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1.
Nature ; 616(7958): 663-664, 2023 04.
Artículo en Inglés | MEDLINE | ID: mdl-37100936
2.
J Am Chem Soc ; 145(31): 17211-17219, 2023 Aug 09.
Artículo en Inglés | MEDLINE | ID: mdl-37498188

RESUMEN

Butenolides are a class of 5-membered lactones that hold great potential as bio-based monomers to replace oil-derived acrylates, of which they are cyclic analogues. Despite this structural resemblance, the reactivity of the unsaturated ester moiety of electron-poor butenolides leans toward that of maleic anhydride, another essential monomer that does not homopolymerize but copolymerizes in a highly alternating fashion with polarized electron-rich comonomers. By studying the reactivity of 5-methoxy and 5-acyloxy butenolides through a combination of kinetics and density functional theory (DFT) experiments, we explain why electron-poor butenolides constitute a missing link between acrylates and maleic anhydride in radical polymerization.

3.
J Phys Chem A ; 127(6): 1387-1394, 2023 Feb 16.
Artículo en Inglés | MEDLINE | ID: mdl-36735995

RESUMEN

The detection and analysis of flavonoids by Raman spectroscopy are of interest in many fields, including medicinal chemistry, food science, and astrobiology. Spectral interpretation would benefit from better identification of the fingerprint vibrational peaks of different flavonoids and how they are affected by intermolecular interactions. The Raman spectra of two flavonoids, flavone and quercetin, were investigated through comparisons between spectra recorded from pure powders and spectra calculated with time dependent density functional theory (TDDFT). For both flavone and quercetin, 17 peaks were assigned to specific molecular vibrations. Both flavonoids were found to have a split peak between 1250-1350 cm-1 that is not predicted by TDDFT calculations on isolated molecules. In each case, it is shown that the addition of hydrogen bonded molecules arranged based on crystal structures reproduces the split peaks. These peaks were due to a stretching vibration of the bond between benzopyrone and phenyl rings and represent a characteristic spectral feature of flavonoids. Spectra of pollen grains from Quercus virginiana were also recorded and exhibit several peaks that correspond to the quercetin spectrum.

4.
Chembiochem ; 21(7): 943-947, 2020 04 01.
Artículo en Inglés | MEDLINE | ID: mdl-31621172

RESUMEN

We report a single-molecule radiotracer that can be labeled independently with 18 F-fluoride or radiometals (64 Cu, 177 Lu) in a single step. A prostate-specific membrane antigen (PSMA)-targeting ligand, armed with both an organotrifluoroborate and a metal-chelator (DOTA), was designed to optionally afford 18 F-, 64 Cu- or 177 Lu-labeled products that were injected into mice bearing prostate cancer (LNCaP) xenografts. PET/CT images and ex vivo biodistribution data show high, specific tumor uptake irrespective of which radionuclide is used, thereby demonstrating a new approach to combining, in a single molecule, 18 F-labeling capabilities for PET imaging with radiometalation for potential imaging and therapeutic applications.


Asunto(s)
Medicina de Precisión , Radiofármacos/química , Animales , Antígenos de Superficie/química , Línea Celular Tumoral , Radioisótopos de Cobre/química , Radioisótopos de Flúor/química , Glutamato Carboxipeptidasa II/química , Compuestos Heterocíclicos con 1 Anillo/química , Humanos , Ligandos , Lutecio/química , Masculino , Ratones , Tomografía Computarizada por Tomografía de Emisión de Positrones , Neoplasias de la Próstata/diagnóstico por imagen , Neoplasias de la Próstata/patología , Radioisótopos/química , Radiofármacos/metabolismo , Distribución Tisular , Trasplante Heterólogo
5.
Phys Rev Lett ; 125(12): 122502, 2020 Sep 18.
Artículo en Inglés | MEDLINE | ID: mdl-33016727

RESUMEN

Reliable neutron-induced-reaction cross sections of unstable nuclei are essential for nuclear astrophysics and applications but their direct measurement is often impossible. The surrogate-reaction method is one of the most promising alternatives to access these cross sections. In this work, we successfully applied the surrogate-reaction method to infer for the first time both the neutron-induced fission and radiative capture cross sections of ^{239}Pu in a consistent manner from a single measurement. This was achieved by combining simultaneously measured fission and γ-emission probabilities for the ^{240}Pu(^{4}He,^{4}He^{'}) surrogate reaction with a calculation of the angular-momentum and parity distributions populated in this reaction. While other experiments measure the probabilities for some selected γ-ray transitions, we measure the γ-emission probability. This enlarges the applicability of the surrogate-reaction method.

6.
Bioorg Med Chem Lett ; 30(2): 126796, 2020 01 15.
Artículo en Inglés | MEDLINE | ID: mdl-31757669

RESUMEN

Dysregulation of the ceramide transport protein CERT is associated to diseases such as cancer. In search for new CERT START domain ligands, N-dodecyl-deoxynojirimycin (N-dodecyl-DNJ) iminosugar was found to display, as a ceramide mimic, significant protein recognition. To reinforce the lipophilic interactions and strengthen this protein binding, a docking study was carried out in order to select the optimal position on which to introduce an additional O-alkyl chain on N-dodecyl-DNJ. Analysis of the calculated poses for three different regioisomers indicated an optimal calculated interaction pattern for N,O3-didodecyl-DNJ. The two most promising regioisomers were prepared by a divergent route and their binding to the CERT START domain was evaluated with fluorescence intensity (FLINT) binding assay. N,O3-didodecyl-DNJ was confirmed to be a new binder prototype with level of protein recognition in the FLINT assay comparable to the best known ligands from the alkylated HPA-12 series. This work opens promising perspectives for the development of new inhibitors of CERT-mediated ceramide trafficking.


Asunto(s)
Glucosamina/análogos & derivados , Proteínas Serina-Treonina Quinasas/química , 1-Desoxinojirimicina/química , 1-Desoxinojirimicina/metabolismo , Sitios de Unión , Ceramidas/metabolismo , Glucosamina/química , Glucosamina/metabolismo , Glicósido Hidrolasas/antagonistas & inhibidores , Glicósido Hidrolasas/metabolismo , Humanos , Ligandos , Simulación del Acoplamiento Molecular , Unión Proteica , Dominios Proteicos , Proteínas Serina-Treonina Quinasas/metabolismo , Estereoisomerismo , Termodinámica
7.
J Eur Acad Dermatol Venereol ; 34(5): 1065-1073, 2020 May.
Artículo en Inglés | MEDLINE | ID: mdl-31953902

RESUMEN

BACKGROUND: Although antiretroviral therapy (ART) has reduced the risk of Kaposi sarcoma (KS), KS cases still occur in HIV-infected people. OBJECTIVE: To describe all KS cases observed between 2010 and 2015 in a country with high ART coverage. METHODS: Retrospective study using longitudinal data from 44 642 patients in the French Dat'AIDS multicenter cohort. Patients' characteristics were described at KS diagnosis according to ART exposure and to HIV-plasma viral load (HIV-pVL) (≤50 or >50) copies/mL. RESULTS: Among the 209 KS cases diagnosed during the study period, 33.2% occurred in ART naïve patients, 17.3% in ART-experienced patients and 49.5% in patients on ART, of whom 23% for more than 6 months. Among these patients, 24 (11.5%) had HIV-pVL ≤50 cp/mL, and 16 (66%) were treated with a boosted-PI-based regimen. The distribution of KS localization did not differ by ART status nor by year of diagnosis. LIMITATIONS: Data on human herpesvirus 8, treatment modalities for KS and response rate were not collected. CONCLUSION: Half of KS cases observed in the study period occurred in patients not on ART, reflecting the persistence of late HIV diagnosis. Factors associated with KS in patients on ART with HIV-pVL ≤50 cp/mL remain to be explored.


Asunto(s)
Síndrome de Inmunodeficiencia Adquirida , Infecciones por VIH , Herpesvirus Humano 8 , Sarcoma de Kaposi , Infecciones por VIH/complicaciones , Infecciones por VIH/tratamiento farmacológico , Infecciones por VIH/epidemiología , Humanos , Estudios Retrospectivos , Sarcoma de Kaposi/epidemiología
8.
Proc Natl Acad Sci U S A ; 114(51): E10965-E10971, 2017 12 19.
Artículo en Inglés | MEDLINE | ID: mdl-29203650

RESUMEN

Newborns are at increased risk of jaundice, a condition in which excess bilirubin accumulates in blood. Left untreated, jaundice can lead to neurological impairment and death. Jaundice resulting from unconjugated hyperbilirubinemia is easily treated with exposure to blue light, and phototherapy systems have been developed for low-resource settings; however, there are no appropriate solutions to diagnose and monitor jaundice in these settings. To address this need we present BiliSpec, a low-cost reader and disposable lateral flow card designed to measure the concentration of total bilirubin from several drops of blood at the point of care. We evaluated the performance of BiliSpec, using blood from normal volunteers spiked with varying amounts of bilirubin; results measured using BiliSpec correlated well with a reference laboratory bilirubinometer (r = 0.996). We then performed a pilot clinical study using BiliSpec to measure total bilirubin in neonates at risk for jaundice at Queen Elizabeth Central Hospital in Blantyre, Malawi. Concentrations measured using BiliSpec correlated well with those measured using a laboratory reference standard in 94 patient samples ranging from 1.1 mg/dL to 23.0 mg/dL in concentration (r = 0.973). The mean difference between bilirubin levels measured with BiliSpec and the reference standard was 0.3 mg/dL (95[Formula: see text] CI: -1.7-2.2 mg/dL).


Asunto(s)
Ictericia Neonatal/diagnóstico , Pruebas en el Punto de Atención , Femenino , Recursos en Salud , Humanos , Recién Nacido , Malaui , Masculino , Monitoreo Fisiológico/instrumentación , Monitoreo Fisiológico/métodos , Reproducibilidad de los Resultados
9.
Ann Chir Plast Esthet ; 65(5-6): 447-478, 2020 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-32861540

RESUMEN

Lower extremity war wounds are characterized by high-energy trauma occasioning loss of complex and pluritissular substances. The support pipeline put into place by the French defense health service (SSA) is designed to rapidly evacuate the injured person from the scene of injury to mainland France, following initial surgery in the framework of a sequential tactic known as "Damage Control Surgery". This strategy is aimed at stabilizing the traumatized individual and enabling his evacuation. Patients are subsequently treated in a restorative surgery unit in a Hôpital d'Instruction des Armées (HIA), a level 1 trauma center (HIA Percy, HIA Saint-Anne) Cooperation between the plastic and orthopedic surgery specialties is essential insofar as it allows for surgical optimization aimed at saving the limb while restoring function to the greatest possible extent. Notwithstanding painstaking application of this common strategy, septic pseudoarthrosis remains the principal and most feared complication, at times rendering impossible any therapeutic solution other than amputation. Whether prosthetic or non-prosthetic, the rehabilitation provided by doctor/physiotherapists is conducive to patients' social and professional reintegration. The nation's duty to assist its wounded veterans is carried out with determination by the French defense ministry. As concerns lower extremity war wounds, the authors detail the reconstruction doctrine based on the 6/7/8/9 rule, in accordance with which strategies for repair of soft tissue and reconstruction of the lost bone substance have been developed.


Asunto(s)
Extremidad Inferior/lesiones , Personal Militar , Heridas Relacionadas con la Guerra/terapia , Algoritmos , Francia , Humanos , Extremidad Inferior/cirugía , Procedimientos de Cirugía Plástica/métodos , Heridas Relacionadas con la Guerra/cirugía
10.
BMC Infect Dis ; 19(1): 278, 2019 Mar 25.
Artículo en Inglés | MEDLINE | ID: mdl-30909885

RESUMEN

BACKGROUND: HIV pre-exposure prophylaxis (PrEP) was implemented in France in November 2015 based on individual-level risk factors for HIV infection. We evaluated the proportion of missed opportunities for PrEP among newly HIV-diagnosed people entering the Dat'AIDS cohort in 2016. METHODS: Multicenter retrospective analysis in 15 French HIV clinical centers of patients with a new diagnosis of HIV infection. Among them we differentiated patients according to the estimated date of infection: those occurring in the PrEP area (a previous negative HIV test in the last 12 months or those with an incomplete HIV-1 western blot (WB) with no HIV-1 anti-Pol-antibody at time of HIV diagnosis) and those in the pre-PrEP area (older infections). Epidemiological, biological and clinical data at HIV diagnosis were collected. Clinicians retrospectively identified potential eligibility for PrEP based on individual-level risk factors for HIV infection among those infected in the PrEP area. RESULTS: Among 966 patients with a new HIV diagnosis, 225 (23.3%) were infected in the PrEP area and 121 (53.8%) had complete data allowing evaluation of PrEP eligibility. Among them, 110 (91%) would have been eligible for PrEP, median age 31 years, with 68 (75.6%) born in France and 10 (11.1%) in Central/West Africa, with more than one previous STI in 19 (15.7%). The main eligibility criteria for PrEP were being a man who had sex with men or transgender 91 (82.7%) with at least one of the following criteria: unprotected anal sex with ≥2 partners in the last 6 months: 67 (60.9%); bacterial sexually transmitted infection in the last 12 months: 33 (30%); Use of psychoactive substances in a sexual context (chemsex): 16 (14.5%). PrEP was indicated for other HIV risk factors in 25 (22.7%). CONCLUSION: With 91% (110/121) of patients infected in the PrEP area eligible for PrEP, this study highlights the high potential of PrEP in avoiding new infection in France but also shows a persistent delay in HIV testing. Thus, an important limit on PrEP implementation in France could be insufficient screening and care access.


Asunto(s)
Fármacos Anti-VIH/uso terapéutico , Infecciones por VIH/prevención & control , Profilaxis Pre-Exposición , Serodiagnóstico del SIDA , Adulto , África Occidental , Estudios de Cohortes , Diagnóstico Tardío , Femenino , Francia , VIH-1 , Homosexualidad Masculina , Humanos , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Conducta Sexual , Parejas Sexuales , Personas Transgénero , Sexo Inseguro
11.
J Tissue Viability ; 28(4): 167-172, 2019 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-31288977

RESUMEN

OBJECTIVES: There is currently a low level of evidence for the impact of patient education on the management of patients with chronic neurological disease at risk of developing pressure ulcers. The objective of this study was to assess the impact of a patient education programme on pressure ulcer prevention in patients with chronic spinal cord injuries. MATERIALS AND METHODS: This study included adult patients with any spinal cord injury, regardless of the cause. Participants attended 2 group workshops focusing on pressure ulcer prevention. Various clinical data were gathered during an initial individual interview and at 3, 6 and 12 months, along with rating scale values from the Hospital Anxiety and Depression Scale, Rosenberg self-esteem scale, Schwarzer self-efficacy scale, a quality of life scale (SF-36) and the revised Skin Management Needs Assessment Checklist (Revised SMnac), which was used as the primary endpoint. RESULTS: Twenty patients were included in the study. The mean patient age was 52 years (SD: 9,8). Sixteen patients had traumatic spinal cord injuries, with a median injury duration of 234 months (IQR: 123-407). Seventy-five percent had had a pressure ulcer in the twelve months prior to the study. Patient education was shown to have a significant impact on skin management ability, with a highly significant increase in the overall revised SMnac score at 3 months. These results were stable over time, from 6 to 12 months. Six patients developed a pressure ulcer during the study (30%). CONCLUSION: This study supports the hypothesis that a therapeutic educational program conducted at the chronic phase in spinal cord injured individuals has an impact.


Asunto(s)
Educación del Paciente como Asunto/normas , Úlcera por Presión/prevención & control , Traumatismos de la Médula Espinal/complicaciones , Adulto , Anciano , Educación/métodos , Educación/normas , Educación/estadística & datos numéricos , Femenino , Francia , Humanos , Masculino , Persona de Mediana Edad , Educación del Paciente como Asunto/métodos , Educación del Paciente como Asunto/estadística & datos numéricos , Úlcera por Presión/psicología , Estudios Prospectivos , Psicometría/instrumentación , Psicometría/métodos , Calidad de Vida/psicología , Cuidados de la Piel/métodos , Cuidados de la Piel/normas , Traumatismos de la Médula Espinal/psicología
12.
Phys Rev Lett ; 121(17): 173901, 2018 Oct 26.
Artículo en Inglés | MEDLINE | ID: mdl-30411929

RESUMEN

In this work, we experimentally show that quantum entanglement can be symmetry protected in the interaction with a single subwavelength plasmonic nanoaperture, with a total volume of V∼0.2λ^{3}. In particular, we experimentally demonstrate that two-photon entanglement can be either completely preserved or completely lost after the interaction with the nanoaperture, solely depending on the relative phase between the quantum states. We achieve this effect by using specially engineered two-photon states to match the properties of the nanoaperture. In this way we can access a symmetry protected state, i.e., a state constrained by the geometry of the interaction to retain its entanglement. In spite of the small volume of interaction, we show that the symmetry protected entangled state retains its main properties. This connection between nanophotonics and quantum optics probes the fundamental limits of the phenomenon of quantum interference.

13.
Chemistry ; 24(10): 2483-2492, 2018 Feb 16.
Artículo en Inglés | MEDLINE | ID: mdl-29281149

RESUMEN

The multivalent effect in glycosidase inhibition is a new topic in glycoscience that has emerged a few years ago, with the discovery of neoglycoclusters displaying strong binding enhancements over the corresponding monovalent inhibitor. Iminosugar-fullerene conjugates with high valencies have been prepared from iminosugar-terminated dendrons and a clickable fullerene hexa-adduct scaffold. The simultaneous grafting of twelve dendrons allows for a very fast dendritic growth thus limiting the number of synthetic steps required to prepare compounds with a high number of peripheral units. The grafting of first- and second-generation dendrons provided fullerodendrimers surrounded by 36 and 108 peripheral iminosugars, respectively. Inhibition studies have been carried out with a panel of glycosidases. In the particular case of Jack bean α-mannosidase, the 108-valent nanoconstruct displays inhibition in the nanomolar range and an additional binding enhancement of one order of magnitude when compared to the 36-valent analogues.

14.
Biofouling ; 34(4): 368-377, 2018 04.
Artículo en Inglés | MEDLINE | ID: mdl-29745778

RESUMEN

The present study was aimed at designing and optimizing a rotating disk reactor simulating high hydrodynamic shear rates (γ), which are representative of cooling circuits. The characteristics of the hydrodynamic conditions in the reactor and the complex approach used to engineer it are described. A 60 l tank was filled with freshwater containing free-living amoebae (FLA) and bacteria. Adhesion of the bacteria and formation of a biofilm on the stainless steel coupons were observed. FLA were able to establish in these biofilms under γ as high as 85,000 s-1. Several physical mechanisms (convection, diffusion, sedimentation) could explain the accumulation of amoeboid cells on surfaces, but further research is required to fully understand and model the fine mechanisms governing such transport under γ similar to those encountered in the industrial environment. This technological advance may enable research into these topics.


Asunto(s)
Amoeba/fisiología , Bacterias , Biopelículas , Fenómenos Fisiológicos Bacterianos , Agua Dulce , Hidrodinámica , Locomoción , Acero Inoxidable
15.
Biofouling ; 34(9): 1020-1031, 2018 10.
Artículo en Inglés | MEDLINE | ID: mdl-30612474

RESUMEN

Low intensity and very low-frequency electromagnetic fields (EMF) used for preventing scaling in water distribution systems were tested for the first time for their potential impact on drinking water biofilms. The assays were carried out in laboratory-scale flow-through reactors that mimic water distribution systems. The drinking water biofilms were not directly exposed to the core of the EMF generator and only subjected to waterborne electromagnetic waves. The density and chlorine susceptibility of nascent or mature biofilms grown under exposure to EMF were evaluated in soft and hard water. This EMF treatment was able to modify CaCO3 crystallization but it did not significantly affect biofilms. Indeed, over all the tested conditions, there was no significant change in cell number, or in the integrity of the cells (membrane, culturability), and no measurable effect of chlorine on the biofilm.


Asunto(s)
Biopelículas/crecimiento & desarrollo , Agua Potable/microbiología , Campos Electromagnéticos , Abastecimiento de Agua/normas , Biopelículas/efectos de los fármacos , Cloro/farmacología
16.
Angew Chem Int Ed Engl ; 57(27): 8002-8006, 2018 07 02.
Artículo en Inglés | MEDLINE | ID: mdl-29722924

RESUMEN

Multivalent design of glycosidase inhibitors is a promising strategy for the treatment of diseases involving enzymatic hydrolysis of glycosidic bonds in carbohydrates. An essential prerequisite for successful applications is the atomic-level understanding of how outstanding binding enhancement occurs with multivalent inhibitors. Herein we report the first high-resolution crystal structures of the Jack bean α-mannosidase (JBα-man) in apo and inhibited states. The three-dimensional structure of JBα-man in complex with the multimeric cyclopeptoid-based inhibitor displaying the largest binding enhancements reported so far provides decisive insight into the molecular mechanisms underlying multivalent effects in glycosidase inhibition.


Asunto(s)
alfa-Manosidasa/metabolismo , Sitios de Unión , Canavalia/enzimología , Dominio Catalítico , Cristalografía por Rayos X , Iminoazúcares/química , Iminoazúcares/metabolismo , Estructura Terciaria de Proteína , Zinc/química , Zinc/metabolismo , alfa-Manosidasa/antagonistas & inhibidores
17.
Phys Rev Lett ; 118(22): 222501, 2017 Jun 02.
Artículo en Inglés | MEDLINE | ID: mdl-28621970

RESUMEN

Fast-neutron-induced fission of ^{238}U at an energy just above the fission threshold is studied with a novel technique which involves the coupling of a high-efficiency γ-ray spectrometer (MINIBALL) to an inverse-kinematics neutron source (LICORNE) to extract charge yields of fission fragments via γ-γ coincidence spectroscopy. Experimental data and fission models are compared and found to be in reasonable agreement for many nuclei; however, significant discrepancies of up to 600% are observed, particularly for isotopes of Sn and Mo. This indicates that these models significantly overestimate the standard 1 fission mode and suggests that spherical shell effects in the nascent fission fragments are less important for low-energy fast-neutron-induced fission than for thermal neutron-induced fission. This has consequences for understanding and modeling the fission process, for experimental nuclear structure studies of the most neutron-rich nuclei, for future energy applications (e.g., Generation IV reactors which use fast-neutron spectra), and for the reactor antineutrino anomaly.

18.
Prog Urol ; 27(17): 1091-1097, 2017 Dec.
Artículo en Francés | MEDLINE | ID: mdl-28964687

RESUMEN

OBJECTIVE: Treatment with transcutaneous posterior tibial neurostimulation (NTPT) has been shown to be effective in the treatment of overactive bladder (OAB), but its outcomes in diabetic patients have never been assessed. The aim of this study was to compare the efficacy of NTPT in diabetic OAB patients and in OAB patients without diabetes. METHODS: A single-center prospective study included all patients treated with NTPT for lower urinary tract storage symptoms between 2012 and 2016. The primary endpoint was symptoms improvement≥50% assessed using a Visual Analog Scale (VAS) two months after starting NTPT. Treatment consisted in a daily 20-minute NTPT single-session. The secondary endpoints were lower urinary tract symptoms reported by bladder diary, the Urinary Symptom Profile, the impact on mood and on daily activities. RESULTS: Seventy-one patients were included, 10 of whom were diabetic. The efficacy rate (EVA>50%) was not significantly different in the diabetic group (70% vs. 44.1%, P=0.17), like the mean EVA efficacy was similar in both groups (4/10 vs. 4/10, P=0.98). OAB USP sub-score diminished significantly in both groups at 2 months (-3 points in the diabetic group; -1.9 points in the non-diabetic group; P=0.03 and P<0.0001, respectively). There was no significant difference between the groups, except for the rate of patients who stopped treatment at 6 months, higher in diabetic patients (100% vs. 63.5%, P=0.04). CONCLUSION: The functional outcomes of NTPT appear to be similar in the treatment of OAB in diabetic patients and in non-diabetic patients. LEVEL OF EVIDENCE: 4.


Asunto(s)
Complicaciones de la Diabetes/terapia , Nervio Tibial , Estimulación Eléctrica Transcutánea del Nervio , Vejiga Urinaria Hiperactiva/terapia , Anciano , Complicaciones de la Diabetes/etiología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Vejiga Urinaria Hiperactiva/etiología
19.
Angew Chem Int Ed Engl ; 56(48): 15257-15261, 2017 11 27.
Artículo en Inglés | MEDLINE | ID: mdl-28984017

RESUMEN

Acylboronate esters/trifluoroborates represent an elusive class of boronates that are of increasing interest for both fundamental study as well as applications at the interface of chemistry and biology. Their preparation has been limited by the use of strongly basic anions, often introduced in multistep reactions. Herein, we demonstrate the facile preparation of acylboronate N-methyliminodiacetyl (MIDA) esters from alkenyl-2-boronate esters through mild dihydroxylation and meta-periodate cleavage. Given the well-known functional-group tolerance of this mild reaction sequence and the availability of alkenyl-2-boronates, this method should greatly increase access to acylboronate MIDA esters.

20.
Chemistry ; 22(15): 5151-5, 2016 Apr 04.
Artículo en Inglés | MEDLINE | ID: mdl-26917097

RESUMEN

A series of cyclopeptoid-based iminosugar clusters has been evaluated to finely probe the ligand content-dependent increase in α-mannosidase inhibition. This study led to the largest binding enhancement ever reported for an enzyme inhibitor (up to 4700-fold on a valency-corrected basis), which represents a substantial advance over the multivalent glycosidase inhibitors previously reported. Electron microscopy imaging and analytical data support, for the best multivalent effects, the formation of a strong chelate complex in which two mannosidase molecules are cross-linked by one inhibitor.


Asunto(s)
Inhibidores Enzimáticos/química , Glicósido Hidrolasas/antagonistas & inhibidores , Glicósido Hidrolasas/química , Iminoazúcares/química , Péptidos Cíclicos/química , alfa-Manosidasa/química , Inhibidores Enzimáticos/farmacología , Glicósido Hidrolasas/farmacología , Iminoazúcares/farmacología , Ligandos , alfa-Manosidasa/farmacología
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