Synthesis of a 3-hydroxyl-free N-acetyl glucosamine disaccharide

A simple and alternative route to a versatile N-acetyl glucosamine disaccharide building block was developed, possessing a free 3-hydroxyl group. In this strategy, the 2,2,2-trichloro-ethoxy carbonyl (Troc) group was used as an amino-and 3-hydroxyl-protecting group.publishersversionpublishe

Assembly of peptidoglycan fragments: a synthetic challenge

SFRH/BD/52207/2013 PTDC/BIA-MIC/30746/2017 UID/QUI/50006/2019 POCI-01-0145-FEDER-007265 UID/Multi/04378/2019Peptidoglycan (PGN) is a major constituent of most bacterial cell walls that is recognized as a primary target of the innate immune system. The availability of pure PGN molecules has become key to different biological studies. This review aims to (1) provide an overview of PGN biosynthesis, focusing on the main biosynthetic intermediates; (2) focus on the challenges for chemical synthesis posed by the unique and complex structure of PGN; and (3) cover the synthetic routes of PGN fragments developed to date. The key difficulties in the synthesis of PGN molecules mainly involve stereoselective glycosylation involving NAG derivatives. The complex synthesis of the carbohydrate backbone commonly involves multistep sequences of chemical reactions to install the lactyl moiety at the O-3 position of NAG derivatives and to control enantioselective glycosylation. Recent advances are presented and synthetic routes are described according to the main strategy used: (i) based on the availability of starting materials such as glucosamine derivatives; (ii) based on a particular orthogonal synthesis; and (iii) based on the use of other natural biopolymers as raw materials.publishersversionpublishe

application in C-H activation catalysis

This work was supported by the Spanish Government, the Spanish National Research Council (CSIC). We also thank Dr Martinez from Novozymes. Publisher Copyright: © 2023 RSC.The effect of the temperature in the synthesis of Pd nanoparticles in the metal-enzyme biohybrids is evaluated. The effect on the formation, size, and morphology of nanoparticles was evaluated using C. antarctica B lipase as the protein scaffold. XRD analyses confirmed the formation of crystalline Pd(0) as the metal species in all cases. TEM analyses revealed spherical crystalline nanoparticles with average diameter size from 2 nm at 4 °C synthesis to 10 nm obtained at 50 °C synthesis. The thermal phenomenon was also critical in the final hybrid formation using more complex enzymes, where the relation of the protein structure and temperature and the influence of the latter has been demonstrated to be critical in the reducing efficiency of the enzyme in the final Pd nanoparticle formation, in the metal species, or even in the final size of the nanoparticles. Different Pd biohybrids were evaluated as catalysts in the C-H activation of protected l-tryptophan under mild conditions. Pd@CALB4 showed the best results, with >99% conversion for C-2 arylation in methanol at room temperature with a TOF value of 64 min−1, being 2 or 4 times higher than that of the other synthesized hybrids. This catalyst showed a very high stability and recyclability, maintaining >95% activity after three cycles of use.publishersversionpublishe

Sulfonic Acid-Functionalized (Bio)Materials as Catalysts for Efficient Amide Bond Synthesis

Funding Information: The authors thank Fundação para a Ciência e Tecnologia (FC&T) for project PTDC/BII‐BIO/30884/2017 and EXPL/BII‐BIO/0436/2021 and also for the researcher contract 2021.03255.CEECIND (M.C.C) and 2020.01614.CEECIND/CP1596/CT0007 (A.F.P.). Authors also thank the support by the Associate Laboratory for Green Chemistry – LAQV, which is financed by national funds from FCT/MCTES (UIDB/50006/2020 and UIDP/50006/2020) and i3 N (LA/P/0037/2020, UIDP/50025/2020 and UIDB/50025/2020 . The National NMR Facility is supported by FC&T (ROTEIRO/0031/2013 – PINFRA/22161/2016, co‐financed by FEDER through COMPETE 2020, POCI, and PORL and FC&T through PIDDAC) and CERMAX through project 022162. We thank Prof. Dr. Carlos A. M. Afonso from the Faculty of Pharmacy, ULisboa for the scientific discussions on the experiments carried out with furfuryl alcohol derivatives. Publisher Copyright: © 2023 The Authors. ChemCatChem published by Wiley-VCH GmbH.Sulfonic acid carbon-(bio)based and natural clays-based catalysts were prepared and investigated for the first time as heterogeneous catalysts for amide bond synthesis by a Ritter reaction. The different SO3H-catalysts were screened using benzyl alcohol and acetonitrile as model substrates, and MWCNT-CSP revealed to be an efficient catalyst, affording the amide in 75 % yield. The practical utility of the catalysts was demonstrated by a diverse range of amides, obtained from alcohols and nitriles, in moderate to good yields. Biomass derived platform alcohols, such as 5-HMF and furfuryl alcohol, were also tested as potential building blocks for the synthesis of biopolymers. The SO3H-catalysts revealed to be a highly efficient and environmentally friendly alternative to the conventional acid catalysts commonly used in the Ritter reaction.publishersversionpublishe

Evaluation of dentinogenesis inducer biomaterials: an in vivo study

When exposure of the pulp to external environment occurs, reparative dentinogenesis can be induced by direct pulp capping to maintain pulp tissue vitality and function. These clinical situations require the use of materials that induce dentin repair and, subsequently, formation of a mineralized tissue. Objective: This work aims to assess the effect of tricalcium silicate cements and mineral trioxide aggregate cements, including repairing dentin formation and inflammatory reactions over time after pulp exposure in Wistar rats. Methodology: These two biomaterials were compared with positive control groups (open cavity with pulp tissue exposure) and negative control groups (no intervention). The evaluations were performed in three stages; three, seven and twenty-one days, and consisted of an imaging (nuclear medicine) and histological evaluation (H&E staining, immunohistochemistry and Alizarin Red S). Results: The therapeutic effect of these biomaterials was confirmed. Nuclear medicine evaluation demonstrated that the uptake of 99mTc-Hydroxymethylene diphosphonate (HMDP) showed no significant differences between the different experimental groups and the control, revealing the non-occurrence of differences in the phosphocalcium metabolism. The histological study demonstrated that in mineral trioxide aggregate therapies, the presence of moderate inflammatory infiltration was found after three days, decreasing during follow-ups. The formation of mineralized tissue was only verified at 21 days of follow-up. The tricalcium silicate therapies demonstrated the presence of a slight inflammatory infiltration on the third day, increasing throughout the follow-up. The formation of mineralized tissue was observed in the seventh follow-up day, increasing over time. Conclusions: The mineral trioxide aggregate (WhiteProRoot®MTA) and tricalcium silicate (Biodentine™) present slight and reversible inflammatory signs in the pulp tissue, with the formation of mineralized tissue. However, the exacerbated induction of mineralized tissue formation with the tricalcium silicate biomaterial may lead to the formation of pulp calcifications

Fiber cavity ring down and gain amplification effect

The effect of an erbium-doped fiber amplifier (EDFA) placed inside the fiber ring of a cavity ring down (CRD) configuration is studied. The limitations and advantages of this configuration are discussed, and the study of the ring-down time as a function of the current applied and gain to the EDFA is also presented. In this case, the power fluctuations in the output signal are strongly dependent on the cavity ring-down time with the EDFA gain.This work was supported by Project "CORAL – Sustainable Ocean Exploitation: Tools and Sensors, NORTE-01-0145-FEDER-000036, financed by the North Portugal Regional Operational Programme (NORTE 2020), under the PORTUGAL 2020 Partnership Agreement, and through the European Regional Development Fund (ERDF). S.S. received a Pos-Doc fellowship (ref. SFRH/BPD/92418/2013) also funded by FCT – Portuguese national funding agency for science, research and technology

Multi-step subcritical water extracts of fucus vesiculosus l. And codium tomentosum stackhouse: Composition, health-benefits and safety

PO-CI-01-0145FEDER-030240Mental health and active aging are two of the main concerns in the 21st century. To search for new neuroprotective compounds, extracts of Codium tomentosum Stackhouse and Fucus vesiculosus L. were obtained through multi-step (four step) subcritical water extraction using a temperature gradient. The safety assessment of the extracts was performed by screening pharmaceutical compounds and pesticides by UHPLC-MS/MS, and iodine and arsenic levels by ICP-MS. Although the extracts were free of pharmaceutical compounds and pesticides, the presence of arsenic and high iodine contents were found in the first two extraction steps. Thus, the health-benefits were only evaluated for the fractions obtained in steps 3 and 4 from the extraction process. These fractions were tested against five brain enzymes implicated in Alzheimer’s, Parkinson’s, and major depression etiology as well as against reactive oxygen and nitrogen species, having been observed a strong enzyme inhibition and radical scavenging activities for the step 4 fractions from both seaweed species. Regarding the variation of the chemical composition during the extraction, step 1 fractions were the richest in phenolic compounds. With the increase in temperature, Maillard reaction, caramelization and thermo-oxidation occurred, and the resulting products positively affected the antioxidant capacity and the neuroprotective effects.publishersversionpublishe

Wilms Tumor 1b Expression Defines a Pro-regenerative Macrophage Subtype and Is Required for Organ Regeneration in the Zebrafish

Organ regeneration is preceded by the recruitment of innate immune cells, which play an active role during repair and regrowth. Here, we studied macrophage subtypes during organ regeneration in the zebrafish, an animal model with a high regenerative capacity. We identified a macrophage subpopulation expressing Wilms tumor 1b (wt1b), which accumulates within regenerating tissues. This wt1b+ macrophage population exhibited an overall pro-regenerative gene expression profile and different migratory behavior compared to the remainder of the macrophages. Functional studies showed that wt1b regulates macrophage migration and retention at the injury area. Furthermore, wt1b-null mutant zebrafish presented signs of impaired macrophage differentiation, delayed fin growth upon caudal fin amputation, and reduced cardiomyocyte proliferation following cardiac injury that correlated with altered macrophage recruitment to the regenerating areas. We describe a pro-regenerative macrophage subtype in the zebrafish and a role for wt1b in organ regeneration.A.B.G.-R. is supported by the Sara Borrell Program (CD11/00165) and CIBER de Enfermedades Cardiovasculares (CB16/11/00286). H.R. was supported by a short-term EMBO fellowship (EMBOSTF7204). I.J.M. was supported by a Marie-Sklodowska-Curie postdoctoral fellowship (PIEF-GA-2012-330728). N.M. is supported by Swiss National Science Foundation grant 31003A_15972 and the European Research Council (starting grant 337703–zebra–Heart). The CNIC is supported by the Instituto de Salud Carlos III (ISCIII), the Ministerio de Ciencia, Innovacio´ n, y Universidades (MCNU), and the Pro CNIC Foundation AGRADECIENTOS: ProCNIC; Severo Ochoa (SEV-2015-0505)S

IL-10 overexpression predisposes to invasive aspergillosis by suppressing antifungal immunity

© 2017 American Academy of Allergy, Asthma & ImmunologyProinflammatory immune responses are critically required for antimicrobial host defenses; however, excessive inflammation has the potential to damage host tissues thereby paradoxically contributing to the progression of infection. A central negative regulator of inflammatory responses is IL-10, an immunosuppressive cytokine with a wide variety of functions across multiple cell types. Although the role of IL-10 during infection appears to vary for different microorganisms, a largely detrimental role has been attributed to this cytokine during fungal disease. Given the variable risk of infection and its outcome among patients with comparable predisposing factors, susceptibility to invasive aspergillosis (IA) is thought to rely largely on genetic predisposition. The initial investigation of genetic variability at the IL10 locus led to the identification of single nucleotide polymorphisms (SNPs) influencing its transcriptional activity; thus, IL-10 may be a reasonable candidate for the genetic regulation of susceptibility to IA in high-risk patients.Supported by the Northern Portugal Regional Operational Programme (NORTE 2020), under the Portugal 2020 Partnership Agreement, through the European Regional Development Fund (FEDER) (NORTE-01-0145-FEDER-000013), the Fundação para a Ciência e Tecnologia (FCT) (contracts IF/00735/2014 to A.C., IF/01390/2014 to E.T., IF/00021/2014 to R.S., and SFRH/BPD/96176/2013 to C.C.), the Conselho de Reitores das Universidades Portuguesas (CRUP), Portugal (Ações Integradas Luso-Alemãs A-43/16), the Deutscher Akademischer Austauschdienst (DAAD) (project-ID 57212690), the Fondo de Investigaciones Sanitarias (Madrid, Spain) (grant #PI12/02688) and the ERA-NET PathoGenoMics (grant #0315900A).info:eu-repo/semantics/publishedVersio

Factors influencing terrestriality in primates of the Americas and Madagascar

Among mammals, the order Primates is exceptional in having a high taxonomic richness in which the taxa are arboreal, semiterrestrial, or terrestrial. Although habitual terrestriality is pervasive among the apes and African and Asian monkeys (catarrhines), it is largely absent among monkeys of the Americas (platyrrhines), as well as galagos, lemurs, and lorises (strepsirrhines), which are mostly arboreal. Numerous ecological drivers and species-specific factors are suggested to set the conditions for an evolutionary shift from arboreality to terrestriality, and current environmental conditions may provide analogous scenarios to those transitional periods. Therefore, we investigated predominantly arboreal, diurnal primate genera from the Americas and Madagascar that lack fully terrestrial taxa, to determine whether ecological drivers (habitat canopy cover, predation risk, maximum temperature, precipitation, primate species richness, human population density, and distance to roads) or species-specific traits (bodymass, group size, and degree of frugivory) associate with increased terrestriality. We collated 150,961 observation hours across 2,227 months from 47 species at 20 sites in Madagascar and 48 sites in the Americas. Multiple factors were associated with ground use in these otherwise arboreal species, including increased temperature, a decrease in canopy cover, a dietary shift away from frugivory, and larger group size. These factors mostly explain intraspecific differences in terrestriality. As humanity modifies habitats and causes climate change, our results suggest that species already inhabiting hot, sparsely canopied sites, and exhibiting more generalized diets, are more likely to shift toward greater ground use