Preparation of Peptide o-Aminoanilides Using a Modified Dawson's Linker for Microwave-Assisted Peptide Synthesis

Published as part of the Cluster Recent Advances in Protein and Peptide Synthesis

Abstract

Based on the structure of Dawson’s 3,4-diaminobenzoic acid (Dbz) linker designed for Fmoc solid-phase peptide-thioester synthesis, the 4-amino-3-nitrobenzoic acid [Dbz(NO₂)] linker was developed for microwave-assisted synthesis. The Dbz(NO₂) linker can be readily converted into the Dbz linker by on-resin reduction with SnCl₂ after construction of the protected peptide resin. Although epimerization of C-terminal amino acid restricts the use of Dbz(NO₂) linker to the synthesis of peptide-Gly-thioester, use of this linker can prevent side reactions that arise when Dbz or Dbz(Aloc) linkers are used in the microwave-assisted synthesis of Gly-rich peptides.

Key words

Dawson’s linker - microwave - NCL - peptide synthesis - thioester

• References and Notes

• 1a Dawson PE. Muir TW. Clark-Lewis I. Kent SB. H. Science 1994; 266: 776
• 1b Dawson PE. Kent SB. H. Annu. Rev. Biochem. 2000; 69: 923
• 1c Kent SB. H. J. Pept. Sci. 2015; 21: 136

Recent reviews:
• 2a Kent SB. H. Chem. Soc. Rev. 2009; 38: 338
• 2b Raibaut L. Ollivier N. Melnyk O. Chem. Soc. Rev. 2012; 41: 7001
• 2c Raibaut L. El Mahdi O. Melnyk O. Top. Curr. Chem. 2015; 363: 103
• 3a Zheng JS. Tang S. Huang YC. Liu L. Acc. Chem. Res. 2013; 46: 2475
• 3b Otaka A. Sato K. Ding H. Shigenaga A. Chem. Rec. 2012; 12: 479
• 3c Boll E. Drobecq H. Ollivier N. Blanpain A. Raibaut L. Desmet R. Vicogne J. Melnyk O. Nat. Protoc. 2015; 10: 269
• 3d Thuaud F. Rohrbacher F. Zwicky A. Bode JW. Helv. Chim. Acta 2016; 99: 868
• 3e Lee CL. Liu H. Wong CT. Chow HY. Li X. J. Am. Chem. Soc. 2016; 138: 10477
• 4 Bang D. Pentelute BL. Kent SB. H. Angew. Chem. Int. Ed. 2006; 45: 3985

For examples of total synthesis using hydrazide-based ligation, see:
• 5a Mong SK. Vinogradov AA. Simon MD. Pentelute BL. ChemBioChem. 2014; 15: 721
• 5b Reif A. Siebenhaar S. Troster A. Schmalzlein M. Lechner C. Velisetty P. Gottwald K. Pohner C. Boos I. Schubert V. Rose-John S. Unverzagt C. Angew. Chem. Int. Ed. 2014; 53: 12125
• 5c Weinstock MT. Jacobsen MT. Kay MS. Proc. Natl. Acad. Sci., U.S.A. 2014; 111: 11679
• 5d Seenaiah M. Jbara M. Mali SM. Brik A. Angew. Chem. Int. Ed. 2015; 54: 12374
• 5e Loibl SF. Harpaz Z. Zitterbart R. Seitz O. Chem. Sci. 2016; 7: 6753
• 6 Blanco-Canosa JB. Dawson PE. Angew. Chem. Int. Ed. 2008; 47: 6851
• 7 Wang JX. Fang GM. He Y. Qu DL. Yu M. Hong ZY. Liu L. Angew. Chem. Int. Ed. 2015; 54: 2194
• 8a Sato T. Saito Y. Aimoto S. J. Pept. Sci. 2005; 11: 410
• 8b Johnson EC. Kent SB. H. Tetrahedron Lett. 2007; 48: 1795
• 9a Mahto SK. Howard CJ. Shimko JC. Ottesen JJ. ChemBioChem. 2011; 12: 2488
• 9b Weidmann J. Dimitrijevic E. Hoheisel JD. Dawson PE. Org. Lett. 2016; 18: 164
• 10a Pedersen SL. Tofteng AP. Malik L. Jensen KJ. Chem. Soc. Rev. 2012; 41: 1826
• 10b Collins JM. Porter KA. Singh SK. Vanier GS. Org. Lett. 2014; 16: 940
• 11a Gunasekera S. Aboye TL. Madian WA. El-Seedi HR. Goransson U. Int. J. Pept. Res. Ther. 2013; 19: 43
• 11b Li YT. Huang YC. Xu Y. Pan M. Li YM. Tetrahedron 2016; 72: 4085
• 11c Pan M. Gao S. Zheng Y. Tan X. Lan H. Tan X. Sun D. Lu L. Wang T. Zheng Q. Huang Y. Wang J. Liu L. J. Am. Chem. Soc. 2016; 138: 7429
• 12 Blanco-Canosa JB. Nardone B. Albericio F. Dawson PE. J. Am. Chem. Soc. 2015; 137: 7197
• 13a Isidro-Llobet A. Alvarez M. Burger K. Spengler J. Albericio F. Org. Lett. 2007; 9: 1429
• 13b Zheng JS. He Y. Zuo C. Cai XY. Tang S. Wang ZA. Zhang LH. Tian CL. Liu L. 2016; 138: 3553
• 14 Hojo K. Maeda M. Iguchi S. Smith T. Okamoto H. Kawasaki K. Chem. Pharm. Bull. 2000; 48: 1740
• 15 The reason of this low nucleophilicity is speculated as follows. The original Dawson’s linker (3,4-diaminobenzoic acid, Dbz) usually uses 3-amino group for peptide-chain elongation, which might be more reactive than the 4-amino group. In our Dbz(NO₂) linker, the 3-amino group is replaced with nitro group, and the 3-nitro group further decreases the remaining 4-amino group.
• 16 Rijkers DT. S. Adams HP. H. M. Hemker HC. Tesser GI. Tetrahedron 1995; 51: 11235
• 17 Fujii K. Ikai Y. Oka H. Suzuki M. Harada K. Anal. Chem. 1997; 69: 5146
• 18a Sakamoto K. Sato K. Shigenaga A. Tsuji K. Tsuda S. Hibino H. Nishiuchi Y. Otaka A. J. Org. Chem. 2012; 77: 6948
• 18b Eto M. Naruse N. Morimoto K. Yamaoka K. Sato K. Tsuji K. Inokuma T. Shigenaga A. Otaka A. Org. Lett. 2016; 18: 4416 General Procedure Under Ar atmosphere, Fmoc-Xaa-OH (Xaa = Leu or Ser(t-Bu), 0.50 mmol) was coupled on an H-Dbz(NO₂)-rink amide resin (45 mg, 0.025 mmol) using POCl₃ (78 μL, 0.50 mmol) and 2,4,6-trimethylpyridine (66 μL, 0.50 mmol) in THF (4.0 mL) at 40 °C for 16 h. In case of Gly, Fmoc-Gly-OH (0.25 mmol) was coupled on an H-Dbz(NO₂)-rink amide resin (45 mg, 0.025 mmol) using POCl₃ (39 μL, 0.25 mmol) and 2,4,6-trimethylpyridine (33 μL, 0.25 mmol) in THF (4.0 mL) at 40 °C for 16 h under Ar atmosphere.
• 19 Di Fenza A. Tancredi M. Galoppini C. Rovero P. Tetrahedron Lett. 1998; 39: 8529
• 20 Resin 7: The peptide assemblies on the Fmoc-Gly-Dbz(NO₂)-Leu-rink amide resin (0.10 mmol) were conducted using microwave-assisted Fmoc SPPS procedure as described in the Supporting Information. In order to evaluate peptide constructed on the resin, a part of the obtained resin 7 (5 mg) was treated with TFA/TIS/H₂O (v/v, 95:2.5:2.5) for 1.5 h to yield a corresponding deprotected peptide. Analytical HPLC: t _R = 14.2 min (10–60% MeCN/0.1% TFA for 25 min); LRMS (ESI⁺): m/z calcd for C₄₅H₆₇N₁₄O₁₃ [M + H]⁺ 1011.5; found: 1011.5. Compound 9: Resin 7 (0.10 mmol) was treated with 6 M SnCl₂, 10 mM HCl/MeOH in DMF for 3 h. Resin 8 thus obtained was treated with TFA/TIS/H₂O (v/v, 95:2.5:2.5) for 1.5 h to give a crude product 9. Analytical HPLC: t _R = 12.1 min (10–60% MeCN/0.1% TFA for 25 min); LRMS (ESI⁺): m/z calcd for C₄₅H₆₉N₁₄O₁₁ [M + H]⁺: 981.5; found: 981.6. Compound 10: Crude 9 was activated using NaNO₂, and thioesterified with sodium 2-sulfanylethanesulfonate to give the title compound. Analytical HPLC: t _R = 8.5 min (10–60% MeCN/0.1% TFA for 25 min); LRMS (ESI⁺): m/z calcd for C₄₅H₆₉N₁₄O₁₁ [M + H]⁺: 859.3; found: 859.4. Compound 11: Resin 8 (0.05 mmol) was activated as described in ref. 6. Then, the resin was treated with TFA/TIS/H₂O (v/v, 95:2.5:2.5) for 1.5 h to give the title product. Analytical HPLC: t _R = 13.4 min (10–60% MeCN/0.1% TFA for 25 min); LRMS (ESI⁺): m/z calcd for C₄₆H₆₇N₁₄O₁₂ [M + H]⁺: 1007.5; found: 1007.5.
• 21 Shichiri M. Ishimaru S. Ota T. Nishikawa T. Isogai T. Hirata Y. Nat. Med. 2003; 9: 1166