212 research outputs found

    Editorial

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    peer reviewedEditorial for the special issue on biobased flow chemistr

    User friendly and flexible Kiliani reaction on ketoses using microreaction technology

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    The Kiliani reaction, i.e. the elongation of the carbon chain by means of cyanide addition to the carbonyl group of carbohydrate derivatives, is studied on lower C3-, C4- and C6-ketoses under continuous flow conditions. Depending on the process parameters, the corresponding cyanohydrins or alpha-hydroxycarboxylic acids are obtained. A simple on-line purification of the effluent is studied using cation exchange resins. Reactions provide high yields and selectivity within short residence times, emphasizing the assets of the continuous flow process versus the batch process

    A perspective on the synthetic potential of biobased building blocks for heterocyclic chemistry

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    peer reviewedHeterocycles are a wide occurrence in molecules with a variety of applications: from the pharmaceutical industry to polymers, cosmetics, food additives and dyes. However, most of their synthetic pathways are based on finite petrobased building blocks. This chapter discusses different renewable feedstock sources, their prominence and compo- sition as well as the challenges faced regarding their transformation into valuable primary building blocks. Following this, a brief overview of secondary building blocks Advances in Heterocyclic Chemistry Copyright # 2024 Elsevier Inc. ISSN 0065-2725 All rights are reserved, including those 1 https://doi.org/10.1016/bs.aihch.2024.04.003 for text and data mining, AI training, and similar technologies. 2 Loïc Bovy and Jean-Christophe M. Monbaliu is discussed before providing examples of their incorporation in (un)fused heterocycles with an emphasis on compounds with known applications. Building upon these separate topics, perspectives aiming at solving the encountered and discussed issues are provided

    Genotype-driven pharmacokinetic simulations of warfarin levels in Puerto Ricans

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    Objectives: The inter-individual variability of warfarin dosing has been linked to genetic polymorphisms. This study was aimed at performing genotype-driven pharmacokinetic (PK) simulations to predict warfarin levels in Puerto Ricans. Methods: Analysis of each individual dataset was performed by one-compartmental modeling using WinNonlin®v6.4. The ke of warfarin given a cytochrome P450 2C9 (CYP2C9) genotype ranged from 0.0189 to 0.0075 h−1. Ka and Vd parameters were taken from literature. Data from 128 subjects were divided into two groups (i.e., wild-types and carriers) and statistical analyses of PK parameters were performed by unpaired t-tests. Results: In the carrier group (n=64), 53 subjects were single-carriers and 11 double-carriers (i.e., *2/*2, *2/*3, *2/*5, *3/*5, and *3/*8). The mean peak concentration (Cmax) was higher for wild-type (0.36±0.12 vs. 0.32±0.14 mg/L). Likewise, the average clearance (CL) parameter was faster among non-carriers (0.22±0.03 vs. 0.17±0.05 L/h; p=0.0001), with also lower area under the curve (AUC) when compared to carriers (20.43±6.97 vs. 24.78±11.26 h mg/L; p=0.025). Statistical analysis revealed a significant difference between groups with regard to AUC and CL, but not for Cmax. This can be explained by the variation of ke across different genotypes. Conclusions: The results provided useful information for warfarin dosing predictions that take into consideration important individual PK and genotyping data

    New insights into the role of<i> VKORC1</i> polymorphisms for optimal warfarin dose selection in Caribbean Hispanic patients through an external validation of a population PK/PD model

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    [EN] Warfarin, an oral anticoagulant, has been used for decades to prevent thromboembolic events. The complex interplay between CYP2C9 and VKORC1 genotypes on warfarin PK and PD properties is not fully understood in special sub-groups of patients. This study aimed to externally validate a population pharmacokinetic/pharma-codynamic (PK/PD) model for the effect of warfarin on international normalized ratio (INR) and to evaluate optimal dosing strategies based on the selected covariates in Caribbean Hispanic patients. INR, and CYP2C9 and VKORC1 genotypes from 138 patients were used to develop a population PK/PD model in NONMEM. The structural definition of a previously published PD model for INR was implemented. A numerical evaluation of the parameter-covariate relationship was performed. Simulations were conducted to determine optimal dosing strategies for each genotype combinations, focusing on achieving therapeutic INR levels. Findings revealed elevated IC50 for G/G, G/A, and A/A VKORC1 haplotypes (11.76, 10.49, and 9.22 mg/L, respectively), in this population compared to previous reports. The model-guided dosing analysis recommended daily warfarin doses of 3-5 mg for most genotypes to maintain desired INR levels, although subjects with combination of CYP2C9 and VKORC1 genotypes * 2/* 2-, * 2/* 3-and * 2/* 5-A/A would require only 1 mg daily. This research underscores the potential of population PK/PD modeling to inform personalized warfarin dosing in populations typically underrepresented in clinical studies, potentially leading to improved treatment outcomes and patient safety. By integrating genetic factors and clinical data, this approach could pave the way for more effective and tailored anticoagulation therapy in diverse patient groups.This research was financially sponsored in part by NASA grant #80 NSSC19M0148 from the EPSCoR program, and by grant #1R16 GM149372 from the National Institute of General Medical Sciences (NIGMS) of the National Institutes of Health (NIH) . The content of this manuscript does not represent the views of the National Institutes of Health, NASA or the United States Government. No funded writing assistance was utilized in the production of this manuscript.Rodríguez-Fernández, K.; Reynaldo-Fernández, G.; Reyes-González, S.; De Las Barreras, C.; Rodríguez-Vera, L.; Vlaar, C.; Monbaliu, JM.... (2024). New insights into the role of VKORC1 polymorphisms for optimal warfarin dose selection in Caribbean Hispanic patients through an external validation of a population PK/PD model. Biomedicine & Pharmacotherapy. 170. https://doi.org/10.1016/j.biopha.2023.11597717

    Exploring molecular antipodes with flow chemistry

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    peer reviewedThis lecture illustrates our work in flow chemistry with chemicals at the antipodes of molecular complexity. The first example deals with the valorization of biomass-derived small platform molecules, and in particular the implementation of a deoxydehydration (DODH) reaction of glycerol towards allyl alcohol under continuous-flow conditions. The combination of a unique reactive dynamic feed solution approach and short exposure to high temperature gave high yield and excellent selectivity in the presence of formic acid, triethyl orthoformate, or a combination of both. The second example deals with the preparation of large bio macromolecules, and in particular the implementation of chemical native ligation towards peptide constructs under continuous-flow conditions. The combination of the unique assets of microfluidic reactors and the development of new reagents/conditions were exploited to perform extremely fast ligations at difficult junctions that are notoriously time-consuming. Ligation times down to 2 min were achieved, with excellent conversion and overall isolated yields for a range of macrocylic peptides bearing up to 29 residues. The reaction conditions were also amenable, upon minor adjustments, to less hindered junctions
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