Electronic Supporting Information. 3-Aminothiophenecarboxylic acid (3-Atc)-induced folding in peptides

Electronic Supplementary Material (ESI for New Journal of Chemistry. This journal is The Royal Society of Chemistry and the Centre National de la Recherche Scientifique 2016 Electronic Supporting Information 3-Aminothiophenecarboxylic acid (3-Atc-induced folding in peptides Tukaram S. Ingole, a Amol S. Kotmale, b Rupesh L. Gawade, c Rajesh G. Gonnade, c Pattuparambil R. Rajamohanan b and Gangadhar J. Sanjayan *a Contents HRMS spectra of compounds S1 S2-S4 1 H NMR spectra of compounds S-S7 13 C and DEPT-13 spectra of compounds S8-S13 DMSO-d 6 titration of compounds of 2, 3, 1 Variable Temperature studies of compounds of 2, 3, 1 2D TOCSY, COSY, HSQC, HMBC and NOESY spectra of 2 2D COSY and NOESY spectra of 3 2D TOCSY, COSY, HSQC, HMBC and NOESY spectra of 1 X-ray crystallographic data of tripeptide 2 Molecular dynamics study of 1 CD spectra of Gly-3-Atc-Pro oligomers S14-S16 S17-S19 S20-S23 S23-S24 S2-S28 S29-S30 S31 S32 S1

HRMS 4a HRMS 2 S2

TUKA-4-TRINHME #884 RT: 3.94 AV: 1 NL: 1.14E9 T: FTMS + p ESI Full ms [10.00-220.00] 100 9 90 8 80 7 70 6 HRMS 433.112 R=3707 C18 H26 O N4 Na S = 433.116-0.9874 Relative Abundance 60 0 4 40 3 30 2 20 411.1691 R=007 C18 H27 O N4 S = 411.1697-1.3101 3 1 10 0 402.6129 R=41200 418.8799 R=42100 449.1249 R=2707 C18 H26 O4 N4 Na S2 = 449.1288-8.23 46.0876 R=400 C16 H22 O N6 Na S2 = 46.098-23.4674 390 39 400 40 410 41 420 42 430 43 440 44 40 4 460 46 470 m/z HRMS S3

TUKA-3-HEX-PRV #961 RT: 4.28 AV: 1 NL:.3E8 T: FTMS + p ESI Full ms [10.00-220.00] Relative Abundance 100 9 90 8 80 7 70 6 60 0 4 40 3 30 HRMS 767.220 R=40207 C36 H43 O9 N6 S2 = 767.227-1.0317 789.2337 R=40207 C36 H42 O9 N6 Na S2 = 789.2347-1.2490 2 20 1 784.2788 R=39807 6 10 0 72.7397 R=26900 80.2060 811.2146 R=38807 R=39107 819.2449 R=26000 827.1836 R=29004 73 740 74 70 7 760 76 770 77 780 78 790 79 800 80 810 81 820 82 830 m/z HRMS 1 S4

10.68 8.11 8.09 7.47 7.4 7.28.36 4.01 4.00 3.88 1.0 1 H NMR (400 MHz, CDCl 3 4a 11.71 8.20 8.19 7.42 7.3 7.27 CDCl3.27.24.16.14 4.73 4.00 3.9 3.94 3.92 3.91 2.24 2.23 2.13 2.0 2.04 1.47 1 H NMR (00 MHz, CDCl 3 2 S

11.80 8.14 7.43 7.29 6.83.43 4.80 4.01 3.94 3.88 3.87 3.8 2.8 2.84 2.40 2.17 2.07 2.0 2.01 1.0 1 H NMR (00 MHz, CDCl 3 3 11.29 9.34 7.68 7.67 7.11 7.08 7.07 7.01 6.90 6.88.99 4.33 3. 3.44 3.43 3.40 3.38 2.0 DMSO-d6 1.71 1.61 1.60 1.8 0.91 1 H NMR (400 MHz, DMSO-d 6 S6

11.76 8.20 8.18 8.17 8.16 7.80 7.47 7.4 7.33 7.28.48.23.20.19.16 4.90 4.88 4. 4.19 4.18 4.12 4.07 4.01 3.93 3.83 3.81 3.79 2.0 2.23 2.21 2.08 2.07 2.06 2.03 1.93 1.8 1.47 1 H NMR (400 MHz, CDCl 3 6 11.64 8.13 7.8 7.4 7.27 CDCl3 6.64.47 4.91 4.90 4.02 4.01 3.92 3.90 3.89 3.88 3.81 2.82 2.81 2.49 2.33 2.2 2.17 2.11 2.04 2.04 1.78 1.47 1 H NMR (700 MHz, CDCl 3 1 S7

167.36 164.44 1.82 143.79 131.7 122.10 110.78 80.0 77.32 77.00 CDCl3 76.68 1.89 44.88 28.24 13 C NMR (100 MHz, CDCl 3 4a 131.6 122.10 1.89 44.88 28.24 DEPT-13 (100 MHz, CDCl 3 4a S8

171.7 167.20 163.9 1.72 144.40 13.7 128.7 128.49 128.23 128.03 122.31 112.0 79.9 77.2 77.00 CDCl3 76.7 66.80 60.6 48.1 44.70 28.26 2.38 13 C NMR (12 MHz, CDCl 3 2 128.7 128.48 128.22 128.02 122.31 66.79 60. 48.1 44.70 28.26 2.41 DEPT-13 (12 MHz, CDCl 3 2 S9

171.69 167.6 16.01 1.84 144.41 129.19 122.00 111.84 80.22 77.2 77.00 CDCl3 76.7 61.69 48.90 44.97 28.30 26.31 13 C NMR (12 MHz, CDCl 3 3 129.19 77.20 48.90 44.97 29.61 28.30 26.31 DEPT-13 (12 MHz, CDCl 3 3 S10

CDCl 3 13 C NMR (100 MHz, CDCl 3 DEPT-13 (100 MHz, CDCl 3 S11

171.80 171.41 167.1 166.63 16.04 163.86 1.84 144.41 13.4 128.9 128.1 128.29 128.01 122.22 112.24 80.06 77.32 77.00 CDCl3 76.68 66.87 61.3 60.63 49.01 48.2 44.84 43.87 31.3 28.30 22.60 14.06 13 C NMR (100 MHz, CDCl 3 6 128.94 128.1 128.28 128.01 122.3 122.22 66.87 61.2 60.62 49.01 48.2 44.83 43.87 31.3 29.64 28.30 2. 22.60 14.06 DEPT-13 (100 MHz, CDCl 3 6 S12

171.6 167.3 166.69 16.14 164.90 1.90 144.23 129.3 128.98 122.41 112.41 80.10 77.18 77.00 CDCl3 76.82 61.8 49.13 48.97 44.81 44.02 28.33 26.3 2.60 13 C NMR (176 MHz, CDCl 3 1 DEPT-13 (176 MHz, CDCl 3 1 S13

Table S1. Titration study of 2 in CDCl 3 ( mm, 400 MHz with DMSO-d 6 (Volume of DMSO- d 6 added at each addition = μl No Volume of DMSO-d6 (µl Chemical Shift ( NH1 NH2 1 0.1 11.69 2.2 11.68 3 10.2 11.67 4 1.3 11.66 20.38 11.64 6 2.43 11.64 7 30.48 11.62 8 3.4 11.61 9 40.6 11.6 10 4.6 11.9 11 0.7 11.8 12 11 Chemical Shift in 10 9 8 7 6 NH1 NH2 0 10 20 30 40 0 Volume of DMSO-d 6 added ( L S14

Table S2. Titration study of 3 in CDCl 3 ( mm, 400 MHz with DMSO-d 6 (Volume of DMSO- d 6 added at each addition = μl No Volume of DMSO-d6 (µl Chemical Shift ( NH1 NH2 NH3 1 0.2 11.77 6.69 2.27 11.7 6.72 3 10.32 11.7 6.7 4 1.42 11.73 6.8 20.48 11.71 6.83 6 2.7 11.69 6.87 7 30.63 11.68 6.9 8 3.7 11.66 6.93 9 40.74 11.6 6.9 10 4.81 11.63 6.97 11 0.84 11.62 6.99 12 11 Chemical Shift ( 10 9 8 7 6 NH1 NH2 NH3 4 0 10 20 30 40 0 Volume of DMSO-d 6 added ( L S1

Table S3. Titration study of 1 in CDCl 3 ( mm, 400 MHz with DMSO-d 6 (Volume of DMSO- d 6 added at each addition = μl No Volume of Chemical Shift ( DMSO-d6 (µl NH1 NH2 NH3 NH4 NH 1 0.43 11.69 7.8 11.69 6.8 2.48 11.66 7.8 11.66 6.66 3 10.3 11.63 7.87 11.63 6.72 4 1.9 11.6 7.87 11.6 6.78 20.62 11.9 7.87 11.9 6.82 6 2.68 11.6 7.88 11.8 6.86 7 30.72 11.4 7.88 11.7 6.89 8 3.7 11.2 7.88 11.6 6.93 9 40.81 11. 7.89 11.4 6.9 10 4.84 11.49 7.89 11.3 6.98 11 0.87 11.47 7.89 11.2 7 12 Chemical Shift in 11 10 9 8 7 6 NH1 NH2 NH3 NH4 NH 0 10 20 30 40 0 Volume of DMSO-d 6 added ( L S16

Table S4. Variable temperature study of 2 ( mm, 400 MHz, CDCl 3 No Temperature (K Chemical Shift in NH1 NH2 1 268.19 11.78 2 273.18 11.76 3 278.17 11.7 4 283.16 11.74 288.1 11.72 6 293.1 11.71 7 298.14 11.69 8 303.13 11.68 9 308.13 11.66 10 313.12 11.6 11 318.1 11.63 12 323.09 11.62 12 11 Chemical Shift in 10 9 8 7 6 NH1 NH2 260 270 280 290 300 310 320 330 Temperature (K S17

Table S. Variable temperature study of 3 ( mm, 400 MHz, CDCl 3 No Temperature (K Chemical Shift in NH1 NH2 NH3 1 268.2 11.88 6.79 2 273.2 11.87 6.78 3 278.24 11.8 6.76 4 283.24 11.83 6.74 288.23 11.81 6.72 6 293.22 11.8 6.71 7 298.2 11.77 6.69 8 303.19 11.76 6.67 9 308.18 11.74 6.6 10 313.18 11.73 6.64 11 318.1 11.71 6.63 12 323.14 11.69 6.61 12 11 Chemical Shift in 10 9 8 7 6 NH1 NH2 NH3 260 270 280 290 300 310 320 330 Temperature (K S18

Table S6. Variable temperature study of 1 ( mm, 400 MHz, CDCl 3 No Temperature Chemical Shift in (K NH1 NH2 NH3 NH4 NH 1 268.62 11.7 8.01 11.84 6.66 2 273.8 11.7 7.98 11.81 6.6 3 278.6 11.74 7.96 11.79 6.64 4 283.3 11.73 7.94 11.73 6.62 288.48 11.72 7.92 11.72 6.6 6 293.46 11.71 7.88 11.71 6.9 7 298.43 11.69 7.8 11.69 6.7 8 303.4 11.66 7.82 11.67 6.7 9 308.38 11.64 7.79 11.66 6.6 10 313.37 11.62 7.77 11.64 6.4 11 318.34 11.61 7.74 11.63 6.2 12 323.32 11.9 7.71 11.61 6.2 12 Chemical Shift in 11 10 9 8 7 6 NH1 NH2 NH3 NH4 NH 260 270 280 290 300 310 320 330 Temperature (K S19

(a 10 12 11 10 9 8 7 6 4 3 2 (b C6H C16,C17,C18, C19,C20H C7H C16,C17,C18, C19,C20H 8. 8.4 8.2 8.0 7.8 7.6 7.4 (c NH1 C14Ha C14Hb C9H 7. 8.0 C12Ha,C2Ha C12Hb,C2Hb C14Hb NH1.2 C14Ha.4 7. 7.4 7.3 C11H Boc C10H 2 4..0 4. 4.0 3. 3.0 2. 2.0 1. Figure S1: TOCSY full spectrum (a of 2 (2 mm, 00 MHz, CDCl 3, 298 K; aromatic (b and aliphatic (c regions shown separately. S20

(a C6H C16,C17, C18,C19, C20H C7H 7. 8.0 8.4 8.2 8.0 7.8 7.6 7.4 (b NH1 C14Ha C14Hb C9H C12Ha, C2Ha C12Hb, C2Hb C10H C11H Boc 2 3 4..0 4. 4.0 3. 3.0 2. 2.0 Figure S2: Partial COSY spectra of 2 (2 mm, 00 MHz, CDCl 3, 298 K; aromatic (a and aliphatic (b regions shown separately. S21

(a C6H C7H C16,C17, C14Hb C18,C19, C20H NH1 C14Ha C9H C12Ha, C2Ha C12Hb, C2Hb C10H C11H Boc 0 100 8 7 6 4 3 2 (b NH2 C6H C7H C16,C17, C18,C19, C20H C14Hb NH1 C14Ha C9H C12Ha, C2Ha C12Hb, C2Hb C10H C11H Boc 0 100 10 12 11 10 9 8 7 6 4 3 2 Figure S3: HSQC (a and HMBC (b full spectra of 2 (2 mm, 00 MHz, CDCl 3, 298 K. S22

10 C14Hb NH1 C14Ha Boc 12 10 8 6 4 2 NH2 NH2/NH1.2 11.8 11.6 C16.17,18, 19, 20H 7.4 7.3 Boc 1. Boc C14Hb Figure S4: 2D NOESY full spectrum and excerpts of 2 (2 mm, 00 MHz, CDCl 3, 298 K. NH2 1.4 1. 1.6 11.7 C9H 1.4 1.6.4.2.0 4.8 10 12 10 8 6 4 2 Figure S: COSY full spectrum (a of 3 (2 mm, 00 MHz, CDCl 3, 298 K. S23

(a C6H C7H (b NH3 NH1 C2H C9H C12Ha C12Hb C14H C10Ha C11H C10Hb Boc 2 7. 8.0 4 8.0 7. 6 7 6 4 3 2 Figure S6: Partial COSY spectra of 3 (2 mm, 00 MHz, CDCl 3, 298 K; aromatic (a and aliphatic (b regions shown separately. 2 4 6 8 10 12 12 10 8 6 4 2 C14H NH1 NH2.4.6 11.9 11.8 Boc C9H 1.4 Boc 1.6 4.9 4.8 4.7 1.4 1.6 2.9 2.8 Figure S7: 2D NOESY full spectrum and excerpts of 3 (2 mm, 00 MHz, CDCl 3, 298 K. S24

(a 10 11 10 9 8 7 6 4 3 2 (b C7H, C18H NH3 C7H, C18H 8 8.2 8.0 7.8 7.6 7.4 (c NH3 C12Ha C2Ha C14Hb C14Ha C9H C21H C12Hb C24H C2Hb C26H C11Ha C22Hb C22Ha C10Ha C10Hb C23H C11Hb 2 3 4.0 4. 4.0 3. 3.0 2. Figure S8: TOCSY full spectrum (a of 1 (6 mm, 700 MHz, CDCl 3, 328 K; aromatic (b and aliphatic (c regions shown separately. S2

(a 10 (b C7H, C18H 12 11 10 9 8 7 6 4 3 2 C7H, C18H NH3 7. (c C2Ha C14Hb C14Ha C21H C9H C12Ha C12Hb C24H C2Hb C26H C10Ha C10Hb C22Ha C22Hb C11Ha C23H, C11Hb Boc 2 8.0 3 8.0 7. 4 3 2 Figure S9. COSY full spectrum (a of 1 (23 mm, 700MHz, CDCl 3, 298 K; aromatic (b and aliphatic (c regions shown separately. 4 (a 0 100 (b C7H, C18H 12 11 10 9 8 7 6 4 3 2 1 NH3 C7H, C18H (c C21H C9H C2Ha C14Hb C14Ha C12Ha C12Hb C24H C2Hb C26H C22Ha C10Ha C10Hb C22Hb C11Ha C23H, C11Hb Boc 12 40 130 8.0 7..0 4. 4.0 3. 3.0 2. 2.0 1. Figure S10. HSQC full spectrum (a of 1 (23 mm, 700MHz, CDCl 3, 298 K; aromatic (b and aliphatic (c regions shown separately. S26 60

(a 0 100 10 C7H, C18H (b 11 10 9 8 7 6 4 3 2 NH3 C7H, C18H 120 (c C21H C9H C2Ha C14Hb C14Ha C12Ha C12Hb C24H C2Hb C26H C10Ha C10Hb C22Ha C22Hb C11Ha C23H, C11Hb Boc 30 40 0 140 8.0 7. 4 3 2 Figure S11. HMBC full spectrum (a of 1 (23 mm, 700MHz, CDCl 3, 298 K; aromatic (b and aliphatic (c regions shown separately. 60 70 80 10 12 10 8 6 4 2 Figure S12. NOESY full spectrum of 1 (6 mm, 700MHz, CDCl 3, 328 K. S27

C24H C2Hb C12Hb C2Ha C14Hb C12Ha C14Ha NH4 NH2 NH2/ C2Hb NH2/ C2Ha NH4/C14Hb NH4/C14Ha NH1 4.0 NH4 NH2 NH2/NH1. 11.6 11.6 NH1 NH4 NH2 C2Ha C2Hb 3.8 4.0 NH3 NH4/NH3 7.6 7.8.4 11.6 NH3 NH NH C9H.0 7.7 C26H 2.8 3.0 6. C21H 4.6 4.8 6.6 6. Figure S13. 2D NOESY extracts of 1 (6 mm, 700MHz, CDCl 3, 328 K. S28

X-ray Crystallography: Single crystal structure of compound 2 was determined by measuring X-ray intensity data on a Bruker SMART APEX II single crystal X- ray CCD diffractometer having graphite-monochromatised (Mo-Kα = 0.71073 Å radiation. The X-ray generator was operated at 0 kv and 30 ma. A preliminary set of cell constants and an orientation matrix were calculated from total 36 frames. The optimized strategy used for data collection consisted different sets of and scans with 0. steps in /. Data were collected keeping the sample-todetector distance fixed at.00 cm. The X-ray data acquisition was monitored by APEX2 program suit. All the data were corrected for Lorentz-polarization and absorption effects using SAINT and SADABS programs integrated in APEX2 package. The structures were solved by direct methods and refined by full matrix least squares, based on F 2, using SHELX-97. Molecular diagrams were generated using ORTEP-3 and Mercury programs. Geometrical calculations were performed using SHELXTL and PLATON. Table 7: X-ray crystallographic data of trimer 2. Crystal Data 2 Formula C 24 H 29 N 3 O 6 S M r 487.6 Crystal Size, mm 0.32 0.2 0.10 Temp. (K 10(2 Crystallizing solvent Ethyl acetate-petroleum ether Crystal Syst. Orthorhombic Space Group P2 1 2 1 2 1 a/å 8.866(3 b/å 12.6487( c/å 21.9234(9 / 0 90 / 0 90 / 0 90 V/Å 3 248.70(16 Z 4 D calc /g cm -3 1.317 μ/mm 1 0.176 F(000 1032 Ab. Correct. multi-scan 2 max 0 Total reflns. 41420 unique reflns. 4322 h, k, l (min, max (-10,10,(-1,1,(-23,26 R int 0.0292 S29

No. of para 311 R1 [I> 2σ(I] 0.031 wr2[i> 2σ(I] 0.0793 R1 [all data] 0.0330 wr2 [all data] 0.0801 goodness-of-fit 1.067 Δ max,δ min (eå -3 0.218,-0.177 CCDC no. 143889 S30

Table 8: noe-derived distance constraints used in molecular modeling for structural elucidation of oligomer 1. Atom I Atom II Chemical Chemical Shift I Shift II Upper Bound Lower Bound C19H NH4 8.178 11.614 3.61 2.98 NH3 NH4 7.721 11.614 3.229 2.642 NH1 NH2.327 11.601 3.473 2.842 C14Ha NH4 4.292 11.614 3.206 2.623 C14Hb NH4 4.100 11.614 3.264 2.670 C2Ha NH2 3.987 11.601 3.17 2.98 C2Hb NH2 3.828 11.601 3.326 2.721 C9H NH3 4.93 7.721 2.822 2.309 C14Ha NH3 4.292 7.721 3.433 2.809 C14Hb NH3 4.100 7.721 3.187 2.607 C21H NH 4.663 6.14 3.204 2.622 C2Ha NH1 3.987.327 3.418 2.797 C2Hb NH1 3.828.327 3.227 2.640 C26H NH 2.833 6.14 2.787 2.280 C10Ha C9H 2.41 4.93 3.38 2.89 C23H C21H 1.991 4.663 3.003 2.47 Boc NH3 1.487 7.721 4.71 3.740 Boc NH1 1.487.327 4.941 4.042 S31

Figure S14. CD spectra of (Gly-3-Atc-Pro n oligomers; tripeptides 2, 3 and hexapeptide 1 at a concentration of 0.1 mm. All CD spectra were recorded in trifluoroethanol at 298 K. S32