Monofluoroalkenes are versatile fluorinated synthons in organic synthesis, medicinal chemistry and materials science. In light of the importance of alkyl-substituted monofluoroalkenes efficient ...synthesis of these moieties still represents a synthetic challenge. Herein, we described a mild and efficient methodology to obtain monofluoroalkenes through a stereospecific palladium-catalyzed alkylation of
-bromofluoroalkenes with primary and strained secondary alkylboronic acids under mild conditions. This novel strategy gives access to a wide range of functionalized tri- and tetrasubstituted monofluoroalkenes in high yield, with good functional group tolerance, independently from the
-bromofluoroalkenes geometry.
Modern scientific research produces datasets of increasing size and complexity that require dedicated numerical methods to be processed. In many cases, the analysis of spectroscopic data involves the ...denoising of raw data before any further processing. Current efficient denoising algorithms require the singular value decomposition of a matrix with a size that scales up as the square of the data length, preventing their use on very large datasets. Taking advantage of recent progress on random projection and probabilistic algorithms, we developed a simple and efficient method for the denoising of very large datasets. Based on the QR decomposition of a matrix randomly sampled from the data, this approach allows a gain of nearly three orders of magnitude in processing time compared with classical singular value decomposition denoising. This procedure, called urQRd (uncoiled random QR denoising), strongly reduces the computer memory footprint and allows the denoising algorithm to be applied to virtually unlimited data size. The efficiency of these numerical tools is demonstrated on experimental data from high-resolution broadband Fourier transform ion cyclotron resonance mass spectrometry, which has applications in proteomics and metabolomics. We show that robust denoising is achieved in 2D spectra whose interpretation is severely impaired by scintillation noise. These denoising procedures can be adapted to many other data analysis domains where the size and/or the processing time are crucial.
Nod-Like Receptor Pyrin domain-containing protein 6 (NLRP6), a member of the Nucleotide-oligomerization domain-Like Receptor (NLR) family of proteins, assembles together with the ASC protein to form ...an inflammasome upon stimulation by bacterial lipoteichoic acid and double-stranded DNA. Besides its expression in myeloid cells, NLRP6 is also expressed in intestinal epithelial cells where it may contribute to the maintenance of gut homeostasis and negatively controls colorectal tumorigenesis. Here, we report that NLRP6 is very faintly expressed in several colon cancer cell lines, detected only in cytoplasmic small dots were it colocalizes with ASC. Consequently, it is very hardly detected by standard western-blotting techniques by several presently available commercial antibodies which, in contrast, highly cross-react with a protein of 90kDa that we demonstrate to be unrelated to NLRP6. We report here these results to caution the community not to confuse the 90kDa protein with the endogenous human NLRP6.
Starch bound proteins mainly include enzymes from the starch biosynthesis pathway. Recently, new functions in starch molecular assembly or active protein targeting were also proposed for starch ...associated proteins. The potato genome sequence reveals 77 loci encoding starch metabolizing enzymes with the identification of previously unknown putative isoforms. Here we show by bottom-up proteomics that most of the starch biosynthetic enzymes in potato remain associated with starch even after washing with SDS or protease treatment of the granule surface. Moreover, our study confirmed the presence of PTST1 (Protein Targeting to Starch), ESV1 (Early StarVation1) and LESV (Like ESV), that have recently been identified in Arabidopsis. In addition, we report on the presence of a new isoform of starch synthase, SS6, containing both K-X-G-G-L catalytic motifs. Furthermore, multiple protease inhibitors were also identified that are cleared away from starch by SDS and thermolysin treatments. Our results indicate that SS6 may play a yet uncharacterized function in starch biosynthesis and open new perspectives both in understanding storage starch metabolism as well as breeding improved potato lines.
An approach based on combinations of various water compatible Lewis acids and l-proline co-catalysts has been evaluated for the direct asymmetric aldol reaction. From this broad screening, chloride ...salts from group 12 elements (ZnCl2, CdCl2, HgCl2) lead to the highest stereoselectivities. Optimized catalytic conditions (catalytic system: l-proline: 20%/ZnCl2: 10%; solvent mixture: DMSO/H2O, 8:2) gave anti aldol products with improved enantioselectivity (>99% ee) compared to a moderately stereoselective procedure based on proline activation only.
Abstract
We provide an original multi-stage approach identifying a gene signature to assess murine fibroblast polarization. Prototypic polarizations (inflammatory/fibrotic) were induced by seeded ...mouse embryonic fibroblasts (MEFs) with TNFα or TGFß1, respectively. The transcriptomic and proteomic profiles were obtained by RNA microarray and LC-MS/MS. Gene Ontology and pathways analysis were performed among the differentially expressed genes (DEGs) and proteins (DEPs). Balb/c mice underwent daily intradermal injections of HOCl (or PBS) as an experimental murine model of inflammation-mediated fibrosis in a time-dependent manner. As results, 1456 and 2215 DEGs, and 289 and 233 DEPs were respectively found in MEFs in response to TNFα or TGFß1, respectively
.
Among the most significant pathways, we combined 26 representative genes to encompass the proinflammatory and profibrotic polarizations of fibroblasts. Based on principal component analysis, this signature deciphered baseline state, proinflammatory polarization, and profibrotic polarization as accurately as RNA microarray and LC-MS/MS did. Then, we assessed the gene signature on dermal fibroblasts isolated from the experimental murine model. We observed a proinflammatory polarization at day 7, and a mixture of a proinflammatory and profibrotic polarizations at day 42 in line with histological findings. Our approach provides a small-size and convenient gene signature to assess murine fibroblast polarization.
We describe here the determination of the alkylation rate of a set of organic superbases by iodomethane in DMF using a microfluidic continuous flow reactor. Surprisingly, log k(Alkylation) follows ...the inverse trend of pK(BH+) of the base. Mayr's equation allows a more quantitative approach. From a synthetic point of view, TMGN and BEMP are demonstrated to be the best choices.
This study proposes a proteomic-based strategy for the identification of the origin species of glues used as binding media and adhesives in artworks. The methodology, based on FTICR high resolution ...mass spectrometry, was evaluated on glues from different animal origin (i.e., bovine, rabbit, and fish). The analysis of the peptide mixture resulting from the enzymatic hydrolysis of the proteins led to the identification of species-specific peptides. Up to 15 specific peptides were identified for the bovine species and three for the rabbit species and, in the case of sturgeon glue, three fish-specific peptides were found by sequence homology to the rainbow trout. Then, the method was applied to authenticate different rabbit skin glue samples, including a 100 year-old sample named “Colle à Doreurs” coming from the “Maison Totin-Frères”. For this sample, two specific peptides of rabbit collagen were identified. To evaluate the method in a complex matrix, model paints composed of lead white, linseed oil, and animal glue were prepared. Species-specific peptides were identified in each paint sample. Finally, a gilt sample from St Maximin church dating from the eighteenth century was analyzed, and 13 peptides specific to bovine collagens were identified starting from very low sample amount (50 μg).
Autoantibodies (Aabs) are frequent in systemic sclerosis (SSc). Although recognized as potent biomarkers, their pathogenic role is debated. This study explored the effect of purified immunoglobulin G ...(IgG) from SSc patients on protein and mRNA expression of dermal fibroblasts (FBs) using an innovative multi-omics approach. Dermal FBs were cultured in the presence of sera or purified IgG from patients with diffuse cutaneous SSc (dcSSc), limited cutaneous SSc or healthy controls (HCs). The FB proteome and transcriptome were explored using liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) and microarray assays, respectively. Proteomic analysis identified 3,310 proteins. SSc sera and purified IgG induced singular protein profile patterns. These FB proteome changes depended on the Aab serotype, with a singular effect observed with purified IgG from anti-topoisomerase-I autoantibody (ATA) positive patients compared to HC or other SSc serotypes. IgG from ATA positive SSc patients induced enrichment in proteins involved in focal adhesion, cadherin binding, cytosolic part, or lytic vacuole. Multi-omics analysis was performed in two ways: first by restricting the analysis of the transcriptomic data to differentially expressed proteins; and secondly, by performing a global statistical analysis integrating proteomics and transcriptomics. Transcriptomic analysis distinguished 764 differentially expressed genes and revealed that IgG from dcSSc can induce extracellular matrix (ECM) remodeling changes in gene expression profiles in FB. Global statistical analysis integrating proteomics and transcriptomics confirmed that IgG from SSc can induce ECM remodeling and activate FB profiles. This effect depended on the serotype of the patient, suggesting that SSc Aab might play a pathogenic role in some SSc subsets.
An efficient continuous‐flow protocol for C–O and C–C bond formation from organoborates by photoredox catalysis under UV irradiation was explored. The combination of a cyclometalated iridium ...photocatalyst, high‐power UV light‐emitting diode irradiation, and microreactor technology resulted in very efficient radical generation. The flow device enabled determination of highly accurate kinetic data that allowed the observation of good correlations with the standard Hammett σ (–0.26 to 0.227) values for a wide variety of substituents on the benzyl moiety (ϱ = –4.70, R2 = 0.98). Good to excellent yields were obtained for a variety of substrates by applying significantly short residence times.
A continuous‐flow protocol for C–O/C–C bond formation from organoborates by photoredox catalysis under UV irradiation is presented. The combination of a cyclometalated iridium photocatalyst and high‐power (HP) UV light‐emitting diodes (LEDs) with a simple microreactor results in radical generation with yields similar to those of the known batch procedure but with remarkably shorter reaction times.
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