-glucan mixture with 10 mm HPTS-C 16, SDS or HPTS HSQC spectra were acquired as matrices of 1024 256 complex data points sampling 143 milliseconds in the direct ( 1 H) and 319 milliseconds in the indirect ( 13 C) dimension. The spectra were acquired with a spectral width of 9 ppm (7183 Hz) in the direct dimension and of 4 ppm (803 Hz) in the indirect dimension with a recycle delay of 1 second. For analysis of the α-glucan mixture alone and in the presence of HPTS, 2 scans were accumulated. The resolved spectra of the α-glucan mixture in the presence of 10 mm HPTS-C 16 and 10 mm SDS were recorded over night with 96 scans. One-dimensional 1 H NMR spectra of the mixture alone and in the presence of 10 mm SDS, HPTS and HPTS-C 16 are shown in Figure S2. Spectra were acquired at 800 MHz by sampling 16384 complex data points for an acquisition time of 1.27 seconds and employing a spectral width of 12820 Hz. 1 H NMR spectra were processed with extensive zero filling and with an exponential line broadening of 0.3 Hz. For analysis of the α-glucan mixture together with HPTS-C 12, HPTS-C 8 and HPTS-C 4 : HSQC spectra were acquired as matrices of 1024 192 complex data points sampling 143 milliseconds in the direct ( 1 H) and 319 milliseconds in the indirect ( 13 C) dimension by accumulating 96 scans for HPTS-C 12 and HPTS-C 8 with a recycle delay of 1 second and by accumulating 76 scans in the case of HPTS-C 4 with a recycle delay of 1 second. For assignment of signals using commercial reference compounds: Mixtures of G 1, G 2, G 3, G 6 and G 8 (each 2 mg/ml) and of G 2, G 4, G 5, G 6 and G 7 (each 2 mg/ml) were prepared and subjected to HSQC spectroscopy for the validation of mixture S3
signal assignments by the use of reference compounds. Both mixtures were analysed in the presence of 10 mm (i) HPTS-C 4, (ii) HPTS-C 8, (iii) HPTS-C 12 or (iv) HPTS-C 16 (Figure S5). The HSQC spectra were acquired as matrices of 1024 256 complex data points sampling 143 milliseconds in the direct ( 1 H) and 319 milliseconds in the indirect ( 13 C) dimension. Spectra were recorded with a spectral width of 9 ppm (7183 Hz) in the direct dimension and of 4 ppm (803 Hz) in the indirect dimension with a recycle delay of 1 second and 8 scans. (a) α(1-4) glucan mixture (b) +10 mm SDS (c) +10 mm HPTS (d) +10 mm HPTS-C16 8 6 4 2 Chemical Shift ( 1 H, ppm) Figure S2. 1 H NMR spectra (300 K, 800 MHz, D 2 O) of the α(1-4) glucan mixture alone (a) and in the presence of 10 mm SDS (b), HPTS (c), and HPTS-C 16 (d). Anomeric regions of the corresponding HSQC spectra are shown in panels a-d of the main text Figure 2. S4
H1 H1β-red H1α-red H2β-red H5β-red H1α-red H1β-red H1 H2β-red H5β-red Figure S3. 1H13C HSQC spectra (300K, 800 MHz, D2O) of the α(1-4) glucan mixture alone (a) and in the presence of 10 mm HPTS-C16 (b). The spectra were recorded with a narrow (2 and 4 ppm) sweep width in the 13C dimension and therefore many signals are multiply aliased. S5
(a) (b) Figure S4. 1 H 13 C HSQC spectra (300 K, 800 MHz, D 2 O) showing (a) H1β reducing end signals and (b) the H5β reducing end signals of the 10 mg/ml α(1 4) glucan mixture in the presence of 10 mm of (i) HPTS-C 4, (ii) HPTS-C 8, (iii) HPTS-C 12 and (iv) HPTS-C 16. S6
(a) (b) (c) Figure S5. 1 H 13 C HSQC spectra (300 K, 800 MHz, D 2 O) showing (a) the H1β reducing end signals, (b) the H2β reducing end signals and (c) the H5β reducing end signals of: in red, a mixture of G 1, G 2, G 3, G 6 and G 8 (each 2 mg/ml) and in blue, a mixture of G 2, G 4, G 5, G 6 and G 7 (each 2 mg/ml) in the presence of 10 mm (i) HPTS-C 4 or (ii) HPTS-C 8, (iii) HPTS-C 12 and (iv) HPTS-C 16. 1 Beeren, S. R.; Hindsgaul, O. Angew. Chem. Int. Ed. 2013, 52, 11265-11268. 2 Beeren, S. R.; Meier, S.; Hindsgaul, O. Chem. Eur. J. 2013, 19, 16314-16319. 3 Johannesen, S. A.; Beeren, S. R.; Blank, D.; Yang, B. Y.; Geyer, R.; Hindsgaul, O. Carbohydr. Res. 2012, 352, 94-100. S7