Fmoc Solid Phase Peptide Synthesis of Oxytocin and Analogues

Kremsmayr, Thomas; Muttenthaler, Markus

doi:10.1007/978-1-0716-1759-5_11

Cited by 10 publications

(9 citation statements)

References 58 publications

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“…The variants were synthesized using standard Fmoc-SPPS and commercial building blocks. 109 In the case of the aza-peptide analogue, we adopted a patent procedure. 110 C α -methylation of Leu 8 ((C α -Me)Leu 8 OT), the introduction of a β 3 -homo amino acid ((β 3 -homo)Leu 8 OT), and backbone N α -methylation ((N α -Me)Gly 9 OT) 111 all prevented peptide bond cleavage in SIF and increased the half-life of OT from a few minutes to several hours ((C α -Me)Leu 8 OT: t 1/2 SIF = 4.4 ± 0.3 h, (β 3 -homo)Leu 8 OT: t 1/2 SIF = 3.6 ± 0.1 h, (N α -Me)Gly 9 OT: t 1/2 SIF = 2.9 ± 0.1 h) ( Figure 2 B and Table 2 ).…”

Section: Resultsmentioning

confidence: 99%

“…Based on the observed degradation path (proceeding via cleavage between Leu 8 and Gly 9 ) (Figure S6), we prepared a series of analogous specifically incorporating common peptide bond mimetics at the site of Leu 8 -Gly 9 (Figure A). The variants were synthesized using standard Fmoc-SPPS and commercial building blocks . In the case of the aza-peptide analogue, we adopted a patent procedure .…”

Section: Resultsmentioning

confidence: 99%

“…Peptides were assembled on a 0.1 mmol scale (1.0 mmol scale for cyclotides), using Fmoc-SPPS chemistry as previously described. 109 Linear peptide synthesis was performed either manually (5 equiv excess of amino acids, 10 min HATU-mediated coupling cycles, 2 × 1 min Fmoc deprotection with 50% piperidine in DMF) or on a PTI Tribute Automatic Peptide Synthesizer (5 equiv excess of amino acids, 30 min HBTU-mediated coupling cycles, 2 × 5 min Fmoc deprotection with 20% piperidine in DMF). Unless otherwise stated, standard orthogonal protected Fmoc amino acids were used as follows: Fmoc-Arg(Pbf)-OH, Fmoc-Asn(Trt)-OH, Fmoc-Asp(OtBu)-OH, Fmoc-Cys(Trt)-OH, Fmoc-Gln(Trt)-OH, Fmoc-Glu(OtBu)-OH, Fmoc-Lys(Boc)-OH, Fmoc-Ser(tBu)-OH, Fmoc-Thr(tBu)-OH, Fmoc-Trp(Boc)-OH, and Fmoc-Tyr(tBu)-OH.…”

Section: Experimental Sectionmentioning

confidence: 99%

“…Peptides were assembled on a 0.1 mmol scale (1.0 mmol scale for cyclotides), using Fmoc-SPPS chemistry as previously described . Linear peptide synthesis was performed either manually (5 equiv excess of amino acids, 10 min HATU-mediated coupling cycles, 2 × 1 min Fmoc deprotection with 50% piperidine in DMF) or on a PTI Tribute Automatic Peptide Synthesizer (5 equiv excess of amino acids, 30 min HBTU-mediated coupling cycles, 2 × 5 min Fmoc deprotection with 20% piperidine in DMF).…”

Section: Experimental Sectionmentioning

confidence: 99%

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On the Utility of Chemical Strategies to Improve Peptide Gut Stability

et al. 2022

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Inherent susceptibility of peptides to enzymatic degradation in the gastrointestinal tract is a key bottleneck in oral peptide drug development. Here, we present a systematic analysis of (i) the gut stability of disulfide-rich peptide scaffolds, orally administered peptide therapeutics, and well-known neuropeptides and (ii) medicinal chemistry strategies to improve peptide gut stability. Among a broad range of studied peptides, cyclotides were the only scaffold class to resist gastrointestinal degradation, even when grafted with non-native sequences. Backbone cyclization, a frequently applied strategy, failed to improve stability in intestinal fluid, but several site-specific alterations proved efficient. This work furthermore highlights the importance of standardized gut stability test conditions and suggests defined protocols to facilitate cross-study comparison. Together, our results provide a comparative overview and framework for the chemical engineering of gut-stable peptides, which should be valuable for the development of orally administered peptide therapeutics and molecular probes targeting receptors within the gastrointestinal tract.

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Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Experimental Sectionmentioning

confidence: 99%

Section: Experimental Sectionmentioning

confidence: 99%

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On the Utility of Chemical Strategies to Improve Peptide Gut Stability

et al. 2022

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“…OT was synthesized by manual Fmoc solid phase peptide synthesis ( Kremsmayr and Muttenthaler, 2022 ). The exact concentration and purity of the peptide was determined via RP-HPLC ( Supplementary Table S1 ) and compared against two peptide standards of known concentration.…”

Section: Resultsmentioning

confidence: 99%

Approaches to Improve the Quantitation of Oxytocin in Human Serum by Mass Spectrometry

et al. 2022

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The neuropeptide oxytocin (OT) regulates several peripheral and central functions and is a molecule of interest in psychiatric diseases such as autism spectrum disorder, schizophrenia, anxiety and depression. The study of OT in human serum samples is however hampered by inconsistent sample preparation and analysis as well as low endogenous blood concentration (1–10 pM). This results in varying reports on OT’s blood levels and interpretation of OT’s role in different (patho)physiological states. Quantitative mass spectrometry (MS) is a highly promising technology to address this problem but still requires large sample volumes to achieve adequate sensitivity and reliability for the quantitation of compounds at low concentrations. We therefore systematically evaluated sample preparation methods for MS to achieve a reliable sample preparation protocol with good peptide recovery, minimal matrix effects and good overall method efficiency in line with FDA guidelines for bioanalytic method development and validation. Additionally, we investigated a strategy to improve the ionization efficiency of OT by adding charged and/or hydrophobic moieties to OT to improve the lower limit of quantitation. Optimized sample preparation in combination with OT modification with a quaternary pyridinium ion improved the sensitivity of OT by ∼40-fold on a tandem triple quadrupole mass spectrometer (API4000 QTRAP), resulting in a lower limit of quantitation of 5 pM in water (linear range 5 pM – 1 mM) and 2 nM in human serum (linear range 2 nM – 1 mM) compared to 200 pM in water and 86 nM in serum with unmodified OT. This approach and protocol provide a solid foundation towards method development for OT quantitation using MS, which should be of high value for fundamental research as well as clinical monitoring of OT upon drug treatments.

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Screening and Exploring the Application of the Multifunctional Antioxidant Peptides MSWLC and TSWLC

Yu,

Wang,

Wang

et al. 2024

Adv Healthcare Materials

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In this study, an antioxidant pentapeptide library is created based on antioxidant characteristics. The peptides are then purified and separated using liquid chromatography/mass spectrometry (LC/MS) and time‐of‐flight mass spectrometry (TOF). Chemical evaluations identify four peptides with excellent antioxidant activity. The four peptides undergo biocompatibility testing with L‐929, NIH 3T3, and Hep‐G2 cells. A model of hydrogen peroxide‐induced cellular damage in G2 cells shows the peptides' protective and reparative effects against oxidative damage. Two peptides, MSWLC and TSWLC, which perform best overall, are chosen for further analysis. To explore the peptides' potential multifunctionality, acute liver inflammation, keratitis, and aging models are established in mice. MSWLC and TSWLC demonstrate anti‐inflammatory and anti‐aging properties. An antioxidant emulsion prepared by emulsification is found to be non‐irritant in a mouse skin irritation test. In a mouse model exposed to ultraviolet radiation, the sunscreen exhibits excellent UV protection and antioxidant effects. These peptides possess potent antioxidant properties and multifunctionality, indicating broad application potential.

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Fmoc Solid Phase Peptide Synthesis of Oxytocin and Analogues

Cited by 10 publications

References 58 publications

On the Utility of Chemical Strategies to Improve Peptide Gut Stability

On the Utility of Chemical Strategies to Improve Peptide Gut Stability

Approaches to Improve the Quantitation of Oxytocin in Human Serum by Mass Spectrometry

Screening and Exploring the Application of the Multifunctional Antioxidant Peptides MSWLC and TSWLC

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