Abstract
The protection of amino acid reactive functionalities including the α-amino group, the side chain (amines, carboxylic acids, alcohols, and thiols), or the carboxylic acid terminus is an essential strategy in peptide chemistry. This is mandatory to prevent polymerization of the amino acids and to minimize undesirable side reactions during the synthetic process. Proper protecting group manipulation strategies can maximize the yield of the desired product or allow the construction of complex peptide-based structures. Thus, the compatibility and orthogonality of each protecting group are key to achieve the proper control of molecular structure. Herein, we describe some common protecting groups and their general unmasking methods, in order to mask and expose amine, carboxylic acid, alcohol, and thiol functionalities to achieve the synthesis of peptides and related molecules.
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References
Fosgerau K, Hoffmann T (2015) Peptide therapeutics: current status and future directions. Drug Discov Today 20:122–128
Isidro-Llobet A, Álvarez M, Albericio F (2009) Amino acid-protecting groups. Chem Rev 109:2455–2504
Rubert Pérez CM, Stephanopoulos N, Sur S, Lee SS, Newcomb C, Stupp SI (2015) The powerful functions of peptide-based bioactive matrices for regenerative medicine. Ann Biomed Eng 43:501–514
Marqus S, Pirogova E, Piva T (2017) Evaluation of the use of therapeutic peptides for cancer treatment. J Biomed Sci 24:21
Rivas-Santiago B, Serrano CJ, Enciso-Moreno JA (2009) Susceptibility to infectious diseases based on antimicrobial peptide production. Infect Immun 77:4690–4695
Boohaker RJ, Lee MW, Vishnubhotla P, Perez JM, Khaled AR (2012) The use of therapeutic peptides to target and to kill cancer cells. Curr Med Chem 19:3794–3804
Cui H, Webber MJ, Stupp SI (2010) Self-assembly of peptide amphiphiles: from molecules to nanostructures to biomaterials. Biopolymers 94:1–18
Hartgerink JD, Beniash E, Stupp SI (2001) Self-assembly and mineralization of peptide-amphiphile nanofibers. Science 294:1684–1688
Conda-Sheridan M, Lee SS, Preslar AT, Stupp SI (2014) Esterase-activated release of naproxen from supramolecular nanofibres. Chem Commun 50:13757–13760
Silva GA, Czeisler C, Niece KL, Beniash E, Harrington DA, Kessler JA, Stupp SI (2004) Selective differentiation of neural progenitor cells by high-epitope density nanofibers. Science 303:1352–1355
Webber MJ, Tongers J, Renault M-A, Roncalli JG, Losordo DW, Stupp SI (2010) Development of bioactive peptide amphiphiles for therapeutic cell delivery. Acta Biomater 6:3–11
Ni M, Hauser CAE (2015) Self-assembled peptide nanostructures for regenerative medicine and biology. In: Castillo-León J, Svendsen WE (eds) Micro and nanofabrication using self-assembled biological nanostructures. William Andrew Publishing, Oxford, pp 63–90
Carpino LA (1987) The 9-fluorenylmethyloxycarbonyl family of base-sensitive amino-protecting groups. Acc Chem Res 20:401–407
Carpino LA, Han GY (1972) 9-Fluorenylmethoxycarbonyl amino-protecting group. J Org Chem 37:3404–3409
Khattab SN, Subirós-Funosas R, El-Faham A, Albericio F (2010) Oxime carbonates: novel reagents for the introduction of Fmoc and Alloc protecting groups, free of side reactions. Eur J Org Chem 2010:3275–3280
Chang CD, Waki M, Ahmad M, Meienhofer J, Lundell EO, Haug JD (1980) Preparation and properties of Nalpha-9-fluorenylmethyloxycarbonylamino acids bearing tert-butyl side chain protection. Int J Pept Protein Res 15:59–66
Fields GB (1995) Methods for removing the fmoc group. In: Pennington MW, Dunn BM (eds) Peptide Synthesis Protocols. Humana, Totowa, NJ, pp 17–27
Carpino LA, Ismail M, Truran GA, Mansour EME, Iguchi S, Ionescu D, El-Faham A, Riemer C, Warrass R (1999) The 1,1-dioxobenzo[b]thiophene-2-ylmethyloxycarbonyl (Bsmoc) amino-protecting group. J Org Chem 64:4324–4338
Gundala C, Tantry SJ, Naik SA, Sureshbabu VV (2009) Synthesis of 1,1-dioxobenzo[b]thiophene-2-ylmethyloxycarbonyl (Bsmoc) protected N-methyl amino acids by reduction of Bsmoc-5-oxazoli-dinones and their use in peptide synthesis. Protein Pept Lett 16:105–111
Carpino LA, Philbin M, Ismail M, Truran GA, Mansour EME, Iguchi S, Ionescu D, El-Faham A, Riemer C, Warrass R, Weiss MS (1997) New family of base- and nucleophile-sensitive amino-protecting groups. a michael-acceptor-based deblocking process. practical utilization of the 1,1-dioxobenzo[b]thiophene-2-ylmethyloxycarbonyl (Bsmoc) group. J Am Chem Soc 119:9915–9916
Carpino LA, Mansour EME (1999) The 2-methylsulfonyl-3-phenyl-1-prop-2- enyloxycarbonyl (Mspoc) amino-protecting group. J Org Chem 64:8399–8401
Carpino LA, Abdel-Maksoud AA, Ionescu D, Mansour EME, Zewail MA (2007) 1,1-dioxonaphtho[1,2-b]thiophene-2-methyloxycarbonyl (α-Nsmoc) and 3,3-dioxonaphtho[2,1-b]thiophene-2-methyloxycarbonyl (β-Nsmoc) amino-protecting groups. J Org Chem 72:1729–1736
Nash IA, Bycroft BW, Chan WC (1996) Dde – a selective primary amine protecting group: a facile solid phase synthetic approach to polyamine conjugates. Tetrahedron Lett 37:2625–2628
Díaz-Mochón JJ, Bialy L, Bradley M (2004) Full orthogonality between Dde and Fmoc: the direct synthesis of PNA−peptide conjugates. Org Lett 6:1127–1129
Tagle LH, Terraza CA, Tundidor-Camba A, Coll D (2015) Silicon-containing poly(esters) with halogenated bulky side groups. Synthesis, characterization and thermal studies. RSC Adv 5:49132–49142
Cros E, Planas M, Barany G, Bardají E (2004) N-tetrachlorophthaloyl (TCP) protection for solid-phase peptide synthesis. Eur J Org Chem 2004:3633–3642
Debenham JS, Debenham SD, Fraser-Reid B (1996) N-tetrachlorophthaloyl (TCP) for ready protection/deprotection of amino sugar glycosides. Bioorg Med Chem 4:1909–1918
Debenham JS, Fraser-Reid B (1996) Tetrachlorophthaloyl as a versatile amine protecting group. J Org Chem 61:432–433
Hojo K, Maeda M, Kawasaki K (2001) A new water-soluble N-protecting group, 2-[phenyl(methyl)sulfonio]ethyloxycarbonyl tetrafluoroborate, and its application to solid phase peptide synthesis in water. J Pept Sci 7:615–618
Hojo K, Maeda M, Kawasaki K (2004) 2-(4-Sulfophenylsulfonyl)ethoxycarbonyl group: a new water-soluble N-protecting group and its application to solid phase peptide synthesis in water. Tetrahedron Lett 45:9293–9295
Weygand F, Frauendorfer E (1970) Reductive elimination of the N-trifluoroacetyl and N-trichloroacetyl group by sodium boron hydride and applications in peptide chemistry. Chem Ber 103:2437–2449
Bellamy AJ, MacCuish A, Golding P, Mahon MF (2007) The use of trifluoroacetyl as an N- and O-protecting group during the synthesis of energetic compounds containing nitramine and/or nitrate ester groups. Propellants Explos Pyrotech 32:20–31
Bartoli S, Jensen KB, Kilburn JD (2003) Trifluoroacetyl as an orthogonal protecting group for guanidines. J Org Chem 68:9416–9422
Alsina J, Giralt E, Albericio F (1996) Use of N-tritylamino acids and PyAOP1 for the suppression of diketopiperazine formation in Fmoc/tBu solid-phase peptide synthesis using alkoxybenzyl ester anchoring linkages. Tetrahedron Lett 37:4195–4198
Behloul C, Guijarro D, Yus M (2004) Detritylation of N-tritylamines via a naphthalene-catalyzed lithiation process. Synthesis 2004:1274–1280
Bregant S, Tabor AB (2005) Orthogonally protected lanthionines: synthesis and use for the solid-phase synthesis of an analogue of nisin ring C. J Org Chem 70:2430–2438
Jones GB, Hynd G, Wright JM, Sharma A (2000) On the selective deprotection of trityl ethers. J Org Chem 65:263–265
Nottingham M, Bethel CR, Pagadala SRR, Harry E, Pinto A, Lemons ZA, Drawz SM, v d AF, Carey PR, Bonomo RA, Buynak JD (2011) Modifications of the C6-substituent of penicillin sulfones with the goal of improving inhibitor recognition and efficacy. Bioorg Med Chem Lett 21:387–393
Zaramella S, Yeheskiely E, Strömberg R (2004) A method for solid-phase synthesis of oligonucleotide 5′-peptide-conjugates using acid-labile α-amino protections. J Am Chem Soc 126:14029–14035
Attard TJ, Reynolds EC, Perich JW (2007) The synthesis of phosphopeptides via the Bpoc-based approach. Org Biomol Chem 5:664–670
Barzilay I, Lapidot Y (1971) The use of o-nitrophenylsulfenyl group as amino protecting group in the synthesis of phosphatidylethanolamine. Chem Phys Lipids 7:93–97
Zervas L, Borovas D, Gazis E (1963) New methods in peptide synthesis. I. Tritylsulfenyl and o-nitrophenylsulfenyl groups as N-protecting groups. J Am Chem Soc 85:3660–3666
Meienhofer J (1965) Cleavage of o-nitrophenylsulphenamides by raney nickel and applications for peptide synthesis. Nature 205:73–75
Sarkar A, Roy SR, Parikh N, Chakraborti AK (2011) Nonsolvent application of ionic liquids: organo-catalysis by 1-alkyl-3-methylimidazolium cation based room-temperature ionic liquids for chemoselective N-tert-butyloxycarbonylation of amines and the influence of the C-2 hydrogen on catalytic efficiency. J Org Chem 76:7132–7140
Chankeshwara SV, Chakraborti AK (2006) Catalyst-free chemoselective N-tert-butyloxycarbonylation of amines in water. Org Lett 8:3259–3262
Englund EA, Gopi HN, Appella DH (2004) An efficient synthesis of a probe for protein function: 2,3-diaminopropionic acid with orthogonal protecting groups. Org Lett 6:213–215
Gibson FS, Bergmeier SC, Rapoport H (1994) Selective removal of an N-BOC protecting group in the presence of a tert-butyl ester and other acid-sensitive groups. J Org Chem 59:3216–3218
McKay FC, Albertson NF (1957) New amine-masking groups for peptide synthesis. J Am Chem Soc 79:4686–4690
Shendage DM, Fröhlich R, Haufe G (2004) Highly efficient stereoconservative amidation and deamidation of α-amino acids. Org Lett 6:3675–3678
Perron V, Abbott S, Moreau N, Lee D, Penney C, Zacharie B (2009) A method for the selective protection of aromatic amines in the presence of aliphatic amines. Synthesis 2009:283–289
Felpin F-X, Fouquet E (2010) A useful, reliable and safer protocol for hydrogenation and the hydrogenolysis of O-benzyl groups: the in situ preparation of an active Pd0/C catalyst with well-defined properties. Chem Eur J 16:12440–12445
Kiso Y, Ukawa K, Akita T (1980) Efficient removal of N-benzyloxycarbonyl group by a ‘push–pull’ mechanism using thioanisole–trifluoroacetic acid, exemplified by a synthesis of Met-enkephalin. Chem Commun 1980:101–102
Fernández-Forner D, Casals G, ES N, Ryder H, Albericio F (2001) Solid-phase synthesis of 4-aminopiperidine analogues using the alloc protecting group: an investigation of Alloc removal from secondary amines. Tetrahedron Lett 42:4471–4474
Lapatsanis L, Milias G, Froussios K, Kolovos M (1983) Synthesis of N-2,2,2-(trichloroethoxycarbonyl)-L-amino acids and N-(9-fluorenylmethoxycarbonyl)-L-amino acids involving succinimidoxy anion as a leaving group in amino acid protection. Synthesis 1983:671–673
Carson JF (1981) N-2,2,2-trichloroethoxycarbonyl-L-amino acids. Synthesis 1981:268–270
Vellemäe E, Stepanov V, Mäeorg U (2010) Mild approach to the deprotection of troc from protected amines using mischmetal and TMSCl. Synth Commun 40:3397–3404
Trost BM, Kalnmals CA, Tracy JS, Bai WJ (2018) Highly chemoselective deprotection of the 2,2,2-trichloroethoxycarbonyl (Troc) protecting group. Org Lett 20(24):8043–8046
Bhushan KR (2006) Light-directed maskless synthesis of peptide arrays using photolabile amino acid monomers. Org Biomol Chem 4:1857–1859
Zhang X, Xi W, Gao G, Wang X, Stansbury JW, Bowman CN (2018) o-Nitrobenzyl-based photobase generators: efficient photoinitiators for visible-light induced thiol-michael addition photopolymerization. ACS Macro Lett 7:852–857
Pothukanuri S, Winssinger N (2007) A highly efficient azide-based protecting group for amines and alcohols. Org Lett 9:2223–2225
Kaiser A, Richert C (2010) Azidomethyl 4-nitrophenyl carbonate – a reagent for the one-step introduction of the azidomethyloxycarbonyl (Azoc) protecting group. Synlett 2010:2267–2270
Hiskey RG, James M (1963) Azomethine chemistry. II. Formation of peptides from oxazolidine-5-ones. J Am Chem Soc 85:578–582
Wuts PGM, Greene TW (2006) Protection for the amino group. In: Wuts PGM, Greene TW (eds) Greene’s protective groups in organic synthesis. Wiley, Hoboken, NJ, pp 696–926
Isidro-Llobet A, Guasch-Camell J, Álvarez M, Albericio F (2005) p-Nitrobenzyloxycarbonyl (pNZ) as a temporary Nα-protecting group in orthogonal solid-phase peptide synthesis – avoiding diketopiperazine and aspartimide formation. Eur J Org Chem 2005:3031–3039
López PE, Isidro-Llobet A, Gracia C, Cruz LJ, García-Granados A, Parra A, Álvarez M, Albericio F (2005) Use of p-nitrobenzyloxycarbonyl (pNZ) as a permanent protecting group in the synthesis of Kahalalide F analogs. Tetrahedron Lett 46:7737–7741
Huang Y-C, Cao C, Tan X-L, Li X, Liu L (2014) Facile solid-phase synthesis of PNA-peptide conjugates using pNZ-protected PNA monomers. Org Chem Front 1:1050–1054
Isidro-Llobet A, López PE, Guasch-Camell J, álvarez M, Albericio F (2006) p-Nitrobenzyloxycarbonyl (pNZ) as an alternative to fmoc for the protection of amines in solid-phase peptide synthesis. In: Blondelle SE (ed) Understanding biology using peptides. Springer, New York, NY
Kessler H, Siegmeier R (1983) 9-Fluorenylmethyl esters as carboxyl protecting group. Tetrahedron Lett 24:281–282
Belshaw PJ, Adamson JG, Lajoie GA (1992) Single step syntheses of ω-9-fluorenylmethyl esters of aspartic and glutamic acids. Synth Commun 22:1001–1005
Martinez J, Laur J, Castro B (1983) Carboxamidomethyl esters (CAM esters) as carboxyl protecting groups. Tetrahedron Lett 24:5219–5222
Mayato C, Dorta RL, Vázquez JT (2008) Methyl esters: an alternative protecting group for the synthesis of O-glycosyl amino acid building blocks. Tetrahedron Lett 49:1396–1398
Di Gioia Maria L, Leggio A, Le Pera A, Liguori A, Perri F, Siciliano C (2004) Alternative and chemoselective deprotection of the α-amino and carboxy functions of N-Fmoc-amino acid and N-Fmoc-dipeptide methyl esters by modulation of the molar ratio in the AlCl3/N,N-dimethylaniline reagent system. Eur J Org Chem 2004:4437–4441
Martinez J, Laur J, Castro B (1985) On the use of carboxamidomethyl esters (cam esters) in the synthesis of model peptides. scope and limitations. Tetrahedron 41:739–743
Chen R, Tolbert TJ (2011) On-resin convergent synthesis of a glycopeptide from HIV gp120 containing a high mannose type N-linked oligosaccharide. Methods Mol Biol 751:343–355
Wang L, Gagey-Eilstein N, Broussy S, Reille-Seroussi M, Huguenot F, Vidal M, Liu W-Q (2014) Design and synthesis of C-terminal modified cyclic peptides as VEGFR1 antagonists. Molecules 19:15391
Roeske R (1963) Preparation of t-butyl esters of free amino acids. J Org Chem 28:1251–1253
Kaul R, Brouillette Y, Sajjadi Z, Hansford KA, Lubell WD (2004) Selective tert-butyl ester deprotection in the presence of acid labile protecting groups with use of ZnBr2. J Org Chem 69:6131–6133
Wuts PGM, Greene TW (2006) Protection for the carboxyl group. In: Wuts PGM, Greene TW (eds) Greene’s protective groups in organic synthesis. Wiley, Hoboken, NJ, pp 431–532
Albericio F (2000) Orthogonal protecting groups for Nα-amino and C-terminal carboxyl functions in solid-phase peptide synthesis. Peptide Sci 55:123–139
Lloyd-Williams P, Albericio F, Giralt E (1997) Chemical approaches to the synthesis of peptides and proteins, vol 10. CRC Press, Boca Raton, FL
Salomon CJ, Mata EG, Mascaretti OA (1996) Selective deprotection of phenacyl, benzyl and methyl esters of N-protected amino acids and dipeptides and N-protected amino acids benzyl ester linked to resins with bis (tributyltin) oxide. J Chem Soc Perkin Trans 1 10:995–999
Hendrickson JB, Kandall C (1970) The phenacyl protecting group for acids and phenols. Tetrahedron Lett 11:343–344
Loffet A, Zhang H (1993) Allyl-based groups for side-chain protection of amino-acids. Int J Pept Protein Res 42:346–351
Thieriet N, Alsina J, Giralt E, Guibé F, Albericio F (1997) Use of Alloc-amino acids in solid-phase peptide synthesis. Tandem deprotection-coupling reactions using neutral conditions. Tetrahedron Lett 38:7275–7278
Bourgault S, Letourneau M, Fournier A (2007) Development of photolabile caged analogs of endothelin-1. Peptides 28:1074–1082
Lodder M, Golovine S, Laikhter AL, Karginov VA, Hecht SM (1998) Misacylated transfer RNAs having a chemically removable protecting group. J Org Chem 63:794–803
Borsuk K, van Delft FL, Eggen IF, ten Kortenaar PB, Petersen A, Rutjes FP (2004) Application of substituted 2-(trimethylsilyl) ethyl esters to suppress diketopiperazine formation. Tetrahedron Lett 45:3585–3588
Wuts PG, Greene TW (2006) Greene’s protective groups in organic synthesis. John Wiley & Sons, Hoboken, NJ
Bajwa JS (1992) Chemoselective deprotection of benzyl esters in the presence of benzyl ethers, benzyloxymethyl ethers and N-benzyl groups by catalytic transfer hydrogenation. Tetrahedron Lett 33:2299–2302
Pennington MW (1994) HF cleavage and deprotection procedures for peptides synthesized using a Boc/Bzl strategy. In: Dunn BM, Pennington MW (eds) Peptide synthesis protocols. Springer, New York, NY, pp 41–62
Yamashiro D, Li CH (1973) Adrenocorticotropins. 44. Total synthesis of the human hormone by the solid-phase method. J Am Chem Soc 95:1310–1315
Demirtaş İ, Büyükkidan B, Elmastaş M (2002) The selective protection and deprotection of ambident nucleophiles with parent and substituted triarylmethyls. Turk J Chem 26:889–896
Barlos K, Gatos D, Koutsogianni S, Schäfer W, Stavropoulos G, Wenging Y (1991) Darstellung und einsatz von N-Fmoc-O-Trt-hydroxyaminosäuren zur “solid phase” synthese von peptiden. Tetrahedron Lett 32:471–474
Corey EJ, Venkateswarlu A (1972) Protection of hydroxyl groups as tert-butyldimethylsilyl derivatives. J Am Chem Soc 94:6190–6191
Goodman M, Meienhofer J (1977) Peptides: proceedings of the 5th American peptide symposium. Halsted Press, Hoboken, NJ
Enomoto H, Morikawa Y, Miyake Y, Tsuji F, Mizuchi M, Suhara H, Fujimura K-i, Horiuchi M, Ban M (2009) Synthesis and biological evaluation of N-mercaptoacylcysteine derivatives as leukotriene A4 hydrolase inhibitors. Bioorg Med Chem Lett 19:442–446
Yajima H, Fujii N, Ogawa H, Kawatani H (1974) Trifluoromethanesulphonic acid, as a deprotecting reagent in peptide chemistry. Chem Commun 3:107–108
Munson MC, García-Echeverría C, Albericio F, Barany G (1992) S-2, 4, 6-trimethoxybenzyl (Tmob): a novel cysteine protecting group for the N. alpha.-(9-fluorenylmethoxycarbonyl)(Fmoc) strategy of peptide synthesis. J Org Chem 57:3013–3018
Acknowledgments
This work was funded by the National Institute of Health-NIGMS, the Nebraska Center for Molecular Target Discovery and Development (1P20GM121316-01A1, PI: Robert Lewis, Project Leader, M.C.-S.), and the American Chemical Society, PRF# 57434-DNI7 (M.C.-S.).
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Conda-Sheridan, M., Krishnaiah, M. (2020). Protecting Groups in Peptide Synthesis. In: Hussein, W., Skwarczynski, M., Toth, I. (eds) Peptide Synthesis. Methods in Molecular Biology, vol 2103. Humana, New York, NY. https://doi.org/10.1007/978-1-0716-0227-0_7
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