Dimitrios Gatos - Academia.edu (original) (raw)

Papers by Dimitrios Gatos

Research paper thumbnail of Application of 4-polystyryltriphenylmethyl chloride to the synthesis of peptides and amino-acid derivatives

Research paper thumbnail of Use of the 2-chlorotrityl chloride resin for microwave-assisted solid phase peptide synthesis

Biopolymers, 2015

A fast and efficient microwave (MW)-assisted solid-phase peptide synthesis protocol using the 2-c... more A fast and efficient microwave (MW)-assisted solid-phase peptide synthesis protocol using the 2-chlorotrityl chloride resin and the Fmoc/tBu methodology, has been developed. The established protocol combines the advantages of MW irradiation and the acid labile 2-chlorotrityl chloride resin. The effect of temperature during the MW irradiation, the degree of resin substitution during the coupling of the first amino acids and the rate of racemization for each amino acid were evaluated. The suggested solid phase methodology is applicable for orthogonal peptide synthesis and for the synthesis of cyclic peptides. © 2015 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 104: 506-514, 2015.

Research paper thumbnail of Properties of myelin altered peptide ligand cyclo(87-99)(Ala91,Ala96)MBP87-99 render it a promising drug lead for immunotherapy of Multiple Sclerosis

European Journal of Medicinal Chemistry, 2015

Multiple sclerosis (MS) is an inflammatory, demyelinating disease of the central nervous system, ... more Multiple sclerosis (MS) is an inflammatory, demyelinating disease of the central nervous system, and it has been established that autoreactive T helper (Th) cells play a crucial role in its pathogenesis. Myelin basic protein (MBP) epitopes are major autoantigens in MS, and the sequence MBP87-99 is an immunodominant epitope. We have previously reported that MBP87-99 peptides with modifications at principal T-cell receptor (TCR) contact sites suppressed the induction of EAE symptoms in rats and SJL/J mice, diverted the immune response from Th1 to Th2 and generated antibodies that did not cross react with the native MBP protein. In this study, the linear and cyclic analogs of the MBP87-99 epitope, namely linear (Ala91,Ala96)MBP87-99 (P2) and cyclo(87-99)(Ala91,Ala96)MBP87-99 (P3), were evaluated for their binding to HLA-DR4, stability to lysosomal enzymes, their effect on cytokine secretion by peripheral blood mononuclear cells (PBMC) derived from MS patients or healthy subjects (controls), and their effect in rat EAE. P1 peptide (wild-type, MBP87-99) was used as control. P2 and P3 did not alter significantly the cytokine secretion by control PBMC, in contrast to P1 that induced moderate IL-10 production. In MS PBMC, P2 and P3 induced the production of IL-2 and IFN-γ, with a simultaneous decrease of IL-10, whereas P1 caused a reduction of IL-10 secretion only. The cellular response to P3 indicated that cyclization did not affect the critical TCR contact sites in MS PBMC. Interestingly, the cyclic P3 analog was found to be a stronger binder to HLA-DR4 compared to linear P2. Moreover, cyclic P3 was more stable to proteolysis compared to linear P2. Finally, both P2 and P3 suppressed EAE induced by an encephalitogenic guinea pig MBP74-85 epitope in Lewis rats whereas P1 failed to do so. In conclusion, cyclization of myelin altered peptide ligand (Ala91,Ala96)MBP87-99 improved binding affinity to HLA-DR4, resistance to proteolysis and antigen-specific immunomodulation, rendering cyclo(87-99)(Ala91,Ala96)MBP87-99 an important candidate drug for MS immunotherapy.

Research paper thumbnail of Evaluation of Polyamide-Polystyrene Block Polymers in Peptide Synthesis and Biochemistry

Understanding Biology Using Peptides, 2006

Research paper thumbnail of ChemInform Abstract: Synthesis of Calcitonin Derivatives by Fragment Condensation in Solution and on 2-Chlorotrityl Resin

ChemInform, 1993

ABSTRACT ChemInform is a weekly Abstracting Service, delivering concise information at a glance t... more ABSTRACT ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Research paper thumbnail of Attachment of histidine, histamine and urocanic acid to resins of the trityl-type

Tetrahedron Letters, 1999

Histidine, histamine and urocanic acid were attached through the N mfunction on resins of the tri... more Histidine, histamine and urocanic acid were attached through the N mfunction on resins of the trityl type. The conditions of the cleavage of these derivatives from the resin were determined. Resin bound histamine was used in the solid phase synthesis of carcinine.

Research paper thumbnail of ChemInform Abstract: Synthesis of Prothymosin α (ProTα), a Protein Consisting of 109 Amino Acids

ChemInform, 1991

ABSTRACT ChemInform is a weekly Abstracting Service, delivering concise information at a glance t... more ABSTRACT ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Research paper thumbnail of Novel synthesis of cyclic amide-linked analogues of angiotensins II and III

Journal of medicinal chemistry, Jan 2, 1994

Cyclic amide-linked angiotension II (ANGII) analogues have been synthesized by novel strategies, ... more Cyclic amide-linked angiotension II (ANGII) analogues have been synthesized by novel strategies, in an attempt to test the ring clustering and the charge relay bioactive conformation recently suggested. These analogues were synthesized by connecting side chain amino and carboxyl groups at positions 1 and 8, 2 and 8, 3 and 8, and 3 and 5, N-terminal amino and C-terminal carboxyl groups at positions 1 and 8, 2 and 8, and 4 and 8, and side chain amino to C-terminal carboxyl group at positions 1 and 8. All these analogues were biologically inactive, except for cyclic [Sar1, Asp3, Lys5]ANGII (analogue 10) which had high contractile activity in the rat uterus assay (30% of ANGII) and [Lys1, Tyr(Me)4, Glu8]ANGII (analogue 7) which had weak antagonist activity (PA2 approximately 6). Precyclic linear peptides synthesized using 2-chlorotrityl chloride resin and N alpha-Fmoc-amino acids with suitable side chain protection were obtained in high yield and purity and were readily cyclized with be...

Research paper thumbnail of Improvements in the Chemical Synthesis of Insulin-Like Peptides

Advances in Experimental Medicine and Biology, 2009

Research paper thumbnail of Application of 2-chlorotrityl resin in solid phase synthesis of (Leu15)-gastrin I and unsulfated cholecystokinin octapeptide. Selective O-deprotection of tyrosine

International journal of peptide and protein research, 1991

The carboxyl terminal dipeptide amide, Fmoc-Asp-Phe-NH2, of gastrin and cholecystokinin (CCK) has... more The carboxyl terminal dipeptide amide, Fmoc-Asp-Phe-NH2, of gastrin and cholecystokinin (CCK) has been attached in high yield through its free side chain carboxyl group to the acid labile 2-chlorotrityl resin. The obtained peptide resin ester has been applied in the solid phase synthesis of partially protected (Leu15)-gastrin I utilising Fmoc-amino acids. Quantitative cleavage of this peptide from resin, with the t-butyl type side chain protection intact is achieved using mixtures of acetic acid/trifluoroethanol/dichloromethane. Under the same conditions complete detritylation of the tyrosine phenoxy function occurs simultaneously. Thus, the solid-phase synthesis of peptides selectively deprotected at the side chain of tyrosine is rendered possible by the use of 2-chlorotrityl resin and Fmoc-Tyr(Trt)-OH. The efficiency of this approach has been proved by the subsequent high-yield synthesis of three model peptides and the CCK-octapeptide.

Research paper thumbnail of Rational Design and Synthesis of Altered Peptide Ligands based on Human Myelin Oligodendrocyte Glycoprotein 35–55 Epitope: Inhibition of Chronic Experimental Autoimmune Encephalomyelitis in Mice

Molecules, 2014

Experimental autoimmune encephalomyelitis (EAE) is a demyelinating disease of the central nervous... more Experimental autoimmune encephalomyelitis (EAE) is a demyelinating disease of the central nervous system and is an animal model of multiple sclerosis (MS). Although the etiology of MS remains unclear, there is evidence T-cell recognition of immunodominant epitopes of myelin proteins, such as the 35-55 epitope of myelin oligodendrocyte glycoprotein (MOG), plays a pathogenic role in the induction of chronic EAE. Cyclization of peptides is of great interest since the limited stability of linear peptides restricts their potential use as therapeutic agents. Herein, we have designed and synthesized a number of linear and cyclic peptides by mutating crucial T cell receptor (TCR) contact residues of the human MOG35-55 epitope. In particular, we have designed and synthesized cyclic altered peptide ligands (APLs) by mutating Arg41 with Ala or Arg41 and Arg46 with Ala. The peptides were synthesized in solid phase on 2-chlorotrityl chloride resin (CLTR-Cl) using the Fmoc/t-Bu methodology. The purity of final products was verified by RP-HPLC and their identification was achieved by ESI-MS. It was found that the substitutions of Arg at positions 41 and 46 with Ala results in peptide analogues that reduce the severity of MOG-induced EAE clinical symptoms in C57BL/6 mice when co-administered with mouse MOG35-55 peptide at the time of immunization.

Research paper thumbnail of Preparation of polymer-bound trityl-hydrazines and their application in the solid phase synthesis of partially protected peptide hydrazides

Letters in Peptide Science, 1996

Polymer-bound N-tritylhydrazines 4 were easily prepared by reacting polymeric tritylchlorides 3 w... more Polymer-bound N-tritylhydrazines 4 were easily prepared by reacting polymeric tritylchlorides 3 with hydrazine. Subsequently, compounds 4 have been successfully applied to the solid phase synthesis of partially protected peptide hydrazides using 1-hydroxybenzotriazolyl esters of Fmoc-or Trt-amino acids. The synthesized peptide hydrazides can be quantitatively split off from the resins by mild acidic treatment, while the benzyl-and tert-butyl protecting groups remain unaffected.

Research paper thumbnail of 2-Chlorotrityl chloride resin

International Journal of Peptide and Protein Research, 1991

The esterification of 2-chlorotrityl chloride resin with Fmoc-amino acids in the presence of DIEA... more The esterification of 2-chlorotrityl chloride resin with Fmoc-amino acids in the presence of DIEA is studied under various conditions. High esterification yields are obtained using 0.6 equiv. Fmoc-amino acid/mmol resin in DCM or DCE, in 25 min, at room temperature. The ...

Research paper thumbnail of ChemInform Abstract: Application of Resins of the Trityl Type in the “Solid-Phase Organic Synthesis” of Thiol-Containing Compounds

Research paper thumbnail of Convergent Synthesis of the Cysteine-rich Mdm2 RING Finger Domain

Understanding Biology Using Peptides, 2006

Research paper thumbnail of ChemInform Abstract: Preparation and Use of N-Fmoc-O-Trt-hydroxyamino Acids in the Solid Phase Synthesis of Peptides

ChemInform, 1991

ABSTRACT ChemInform is a weekly Abstracting Service, delivering concise information at a glance t... more ABSTRACT ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Research paper thumbnail of Synthesis of the very acid-sensitive Fmoc-Cys(Mmt)-OH and its application in solid-phase peptide synthesis

International Journal of Peptide and Protein Research, 1996

S-4-methoxytrityl cysteine was synthesized and converted into the corresponding Fmoc-Cys(Mmt)-OH ... more S-4-methoxytrityl cysteine was synthesized and converted into the corresponding Fmoc-Cys(Mmt)-OH by its reaction with Fmoc-OSu. As compared to the corresponding Fmoc-Cys(Trt)-OH, the S-Mmt-function was found to be considerably more acid labile. Quantitative S-Mmt-removal occurs selectively in the presence of groups of the tert butyl type and S-Trt by treatment with 0.5-1.0% TFA. The new derivative was successfully utilized in the SPPS of Tyr1-somatostatin on 2-chlorotrityl resin. In this synthesis groups of the Trt-type were exclusively used for amino acid side-chain protection. Quantitative cleavage from the resin and complete deprotection was performed by treatment with 3% TFA in DCM-TES (95:5) for 30 min at RT. We observed no reduction of tryptophan under these conditions.

Research paper thumbnail of Two-directional solid phase peptide synthesis

Research paper thumbnail of ChemInform Abstract: 9-Fluorenylmethyloxycarbonyl/tButyl-Based Convergent Protein Synthesis

ChemInform, 2000

ABSTRACT ChemInform is a weekly Abstracting Service, delivering concise information at a glance t... more ABSTRACT ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Research paper thumbnail of ChemInform Abstract: Convergent Peptide Synthesis

ChemInform, 2000

ABSTRACT ChemInform is a weekly Abstracting Service, delivering concise information at a glance t... more ABSTRACT ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Research paper thumbnail of Application of 4-polystyryltriphenylmethyl chloride to the synthesis of peptides and amino-acid derivatives

Research paper thumbnail of Use of the 2-chlorotrityl chloride resin for microwave-assisted solid phase peptide synthesis

Biopolymers, 2015

A fast and efficient microwave (MW)-assisted solid-phase peptide synthesis protocol using the 2-c... more A fast and efficient microwave (MW)-assisted solid-phase peptide synthesis protocol using the 2-chlorotrityl chloride resin and the Fmoc/tBu methodology, has been developed. The established protocol combines the advantages of MW irradiation and the acid labile 2-chlorotrityl chloride resin. The effect of temperature during the MW irradiation, the degree of resin substitution during the coupling of the first amino acids and the rate of racemization for each amino acid were evaluated. The suggested solid phase methodology is applicable for orthogonal peptide synthesis and for the synthesis of cyclic peptides. © 2015 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 104: 506-514, 2015.

Research paper thumbnail of Properties of myelin altered peptide ligand cyclo(87-99)(Ala91,Ala96)MBP87-99 render it a promising drug lead for immunotherapy of Multiple Sclerosis

European Journal of Medicinal Chemistry, 2015

Multiple sclerosis (MS) is an inflammatory, demyelinating disease of the central nervous system, ... more Multiple sclerosis (MS) is an inflammatory, demyelinating disease of the central nervous system, and it has been established that autoreactive T helper (Th) cells play a crucial role in its pathogenesis. Myelin basic protein (MBP) epitopes are major autoantigens in MS, and the sequence MBP87-99 is an immunodominant epitope. We have previously reported that MBP87-99 peptides with modifications at principal T-cell receptor (TCR) contact sites suppressed the induction of EAE symptoms in rats and SJL/J mice, diverted the immune response from Th1 to Th2 and generated antibodies that did not cross react with the native MBP protein. In this study, the linear and cyclic analogs of the MBP87-99 epitope, namely linear (Ala91,Ala96)MBP87-99 (P2) and cyclo(87-99)(Ala91,Ala96)MBP87-99 (P3), were evaluated for their binding to HLA-DR4, stability to lysosomal enzymes, their effect on cytokine secretion by peripheral blood mononuclear cells (PBMC) derived from MS patients or healthy subjects (controls), and their effect in rat EAE. P1 peptide (wild-type, MBP87-99) was used as control. P2 and P3 did not alter significantly the cytokine secretion by control PBMC, in contrast to P1 that induced moderate IL-10 production. In MS PBMC, P2 and P3 induced the production of IL-2 and IFN-γ, with a simultaneous decrease of IL-10, whereas P1 caused a reduction of IL-10 secretion only. The cellular response to P3 indicated that cyclization did not affect the critical TCR contact sites in MS PBMC. Interestingly, the cyclic P3 analog was found to be a stronger binder to HLA-DR4 compared to linear P2. Moreover, cyclic P3 was more stable to proteolysis compared to linear P2. Finally, both P2 and P3 suppressed EAE induced by an encephalitogenic guinea pig MBP74-85 epitope in Lewis rats whereas P1 failed to do so. In conclusion, cyclization of myelin altered peptide ligand (Ala91,Ala96)MBP87-99 improved binding affinity to HLA-DR4, resistance to proteolysis and antigen-specific immunomodulation, rendering cyclo(87-99)(Ala91,Ala96)MBP87-99 an important candidate drug for MS immunotherapy.

Research paper thumbnail of Evaluation of Polyamide-Polystyrene Block Polymers in Peptide Synthesis and Biochemistry

Understanding Biology Using Peptides, 2006

Research paper thumbnail of ChemInform Abstract: Synthesis of Calcitonin Derivatives by Fragment Condensation in Solution and on 2-Chlorotrityl Resin

ChemInform, 1993

ABSTRACT ChemInform is a weekly Abstracting Service, delivering concise information at a glance t... more ABSTRACT ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Research paper thumbnail of Attachment of histidine, histamine and urocanic acid to resins of the trityl-type

Tetrahedron Letters, 1999

Histidine, histamine and urocanic acid were attached through the N mfunction on resins of the tri... more Histidine, histamine and urocanic acid were attached through the N mfunction on resins of the trityl type. The conditions of the cleavage of these derivatives from the resin were determined. Resin bound histamine was used in the solid phase synthesis of carcinine.

Research paper thumbnail of ChemInform Abstract: Synthesis of Prothymosin α (ProTα), a Protein Consisting of 109 Amino Acids

ChemInform, 1991

ABSTRACT ChemInform is a weekly Abstracting Service, delivering concise information at a glance t... more ABSTRACT ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Research paper thumbnail of Novel synthesis of cyclic amide-linked analogues of angiotensins II and III

Journal of medicinal chemistry, Jan 2, 1994

Cyclic amide-linked angiotension II (ANGII) analogues have been synthesized by novel strategies, ... more Cyclic amide-linked angiotension II (ANGII) analogues have been synthesized by novel strategies, in an attempt to test the ring clustering and the charge relay bioactive conformation recently suggested. These analogues were synthesized by connecting side chain amino and carboxyl groups at positions 1 and 8, 2 and 8, 3 and 8, and 3 and 5, N-terminal amino and C-terminal carboxyl groups at positions 1 and 8, 2 and 8, and 4 and 8, and side chain amino to C-terminal carboxyl group at positions 1 and 8. All these analogues were biologically inactive, except for cyclic [Sar1, Asp3, Lys5]ANGII (analogue 10) which had high contractile activity in the rat uterus assay (30% of ANGII) and [Lys1, Tyr(Me)4, Glu8]ANGII (analogue 7) which had weak antagonist activity (PA2 approximately 6). Precyclic linear peptides synthesized using 2-chlorotrityl chloride resin and N alpha-Fmoc-amino acids with suitable side chain protection were obtained in high yield and purity and were readily cyclized with be...

Research paper thumbnail of Improvements in the Chemical Synthesis of Insulin-Like Peptides

Advances in Experimental Medicine and Biology, 2009

Research paper thumbnail of Application of 2-chlorotrityl resin in solid phase synthesis of (Leu15)-gastrin I and unsulfated cholecystokinin octapeptide. Selective O-deprotection of tyrosine

International journal of peptide and protein research, 1991

The carboxyl terminal dipeptide amide, Fmoc-Asp-Phe-NH2, of gastrin and cholecystokinin (CCK) has... more The carboxyl terminal dipeptide amide, Fmoc-Asp-Phe-NH2, of gastrin and cholecystokinin (CCK) has been attached in high yield through its free side chain carboxyl group to the acid labile 2-chlorotrityl resin. The obtained peptide resin ester has been applied in the solid phase synthesis of partially protected (Leu15)-gastrin I utilising Fmoc-amino acids. Quantitative cleavage of this peptide from resin, with the t-butyl type side chain protection intact is achieved using mixtures of acetic acid/trifluoroethanol/dichloromethane. Under the same conditions complete detritylation of the tyrosine phenoxy function occurs simultaneously. Thus, the solid-phase synthesis of peptides selectively deprotected at the side chain of tyrosine is rendered possible by the use of 2-chlorotrityl resin and Fmoc-Tyr(Trt)-OH. The efficiency of this approach has been proved by the subsequent high-yield synthesis of three model peptides and the CCK-octapeptide.

Research paper thumbnail of Rational Design and Synthesis of Altered Peptide Ligands based on Human Myelin Oligodendrocyte Glycoprotein 35–55 Epitope: Inhibition of Chronic Experimental Autoimmune Encephalomyelitis in Mice

Molecules, 2014

Experimental autoimmune encephalomyelitis (EAE) is a demyelinating disease of the central nervous... more Experimental autoimmune encephalomyelitis (EAE) is a demyelinating disease of the central nervous system and is an animal model of multiple sclerosis (MS). Although the etiology of MS remains unclear, there is evidence T-cell recognition of immunodominant epitopes of myelin proteins, such as the 35-55 epitope of myelin oligodendrocyte glycoprotein (MOG), plays a pathogenic role in the induction of chronic EAE. Cyclization of peptides is of great interest since the limited stability of linear peptides restricts their potential use as therapeutic agents. Herein, we have designed and synthesized a number of linear and cyclic peptides by mutating crucial T cell receptor (TCR) contact residues of the human MOG35-55 epitope. In particular, we have designed and synthesized cyclic altered peptide ligands (APLs) by mutating Arg41 with Ala or Arg41 and Arg46 with Ala. The peptides were synthesized in solid phase on 2-chlorotrityl chloride resin (CLTR-Cl) using the Fmoc/t-Bu methodology. The purity of final products was verified by RP-HPLC and their identification was achieved by ESI-MS. It was found that the substitutions of Arg at positions 41 and 46 with Ala results in peptide analogues that reduce the severity of MOG-induced EAE clinical symptoms in C57BL/6 mice when co-administered with mouse MOG35-55 peptide at the time of immunization.

Research paper thumbnail of Preparation of polymer-bound trityl-hydrazines and their application in the solid phase synthesis of partially protected peptide hydrazides

Letters in Peptide Science, 1996

Polymer-bound N-tritylhydrazines 4 were easily prepared by reacting polymeric tritylchlorides 3 w... more Polymer-bound N-tritylhydrazines 4 were easily prepared by reacting polymeric tritylchlorides 3 with hydrazine. Subsequently, compounds 4 have been successfully applied to the solid phase synthesis of partially protected peptide hydrazides using 1-hydroxybenzotriazolyl esters of Fmoc-or Trt-amino acids. The synthesized peptide hydrazides can be quantitatively split off from the resins by mild acidic treatment, while the benzyl-and tert-butyl protecting groups remain unaffected.

Research paper thumbnail of 2-Chlorotrityl chloride resin

International Journal of Peptide and Protein Research, 1991

The esterification of 2-chlorotrityl chloride resin with Fmoc-amino acids in the presence of DIEA... more The esterification of 2-chlorotrityl chloride resin with Fmoc-amino acids in the presence of DIEA is studied under various conditions. High esterification yields are obtained using 0.6 equiv. Fmoc-amino acid/mmol resin in DCM or DCE, in 25 min, at room temperature. The ...

Research paper thumbnail of ChemInform Abstract: Application of Resins of the Trityl Type in the “Solid-Phase Organic Synthesis” of Thiol-Containing Compounds

Research paper thumbnail of Convergent Synthesis of the Cysteine-rich Mdm2 RING Finger Domain

Understanding Biology Using Peptides, 2006

Research paper thumbnail of ChemInform Abstract: Preparation and Use of N-Fmoc-O-Trt-hydroxyamino Acids in the Solid Phase Synthesis of Peptides

ChemInform, 1991

ABSTRACT ChemInform is a weekly Abstracting Service, delivering concise information at a glance t... more ABSTRACT ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Research paper thumbnail of Synthesis of the very acid-sensitive Fmoc-Cys(Mmt)-OH and its application in solid-phase peptide synthesis

International Journal of Peptide and Protein Research, 1996

S-4-methoxytrityl cysteine was synthesized and converted into the corresponding Fmoc-Cys(Mmt)-OH ... more S-4-methoxytrityl cysteine was synthesized and converted into the corresponding Fmoc-Cys(Mmt)-OH by its reaction with Fmoc-OSu. As compared to the corresponding Fmoc-Cys(Trt)-OH, the S-Mmt-function was found to be considerably more acid labile. Quantitative S-Mmt-removal occurs selectively in the presence of groups of the tert butyl type and S-Trt by treatment with 0.5-1.0% TFA. The new derivative was successfully utilized in the SPPS of Tyr1-somatostatin on 2-chlorotrityl resin. In this synthesis groups of the Trt-type were exclusively used for amino acid side-chain protection. Quantitative cleavage from the resin and complete deprotection was performed by treatment with 3% TFA in DCM-TES (95:5) for 30 min at RT. We observed no reduction of tryptophan under these conditions.

Research paper thumbnail of Two-directional solid phase peptide synthesis

Research paper thumbnail of ChemInform Abstract: 9-Fluorenylmethyloxycarbonyl/tButyl-Based Convergent Protein Synthesis

ChemInform, 2000

ABSTRACT ChemInform is a weekly Abstracting Service, delivering concise information at a glance t... more ABSTRACT ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Research paper thumbnail of ChemInform Abstract: Convergent Peptide Synthesis

ChemInform, 2000

ABSTRACT ChemInform is a weekly Abstracting Service, delivering concise information at a glance t... more ABSTRACT ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.