Drug Molecules Research Articles

Positron emission tomography guided synergistic treatment of melanoma using multifunctional zirconium-hematoporphyrin nanosonosensitizers

Sonodynamic therapy (SDT) has emerged as a useful approach for tumor treatment. However, its widespread application is impeded by poor pharmacokinetics of existing sonosensitizers. Here we developed a metal-organic nanoplatform, wherein a small-molecule sonosensitizer (hematoporphyrin monomethyl ether, HMME) was ingeniously coordinated with zirconium, resulting in a multifunctional nanosonosensitizer termed Zr-HMME. Through post-synthetic modifications involving PEGylation and tumor-targeting peptide (F3) linkage, a nanoplatform capable of homing on melanoma was produced, which could elicit robust immune responses to suppress tumor lung metastasis in the host organism. Importantly, after seamless incorporation of positron-emitting 89Zr into this nanosonosensitizer, positron emission tomography (PET) could be used to monitor its in vivo pharmacokinetics. PET imaging studies revealed that this nanoplatform exhibited potent tumor accumulation and strong in vivo stability. Using intrinsic fluorescence from HMME, a dual-modal diagnostic capability (fluorescence and PET) was confirmed for this nanosonosensitizer. In addition, the mechanisms of how this nanoplatform interacted with immune system were also investigated. The collective data proved that the coordination structure between small-molecule drug cargos and metals may enhance the functions of each other while mitigating their weaknesses. This straightforward approach can expand the potential applications of suitable drug molecules.

Formulation and evaluation of Dorzolamide hydrochloride microsponges loaded in situ gel for ocular administration

Due to the unique structure of the eye, which inhibits the entry of drug molecules into the desired site, the ophthalmic delivery of the drug has been one of the most challenging tasks for a pharmaceutical scientist. For this reason, in this investigation a novel microsponge for an anti-glaucoma drug, Dorzolamide hydrochloride, was formulated as in situ gel for ocular administration with an aim to improve its therapeutic efficacy and reduce the systemic adverse effects. The microsponges were prepared by the quasi emulsion solvent diffusion method and was incorporated into 20% pluronic F-127 which led to consistent in situ gel at 35°C. They were evaluated for physicochemical properties like pH, gelling capacity, gelation time, rheological properties and release profile and ocular irritancy test. The prepared Dorzolamide hydrochloride microsponges showed high entrapment efficiency of 85% and mean particle size of 2 μm with polydispersity index (PDI) of 0.77 which are ideal for ocular delivery. These microsponges is formulated into in situ gel which showed higher therapeutic efficacy compared to free drug in gel. It was found to be non-irritant to the rabbit’s eye. These results confirms that Dorzolamide hydrochloride microsponges in situ gels have promising features, benefits and advantages for a novel ophthalmic drug delivery to treat glaucoma.

Predicting anti-trypanosome effect of carbazole-derived compounds by powerful SVM with novel kernel function and comprehensive learning PSO.

In order to predict the anti-trypanosome effect of carbazole-derived compounds by quantitative structure-activity relationship, five models were established by the linear method, random forest, radial basis kernel function support vector machine, linear combination mix-kernel function support vector machine, and nonlinear combination mix-kernel function support vector machine (NLMIX-SVM). The heuristic method and optimized CatBoost were used to select two different key descriptor sets for building linear and nonlinear models, respectively. Hyperparameters in all nonlinear models were optimized by comprehensive learning particle swarm optimization with low complexity and fast convergence. Furthermore, the models' robustness and reliability underwent rigorous assessment using fivefold and leave-one-out cross-validation, y-randomization, and statistics including concordance correlation coefficient (CCC), [Formula: see text] , [Formula: see text] , and [Formula: see text] . Among all the models, the NLMIX-SVM model, which was established by support vector regression using a nonlinear combination of radial basis kernel function, sigmoid kernel function, and linear kernel function as a new kernel function, demonstrated excellent learning and generalization abilities as well as robustness: [Formula: see text] = 0.9581, mean square error (MSE) = 0.0199 for the training set and [Formula: see text] = 0.9528, MSE = 0.0174 for the test set. [Formula: see text] , [Formula: see text] , CCC, [Formula: see text] , [Formula: see text], and [Formula: see text] are 0.9539, 0.8908, 0.9752, 0.9529, 0.9528, and 0.9633, respectively. The NLMIX-SVM method proved to be a promising way in quantitative structure-activity relationship research. In addition, molecular docking experiments were conducted to analyze the properties of new derivatives, and a new potential candidate drug molecule was ultimately found. In summary, this study will provide help for the design and screening of novel anti-trypanosome drugs.

Fluorescence Thermal Shift Assay based High Through-put Screening in Small Molecule Drug Discovery: A Brief Overview

Background: The Early drug discovery process was majorly phenotypic, lacking target specificity, and mechanism of action causing short and/or long-term toxicological impacts on the patients leading to several drug withdrawals from the market. Biochemical procedures and methods used in drug discovery and development make it lengthy in terms of time requiring approx. 15 years with the investment of billions of dollars for a new drug molecule. Technological advancement leading to the identification of protein structures through crystallography paved a new path toward targeted drug discovery. Objective: This paper provides a brief overview of the use of the fluorescence thermal shift assay (FTSA) as a high throughput (HTS) screening technique in small molecule drug discovery. Methods: The article discusses the principles of thermal denaturation techniques and how they are applied in drug discovery. It highlights the advantages of FTSA over other biophysical methods, including its label-free, cost-effective, and high HTS nature. The review also presents a comparative analysis of FTSA with techniques such as isothermal titration calorimetry (ITC), mass spectrometry (MS), nuclear magnetic resonance (NMR), surface plasmon resonance (SPR), X-ray crystallography(X-RD), circular dichroism (CD), and differential scanning calorimetry (DSC). Results: The FTSA technique is described as a powerful tool that addresses the limitations of larger protein requirements, specific assay development, and low HTS associated with other thermal denaturation methods. Unlike biochemical and cellular assays that measure secondary effects, FTSA directly estimates the binding of small molecules to target proteins. Conclusion: The review concludes that FTSA is the only biophysical method that satisfies the three key prerequisites of being label-free, cost-effective, and suitable for high HTS screening in small molecule drug discovery.

Effectiveness of Biological Assays as an Alternative Method to Determine the Potency of Antibiotics: A Review

In this review, chemical and biological assays performed in the pharmaceutical industry to determine the potency and bioactivity of antibiotics are discussed. Though commonly employed chemical methods can measure the potency of antibiotics, inefficiency to estimate the bioactivity is one of their major limitations. Due to their sensitivity and cost-effectiveness, common microbiological assays can serve as alternative methods. Several factors like doses of antibiotics, homogeneity of agar medium, inoculum concentration, chemical composition of agar media, size and solubility of samples or drug molecules, pH, relative humidity and exposure time can influence microbiological assays. Based on specific requirement and experimental targets, agar diffusion assays are designed focusing on their costs, errors, accuracy and simplicity. To avoid the misuse and overuse of antibiotics that leads to drug-resistance, parameters like zone of inhibition, minimum inhibitory concentration, minimum bactericidal concentration, mutation prevention concentration and critical concentration are also conversed in this study. Finally, microbiological and high-performance liquid chromatography methods were specifically compared for their sensitivity, accuracy and assessment of biological activity with minimal cost. Due to their advantages and disadvantages, parallel use of both bioassays and chemical methods are suggested to precisely determine the potency of antibiotics.

Two-Dimensional Cu(II)-MOF with Lewis Acid-Base Bifunctional Sites for Chemical Fixation of CO2 and Bioactive 1,4-DHP Synthesis via Hantzsch Condensation.

Five- and six-membered heterocycles containing nitrogen or oxygen have been considered as privileged scaffolds in organic chemistry and the chemical industry because of their usage in high-value commodities. Herein, we report a two-dimensional (2D) Cu(II)-based MOF catalyst, IITKGP-40, via the strategic employment of ample Lewis acid-base bifunctional sites (open metal nodes and free pyrazine moieties) along the pore wall. IITKGP-40 could convert toxic CO2 to cyclic carbonates in an atom-economical manner under solvent-free conditions and aromatic aldehyde to bioactive 1,4-DHPs via Hantzsch condensation. Exceptional catalytic performance (99%) and turnover number under mild reaction conditions for CO2 fixation using sterically hindered styrene oxide, and good-to-excellent yields for a wide range of aromatic aldehydes toward 1,4-dihydropyridines (1,4-DHPs) make IITKGP-40 promising as a multipurpose heterogeneous catalyst. Moreover, to demonstrate the practical utility of the catalyst, two biologically important drug molecules, diludine and nitrendipine analogue, have also been synthesized. IITKGP-40 is recyclable for at least three consecutive runs without significant loss of activity, making it promising for real-time applications.

Different Drug Mobilities in Hydrophobic Cavities of Host–Guest Complexes between β-Cyclodextrin and 5-Fluorouracil at Different Stoichiometries: A Molecular Dynamics Study in Water

Cyclodextrins (CDs) are cyclic oligosaccharides able to form noncovalent water-soluble complexes useful in many different applications for the solubilization, delivery, and greater bioavailability of hydrophobic drugs. The complexation of 5-fluorouracil (5-FU) with natural or synthetic cyclodextrins permits the solubilization of this poorly soluble anticancer drug. In this theoretical work, the complexes between β-CD and 5-FU are investigated using molecular mechanics (MM) and molecular dynamics (MD) simulations in water. The inclusion complexes are formed thanks to the favorable intermolecular interactions between β-CD and 5-FU. Both 1:1 and 1:2 β-CD/5-FU stoichiometries are investigated, providing insight into their interaction geometries and stability over time in water. In the 1:2 β-CD/5-FU complexes, the intermolecular interactions affect the drug’s mobility, suggesting a two-step release mechanism: a fast release for the more exposed and hydrated drug molecule, with greater freedom of movement near the β-CD rims, and a slow one for the less-hydrated and well-encapsulated and confined drug. MD simulations study the intermolecular interactions between drugs and specific carriers at the atomistic level, suggesting a possible release mechanism and highlighting the role of the impact of the drug concentration on the kinetics process in water. A comparison with experimental data in the literature provides further insights.

Radical Decarboxylation-Initiated SH2' Reaction of β,β-Difluoroenol Sulfonates: Access to α,α-Difluoroketones.

Reported herein is a novel radical decarboxylation-initiated SH2' reaction of β,β-difluoroenol sulfonates. This transformation is characterized by mild reaction conditions, a broad substrate scope, and late-stage modification of drug molecules, providing general and mechanistically distinct access to bioactive and synthetically versatile α,α-difluoroketones. Preliminary mechanistic studies demonstrate that this reaction proceeds through a succession of silver-mediated decarboxylative radical generation and radical-addition-induced β-elimination of the sulfonyl radical.

Highly Efficient One‐pot Electrosynthesis of Oxime Ethers from NOx over Ultrafine MgO Nanoparticles Derived from Mg‐based Metal‐Organic Frameworks

AbstractOxime ethers are attractive compounds in medicinal scaffolds due to the biological and pharmaceutical properties, however, the crucial and widespread step of industrial oxime formation using explosive hydroxylamine (NH2OH) is insecure and troublesome. Herein, we present a convenient method of oxime ether synthesis in a one‐pot tandem electrochemical system using magnesium based metal‐organic framework‐derived magnesium oxide anchoring in self‐supporting carbon nanofiber membrane catalyst (MgO‐SCM), the in situ produced NH2OH from nitrogen oxides electrocatalytic reduction coupled with aldehyde to produce 4‐cyanobenzaldoxime with a selectivity of 93 % and Faraday efficiency up to 65.1 %, which further reacted with benzyl bromide to directly give oxime ether precipitate with a purity of 97 % by convenient filtering separation. The high efficiency was attributed to the ultrafine MgO nanoparticles in MgO‐SCM, effectively inhibiting hydrogen evolution reaction and accelerating the production of NH2OH, which rapidly attacked carbonyl of aldehydes to form oximes, but hardly crossed the hydrogenation barrier of forming amines, thus leading to a high yield of oxime ether when coupling benzyl bromide nucleophilic reaction. This work highlights the importance of kinetic control in complex electrosynthetic organonitrogen system and demonstrates a green and safe alternative method for synthesis of organic nitrogen drug molecules.

Iridium(Ir) decorated silicon Carbide (SiC) nanosheet as a promising sensitive material for detection of γ-Hydroxybutyric acid drug based on the DFT approach

The Food and Drug Administration (FDA) has banned gamma-Hydroxybutyric acid (HBA), which is widely utilised for drug-facilitated sexual assaults across the world. As a result, it is crucial for law enforcement and drug organisations to detect HBA in biological settings. There has been substantial interest in 2D chemical nanosensors for gaseous and biological molecule detection. This paper studied the sensing performance of bare and Ir-decorated SiC nanosheets for HBA detection through the TPSS density functional. The bare SiC nanosheets were found to have insignificant responsiveness to HBA (almost 7.3 at 298 K) due to their small binding energy with the drug molecules (−0.26 eV). The Ir-decorated SiC nanosheets, however, showed superb performance in adsorbing HBA on an Si–C bond, with a binding energy of −2.54 eV. The Ir-decorated SiC nanosheets enabled strong HBA adsorption (binding energy = −1.35 eV). Therefore, the decoration of SiC sheets with Ir atoms remarkably enhanced their responsiveness to HBA molecules from 7.3 to 495.4. The recovery time for the desorption of HBA molecules from the surface of the Ir-decorated SiC nanosheets was estimated to be 1.09 s. It was concluded that Ir-decorated SiC nanosheets are a promising nanosensor to detect HBA.

Comparative Analysis of Chemical Descriptors by Machine Learning Reveals Atomistic Insights into Solute-Lipid Interactions.

This study explores the research area of drug solubility in lipid excipients, an area persistently complex despite recent advancements in understanding and predicting solubility based on molecular structure. To this end, this research investigated novel descriptor sets, employing machine learning techniques to understand the determinants governing interactions between solutes and medium-chain triglycerides (MCTs). Quantitative structure-property relationships (QSPR) were constructed on an extended solubility data set comprising 182 experimental values of structurally diverse drug molecules, including both development and marketed drugs to extract meaningful property relationships. Four classes of molecular descriptors, ranging from traditional representations to complex geometrical descriptions, were assessed and compared in terms of their predictive accuracy and interpretability. These include two-dimensional (2D) and three-dimensional (3D) descriptors, Abraham solvation parameters, extended connectivity fingerprints (ECFPs), and the smooth overlap of atomic position (SOAP) descriptor. Through testing three distinct regularized regression algorithms alongside various preprocessing schemes, the SOAP descriptor enabled the construction of a superior performing model in terms of interpretability and accuracy. Its atom-centered characteristics allowed contributions to be estimated at the atomic level, thereby enabling the ranking of prevalent molecular motifs and their influence on drug solubility in MCTs. The performance on a separate test set demonstrated high predictive accuracy (RMSE = 0.50) for 2D and 3D, SOAP, and Abraham Solvation descriptors. The model trained on ECFP4 descriptors resulted in inferior predictive accuracy. Lastly, uncertainty estimations for each model were introduced to assess their applicability domains and provide information on where the models may extrapolate in chemical space and, thus, where more data may be necessary to refine a data-driven approach to predict solubility in MCTs. Overall, the presented approaches further enable computationally informed formulation development by introducing a novel in silico approach for rational drug development and prediction of dose loading in lipids.

#2263 Computational drug repurposing screen targeting PLA2R antibody binding

Abstract Background and Aims Approximately 60% of patients with membranous nephropathy have antibodies against the phospholipase A2 receptor (PLA2R). The cysteine rich (CysR) epitope of PLA2R is a likely site of protein-antibody interaction. Current treatment regimens for membranous nephropathy involve maximal conservative management or systemic immunosuppression in severe cases. We have developed protocols and programs for an in silico high-throughput repurposing screen using structural modelling, docking, and molecular dynamics (MD). Uniquely, our approach uses a bespoke interface on Google Colab for graphic processing units to run the MD simulations. We describe their application to a repurposing screen aiming to identify larger licensed drug molecules capable of impeding antibody-protein interactions at the site of the CysR epitope. Method A complete model of PLA2R was obtained from I-TASSER using the canonical sequence on the UNIPROT database. This structure was equilibrated using a five nanosecond molecular dynamics (MD) simulation. The simulation was prepared using CHARMM-GUI and run on the GROMACS-ON-COLAB platform. The centroid of the MD system between three and five nanoseconds was used for docking experiments using PLANTS PLP with a study area that included the CysR epitope. A library of compounds listed in the British National Formulary was used for the docking studies. The results would be analysed by PLANTS energy and by key residue overlap score. Results Viable docking results were obtained for 891 of the 1510 compounds tested. 60 of these compounds were in contact with at least 10% of the residues in the CysR region. By restricting these results to compounds in the lowest 20% of the total sample for calculated binding energy, 22 compounds remained. 16 of these compounds have been assessed for their safety for oral or intravenous use. These sixteen compounds were then identified for further investigation by MD to assess the stability of the identified interactions. The sixteen compounds include Lymecycline, Trazodone, Mirabegron, Sulfasalazine, Methotrexate, Rosuvastatin and Montelukast. Conclusion Structural bioinformatics methods provide a relatively fast and economical option for identifying protein-drug interactions that could result in new treatment strategies. The compounds identified for investigation are used for an array of different health conditions. However, they all share the chemical properties of large molecular weight and have the potential to form multiple hydrogen bonds. If validated experimentally, these compounds could provide new treatment options for PLA2R antibody positive membranous nephropathy.

Ullmann-Type N-, S-, and O-Arylation Using a Well-Defined 7-Azaindole-N-oxide (7-AINO)-Based Copper(II) Catalyst: Scope and Application to Drug Synthesis.

An air-stable, robust, and well-defined copper(II)-7-azaindole-N-oxide-based catalyst [Cu2II(7-AINO)4] (abbreviated as Cu(II)-7-AINO) has been demonstrated as an efficient catalyst for various Ullmann-type coupling reactions. This easily prepared and cost-effective catalyst facilitates the arylation and heteroarylation of diverse N-, S-, and O-nucleophiles, including azoles, aminoazoles, (hetero)arylthiols, and phenols. Notably, they also exhibit substantial compatibility with a wide range of functional groups. Furthermore, the catalyst demonstrates significant selectivity for -NH sites of aminoazoles and -SH sites of aminothiophenols over -NH2 sites in both cases, enhancing its versatility. Exploiting the catalyst's chemo- and regioselective properties, we have successfully demonstrated the applicability of our methodology in synthesizing various drug molecules. Specifically, Epirizole analogue, Nilotinib, and Vortioxetine were successfully synthesized using our protocol.

Accelerated Screening of Alternative DNA Base‐Organic Molecule‐Base Architectures via Integrated Theory and Experiment

Organic molecule‐mediated noncanonical DNA self‐assembly expands the standard DNA base‐pairing alphabets. However, only a very limited number of small molecules have been recognized as mediators because of the tedious and complicated experiments like crystallization and microscopy imaging. Here we present an integrative screening protocol incorporating molecular dynamics (MD) for fast theoretical simulation and native polyacrylamide gel electrophoresis for convenient experimental validation. Melamine, the molecule that was confirmed mediating noncanonical DNA base‐pairing, and 38 other candidate molecules were applied to demonstrate the feasibility of this protocol. We successfully identified seven stable noncanonical DNA duplex structures, and another eight novel structures with sub‐stability. In addition, we discovered that hairpins at both ends can significantly stabilize the noncanonical DNA structures, providing a guideline to design small organic molecule‐incorporated DNA structures. Such an efficient screening protocol will accelerate the design of alternative DNA‐molecule architectures beyond Watson‐Crick pairs. Considering the wide range of potential mediators, it will also facilitate applications such as noncovalent, highly dense loading of drug molecules in DNA‐based delivery system and probe design for sensitive detection of certain molecules.

Accelerated Screening of Alternative DNA Base-Organic Molecule-Base Architectures via Integrated Theory and Experiment.

Organic molecule-mediated noncanonical DNA self-assembly expands the standard DNA base-pairing alphabets. However, only a very limited number of small molecules have been recognized as mediators because of the tedious and complicated experiments like crystallization and microscopy imaging. Here we present an integrative screening protocol incorporating molecular dynamics (MD) for fast theoretical simulation and native polyacrylamide gel electrophoresis for convenient experimental validation. Melamine, the molecule that was confirmed mediating noncanonical DNA base-pairing, and 38 other candidate molecules were applied to demonstrate the feasibility of this protocol. We successfully identified seven stable noncanonical DNA duplex structures, and another eight novel structures with sub-stability. In addition, we discovered that hairpins at both ends can significantly stabilize the noncanonical DNA structures, providing a guideline to design small organic molecule-incorporated DNA structures. Such an efficient screening protocol will accelerate the design of alternative DNA-molecule architectures beyond Watson-Crick pairs. Considering the wide range of potential mediators, it will also facilitate applications such as noncovalent, highly dense loading of drug molecules in DNA-based delivery system and probe design for sensitive detection of certain molecules.

Naphthyl‐Based Chalcone Derivatives: A Multifaceted Player in Medicinal Chemistry

AbstractResearch has placed a great deal of emphasis on molecule development and discovery with substantial biological profiling in recent years. Despite the significant side effects, medicinal chemists have long strived to synthesize drug molecules with the highest level of therapeutic activity and the lowest possible level of toxicity. The naphthyl‐based chalcone derivatives have drawn attention due to their simple structures and wide range of pharmacological effects. The main focus of this review is to outline the biologically active molecules based on naphthyl moiety‐substituted chalcone derivatives developed over the years. A synopsis of pharmacological screening, including relevant structure‐activity relationships, action mechanisms, and possible therapeutic applications, is provided in this article. It is true that prospective hybrids combining the naphthyl moiety with different chalcone pharmacophores are needed to address drug resistance and improve specificity. Therefore, this review may be useful in the development and design of new, highly successful therapeutic drugs based on previously reported methodologies.

Dynamic microphysiological system chip platform for high-throughput, customizable, and multi-dimensional drug screening

Spheroids and organoids have attracted significant attention as innovative models for disease modeling and drug screening. By employing diverse types of spheroids or organoids, it is feasible to establish microphysiological systems that enhance the precision of disease modeling and offer more dependable and comprehensive drug screening. High-throughput microphysiological systems that support optional, parallel testing of multiple drugs have promising applications in personalized medical treatment and drug research. However, establishing such a system is highly challenging and requires a multidisciplinary approach. This study introduces a dynamic Microphysiological System Chip Platform (MSCP) with multiple functional microstructures that encompass the mentioned advantages. We developed a high-throughput lung cancer spheroids model and an intestine-liver-heart-lung cancer microphysiological system for conducting parallel testing on four anti-lung cancer drugs, demonstrating the feasibility of the MSCP. This microphysiological system combines microscale and macroscale biomimetics to enable a comprehensive assessment of drug efficacy and side effects. Moreover, the microphysiological system enables evaluation of the real pharmacological effect of drug molecules reaching the target lesion after absorption by normal organs through fluid-based physiological communication. The MSCP could serves as a valuable platform for microphysiological system research, making significant contributions to disease modeling, drug development, and personalized medical treatment.

Synthesis of Membrane-Permeable Macrocyclic Peptides via Imidazopyridinium Grafting.

Macrocyclic peptides (MPs) are a class of compounds that have been shown to be particularly well suited for engaging difficult protein targets. However, their utility is limited by their generally poor cell permeability and bioavailability. Here, we report an efficient solid-phase synthesis of novel MPs by trapping a reversible intramolecular imine linkage with a 2-formyl- or 2-keto-pyridine to create an imidazopyridinium (IP+)-linked ring. This chemistry is useful for the creation of macrocycles of different sizes and geometries, including head-to-side and side-to-side chain configurations. Many of the IP+-linked MPs exhibit far better passive membrane permeability than expected for "beyond Rule of 5" molecules, in some cases exceeding that of much lower molecular weight, traditional drug molecules. We demonstrate that this chemistry is suitable for the creation of libraries of IP+-linked MPs and show that these libraries can be mined for protein ligands.

Biocatalytic Strategy for the Highly Stereoselective Synthesis of Fluorinated Cyclopropanes

Fluorinated cyclopropanes are highly desired pharmacophores in drug discovery owing to the rigidity nature of the cyclopropane ring and the beneficial effects of C–F bonds on the pharmacokinetic properties, cell permeability, and metabolic stability of drug molecules. Herein a biocatalytic strategy for the stereoselective synthesis of mono‐fluorinated and gem‐difluoro cyclopropanes is reported though the use of engineered myoglobin‐based catalysts. In particular, this system allows for a broad range of gem‐difluoro alkenes to be cyclopropanated in the presence of diazoacetonitrile with excellent diastereo and enantiocontrol (up to 200:1 d.r. and 99% e.e.), thereby enabling a transformation not currently accessible with chemocatalytic methods. The synthetic utility of the present approach is further exemplified through the gram‐scale synthesis of a key gem‐difluorinated cyclopropane intermediate useful for the preparation of fluorinated bioactive molecules.

Biocatalytic Strategy for the Highly Stereoselective Synthesis of Fluorinated Cyclopropanes.

Fluorinated cyclopropanes are highly desired pharmacophores in drug discovery owing to the rigidity nature of the cyclopropane ring and the beneficial effects of C-F bonds on the pharmacokinetic properties, cell permeability, and metabolic stability of drug molecules. Herein a biocatalytic strategy for the stereoselective synthesis of mono-fluorinated and gem-difluoro cyclopropanes is reported though the use of engineered myoglobin-based catalysts. In particular, this system allows for a broad range of gem-difluoro alkenes to be cyclopropanated in the presence of diazoacetonitrile with excellent diastereo and enantiocontrol (up to 200:1 d.r. and 99% e.e.), thereby enabling a transformation not currently accessible with chemocatalytic methods. The synthetic utility of the present approach is further exemplified through the gram-scale synthesis of a key gem-difluorinated cyclopropane intermediate useful for the preparation of fluorinated bioactive molecules.