* All experimental methods are cited from the reference, please refer to the original source for details. We do not guarantee the accuracy of the content in the reference.
Nα-(9-fluorenylmethyloxycarbonyl)-Nγ-2,2,4,6,7-pentamethyldihydrobenzofuran-5-sulfonyl-L-arginine[ No CAS ]
Ac-L-E(OtBu)-G-R(Pfb)-E(OtBu)-K(Boc)-V-R(Pfb)-A-K(Ac)-I-Aib-Aib-E(OtBu)-G-K(Dde)-S(tBu)-T(tBu)-F-S(tBu)-Mly(Boc)-R(Pfb)-A-K(Ac)-NH-Rink Amide Resin, Ac - acetyl, Aib - 2-amino-isobutyric acid, Boc - tert-butyloxycarbonyl, Dde - 1-(4,4-dimethyl-2,6-dioxocyclohex-1-ylidene)ethyl, Mly - α-methyl-lysine, Pfb - 2,2,4,6,7-pentamethyldihydrobenzofuran-5-sulfonyl, tBu - tert-butyl[ No CAS ]
Yield
Reaction Conditions
Operation in experiment
2.A Loading of Fmoc-Lys(Ac)-OH on Rink Amide Resin (0433) In a 100 ml reactor equipped with a sintered glass at the bottom, 6 g of Novabiochem or ChemImpex Rink amide AM resin (Low Loading 0.47 mmol/g) was swelled in 40 ml of DMF. The solvent was drained and 30 ml of 20% piperidine in DMF solution were added. After 15 min shaking, the solvent was drained. This was repeated twice to ensure complete Fmoc protecting group removal. The resin was washed with 5×30 ml DMF. (0434) In a separate flask a solution containing Fmoc-Lys(Ac)-OH (3.5 g, 8 mmol, 3 eq.) HOBT.H2O (1.3 g 8.5 mmol) in 30 ml DMF was prepared. Diisopropylcarbodiimide (DIC) (1 g, 8.5 mmol) was added to this solution and after 5 min the resulting mixture was added to the resin. The suspension was shaken on a stirring plate for 4 h or until completion of the reaction as judged by Kaiser Test (Ninhidrin test) on an aliquot part of the resin. (0435) The solvent was then drained and the resin washed 3 times with 30 ml DMF. Fmoc-Lys(Ac)-NH2 loaded resin was used immediately for subsequent steps or stored wet at 4 C. until needed. (0436) 2.B. Synthesis of Peptide Having the SEQ ID NO: 3 (0437) The following synthesis was performed using 5 times an amount of resin obtained at step 2.A. corresponding to 0.2 mmol of Fmoc-Lys(Ac)-NH2 each. The syntheses were performed separately on each individual batches using a CEM Liberty Blue microwave peptide synthesizer to assemble the second and third residue of the peptide sequence (starting from the C-terminus). (0438) Peptide synthesis was performed by using DIC 0.5M/Oxyma 1M in DMF. (0439) All amino acids were introduced with double couplings using standard heating protocol. (0440) The resin was removed from the synthesizer and Fmoc-alpha-methyl-lysine(Boc)-OH (3 eq.) was coupled manually using 3 eq. Oxyma and 3 eq. DIC with microwave heating (75 C. 15 sec. and 90 C. 110 sec). The completion of the reaction was controlled by Kaiser test. If positive, DIC 3 eq. was added followed by microwave heating as above. When coupling of Fmoc-alpha-methyl-lysine(Boc)-OH was complete the rest of the peptide sequence was assembled using a CEM Liberty Blue microwave peptide synthesizer. (0442) All amino acids were introduced with double couplings at 90 C. as above, with the exception of amino-isobutyric acid at position 21 and serine at position 29 for which a triple coupling at 90 for 2 minutes was performed. Fmoc-Lys(Dde)-OH was used at position 25. (0443) At the end of the 5 syntheses, the 5 batches of resin were combined and transferred into a 50 mL polypropylene syringe and the peptide was acetylated at N-terminus with acetic anhydride (944 10 mmol) in DMF (30 mL) for 20 minutes, repeating the cycle twice. (0444) Then, Dde protecting group on Lysine 25 side chain was removed by percolating 50 mL of a solution of hydrazine 5% w/v in DMF, followed by DMF washes (5×20 ml). The reaction was monitored by Kaiser Test and cleavage of an aliquot part of resin and UPLC/MS analysis. (0445) Three TTDS spacer units were introduced by single coupling by performing three times the following procedure: To the resin a solution of Fmoc-TTDS-OH (1.62 g, 3 mmol) in 30 mL of DMF were added followed by HOAt (5 ml of a 0.6 ml solution in DMF, 3 mmol) and DIC (1 ml, 6 mmol). The syringe was agitated on an orbital table for 18 h. The reaction was monitored by Kaiser Test. The resin was washed with DMF (2×30 mL). Then to the resin, 30 mL of 20% v/v of piperidine in DMF was added. The syringe was agitated on an orbital table for 20 min. This deprotection procedure was repeated a second time and the resin was washed with DMF (2×30 mL) and dichloromethane (3×30 mL). (0446) The three gamma-glutamic acids spacers were introduced by performing a double coupling of each Fmoc-Glu-OtBu. Thus the following procedure was applied three times: To the resin a solution (4S)-5-tert-butoxy-4-(9H-fluoren-9-yl methoxy carbonylamino)-5-oxo-pentanoic acid (Fmoc-Glu-OtBu) (1.275 g, 3 mmol) in of 30 mL of DMF were added followed by HOAt (5 ml of a 0.6 ml solution in DMF 3 mmol) and DIC (1 ml, 6 mmol). The syringe was agitated on an orbital table for 4 h. The resin was washed with DMF (2×20 mL) and the coupling was repeated a second time. The reaction was monitored by Kaiser Test. The resin was washed with DMF (2×30 mL). Then to the resin, 30 mL of 20% v/v of piperidine in DMF was added. The syringe was agitated on an orbital table for 20 min. This deprotection procedure was repeated a second time and the resin was washed with DMF (3×30 mL) and dichloromethane (3×30 mL). (0448) Finally, the peptide was acylated with palmitic acid (768 mg, 3 mmol), HOAt (5 ml of a 0.6 M solution in DMF, 3 mmol) and DIC (1 ml, 6 mmol) activation in DMF (30 mL) for 2.5 h. The resin was washed with DMF (2×30 mL) and dichloromethane (3×30mL) and dried under vacuum. (0449) The cleavage of the peptide from the resin was performed using a solution phenol (6.25 g), water (6.25 mL) and TIPS (3 mL) ...
Chemistry
Pharmaceutical Intermediates
Inhibitors/Agonists
Material Science
For Research Only
120K+ Compounds
Competitive Price
1-2 Day Shipping
