[NH:1](C(C)=O)[C@H](C(N[C@H](C(O)=O)CCCCN)=O)CC1C=CC=CC=1.N(C(C)=O)[C@H](C(N[C@H](C(O)=O)CCCCNC(=C1C(=O)CC(C)(C)CC1=O)CC(C)C)=O)CC1C=CC=CC=1.C(O)(C(F)(F)F)=O.N1CCCCC1.NN.[NH2:79][C@H:80]([C:88]([OH:90])=[O:89])[CH2:81][C:82]1[CH:87]=[CH:86][CH:85]=[CH:84][CH:83]=1.N[C@H](C(O)=O)CCCCN>C(Cl)Cl.CS(C)=O>[NH3:1].[NH2:79][C@H:80]([C:88]([OH:90])=[O:89])[CH2:81][C:82]1[CH:87]=[CH:86][CH:85]=[CH:84][CH:83]=1Ac-Phe-Lys-OH and Ac-Phe-Lys(ivDde)-OH. Cleavage of the synthesized peptides from resin was accomplished using 1% TFA in DCM (twice resin bed volume) for 2 min. For each sample, aliquots were dried on a speed-vac and directly used for HPLC or MALDI-TOF analysis. HPLC Column was reverse phase (Waters RP-18, 8C1810μ). Elute solvents were water and acetonitrile containing 0.1% or 0.08% TFA, respectively. The gradient used was 15 to 95% of water in acetonitrile in 16 min with a flow rate of 3 mL/min. Ac-Phe-Lys(ivDde)-OH by photogenerated piperidine synthesis, Rt=8.55 min; piperidine synthesis, Rt=8.57 min. Ac-Phe-Lys-OH, by photogenerated piperidine and hydrazine synthesis, Rt=3.55 min; regular synthesis (piperidine and hydrazine) Rt=3.54 min 1H NMR (300 MHz, DMSO d6): Ac-Phe-Lys(ivDde)-OH synthesized using either photogenerated piperidine or piperidine gave identical NMR spectra; δ 13.60 (s, 1H, NH), 12.62 (br s, COOH), 8.27 (d, J=8.1 Hz, 1H, CONH), 8.06 (d, J=7.8 Hz, 1H, CONH), 7.22 (m, 5H, ArH), 4.51 (m, 1H, αCH), 4.18 (m, 1H, αCH), 3.38 (m, Phe βCH2, Lys εCH2), 3.00 (m, 2H; ivDde CH2), 2.25 (s, 4H, ivDde CH2), 1.80 (m, βCH2), 1.72 (s, CH3), 1.58 (m, ivDde CH, Lys δCH2), 1.40 (m, 2H, γCH2), 0.92 (s, 6H, CH3), 0.88 (s, 6H, CH3). Ac-Phe-Lys-OH (both dipeptides synthesized using either photogenerated piperidine and hydrazine versus piperidine and hydrazine-gave identical NMR spectra), δ 12.67 (br s, COOH), 8.31 (d, J=7.8 Hz, 1H, CONH), 8.09 (d, J=7.8 Hz, 1H, CONH), 7.65 (s, NH3)H, 7.22 (m, 5H, ArH), 4.51 (m, 1H, αCH), 4.18 (m, 1H, αCH), 3.34 (m, 1H, Phe βCH), 2.98 (m, 1H, Phe βCH), 2.74 (m, 2H, εCH2), 1.72 (s, 3H, CH3), 1.58 (m, βCH2), 1.55 (m, δCH2), 1.34(m, γCH2). Mass analysis (MALDI-TOF): calculated for Ac-Phe-Lys(ivDde)-OH 541.7, found 541.9 for that by photogenerated piperidine synthesis and found 541.8 for that by piperidine; calculated for Ac-Phe-Lys-OH 335.4, found 335.5 for that by photogenerated piperidine and hydrazine, found 335.5 for that by piperidine and hydrazine.
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