10.1071/C15460_AC CSIR 2016 Australian Journal of Chemistry 69 (3), 328-335 Supplementary Material Synthesis and Characterization of Bradykinin Derivatives Based on a β-cyclodextrin Core Rachel J. Stephenson, A,C,[1] Fran Wolber, B Paul G. Plieger, A and David R. K. arding A A Institute of Fundamental Sciences, Massey University, Private Bag 11-222, Turitea Campus, Palmerston orth 4442, ew Zealand. B Institute of Food, utrition & uman ealth, Massey University, Private Bag 11-222, Turitea Campus, Palmerston orth 4442, ew Zealand. C Corresponding author: Email: r.stephenson@uq.edu.au Contents Synthesis of 2... 2 Synthesis of 3... 5 Synthesis of fluorenylmethyloxycarbonyl-ε-aminocaproic acid... 7 Synthesis of 4... 8 Synthesis of 5... 10 Synthesis of 6, a bradykinin -terminal benzene sulfonamide... 11 Synthesis of 7, a bradykinin C-terminal benzene sulfonamide... 13 Synthesis of 8, a bradykinin C- and -terminal benzene sulfonamide... 14 Synthesis of 9... 16 Synthesis of 10... 17 Synthesis of 4-fluorenylmethyloxycarbonyl (Fmoc) aminobenzenesulfonylchloride (11)... 18 References... 20 1
Synthesis of 2 2 2 2 2 5 BK was assembled manually on Rink resin (0.69 mmol/g, 0.138 mmol, 200 mg, 1 eq) coupling Fmoc-L-amino acids (0.144 mmol, 4 eq) using TBTU (46 mg, 0.144 mmol, 4 eq), Bt (19 mg, 0.144 mmol, 4 eq), and DIEA (20μL, 0.288 mmol, 8 eq) and mono-6 A - fluorenylmethyloxycarbonylamino-mono-6 X -succinyl- -cyclodextrin [2] (1, 209 mg, 0.144 mol, 4 eq) was coupled using EDC (4 eq, 0.144 mmol), DIEA (4 eq, 0.144 mmol) in pyridine/dmf respectively. The peptide was cleaved from the resin [3-4]. RP-PLC with a Shimadzu LC-6 system equipped with a 15-µm, 300-Å Phenomenex guard column and a separation column (250 by 21.20 mm) was used to purify the peptides. Wavelength of analysis at 214 nm. Buffer A: 98% 2, 2% MeC, 0.1% TFA; Buffer B: 90% MeC, 10% 2, 0.1% TFA. The peptide fractions (50µL) were analysed with either a Waters Alliance T 2790 PLC instrument coupled to a Micromass ZMD 4000 ESI-MS using infusion injection or a Waters Alliance Micromass LR-MS (MALDI-TF) MS using α-cyanohydroxycinnamic acid as the matrix (2 mg/ml in 1:1 acetonitrile:methanol). Collation of the pure fractions and freeze-drying yielded a pure product. The time programme used for purification is given in Table 1. The product eluted at 42% B as a white fluffy solid (2.0 mg, 2%). 2
Table 1 RP-PLC purification of analogue 2 Time (min) % Mobile phase B Time (min) % Mobile phase B 0 5 100 50 5 5 105 100 15 12 110 5 20 20 120 STP LR-MS: m/z (%, assignment) 2388.52 (80, M+) + R-MS: m/z C 102 158 18 47 (M+) + 2387.0532, actual 2387.0601 1 MR (d6-dms, 500 Mz): δ 1.148-2.109 (m, 19, proline 2β, proline 2γ, proline 3β, arginine 1β, arginine 1α, proline 3β *), 2.149-2.243 (m, 1, phenylalanine 2β ), 2.596-3.897 (m, 511, phenylalanine 2β * phenylalanine 5β, arginine 9α, arginine 9α, proline 7γ, proline 3γ, arginine 1γ, serine 6β, proline 7γ, proline 3γ, proline 2γ, glycine α, CD 2-6, CD 6), 4.071-4.418 (m, 4* arginine 9, proline 3, proline 7 ), 4.457-4.748 (m, 4, phenylalanine 8, phenylalanine 5, serine 8, proline 2 ), 4.803-4.996 (m, 7, C 1), 5.564-5.944 (m, 14, C 2, 3), 6.941-7.033 (br s, 1, *), 7.099-7.325 (m, 17, phenylalanine aromatics), 7.471-7.537 (dd, 3, phenylalanine aromatics), 7.602-7.620 (s, 1, phenylalanine aromatics), 7.625-7.656 (dt, 2, phenylalanine aromatics), 7.759-7.806 (m, 1, glycine ), 7.848-7.878 (dd, 1, phenylalanine aromatics), 7.879-7.977 (m, 4, sulfonamide aromatics), 8.017-8.071 (m, 2, sulfonamide aromatics, arginine 9 ), 8.372-8.423 (m, 1, phenylalanine 5 ), 8.689-8.727 (d, 1, serine 6 ), where * denotes unassigned peaks associated with arginine 1α, phenylalanine 8α, proline 3β, proline 3γ, proline 7β, proline 7γ, arginine 9β, arginine 1γ, arginine 9β, arginine 9γ, proline 7, or proline 13 4 C-DEPT MR (d6- DMS, 700 Mz): δ 25.201 (succinyl C 2 ), 25.280 (succinyl C 2 ), 25.322 (BK), 27.658 (BK), 28.290 (BK), 28.380 (BK), 29.211 (BK), 29.221 (BK), 29.313 (BK), 29.458 (BK), 29.550 (BK), 29.800 (BK), 29.802 (BK), 29.856 (BK), 29.998 (BK), 30.095 (BK), 37.525 (BK), 38.218 (BK), 40.790 (BK), 40.958 (BK), 42.225 (BK), 46.416 (BK), 47.320 (BK), 47.438 (BK), 52.500 (BK), 53.168 (BK), 53.199 (BK), 53.899 (BK), 53.978 (BK), 54.256 (BK), 58.359 (BK), 58.894 (BK), 59.585 (BK), 59.698 (BK), 59.789 (BK), 59.945 (BK), 60.000 (CD C6), 60.021 (CD C6), 60.078 (CD C6), 60.279 (CD C6), 60.346 (CD C6), 60.438 (CD C6), 60.599 (CD C6), 60.788 (CD C6), 60.899 (CD C6), 62.199 (CD), 63.733 (CD), 63.788 (CD), 69.345 (CD), 69.456 (CD), 69.465 (CD), 72.558 (CD), 72.599 (CD), 72.839 3
(CD), 72.889 (CD), 73.301 (CD), 73.458 (CD), 73.598 (CD), 81.385 (CD), 81.439 (CD), 81.602 (CD), 81.739 (CD), 81.940 (CD), 82.140 (CD), 82.155 (CD), 82.308 (CD), 82.315 (CD), 82.402 (CD), 82.551 (CD), 82.649 (CD), 82.915 (CD), 84.058 (CD), 102.239 (CD C1), 102.345 (CD C1), 102.389 (CD C1), 102.504 (CD C1), 102.785 (CD C1), 102.669 (CD C1), 102.878 (CD C1), 102.968 (CD C1), 126.612 (phenylalanine aromatics), 126.732 (phenylalanine aromatics), 128.474 (phenylalanine aromatics), 128.578 (phenylalanine aromatics), 129.515 (phenylalanine aromatics), 129.594 (phenylalanine aromatics) 4
Synthesis of 3 2 2 2 2 5 The BK peptide 3 was assembled manually on Rink resin (0.73 mmol/g, 0.0365 mmol, 50 mg) using Fmoc-SPPS as per 2. The peptide was cleaved and the crude product was purified as per analogue 2 eluting at 31.5% B as a white fluffy solid (40.5 mg, 9%). LR-MS: m/z (%, assignment) 2275.32 (100, M+) +, 1137.99 (90, M+2) +2 R-MS: m/z C 96 149 17 46 (M+2) +2 1137.9912, actual 1137.9916 1 MR (d6-dms, 700 Mz): δ 1.219-1.287 (m, 1, proline), 1.433-2.245 (m 17, arginine, arginine*), 2.314-2.416 (m, 4, phenylalanine), 2.587-2.635 (m, 1, phenylalanine), 2.698-2.803 (m, 3* arginine, proline), 2.942-3.144 (m, 9, serine, glycine), 3.432-3.92 (m, 33, CD 2-6, CD 6), 4.254-4.687 (m, 11* arginine, proline 3, proline 7, phenylalanine 8, phenylalanine 5, serine 8, proline 2 ), 4.799-4.913 (m, 7, C 1), 5.59-5.884 (m, 14, C 2, 3), 6.731-6.858 (br s, 2, terminal 2 ), 7.131-7.287 (m, 10, phenylalanine aromatics), 7.30-7.433 (m, 2, terminal 2 ), 7.88-8.019 (s, 1, ), 8.082-8.172 (m, 2, ), 8.281-8.337 (m, 1, ) where * denotes unassigned peaks associated with the bradykinin 13 C MR (d6-dms, 700 Mz): δ 25.121 (succinyl C 2 ), 25.275 (succinyl C 2 ), 25.301 (BK), 27.656 (BK), 28.293 (BK), 28.363 (BK), 29.119 (BK), 29.203 (BK), 29.311 (BK), 29.450 (BK), 29.543 (BK), 29.642 (BK), 29.796 (BK), 29.855 (BK), 29.990 (BK), 30.082 (BK), 37.522 (BK), 38.216 (BK), 40.785 (BK), 40.936 (BK), 42.224 (BK), 46.404 (BK), 47.235 (BK), 47.430 (BK), 52.496 5
(BK), 53.158 (BK), 53.188 (BK), 53.897 (BK), 53.972 (BK), 54.281 (BK), 58.350 (BK), 58.873 (BK), 59.554 (BK), 59.703 (BK), 59.925 (BK), 59.950 (BK), 60.008 (CD C6), 60.023 (CD C6), 60.078 (CD C6), 60.275 (CD C6), 60.343 (CD C6), 60.436 (CD C6), 60.591 (CD C6), 60.766 (CD C6), 60.903 (CD C6), 62.192 (CD), 63.732 (CD), 63.788 (CD), 69.323 (CD), 69.419 (CD), 69.448 (CD), 72.504 (CD), 72.667 (CD), 72.835 (CD), 72.885 (CD), 73.317 (CD), 73.449 (CD), 73.539 (CD), 81.380 (CD), 81.435 (CD), 81.587 (CD), 81.720 (CD), 81.938 (CD), 82.138 (CD), 82.171 (CD), 82.278 (CD), 82.329 (CD), 82.411 (CD), 82.512 (CD), 82.644 (CD), 82.912 (CD), 83.050 (CD), 102.235 (CD C1), 102.317 (CD C1), 102.374 (CD C1), 102.447 (CD C1), 102.622 (CD C1), 102.659 (CD C1), 102.872 (CD C1), 102.965 (CD C1), 126.758 (phenylalanine aromatics), 126.817 (phenylalanine aromatics), 128.467 (phenylalanine aromatics), 128.543 (phenylalanine aromatics), 129.557 (phenylalanine aromatics), 129.657 (phenylalanine aromatics), 138.028, 138.078, 157.066, 157.207, 158.016, 158.187, 158.360, 158.532, 168.831, 169.009, 170.087, 170.121, 170.318, 171.315, 171.414, 171.454, 171.632, 171.743, 171.793, 172.161, 172.211, 172.805, 172.829, 172.863, 173.436, 173.485, 173.632 6
Synthesis of fluorenylmethyloxycarbonyl-ε-aminocaproic acid Adapted from Liskamp et al [5]. Fmoc-Su (2.55 g, 7.5 mmol, 1 eq) dissolved in dioxane (5 ml) was added dropwise to a stirred solution of ε-aminocaproic acid (1.00 g, 7.5 mmol, 1 eq) and ac 3 (0.804 g, 7.5 mmol, 1 eq) dissolved in water (5 ml). This solution was stirred overnight at rt. The solvent was removed in vacuo and the resiude was then dissolved in EtAc (40 ml) and acidified with Cl (50 ml, 1 mol/l). The solution was extracted with ether (1 x 50 ml) and the organic layer was washed with water (2x 50 ml) and the organic layer was dried over MgS 4. Filtration and evaporation to dryness in vacuo yielded a cream powder (1.65 g, 61.5%). o further purification was done. MALDI: m/z (DMF, %, assignment) 354.28 (100, M+) + 1 MR (500 Mz, d6-dms): 1.247 (p, J = 6.82 z, 2, C 2 ), 1.388 (dd, J = 7.05 z, 2, C 2 ), 1.489 (p, J = 7.43 z, 2, C 2 ), 2.174 (dt, J = 7.44 z, 2, C 2 ), 2.961 (q, J = 6.78 z, 2, C 2 ), 4.211 (t, J = 7.31 z, 2, Fmoc C), 4.291(d, J = 6.97 z, 2, Fmoc C 2 ), 7.265 (t, J = 5.35 z, 2, ), 7.320 (q, J = 8.04 z, 2, aromatics), 7.419 (t, J = 6.32 z, 2, aromatics), 7.692 (d, J = 7.19 z, 2, aromatics), 7.891 (d, J = 7.48 z, 2, aromatics) 13 C MR (500 Mz, d6-dms): 24.85, 26.33, 29.64, 34.44, 40.55, 47.25, 65.15, 120.49, 120.56, 121.84, 125.61, 127.75, 128.04, 129.39 7
Synthesis of 4 2 2 2 2 5 Analogue 4 was manually assembled on Rink resin (0.73 mmol/g, 0.108 mmol, 150 mg, 1 eq) by coupling analogue 1 [4] (628 mg, 0.432 mmol, 4 eq) to resin bound bradykinin as per analogue 2. Fmoc-aminocaproic acid (153 mg, 0.432 mmol, 4 eq) was coupled using TBTU (139 mg, 0.432 mmol, 4 eq), Bt, (58 mg, 0.432 mmol, 4 eq) and DIEA (151 µl, 0.864 mmol, 8 eq) in excess. An acetonitrile stepwise gradient as per analogue 2 was used to purify the product from the crude material at a wavelength of 254 nm. The partially-purified product eluted between 38-42% B. A repeat PLC was done giving a pure product with a yield of 4.5 mg (2%). LR-MS: m/z (%, assignment) 2388.41 (80, M+) + R-MS: m/z C 102 160 18 47 (M+2) +2 1194.5315, actual 1194.5336 1 MR (500 Mz, d 6 -DMS): δ 1.139-2.215 (m, 33, aminocaproic acid 3 x C 2 *), 2.30-2.40 (m, 2*), 2.595-3.187 (m, 21, aminocaproic acid 1 x C 2, glycine x C 2 *), 3.41-3.914 (m, 44, CD 2-6*), 4.117-4.324 (m, 6, glycine x C 2 *), 14.397-4.604 (m, 9, CD 1*), 4.795-4.97 (m, 7, CD 1), 5.60-5.872 (m, 14, CD 2, 3), 7.063-7.294 (m, 18, Phe aromatics*), 7.467-7.531 (m, 1*), 7.831-8.04 (m, 8
4, glycine x C 2 *) DEPT 13 C MR (500 Mz, d 6 -DMS): δ 24.11 (aminocaproic acid C 2 ), 24.32 (aminocaproic acid C 2 ), 24.98 (aminocaproic acid C 2 ), 25.018 (BK), 25.221 (BK), 25.67 (aminocaproic acid C 2 ), 27.98 (BK), 29.08, (aminocaproic acid C 2 ), 29.15 (BK), 29.36 (aminocaproic acid C 2 ), 29.472 (BK), 29.67 (aminocaproic acid C 2 ), 38.09 (BK), 30.23 (aminocaproic acid C 2 ), 34.27 (aminocaproic acid C 2 ), 34.45 (aminocaproic acid C 2 ), 34.53 (aminocaproic acid C 2 ), 35.40 (BK), 36.42 (BK), 39.98 (BK), 40.19 (aminocaproic acid C 2 ), 40.94 (BK), 41.05 (BK), 41.17 (BK), 42.30 (BK), 46.911 (BK), 47.223 (BK), 51.989 (BK), 53.068 (BK), 54.526 (BK), 54.884 (BK), 58.058 (BK), 60.104 (BK), 60.323 (BK), 60.438 (CD C6), 60.474 (CD C6), 60.494 (CD C6), 60.538 (CD C6), 62.416 (BK), 72.412-72.896 (CD), 73.368-73.62 (CD), 81.937-82.417 (CD), 102.311-102.612 (CD C1), 126.821 (BK), 126.847 (BK), 128.478 (BK), 128.580 (BK), 129.537 (BK), 129.555 (BK), 129.607 (BK) * denotes unassigned bradykinin peaks 9
Synthesis of 5 2 2 2 2 5 Analogue 5 was manually assembled on Rink resin using as per analogue 4. RP-PLC purification as per analogue 2. The clean product eluted at 42% B yielding 2.0 mg (2%) white fluffy solid. LR-MS: m/z (%, assignment) 2388.52 (80, M+) + R-MS: m/z C 102 160 18 47 (M+2) +2 1194.5315, actual 1194.5336 10
Synthesis of 6, a bradykinin -terminal benzene sulfonamide C C C C C C C 2 C C C 2 C C C 2 C C C 2 C 2 C C 2 C C 2 2 C C 2 2 2 S C 2 C + 2 C + 2 Peptide synthesis as per 6 was used to synthesise the -terminal peptide sulfonamide 7 on Rink resin. Briefly, Rink resin was swollen in DMF overnight followed by deprotection using 20% piperidine in DMF solution (2 x 5 minutes). Amino acids (4 eq) were coupled to the resin using TBTU (4 eq), Bt (4 eq), DIEA (8 eq) in DMF with the coupling time depending upon the amino acid. 4-Carboxybenzenesulfonamide (4 eq) was coupled to the resin using TBTU (4 eq), Bt (4 eq), DIEA (8 eq) in DMF overnight. A Kaiser test 13 was used to determine if each Fmoc-protected amino acid coupling was successful. TFA cleavage and RP-PLC purification were as per 2 with the pure product eluting at 41% B (12 mg, 4%). LR-MS (MALDI): m/z (%, assignment) 1243.027 (100, M+1) + LR-MS (ESI-MS): m/z (%, assignment) 623.04 (100, M+2) +2 R-MS: m/z C 57 79 17 13 S (M+) + 1242.5837, actual 1242.5788 1 MR (d6-dms, 500 Mz): δ 1.148-2.109 (m, 19, proline 2β, proline 2γ, proline 3β, arginine 1β, arginine 1α, proline 3β *), 2.149-2.243 (m, 1, phenylalanine 2β ), 2.728-2.904 (m, 2, phenylalanine 2β *), 2.994-3.171 (m, 6, phenylalanine 5β, arginine 9α, arginine 9α ), 3.414-3.878 (m, 11, proline 7γ, proline 3γ, arginine 1γ, serine 6β, proline 7γ, proline 3γ, proline 2γ, glycine α ), 4.071-4.418 (m, 4* arginine 9, proline 3, proline 7 ), 4.457-4.748 (m, 4, phenylalanine 8, phenylalanine 5, serine 8, proline 2 ), 6.941-7.033 (br s, 1, *), 7.099-7.325 (m, 17, phenylalanine aromatics), 7.471-7.537 (dd, 3, phenylalanine aromatics), 7.602-7.620 (s, 1, phenylalanine aromatics), 7.625-7.656 (dt, 2, phenylalanine aromatics), 7.759-7.806 (m, 1, glycine ), 7.848-7.878 (dd, 1, phenylalanine aromatics), 7.879-7.977 (m, 4, sulfonamide aromatics), 8.017-8.071 (m, 2, sulfonamide aromatics, arginine 9 ), 8.372-8.423 (m, 1, phenylalanine 5 ), 8.689-8.727 (d, 1, serine 6 ), where * denotes unassigned peaks associated with arginine 1α, phenylalanine 8α, proline 3β, proline 3γ, proline 7β, 11
proline 7γ, arginine 9β, arginine 1γ, arginine 9β, arginine 9γ, proline 7, or proline 13 4 C DEPT-135 MR (d6-dms, 500 Mz): δ 24.98 (C 2 ), 25.05 (C 2 ), 25.13 (C 2 ), 29.36 (C 2 ), 51.48, 58.16, 60.08, 122.97, 126.03, 126.29, 126.68, 126.78, 127.51, 128.48, 128.58, 128.56, 129.14, 129.42, 129.50, 129.57, 130.53, 130.62, 185.33 12
Synthesis of 7, a bradykinin C-terminal benzene sulfonamide C 2 C 2 2 C 2 C 2 2 C S 2 2 C 2 C 2 C 2 C + 2 2 C C + 2 Analogue 7 was assembled manually on Rink resin (0.073 mmol, 100 mg, 1 eq). The resin was swollen overnight in DMF (100%). 20% Piperidine in DMF (2 x 10 minutes) was used for Fmoc deprotection of all the amino acids. Fmoc-L-amino acids (2.00 mmol, 4 eq) were coupled overnight (followed by a second recoupling) using TBTU (2.00 mmol, 4 eq) and DIEA (4.00 mmol, 8 eq) in excess as activating agents. The Kaiser test was used to determine whether the amino acids had coupled successfully. The incorporation of a C-terminal sulfonamide onto the peptides was achieved using Fmoc-aminobenzenesulfonylchloride (11, 4 eq) coupling directly onto deprotected Rink resin with a 1:1 pyridine in DCM slurry overnight followed by a Kaiser test 13 to ensure a complete coupling. The resin bound sulfonamide was then treated with 20% piperidine in DMF (2 x 5 minutes) at rt for the removal of the Fmoc group. For the final deprotection, the resin was washed with a 20% piperidine in DMF solution (four times) and then agitated (2 x 5 minutes) in this solution. The resin was then first washed with DMF and then a 50% solution of DCM/Me before being well suction dried. The resin bound peptide was then freeze-dried prior to cleavage (2.10 g). The resin bound peptide was deprotected and cleaved from the support using a freshly made solution of TFA/ 2 /thioanisole/edt as per 2. RP-PLC as per 2 eluting the pure product eluted between 39-46% B with a yield of 1.4 mg (5%). LR-MS: m/z (%, assignment) 1214.79 (100, M+) +1 R-MS: m/z C 56 81 17 12 S (M+2) +2 607.7967, actual 607.7980 Partial MR analysis 1 MR (d6-dms, 500 Mz): δ 7.108-7.311 (m, 10, phenylalanine aromatics) CSY 1 MR (d6-dms, 500 Mz): δ 7.42, 7.581, 7.716, 7.752, 7.816, 7.94 (m, 1, glycine ), 8.169, 8.208, 8.34, 8.383, 8.422 13
Synthesis of 8, a bradykinin C- and -terminal benzene sulfonamide C C C C C C C 2 C C C 2 C C C 2 C C C 2 C C C 2 C S 2 2 C 2 2 C C 2 2 2 S C 2 C + 2 C + 2 Peptide synthesis as per 6 was employed to synthesise the -and C-terminal peptide sulfonamide ix on Rink resin. Briefly, Rink resin was swollen in DMF overnight followed by deprotection using a 20% piperidine in DMF solution (2 x 5 minutes). Amino acids (4 eq) were coupled to the resin using TBTU (4 eq), Bt (4 eq), DIEA (8 eq) in DMF with the coupling time depending upon the amino acid. A Kaiser test 13 was used to determine if the couplings were successful. 4-Carboxybenzenesulfonamide (4 eq) was coupled to the resin using TBTU (4 eq), Bt (4 eq), DIEA (8 eq) in DMF overnight. Fmocaminobenzenesulfonylchloride (11, 4 eq) was coupled directly onto deprotected Rink resin with a 1:1 pyridine in DCM slurry overnight followed by a Kaiser test to ensure a complete coupling. The resin bound sulfonamide was then treated with 20% piperidine in DMF (2 x 5 minutes) at rt for the removal of the Fmoc group. TFA cleavage and RP-PLC purification as per 2. The pure product eluted 10-12%B (1 mg, 0.7%). LR-MS: m/z (%, assignment) 1397.68 (95, M+1) + 1 MR (d6-dms, 500 Mz): δ 1.37-2.22 (m, 13, proline 2β, proline 2γ, proline 3β, arginine 1β, arginine 1α, proline 3β, phenylalanine 2 *), 2.63-2.82 (m, 3*), 2.87-3.86 (m, 54* including water peak), 4.14-4.37 (m, 4*), 4.42-4.76 (m, 6, phenylalanine 8, phenylalanine 5, serine 8, proline 2 ), 5.33-5.45 (m, 1*), 7.09-7.30 (m, 18, phenylalanine and sulfonamide aromatics), 7.46-7.60 (m, 5*), 7.71-7.80 (m, 1, glycine ), 7.83-8.05 (m, 9*), 8.26-8.33 (d, J = 7.21 z, 1, phenylalanine 5 ), 8.71-8.76 (d, J = 7.55 z, 1, serine 6 ) 13 C DEPT-135 MR (d6-dms, 500 Mz): δ 24.91 (C 2 ), 25.04 (C 2 ), 25.28 (C 2 ), 25.49 (C 2 ), 28.30 (C 2 ), 28.35 (C 2 ), 29.29 (C 2 ), 29.49 (C 2 ), 37.46 (C 2 ), 40.81 (C 2 ), 41.04 (C 2 ), 47.19 (C 2 ), 47.39 (C 2 ), 47.42 (C 2 ), 47.79 (C 2 ), 51.43, 52.42, 52.45, 53.10, 53.92, 54.47, 58.11, 59.36 (C 2 ), 59.94, 59.97, 60.21, 14
62.21 (C 2 ), 112.99, 126.02, 126.70, 126.75, 126.81, 128.47, 128.56, 128.61, 129.53, 129.61 where * denotes unassigned peaks associated with the bradykinin peptide 15
Synthesis of 9 2 S 2 2 2 2 5 BK-CD was assembled manually on Rink resin (100 mg, 0.072 mmol, 1 eq) using Fmoc- SPPS as per analogue 2. Followed deprotection of the last amino acid in sequence using a 20% piperidine in DMF solution (2 x 5 minutes), 4-carboxybenzenesulfonamide (4 eq) was coupled to the resin using TBTU (4 eq), Bt (4 eq), DIEA (8 eq) in DMF overnight. TFA cleavage and PLC purification as per analogue 2 with the pure product eluting at 47% B (1.2 mg, 0.7%). LR-MS: m/z (%, assignment) 2429.81 (50, M+a) + R-MS: m/z C 102 154 18 48 S 1 (M+2) +2 1215.4851, actual 1215.4860 16
Synthesis of 10 2 2 2 S 2 2 5 BK-sulfonamide was assembled manually on Rink resin (50 mg, 0.0365 mmol, 1 eq) using Fmoc-SPPS as per 7. CD analogue 1 was coupled to the resin using EDC (4 eq, 0.144 mmol) and DIEA (4 eq, 0.144 mmol) in pyridine/dmf overnight followed by a recoupling. TFA cleavage and PLC purification as per 2 afforded the pure product eluting at 42% B (0.4 mg, 0.4%). LR-MS: m/z (%, assignment) 2458.31 (80, M+) +, 1229.46 (80, M+2) 2+ R-MS: m/z C 103 154 18 49 S (M+2) +2 1229.4911, actual 1229.4896 Partial MR analysis 1 MR (500 Mz, d 6 -DMS): δ 4.802-4.92 (m, 7, CD 1), 5.657-5.884 (m, 14, CD 2, 3), 7.16-7.316 (m, 10, phenylalanine aromatics) 17
Synthesis of 4-fluorenylmethyloxycarbonyl (Fmoc) aminobenzenesulfonylchloride (11) Adapted from Liskamp et al [5]. 4-aminobenzenesulfonic acid (1.0 g, 2.5 mmol, 1 eq), dry toluene (50 ml), dry DMF (5 ml), and excess thionyl chloride (2 ml) were allowed to stir at rt overnight followed by quenching with ice-water, neutralisation with ac 3 and extraction of the aqueous phase with EtAc (2 x 10 ml). The organic phase was then concentrated in vacuo and recrystallised (twice) with a benzene/hexane mixture forming a white solid (11, 620 mg, 60%). 1 MR (500 Mz, d 6 -DMS): 4.319 (t, J = 6.50 z, 1, Fmoc C), 4.494 (d, J = 6.21 z, 2, Fmoc C 2 ), 7.326-7.524 (m, 8, aromatics), 7.761 (d, J = 6.97 z, 2, aromatics), 7.915 (d, J = 7.75 z, 2, aromatics) 13 C MR (500 Mz, d 6 -DMS): 47.08, 66.12, 117.61, 120.64, 125.61, 126.65, 127.60, 128.16 To further assess the nature of 11, 50 mg of the sample was dissolved in DMS. TEA (1.1 eq) and benzylamine (1.1 eq) was added, and the reaction allowed to stir at rt overnight. MS results showed presence of the (M+2) +2 peak for analogue 12. A loss of the Fmoc group was also observed. It is also noted that the solubility of the chloride species (11, soluble in DMF) was notably different from the 4-aminobenzenesulfonic acid starting material, only sparingly soluble in DMS). Stability tests Before addition to the resin, analogue 11 was tested for its stability under standard Fmoc- SPPS reaction conditions. These conditions and results are given in Table 2. 18
Table 2 Stability test conditions and results (as determined by MALDI-TF analysis) for analogue 11 when exposed to standard Fmoc SPPS reaction conditions. Reaction Conditions Reaction Time (ours) Results 100% DMF 24 100% DCM 24 20% piperidine in DMF 0.5 20% piperidine in DMF 1.0 95% TFA cleavage mixture 3.0 100% TFA 24 o change Fmoc lost o change Fmoc-UV coupling tests Coupling tests were performed on analogue 11 to see if the exchange of the acid group for a sulfonyl chloride group would aid its coupling to Rink resin. For Fmoc coupling test details refer to White and Chan [6]. The conditions tested and results are given in Table 3. The coupling of 11 to Sieber resin using the same method was also tested. Experimental details and results are given in Table 3 with the highlighted results used in the rest of this study. Table 3 Experimental details and results for the coupling of 11 (4 eq in each experiment coupling overnight) to Rink resin Coupling Agents Results (%) TBTU/DIEA 18 Bt/DIEA 19 1:1 pyridine: DCM slurry 40 1:1 pyridine: DMF 18 1:1 pyridine: TF 36 1:1 pyridine: water 7 1:1 pyridine: DMS 21 Pyridine 30 19
References (1) ew Address: Rachel J Stephenson. School of Chemistry and Molecular Biosciences, The University of Queensland, St. Lucia 4072, QLD, Australia. (2) White, R. J., Plieger, P. G., and arding, D. R. K. (2009) Tet. Lett. 51 (5), 800-803. (3) Tabushi, I., abeshima, T., Kitaguchi,., and Yamamura, K. (1982) J. Am. Chem. Soc. 104, 2017-2019 (4) Sollogoub, M. (2009) Euro. J. rg. Chem. 9, 1295-1303. (5) Brouwer, A. J., Monnee, M. C. F., and Liskamp, R. M. J. (2000) Synthesis. (11), 1579-1584. (6) Chan, W. C., and White, P. D. (2000) Fmoc solid phase peptide synthesis. A practical approach. xford University Press: xford ew York. p61 20