Browse
Submit Data
Databases
API
Help

Dataset Information

15 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Oxidation of peptides by methyl(trifluoromethyl)dioxirane: the protecting group matters.

ABSTRACT: Representative Boc-protected and acetyl-protected peptide methyl esters bearing alkyl side chains undergo effective oxidation using methyl(trifluoromethyl)dioxirane (1b) under mild conditions. We observe a protecting group dependency in the chemoselectivity displayed by the dioxirane 1b. N-Hydroxylation occurs in the case of the Boc-protected peptides, and side chain hydroxylation takes place in the case of acetyl-protected peptides. Both are attractive transformations since they yield derivatized peptides that serve as valuable synthons.

SUBMITTER: Rella MR

PROVIDER: S-EPMC3220948 | biostudies-other | 2007 Jan

REPOSITORIES: biostudies-other

ACCESS DATA

Json Xml

Publications

Oxidation of peptides by methyl(trifluoromethyl)dioxirane: the protecting group matters.

Rella Maria Rosaria MR Williard Paul G PG

The Journal of organic chemistry 20070101 2

Representative Boc-protected and acetyl-protected peptide methyl esters bearing alkyl side chains undergo effective oxidation using methyl(trifluoromethyl)dioxirane (1b) under mild conditions. We observe a protecting group dependency in the chemoselectivity displayed by the dioxirane 1b. N-Hydroxylation occurs in the case of the Boc-protected peptides, and side chain hydroxylation takes place in the case of acetyl-protected peptides. Both are attractive transformations since they yield derivatiz ...[more]

PMID: 17221970

Similar Datasets

Polymerization of Protecting-Group-Free Peptides via ROMP.

Project description:A study was conducted to survey the tolerance of ring-opening metathesis polymerization (ROMP) with respect to amino acid (a.a) identity of pentapeptide-modified norbornene-based monomers. A library of norbornyl-pentapeptides were prepared with the general structure, norbornyl-GX2PLX5, where residue 'X' was changed at each of the two positions (2 or 5) alternately to consist of the natural amino acids F, A, V, R, S, K, N, T, M, Q, H, W, C, Y, E, Q, and D. Each peptide monomer, free of protecting groups, was mixed in turn under a standard set of polymerization conditions with the ROMP initiator (IMesH2)C5H5N)2(Cl)2Ru=CHPh. Two sets of polymerization reactions were performed, one with Monomer:Initiator (M:I) ratio of 20:1, and another with M:I of 200:1. For the nucleophilic amino acids cysteine and lysine, polymerization reactions were quantitatively compared to those of their protected analogues. Furthermore, we describe polymerization of macromonomers containing up to 30 a.a. to test for tolerance of ROMP to peptide molecular weight. These reactions were studied via SEC-MALS and NMR. Finally, with knowledge of sequence scope in hand, we prepared a set of enzyme-substrate containing brush polymers and studied them with respect to their bioactivity.

| S-EPMC3762507 | biostudies-literature

Protecting group free radical C-H trifluoromethylation of peptides.

Project description:Two radical-based approaches have been developed to effect the trifluoromethylation of aryl C-H bonds in native peptides either using stoichiometric oxidant or visible light photoredox catalysis. The reported methods are able to derivatize tyrosine and tryptophan sidechains under biocompatible conditions, and a number of examples are reported involving fully unprotected peptides with up to 51 amino acids. The development of this chemistry adds to the growing array of chemical methods for selectively modifying amino acid residues in the context of complex peptides. The direct incorporation of trifluoromethyl groups into biopolymers enables the study of a range of biological and biochemical systems, and preliminary results indicate this method can be extended to the incorporation of other fluoroalkyl groups for bioconjugation applications.

| S-EPMC5941281 | biostudies-literature

Protecting biodiversity when money matters: maximizing return on investment.

Project description:BackgroundConventional wisdom identifies biodiversity hotspots as priorities for conservation investment because they capture dense concentrations of species. However, density of species does not necessarily imply conservation 'efficiency'. Here we explicitly consider conservation efficiency in terms of species protected per dollar invested.Methodology/principal findingsWe apply a dynamic return on investment approach to a global biome and compare it with three alternate priority setting approaches and a random allocation of funding. After twenty years of acquiring habitat, the return on investment approach protects between 32% and 69% more species compared to the other priority setting approaches. To correct for potential inefficiencies of protecting the same species multiple times we account for the complementarity of species, protecting up to three times more distinct vertebrate species than alternate approaches.Conclusions/significanceIncorporating costs in a return on investment framework expands priorities to include areas not traditionally highlighted as priorities based on conventional irreplaceability and vulnerability approaches.

| S-EPMC2212107 | biostudies-literature

Synthesis of glutamic acid and glutamine peptides possessing a trifluoromethyl ketone group as SARS-CoV 3CL protease inhibitors.

Project description:Trifluoromethyl-?-amino alcohol 11 [(4S)-tert-butyl 4-amino-6,6,6-trifluoro-5-hydroxyhexanoate] was synthesized in five steps starting from Cbz-l-Glu-OH 5 where the key step involved the introduction of the trifluoromethyl (CF3) group to oxazolidinone 7, resulting in the formation of silyl ether 8 [(4S,5S)-benzyl 4-(2-(tert-butoxycarbonyl)ethyl)-5-(trifluoromethyl)-5-(trimethylsilyloxy)oxazolidine-3-carboxylate]. Compound 11 was then converted into four tri- and tetra-glutamic acid and glutamine peptides (1-4) possessing a CF3-ketone group that exhibited inhibitory activity against severe acute respiratory syndrome coronavirus protease (SARS-CoV 3CLpro).

| S-EPMC7111793 | biostudies-literature

A Catalytic Approach for Enantioselective Synthesis of Homoallylic Alcohols Bearing a <i>Z</i>-Alkenyl Chloride or Trifluoromethyl Group. A Concise and Protecting Group-Free Synthesis of Mycothiazole.

Project description:A protecting group-free strategy is presented for diastereo- and enantioselective routes that can be used to prepare a wide variety of Z-homoallylic alcohols with significantly higher efficiency than is otherwise feasible. The approach entails the merger of several catalytic processes and is expected to facilitate the preparation of bioactive organic molecules. More specifically, Z-chloro-substituted allylic pinacolatoboronate is first obtained through stereoretentive cross-metathesis between Z-crotyl-B(pin) (pin = pinacolato) and Z-dichloroethene, both of which are commercially available. The organoboron compound may be used in the central transformation of the entire approach, an α- and enantioselective addition to an aldehyde, catalyzed by a proton-activated, chiral aminophenol-boryl catalyst. Catalytic cross-coupling can then furnish the desired Z-homoallylic alcohol in high enantiomeric purity. The olefin metathesis step can be carried out with substrates and a Mo-based complex that can be purchased. The aminophenol compound that is needed for the second catalytic step can be prepared in multigram quantities from inexpensive starting materials. A significant assortment of homoallylic alcohols bearing a Z-F3C-substituted alkene can also be prepared with similar high efficiency and regio-, diastereo-, and enantioselectivity. What is more, trisubstituted Z-alkenyl chloride moiety can be accessed with similar efficiency albeit with somewhat lower α-selectivity and enantioselectivity. The general utility of the approach is underscored by a succinct, protecting group-free, and enantioselective total synthesis of mycothiazole, a naturally occurring anticancer agent through a sequence that contains a longest linear sequence of nine steps (12 steps total), seven of which are catalytic, generating mycothiazole in 14.5% overall yield.

| S-EPMC7017881 | biostudies-literature

Concerning selectivity in the oxidation of peptides by dioxiranes. Further insight into the effect of carbamate protecting groups.

Project description:With use of methyl(trifluoromethyl)dioxirane (TFDO), the oxidation of some tripeptide esters protected at the N-terminus with carbamate or amide groups could be achieved efficiently under mild conditions with no loss of configuration at the chiral centers. Expanding on preliminary investigations, it is found that, while peptides protected with amide groups (PG = Ac-, Tfa-, Piv-) undergo exclusive hydroxylation at the side chain, their analogues bearing a carbamate group (PG = Cbz-, Moc-, Boc-, TcBoc-) give competitive and/or concurrent hydroxylation at the terminal N-H moiety. Valuable nitro derivatives are also formed as a result of oxidative deprotection of the carbamate group with excess dioxirane. A rationale is proposed to explain the dependence of the selectivity upon the nature of the protecting group.

| S-EPMC2922685 | biostudies-other

A Divalent Protecting Group for Benzoxaboroles.

Project description:1-Dimethylamino-8-methylaminonaphthalene is put forth as a protecting group for benzoxaboroles. The ensuing complex is fluorescent, charge-neutral, highly stable under basic conditions, stable to anhydrous acid, and readily cleavable in aqueous acid to return the free benzoxaborole.

| S-EPMC3910298 | biostudies-literature

AIF inhibits tumor metastasis by protecting PTEN from oxidation.

Project description:Apoptosis-inducing factor (AIF) exerts dual roles on cell death and survival, but its substrates as a putative oxidoreductase and roles in tumorigenesis remain elusive. Here, we report that AIF physically interacts with and inhibits the oxidation of phosphatase and tensin homolog on chromosome ten (PTEN), a tumor suppressor susceptible for oxidation-mediated inactivation. More intriguingly, we also identify PTEN as a mitochondrial protein and the ectopic expression of mitochondrial targeting sequence-carrying PTEN almost completely inhibits Akt phosphorylation in PTEN-deficient cells. AIF knockdown causes oxidation-mediated inactivation of the lipid phosphatase activity of PTEN, with ensuing activation of Akt kinase, phosphorylation of the Akt substrate GSK-3β, and activation of β-catenin signaling in cancer cells. Through its effect on β-catenin signaling, AIF inhibits epithelial-mesenchymal transition (EMT) and metastasis of cancer cells in vitro and in orthotopically implanted xenografts. Accordingly, the expression of AIF is correlated with the survival of human patients with cancers of multiple origins. These results identify PTEN as the substrate of AIF oxidoreductase and reveal a novel function for AIF in controlling tumor metastasis.

| S-EPMC4641507 | biostudies-literature

Nitrodibenzofuran: A One- and Two-Photon Sensitive Protecting Group That Is Superior to Brominated Hydroxycoumarin for Thiol Caging in Peptides.

Project description:Photoremovable protecting groups are important for a wide range of applications in peptide chemistry. Using Fmoc-Cys(Bhc-MOM)-OH, peptides containing a Bhc-protected cysteine residue can be easily prepared. However, such protected thiols can undergo isomerization to a dead-end product (a 4-methylcoumarin-3-yl thioether) upon photolysis. To circumvent that photoisomerization problem, we explored the use of nitrodibenzofuran (NDBF) for thiol protection by preparing cysteine-containing peptides where the thiol is masked with an NDBF group. This was accomplished by synthesizing Fmoc-Cys(NDBF)-OH and incorporating that residue into peptides by standard solid-phase peptide synthesis procedures. Irradiation with 365 nm light or two-photon excitation with 800 nm light resulted in efficient deprotection. To probe biological utility, thiol group uncaging was carried out using a peptide derived from the protein K-Ras4B to yield a sequence that is a known substrate for protein farnesyltransferase; irradiation of the NDBF-caged peptide in the presence of the enzyme resulted in the formation of the farnesylated product. Additionally, incubation of human ovarian carcinoma (SKOV3) cells with an NDBF-caged version of a farnesylated peptide followed by UV irradiation resulted in migration of the peptide from the cytosol/Golgi to the plasma membrane due to enzymatic palmitoylation. Overall, the high cleavage efficiency devoid of side reactions and significant two-photon cross-section of NDBF render it superior to Bhc for thiol group caging. This protecting group should be useful for a plethora of applications ranging from the development of light-activatable cysteine-containing peptides to the development of light-sensitive biomaterials.

| S-EPMC5026405 | biostudies-literature

Epoc group: transformable protecting group with gold(iii)-catalyzed fluorene formation.

Project description:This study presents the novel concept of a transformable protecting group, which changes its properties through structural transformation. Based on this concept, we developed a 2-(2-ethynylphenyl)-2-(5-methylfuran-2-yl)-ethoxycarbonyl (Epoc) group. The Epoc group was transformed into an Fmoc-like structure with gold(iii)-catalyzed fluorene formation and was removable under Fmoc-like mild basic conditions post-transformation even though it was originally stable under strongly basic conditions. As an application for organic synthesis, the Epoc group provides the novel orthogonality of gold(iii)-labile protecting groups in solid-phase peptide synthesis. In addition, the high turnover number of fluorene formation in aqueous media is suggestive of the applicability of the Epoc group to biological systems.

| S-EPMC8372321 | biostudies-literature

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data