Protecting group chemistry plays a pivotal role during peptide synthesis. For the synthesis of cysteinyl peptides, this is more significant as cysteine (Cys) involved in formation two key bonds─the amide and disulfide. Cys also poses itself one most sensitive amino acid residues synthesis, especially for occurrence side reactions such racemization, elimination, alkylation, etc. The magnitude these dependent on several factors including choice appropriate protecting groups thiol....

N,N‐dimethylformamide (DMF) and trifluoroacetic acid (TFA) are the two solvents/reagents most widely used in solid‐phase peptide synthesis (SPPS). While DMF is already regulated Europe, TFA—a member of polyfluoroalkyl substances (PFAS) family—is expected to face similar restrictions soon. These compounds break down slowly pose risks human health environment. Herein, use so‐called “green par excellence”, methanesulfonic (MSA), substitution TFA discussed. As MSA stronger than TFA, it diluted...

Cysteine (Cys) is the most versatile amino acid-forming part of a peptide chain but at same time complex. Its presence associated with large number side reactions. In particular, formation S-tert-butylated Cys residues results from reaction liberated thiol tBu cations coming tBu-based protecting groups. Here, we have studied this using different scavengers such as alkyl and aryl thiols (DTT, 1,4-BDMT), thioethers (DMS, thioanisole), sulfur-free compounds m-cresol, anisole, PPh3 TCEP in...

Acetamidomethyl (Acm)-protected cysteine derivatives are essential components of multi-disulfide synthesis, particularly due to the availability multimodal removal conditions for Acm protection. Most these harsh and commonly used remove protection at last step regioselective synthesis a multi-disulfide, implying that is performed in absence other Cys thiol protections. In this context, N-chlorosuccinimide (NCS)-mediated concomitant disulfide bridge formation provides fast reliable way...

Two new disulfide-based protecting groups (SIT and MOT) are proposed for Cys thiol in the substitution of StBu, which is often difficult to remove. Both based on a secondary with branched point β-position an efficient modulation its lability and/or stability. This unique structure allows them be fully compatible Fmoc/tBu SPPS. At end synthesis, these removed straightforward manner dithiothreitol some H2O.

The solid-phase peptide synthesis (SPPS) of the C-terminal sequence hGH with one extra Tyr attached to its N-terminus (total 16 residues a disulfide bridge) has been accomplished for first time by optimizing several synthetic parameters. First all, two Ser (positions 9 and 13 molecule) have introduced as single amino acid, Fmoc-Ser(ψMe,Mepro)-OH, demonstrating that acylation these hindered moieties is possible. This allows us avoid use corresponding dipeptides, Fmoc-AA-Ser(ψMe,Mepro)-OH,...

Cysteine (Cys) is a key amino acid in many therapeutic peptides. For research and industrial purposes, solid-phase peptide synthesis the method of choice for preparation most The C-terminal Cys acids problematic because it accompanied by side reaction, namely, abstraction α-H from residue, which leads to formation three products: epimer two N-piperidinyl-Ala Here, we used chlorotrityl chloride resin conduct rational in-depth study this reaction. following variables were examined: removal...

Chemoselective disulfide formation is accomplished through a thiol-disulfide interchange approach using sec-isoamyl mercaptan (SIT) as an alkyl sulfenyl-protecting group of one the Cys residues involved in pairing. SIT has dual and unique characteristic, acting masking during synthesis directing presence free thiol. This novel illustrated by several peptides biological interest.

Morpholine, which scores 7.5 in terms of greenness and is not a regulated substance, could be considered strong contender for Fmoc removal solid‐phase peptide synthesis (SPPS). Morpholine dimethylformamide (DMF) (50%–60%) efficiently removes SPPS, minimizes the formation diketopiperazine, almost avoids aspartimide formation. As proof concept, somatostatin has been synthesized using 50% morpholine DMF with same purity as when 20% piperidine–DMF.

Abstract Introduction The successful synthesis of a peptide requires the synchronization several processes, including efficient execution protecting group chemistry. For cysteine (Cys)-peptides, this is more crucial because trifunctional Cys has free thiol in its side chain. During synthesis, function remains protected with suitable groups and can be removed after using appropriate methods. Sec-isoamyl mercaptan (SIT) versatile disulfide-based for chain thiol. removal SIT from achieved mild...

We report a case of 24-year-old man who presented with complaint reduced mouth opening and burning sensation. On examination, he was clinically diagnosed oral submucous fibrosis (OSF). Following routine biopsy histopathological confirmation OSF, the patient supplemented zinc acetate along vitamin A followed up for 4 months. treatment reported increased Histopathologically re-epithelialisation evident appearance normal rete pegs. The data opening, collagen content epithelial thickness six...

Clinical proteomics is an emerging field that will have great impact on molecular diagnosis, identification of disease biomarkers, drug discovery and clinical trials in the post-genomic era. Protein profiling tissues fluids pathological control other techniques play important role diagnosis with therapeutics personalized healthcare. We introduced a new robust diagnostic method based ADTboost algorithm, novel algorithm data analysis to improve classification accuracy. It generates rules,...

Abstract Nonalcoholic fatty liver disease (NAFLD), which is characterized by excess accumulation of triglyceride in hepatocytes, the major cause chronic worldwide and no approved drug available. The mechanistic target rapamycin (mTOR) complexes has been implicated promoting lipogenesis fat liver, thus, serve as attractive targets. generation non‐ or low cytotoxic mTOR inhibitors required because existing are not useful for NAFLD therapy. New compounds based on privileged adenosine...

Clinical proteomics is an emerging field that will have great impact on molecular diagnosis, identification of disease biomarkers, drug discovery and clinical trials in the post-genomic era. Protein profiling tissues fluids pathological control other techniques play important role diagnosis with therapeutics personalized healthcare. We introduced a new robust diagnostic method based ADTboost algorithm, novel data analysis to improve classification accuracy. It generates rules, which are...