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Peroxisome proliferator-activated receptor gamma (PPARγ) is a nuclear receptor transcription factor that regulates gene expression programs in response to ligand binding. Endogenous and synthetic ligands, including covalent antagonist inhibitors GW9662 and T0070907, are thought to compete for the orthosteric pocket in the ligand-binding domain (LBD). However, we previously showed that synthetic PPARγ ligands can cooperatively cobind with and reposition a bound endogenous orthosteric ligand to an alternate site, synergistically regulating PPARγ structure and function (Shang et al., 2018). Here, we reveal the structural mechanism of cobinding between a synthetic covalent antagonist inhibitor with other synthetic ligands. Biochemical and NMR data show that covalent inhibitors weaken-but do not prevent-the binding of other ligands via an allosteric mechanism, rather than direct ligand clashing, by shifting the LBD ensemble toward a transcriptionally repressive conformation, which structurally clashes with orthosteric ligand binding. Crystal structures reveal different cobinding mechanisms including alternate site binding to unexpectedly adopting an orthosteric binding mode by altering the covalent inhibitor binding pose. Our findings highlight the significant flexibility of the PPARγ orthosteric pocket, its ability to accommodate multiple ligands, and demonstrate that GW9662 and T0070907 should not be used as chemical tools to inhibit ligand binding to PPARγ., Competing Interests: JS, DK No competing interests declared, (© 2024, Shang and Kojetin.)

Ovarian cancer is the deadliest gynecological malignancy, representing 2.5 % of all female cancers and accounting for 5 % of female cancer-related fatalities. Despite numerous strategies in its treatment, the disease shows a high recurrence rate and a low survival rate. Consequently, there is a growing focus on targeted therapies in ovarian cancer treatment. It is well-known that VEGFR and LPA pathways undergo alterations in ovarian cancer and stimulate survival, adhesion, migration, invasion, tumor growth and angiogenesis. Cabozantinib (CBZ) is a multi-receptor tyrosine kinase inhibitor that effectively targets MET, VEGFR-1, 2, 3, FLT3, c-KIT, and RET. Ki16425 is a selective inhibitor of LPA receptors 1, 2, and 3. Therefore, targeting LPA receptors and combining with VEGFR inhibitor is a strategic approach for ovarian cancer treatment. In this study, it was aimed to prepare polymer-drug nanoconjugate for both VEGFR and LPAR inhibition. For this, O-(2-Carboxyethyl) polyethylene glycol (PEG 5000 ) which advantages are known in cancer studies, was chosen as the carrier system, and a nanoconjugate containing Ki16425 and CBZ (Ki-PEG-CBZ) was synthesized and its potential was evaluated. Initially, CBZ and Ki16425 were conjugated to the PEG 5000 through pH-sensitive hydrazone and ester bonds. After nanoconjugate characterization, in vitro release and its ovarian cancer treatment potential were evaluated on A2780, OVCAR3 and SKOV3 ovarian cancer cell lines. A nanoconjugate was obtained with a particle size of 169 ± 15.23 nm, a zeta potential of -13.5 ± 1.21 mV, and a release profile lasting 48 h, containing CBZ and Ki16425 with drug loading efficiencies of 73.71 ± 0.53 % and 77.72 ± 2.51 %, respectively. In vitro studies have demonstrated that Ki-PEG-CBZ is highly effective against ovarian cancer. We suggest that the developed polymer-drug nanoconjugate is an effective and safe nanoconjugate for the treatment of ovarian cancer., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Production of patient-specific dosage forms is important to improve patient adherence and effectiveness while reducing the prevalence and severity of adverse effects. Due to its possibility of rapid prototyping 3D printing can be used to produce individual dosages while utilizing techniques such as hot melt extrusion to increase the bioavailability of poorly soluble drugs. In this work, Parteck MXP and Kollicoat IR were used as water-soluble polymer bases for formulation development for 3D printing of various dosages incorporating cabozantinib while enabling immediate release. The effect of tablet design and the excipients sorbitol, croscarmellose sodium, and sodium starch glycolate was investigated for this goal. A way to calculate the size of tablets for predetermined dosages is proposed to enable the printing of individual strengths from one formulation. Rheological data were collected to deepen the understanding of the role of melt viscosity in 3D printing and hot melt extrusion processes. The production of immediate-release cabozantinib tablets containing every therapeutically relevant dosage in a single unit produced by two-step 3D printing was realized., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier B.V. All rights reserved.)

A novel and robust electrochemical sensing tool for the determination of vismodegib (VIS), an anticancer drug, has been developed by integrating the selective recognition capabilities of molecularly imprinted polymer (MIP) and the sensitivity enhancement capability of metal-organic framework (MOF). Prior to this step, the electrochemical behavior of VIS was investigated using a bare glassy carbon electrode (GCE). It was observed that in 0.5 M H 2 SO 4 solution as electrolyte, VIS has an oxidation peak around 1.3 V and the oxidation mechanism is diffusion controlled. The determination of VIS in a standard solution using a bare GCE showed a linear response in the concentration range from 2.5 μM to 100 μM, with a limit of detection (LOD) of 0.75 μM. Since sufficient sensitivity and selectivity could not be achieved with bare GCE, a MIP sensor was developed in the next step of the study. For this purpose, the GCE surface was first modified by drop casting with as-synthesized Co-MOF. Subsequently, a MIP network was synthesized via a thermal polymerization approach using 2-acrylamido-2-methylpropanesulfonic acid (AMPS) as monomer and VIS as template. MOFs are ideal electrode materials due to their controllable and diverse morphologies and modifiable surface properties. These characteristics enable the development of MIPs with more homogeneous binding sites and high affinity for target molecules. Integrating MOFs could help the performance of sensors with the desired stability and reproducibility. Electrochemical analysis revealed an observable enhancement of the output signal by the incorporation of MOF molecules, which is consistent with the sensitivity-enhancing role of MOF by providing more anchoring sites for the attachment of the polymer texture to the electrode surface. This MOF-MIP sensor exhibited impressive linear dynamic ranges ranging from 0.1 to 1.0 pM for VIS, with detection limits in the low picomolar range. In addition, the MOF-MIP sensor offers high accuracy, selectivity and precision for the determination of VIS, with no interference observed from complex media of serum samples. Additionally, in this study, Analytical GREEnness metric (AGREE), Analytical GREEnness preparation (AGREEprep) and Blue Applicability Grade Index (BAGI) were used to calculate the green profile score., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper. The authors also declare that there is no conflict of interests., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Peroxisome proliferator-activated receptor γ (PPARγ) belongs to the nuclear receptor superfamily and is involved in the inflammatory process. Previously, we synthesized the ligands of PPARγ that possess the hybrid structure of a food-derived cinnamic acid derivative (CA) and GW9662, an irreversible PPARγ antagonist. These ligands activate the transcription of PPARγ through the covalent bond formation with the Cys285 residue of PPARγ, whereas their anti-inflammatory effect has not been examined yet. Here, we show the anti-inflammatory effect of the covalent PPARγ ligands in RAW264 cells, murine macrophage-like cells. GW9662 suppressed the production of nitric oxide (NO) stimulated by lipopolysaccharide and exerted a synergistic effect in combination with CA. The compounds bearing their hybrid structure dramatically inhibited NO production and transcription of proinflammatory cytokines. A comparison study suggested that the 2-chloro-5-nitrobenzoyl group of the ligands is important for anti-inflammation. Furthermore, we synthesized an alkyne-tagged analogue that becomes an activity-based probe for future mechanistic study., (© The Author(s) 2024. Published by Oxford University Press on behalf of Japan Society for Bioscience, Biotechnology, and Agrochemistry.)

Prostate cancer (PC) is the fifth leading cause of cancer-related deaths among men worldwide. Prostate-specific membrane antigen (PSMA), a molecular target of PC, is clinically used for the treatment and diagnosis of PC using radioligand approaches. However, no PSMA-based chemotherapies have yet been approved by the FDA. Here, we present a novel therapeutic approach using PSMA-targeted 2-deoxyglucose-dendrimer (PSMA-2DG-D) for targeted delivery of a potent tyrosine kinase inhibitor, cabozantinib (Cabo), selectively to PC cells. PSMA-2DG-D demonstrates intracellular localization in PSMA (+) PC cells through PSMA-mediated internalization. This PSMA-specific targeting translates to enhanced efficacy of Cabo compared to the free drug when conjugated to PSMA-2DG-D. Furthermore, systemically administered fluorescently labeled PSMA-2DG-D-Cy5 specifically targets PSMA (+) tumors with minimal off-target accumulation in the PC3-PIP tumor xenograft mouse model. This demonstrates that the PSMA-2DG-D platform is a promising new delivery system for potent chemotherapeutics, where systemic side effects are a significant concern.

The binding mechanism of molecular interaction between bicalutamide and human serum albumin (HSA) in a pH 7.4 phosphate buffer was studied using various spectroscopic techniques in combination with molecular modeling. Fluorescence data revealed that the fluorescence quenching of HSA by bicalutamide was a static quenching procedure. The binding constants and number of binding sites were evaluated at different temperatures. The thermodynamic parameters, ΔH and ΔS, were calculated to be 4.30 × 10 4  J·mol -1 and 245 J·mol -1 ·K -1 , respectively, suggesting that the binding of bicalutamide to HSA was driven mainly by hydrophobic interactions and hydrogen bonds. The displacement studies indicated neither Sudlow's site I nor II but subdomain IB as the main binding site for bicalutamide on HSA. The binding distance between bicalutamide and HSA was determined to be 3.54 nm based on the Förster theory. Analysis of circular dichroism, synchronous, and 3D fluorescence spectra demonstrated that HSA conformation was slightly altered in the presence of bicalutamide., (© 2024 John Wiley & Sons Ltd.)

Intra-articular injection of drugs is an effective strategy for osteoarthritis (OA) treatment. However, the complex microenvironment and limited joint space result in rapid clearance of drugs. Herein, a nanogel-based strategy is proposed for prolonged drug delivery and microenvironment remodeling. Nanogel is constructed through the functionalization of hyaluronic acid (HA) by amide reaction on the surface of Kartogenin (KGN)-loaded zeolitic imidazolate framework-8 (denoted as KZIF@HA). Leveraging the inherent hydrophilicity of HA, KZIF@HA spontaneously forms nanogels, ensuring extended drug release in the OA microenvironment. KZIF@HA exhibits sustained drug release over one month, with low leakage risk from the joint cavity compared to KZIF, enhanced cartilage penetration, and reparative effects on chondrocytes. Notably, KGN released from KZIF@HA serves to promote extracellular matrix (ECM) secretion for hyaline cartilage regeneration. Zn 2+ release reverses OA progression by promoting M2 macrophage polarization to establish an anti-inflammatory microenvironment. Ultimately, KZIF@HA facilitates cartilage regeneration and OA alleviation within three months. Transcriptome sequencing validates that KZIF@HA stimulates the polarization of M2 macrophages and secretes IL-10 to inhibit the JNK and ERK pathways, promoting chondrocytes recovery and enhancing ECM remodeling. This pioneering nanogel system offers new therapeutic opportunities for sustained drug release, presenting a significant stride in OA treatment strategies., (© 2024 Wiley‐VCH GmbH.)

In situ mesenchymal stem cells (MSCs) regenerative therapy holds promising potential for treating osteoarthritis. However, MSCs engraftment and intra-articular inflammation limit the therapeutic efficacy of this approach. This study introduces porous microspheres (PMs) composed of aldehyde-modified poly(lactic-co-glycolic acid), that encapsulate platelet derived growth factor-AB and kartogenin. Metformin (Met) is also incorporated onto the microsphere through a Schiff base reaction to create PMs@Met. In vitro, in vivo and ex experiments revealed that PMs@Met can be injected into the joint cavity, effectively recruiting endogenous MSCs in situ. This approach creates a favorable environment for MSCs proliferation. It also controls the intra-articular inflammatory environment by modulating the polarization of synovial macrophages, ultimately promoting cartilage repair. In summary, our study presents an innovative tissue engineering strategy for the treatment of osteoarthritis-induced articular cartilage injuries. STATEMENT OF SIGNIFICANCE: Cell therapy using autologous mesenchymal stem cells (MSCs) has potential to slow the progression of osteoarthritis (OA). Nonetheless, there are some disadvantages to adopting in situ MSCs therapy, including difficulties with MSC engraftment into cartilage-deficient regions, the effect of intra-articular inflammation on MSC therapeutic efficacy, and attaining selective chondrogenic MSC differentiation. We created injectable PLGA microspheres (PMs) that were loaded with PDGF-AB and KGN. Metformin was bonded to the surface of microspheres using a Schiff base reaction. The microspheres can recruit intra-articular MSCs and encourage their development into chondrocytes. The microspheres actively modulate the inflammatory joint environment by altering synovial macrophage polarization, thereby supporting MSCs in effective cartilage treatment. To summarize, microspheres hold great potential in the treatment of OA., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier Ltd.)

We designed and synthesized an N-ortho -nitrobenzylated benzanilide-based amino acid having a cis -amide structure that facilitates cyclization of peptides containing it. Photo-induced removal of the nitrobenzyl group from this residue in the resulting cyclized peptides dramatically alters their conformation and passive membrane permeability via complete cis -amide to trans -amide conversion.

Occupancy of prostate cancer (PCa) cell androgen receptors (AR) signals proliferation, therefore testosterone biosynthesis inhibitors and AR antagonists are important PCa treatments. Conversely, androgen mimics (e.g., prednisone) used in management of PCa might cause proliferation. The balance between PCa proliferation and inhibition predicts treatment success. We used in silico molecular modelling to explore interactions between ARs, androgens (testosterone, dihydrotestosterone (DHT)) and drugs used to treat (bicalutamide) and manage (dexamethasone, prednisone, hydrocortisone) PCa. We found that hydrogen (H-) bonds between testosterone, DHT and Arg752, Asn705 and Thr877 followed by ligand binding cleft hydrophobic interactions signal proliferation, whereas bicalutamide antagonism is via Phe764 interactions. Hydrocortisone, dexamethasone and prednisone H-bond Asn705 and Thr877, but not Arg752 in the absence of a water molecule. Studies with a bicalutamide agonist AR mutation showed different amino acid interactions, indicating testosterone and DHT would not promote proliferation as effectively as via the native receptor. However, hydrocortisone and bicalutamide form Arg752 and Asn705 H-bonds indicating agonism. Our results suggest that as PCa progresses the resulting mutations will change the proliferative response to androgens and their drug mimics, which have implications for the treatment of prostate cancer., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

The study presents a thorough and detailed analysis of bicalutamide's structural and conformational properties. Quantum chemical calculations were employed to explore the conformational properties of the molecule, identifying significant energy differences between conformers. Analysis revealed that hydrogen bonds stabilise the conformers, with notable variations in torsion angles. Conformers were classified into 'closed' and 'open' types based on the relative orientation of the cyclic fragments. NOE spectroscopy in different solvents (CDCl 3 and DMSO-d 6 ) was used to study the conformational preferences of the molecule. NOESY experiments provided the predominance of 'closed' conformers in non-polar solvents and a significant presence of 'open' conformers in polar solvents. The proportions of open conformers were 22.7 ± 3.7% in CDCl 3 and 59.8 ± 6.2% in DMSO-d 6 , while closed conformers accounted for 77.3 ± 3.7% and 40.2 ± 6.2%, respectively. This comprehensive study underscores the solvent environment's impact on its structural behaviour. The findings significantly contribute to a deeper understanding of conformational dynamics, stimulating further exploration in drug development.

Platensilin, platensimycin, and platencin are potent inhibitors of β-ketoacyl-acyl carrier protein synthase (FabF) in the bacterial and mammalian fatty acid synthesis system, presenting promising drug leads for both antibacterial and antidiabetic therapies. Herein, a bioinspired skeleton reconstruction approach is reported, which enables the unified synthesis of these three natural FabF inhibitors and their skeletally diverse analogs, all stemming from a common ent -pimarane core. The synthesis features a diastereoselective biocatalytic reduction and an intermolecular Diels-Alder reaction to prepare the common ent -pimarane core. From this intermediate, stereoselective Mn-catalyzed hydrogen atom-transfer hydrogenation and subsequent Cu-catalyzed carbenoid C-H insertion afford platensilin. Furthermore, the intramolecular Diels-Alder reaction succeeded by regioselective ring opening of the newly formed cyclopropane enables the construction of the bicyclo[3.2.1]-octane and bicyclo[2.2.2]-octane ring systems of platensimycin and platencin, respectively. This skeletal reconstruction approach of the ent -pimarane core facilitates the preparation of analogs bearing different polycyclic scaffolds. Among these analogs, the previously unexplored cyclopropyl analog 47 exhibits improved antibacterial activity (MIC 80 = 0.0625 μg/mL) against S. aureus compared to platensimycin.

The degradation of three anti-cancer drugs (ADs), Capecitabine (CAP), Bicalutamide (BIC) and Irinotecan (IRI), in ultrapure water by ozonation and UV-irradiation was tested in a bench-scale reactor and AD concentrations were measured through ultra-high-performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS). A low-pressure mercury UV (LP-UV) lamp was used and degradation by UV (λ = 254 nm) followed pseudo-first order kinetics. Incident radiation in the reactor was measured via chemical actinometry using uridine. The quantum yields (φ) for the degradation of CAP, BIC and IRI were 0.012, 0.0020 and 0.0045 mol Einstein -1 , respectively. Ozone experiments with CAP and IRI were conducted by adding ozone stock solution to the reactor either with or without addition of tert-butanol (t-BuOH) as radical quencher. Using this experimental arrangement, no degradation of BIC was observed, so a semi-batch setup was employed for the ozone degradation experiments of BIC. Without t-BuOH, apparent second order reaction rate constants for the reaction of the ADs with molecular ozone were determined to be 3.5 ± 0.8 ∙ 10 3  L mol -1 s -1 (CAP), 7.9 ± 2.1 ∙ 10 -1  L mol -1 s -1 (BIC) and 1.0 ± 0.3 ∙ 10 3  L mol -1 s -1 (IRI). When OH-radicals (∙OH) were quenched, rate constants were virtually the same for CAP and IRI. For BIC, a significantly lower constant of 1.0 ± 0.5 ∙ 10 -1  L mol -1 s -1 was determined. Of the tested substances, BIC was the most recalcitrant, with the slowest degradation during both ozonation and UV-irradiation. The extent of mineralization was also determined for both processes. UV irradiation was able to fully degrade up to 80% of DOC, ozonation up to 30%. Toxicity tests with Daphnia magna (D. magna) did not find toxicity for fully degraded solutions of the three ADs at environmentally relevant concentrations., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Cancer is a disease of mutation and lifestyle modifications. A large number of normal genes can transform normal cells to cancer cells due to their deregulations including overexpression and loss of expression. Signal transduction is a complex signaling process that involves multiple interactions and different functions. C-Jun N-terminal kinases (JNKs) is an important protein involved in signaling process. JNK mediated pathways can detect, integrate, and amplify various external signals that may cause alterations in gene expression, enzyme activities, and different cellular functions that affect cellular behavior like metabolism, proliferation, differentiation, and cell survival. In this study, we performed molecular docking protocol (MOE) to predict the binding interactions of some known anticancer 1-hydroxynaphthalene-2-carboxanilides candidates. A set of 10 active compounds was retrieved after initial screening on the basis of docking scores, binding energies, and number of interactions and was re-docked in the active site of JNK protein. The results were further validated through molecular dynamics simulation and MMPB/GBSA calculations. The active compounds 4p and 5 k were ranked on top. After computationally exploring interactions of 1-hydroxynaphthalene-2-carboxanilides with JNK protein, we believe compounds 4p and 5 k can serve as potential inhibitors of JNK protein. It is believed that the results of current research would help to develop novel and structurally diverse anticancer compounds that will be useful not only treat cancer but also for the medication for the other diseases caused by protein deregulation., (© 2023. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Despite advanced diagnosis and detection technologies, prostate cancer (PCa) is the most prevalent neoplasms in males. Dysregulation of the androgen receptor (AR) is centrally involved in the tumorigenesis of PCa cells. Acquisition of drug resistance due to modifications in AR leads to therapeutic failure and relapse in PCa. An overhaul of comprehensive catalogues of cancer-causing mutations and their juxta positioning on 3D protein can help in guiding the exploration of small drug molecules. Among several well-studied PCa-specific mutations, T877A, T877S and H874Y are the most common substitutions in the ligand-binding domain (LBD) of the AR. In this study, we combined structure as well as dynamics-based in silico approaches to infer the mechanistic effect of amino acid substitutions on the structural stability of LBD. Molecular dynamics simulations allowed us to unveil a possible drug resistance mechanism that acts through structural alteration and changes in the molecular motions of LBD. Our findings suggest that the resistance to bicalutamide is partially due to increased flexibility in the H 12 helix, which disturbs the compactness, thereby reducing the affinity for bicalutamide. In conclusion, the current study helps in understanding the structural changes caused by mutations and could assist in the drug development process.Communicated by Ramaswamy H. Sarma.

Metamifop has been used to control gramineous weeds in paddy fields and may form residues in rice. In this study, the residue analysis method for metamifop and the metabolites was set up based on high-performance liquid chromatography-mass spectrometry and the chiral analysis method was also developed. The enantioselective degradation and residue of metamifop in rice processing were studied, and the major metabolites were monitored. The removal rate of metamifop by washing could reach 60.03%, while the loss in rice and porridge cooking was less than 16%. No decrease was found in fermentation into fermented grains, but metamifop was degraded in the process of rice wine fermentation with half-lives of around 9.5 days. N-(2-fluorophenyl)-2-(4-hydroxyphenoxy)-N-methylpropionamide and 6-chlorobenzo [d] oxazole-2 (3H)-one were found to be the major metabolites. This study reveals the enantioselective residue of metamifop in rice processing, which helps understand the potential risk in food consumption., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Ubiquitin-specific proteases (USPs) 28 is overexpressed in multiple types of cancers. The development of potent USP28 inhibitors is still in primitive stage. We previously reported our discovery of Vismodegib as a USP28 inhibitor by screening a commercially available drug library. Herein, we report our efforts to solve the cocrystal structure of Vismodegib bound to USP28 for the first time and subsequent structure-based optimization leading to a series of Vismodegib derivatives as potent USP28 inhibitors. Based on the cocrystal structure, elaborative SARs exploration was carried out to afford much more potent USP28 inhibitors than Vismodegib. The representative compounds 9l, 9o and 9p bearing high potency on USP28 showed high selectivity over USP2, USP7, USP8, USP9x, UCHL3 and UCHL5. The detailed cellular assay suggested that compounds 9l, 9o and 9p could cause cytotoxicity in both human colorectal cancer and lung squamous carcinoma cells and significantly enhance the sensitivity of colorectal cancer cells to Regorafenib. Further immunoblotting analysis indicated that compounds 9l, 9o and 9p could dose-dependently down-regulate the cellular level of c-Myc through ubiquitin-proteasome system and anti-cancer effects could mainly be attributed to their inhibition on USP28 but not involving the Hedgehog-Smoothened pathway. Thus, our work provided a series of novel and potent USP28 inhibitors derived from Vismodegib and may contribute to the development of USP28 inhibitors., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Masson SAS. All rights reserved.)

Molecule interacting with CasL 2 (MICAL2), a cytoskeleton dynamics regulator, are strongly expressed in several human cancer types, especially at the invasive front, in metastasizing cancer cells and in the neo-angiogenic vasculature. Although a plethora of data exist and stress a growing relevance of MICAL2 to human cancer, it is worth noting that only one small-molecule inhibitor, named CCG-1423 (1), is known to date. Herein, with the aim to develop novel MICAL2 inhibitors, starting from CCG-1423 (1), a small library of new compounds was synthetized and biologically evaluated on human dermal microvascular endothelial cells (HMEC-1) and on renal cell adenocarcinoma (786-O) cells. Among the novel compounds, 10 and 7 gave interesting results in terms of reduction in cell proliferation and/or motility, whereas no effects were observed in MICAL2-knocked down cells. Aside from the interesting biological activities, this work provides the first structure-activity relationships (SARs) of CCG-1423 (1), thus providing precious information for the discovery of new MICAL2 inhibitors.

PtmU3 is a newly identified nonheme diiron monooxygenase, which installs a C-5 β-hydroxyl group into the C-19 CoA-ester intermediate involved in the biosynthesis of unique diterpene-derived scaffolds of platensimycin and platencin. PtmU3 possesses a noncanonical diiron active site architecture of a saturated six-coordinate iron center and lacks the μ-oxo bridge. Although the hydroxylation process is a simple reaction for nonheme mononuclear iron-dependent enzymes, how PtmU3 employs the diiron center to catalyze the H-abstraction and OH-rebound is still unknown. In particular, the electronic characteristic of diiron is also unclear. To understand the catalytic mechanism of PtmU3, we constructed two reactant models in which both the Fe1 II -Fe2 III -superoxo and Fe1 II -Fe2 IV ═O are considered to trigger the H-abstraction and performed a series of quantum mechanics/molecular mechanics calculations. Our calculation results reveal that PtmU3 is a special monooxygenase, that is, both atoms of the dioxygen molecule can be incorporated into two molecules of the substrate by the successive reactions. In the first-round reaction, PtmU3 uses the Fe1 II -Fe2 III -superoxo to install a hydroxyl group into the substrate, generating the high-reactive Fe1 II -Fe2 IV ═O complex. In the second-round reaction, the Fe1 II -Fe2 IV ═O species is responsible for the hydroxylation of another molecule of the substrate. In the diiron center, Fe2 adopts the high spin state ( S = 5/2) during the catalysis, whereas for Fe1, in addition to its structural role, it may also play an assistant role for Fe1 catalysis. In the two successive OH-installing steps, the H-abstraction is always the rate-liming step. E241 and D308 not only act as bridging ligands to connect two Fe ions but also take part in the electron reorganization. Owing to the high reactivity of Fe1 II -Fe2 IV ═O compared to Fe1 II -Fe2 III -superoxo, besides the C5-hydroxylation, the C3- or C18-hydroxylation was also calculated to be feasible.

Peroxisome proliferator-activated receptor gamma (PPARγ), a member of the nuclear receptor superfamily is an excellent example of targets that orchestrates cancer, inflammation, lipid and glucose metabolism. We report a protocol for the development of novel PPARγ antagonists by employing 3D QSAR based virtual screening for the identification of ligands with anticancer properties. The models are generated based on a large and diverse set of PPARγ antagonist ligands by the HYPOGEN algorithm using Discovery Studio 2019 drug design software. Among the 10 hypotheses generated, Hypotheses 2 showed the highest correlation coefficient values of 0.95 with less RMS deviation of 1.193. Validation of the developed pharmacophore model was performed by Fischer's randomization and screening against test and decoy set. The GH score or goodness score was found to be 0.81 indicating moderate to a good model. The selected pharmacophore model Hypo 2 was used as a query model for further screening of 11,145 compounds from the PubChem, sc-PDB structure database, and designed novel ligands. Based on fit values and ADMET filter, the final 10 compounds with the predicated activity of ≤ 3 nM were subjected for docking analysis. Docking analysis revealed the unique binding mode with hydrophobic amino acid that can cause destabilization of the H12 which is an important molecular mechanism to prove its antagonist action. Based on high CDocker scores, Cpd31 was synthesized, purified, analyzed and screened for PPARγ competitive binding by TR-FRET assay. The biochemical protein binding results matched the predicted results. Further, Cpd31 was screened against cancer cells and validated the results., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

In this study, three natural biomaterials, Locust bean gum (LBG), Xanthan gum (XG), and Mastic gum (MG), were combined to form cryogel scaffolds. Thermal and chemical characterizations revealed the successful blend formation from LBG-XG (LX) and LBG-XG-MG (LXM) polymers. All blends resulted in macro-porous scaffolds with interconnected pore structures under the size of 400 μm. The swollen cryogels had similar mechanical properties compared with other polysaccharide-based cryogels. The mean tensile and compressive modulus values of the wet cryogels were in the range of 3.5-11.6 kPa and 82-398 kPa, respectively. The sustained release of the small molecule Kartogenin from varying concentrations and ratios of cryogels was in between 32 and 66% through 21 days of incubation. Physical, mechanical, and chemical properties make LX and LXM polysaccharide-based cryogels promising candidates for cartilage and other soft tissue engineering, and drug delivery applications., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Development of inhibitors targeting CDK12/13 is of increasing interest as a potential therapy for cancers as these compounds inhibit transcription of DNA damage response (DDR) genes. We previously described THZ531, a covalent inhibitor with selectivity for CDK12/13. In order to elucidate structure-activity relationship (SAR), we have undertaken a medicinal chemistry campaign and established a focused library of THZ531 analogs. Among these analogs, BSJ-01-175 demonstrates exquisite selectivity, potent inhibition of RNA polymerase II phosphorylation, and downregulation of CDK12-targeted genes in cancer cells. A 3.0 Å co-crystal structure with CDK12/CycK provides a structural rational for selective targeting of Cys1039 located in a C-terminal extension from the kinase domain. With moderate pharmacokinetic properties, BSJ-01-175 exhibits efficacy against an Ewing sarcoma tumor growth in a patient-derived xenograft (PDX) mouse model following 10 mg/kg once a day, intraperitoneal administration. Taken together, BSJ-01-175 represents the first selective CDK12/13 covalent inhibitor with in vivo efficacy reported to date., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: N.S.G. is a founder, science advisory board member (SAB) and equity holder in Gatekeeper, Syros, Petra, C4, B2S, Aduro and Soltego. The Gray lab receives or has received research funding from Novartis, Takeda, Astellas, Taiho, Janssen, Kinogen, Voronoi, Her2llc, Deerfield. Ephiphanes and Sanofi. N.S.G., T. Z. and B. J. are named inventors on patent applications covering compounds described in this manuscript., (Copyright © 2021 Elsevier Masson SAS. All rights reserved.)

In this study, we fabricated two different arrangements of laminated composite scaffolds based on Alginate:Alginate sulfate hydrogel, PCL:Gelatin electrospun mat, and Kartogenin-PLGA nanoparticles (KGN-NPs). The optimized composite scaffold revealed a range of advantages such as improved mechanical features as well as less potential of damage (less dissipated energy), interconnected pores of hydrogel and fiber with adequate pore size, excellent swelling ratio, and controlled biodegradability. Furthermore, the synthesized KGN-NPs with spherical morphology were incorporated into the composite scaffold and exhibited a linear and sustained release of KGN within 30 days with desirable initial burst reduction (12% vs. 20%). Additionally, the cytotoxicity impact of the composite was evaluated. Resazurin assay and Live/Dead staining revealed that the optimized composite scaffold has no cytotoxic effect and could improve cell growth. Overall, according to the enhanced mechanical features, suitable environment for cellular growth, and sustained drug release, the optimized scaffold would be a good candidate for tissue regeneration., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Epigenetic regulation by histone deacetylase (HDAC) is associated with synaptic plasticity and memory formation, and its aberrant expression has been linked to cognitive disorders, including Alzheimer's disease (AD). This study aimed to investigate the role of class IIa HDAC expression in AD and monitor it in vivo using a novel radiotracer, 6-(tri-fluoroacetamido)-1-hexanoicanilide ([ 18 F]TFAHA). A human neural cell culture model with familial AD (FAD) mutations was established and used for in vitro assays. Positron emission tomography (PET) imaging with [ 18 F]TFAHA was performed in a 3xTg AD mouse model for in vivo evaluation. The results showed a significant increase in HDAC4 expression in response to amyloid-β (Aβ) deposition in the cell model. Moreover, treatment with an HDAC4 selective inhibitor significantly upregulated the expression of neuronal memory-/synaptic plasticity-related genes. In [ 18 F]TFAHA-PET imaging, whole brain or regional uptake was significantly higher in 3xTg AD mice compared with WT mice at 8 and 11 months of age. Our study demonstrated a correlation between class IIa HDACs and Aβs, the therapeutic benefit of a selective inhibitor, and the potential of using [ 18 F]TFAHA as an epigenetic radiotracer for AD, which might facilitate the development of AD-related neuroimaging approaches and therapies.

Here we report the direct conversion of strong, aliphatic C( sp 3 )-H bonds into the corresponding alkyl sulfinic acids via decatungstate photocatalysis. This transformation has been applied to a diverse range of C( sp 3 )-rich scaffolds, including natural products and approved pharmaceuticals, providing efficient access to complex sulfur-containing products. To demonstrate the broad potential of this methodology for the divergent synthesis of pharmaceutically relevant molecules, procedures for the diversification of the sulfinic acid products into a range of medicinally relevant functional groups have been developed.

The GLUT is a key regulator of glucose metabolism and is widely expressed on the surface of most cells of the body. GLUT provides a variety of nutrients for the growth, proliferation and differentiation of cells. In recent years, the development of drugs affecting the energy intake of tumor cells has become a research hotspot. GLUT inhibitors are gaining increased attention because they can block the energy supply of malignant tumors. Herein, we elaborate on the structure and function of GLUT1, the structural and functional differences among GLUT1-4 transporters and the relationship between GLUT1 and tumor development, as well as GLUT1 transporter inhibitors, to provide a reference for the development of new GLUT1 inhibitors.

In the current work, the binding interaction of cabozantinib with salmon sperm DNA (SS-DNA) was studied under simulated physiological conditions (pH 7.4) using fluorescence emission spectroscopy, UV-Vis absorption spectroscopy, viscosity measurement, ionic strength measurement, FT-IR spectroscopy, and molecular modeling methods. The obtained experimental data demonstrated an apparent binding interaction of cabozantinib with SS-DNA. The binding constant (K b ) of cabozantinib with SS-DNA evaluated from the Benesi-Hildebrand plot was equal to 5.79 × 10 5 at 298 K. The entropy and enthalpy changes (∆S 0 and ∆H 0 ) in the binding interaction of SS-DNA with cabozantinib were 44.13 J mol -1 K -1 and -19.72 KJ mol -1 , respectively, demonstrating that the basic binding interaction forces are hydrophobic and hydrogen bonding interactions. Results from UV-Vis absorption spectroscopy, competitive binding interaction with rhodamine B or ethidium bromide, and viscosity measurements revealed that cabozantinib binds to SS-DNA via minor groove binding. The molecular docking results revealed that cabozantinib fits into the AT-rich region of the B-DNA minor groove and the binding site of cabozantinib was 4 base pairs long. Moreover, cabozantinib has eight active torsions, implying a high degree of flexibility in its structure, which played a significant role in the formation of a stable cabozantinib-DNA complex., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Triple-negative breast cancer (TNBC) has an unfavorable prognosis attribute to its low differentiation, rapid proliferation and high distant metastasis rate. PI3K/Akt/mTOR as an intracellular signaling pathway plays a key role in the cell proliferation, migration, invasion, metabolism and regeneration. In this work, we designed and synthesized a series of anilide (dicarboxylic acid) shikonin esters targeting PI3K/Akt/mTOR signaling pathway, and assessed their antitumor effects. Through three rounds of screening by computer-aided drug design method (CADD), we preliminarily obtained sixteen novel anilide (dicarboxylic acid) shikonin esters and identified them as excellent compounds. CCK-8 assay results demonstrated that compound M9 exhibited better antiproliferative activities against MDA-MB-231, A549 and HeLa cell lines than shikonin (SK), especially for MDA-MB-231 (M9: IC 50  = 4.52 ± 0.28 μM; SK: IC 50  = 7.62 ± 0.26 μM). Moreover, the antiproliferative activity of M9 was better than that of paclitaxel. Further pharmacological studies showed that M9 could induce apoptosis of MDA-MB-231 cells and arrest the cell cycle in G2/M phase. M9 also inhibited the migration of MDA-MB-231 cells by inhibiting Wnt/β-catenin signaling pathway. In addition, western blot results showed that M9 could inhibit cell proliferation and migration by down-regulating PI3K/Akt/mTOR signaling pathway. Finally, a three-dimensional quantitative structure-activity relationship (3D-QSAR) model was also constructed to provide a basis for further development of shikonin derivatives as potential antitumor drugs through structure-activity relationship analysis. To sum up, M9 could be a potential candidate for TNBC therapy., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Cartilage regeneration using biomaterial-guided delivery systems presents improved therapeutic efficacy of the biomolecules while minimizing side effects. Here, our hypothesis was to design a multilayer scaffold of chitosan (CS) hydrogel and polycaprolactone (PCL) mat to enhance the mechanical properties, integrity and stability of CS, especially for subsequent in vivo transplantation. After conjugation of the Kartogenin (KGN) into this structure, its gradual release can promote chondrogenesis of mesenchymal stem cells (MSCs). Initially, a thin electrospun PCL layer was sandwiched between two CS hydrogels. Subsequently, KGN was superficially immobilized onto the CS matrix. The successful conjugation was confirmed by scanning electron microscopy (SEM) and infrared spectroscopy. These novel KGN-conjugated scaffolds possessed lower swelling and higher compressive modulus and showed gradual release of KGN in longer retention times. Immunofluorescent and histological staining represented more cells located in lacunae as well as more Coll2 and Sox9 positive cells on KGN-conjugated scaffolds. Gene expression analysis also revealed that SOX9, COLL2 and ACAN expression levels were higher in the presence of KGN, while COLLX expression was down-regulated, indicating a hypertrophy phenomenon with synergistic effect of TGF-β. This multilayer structure not only facilitates the effective treatment, but also provides a proper mechanical structure for cartilage engineering., Competing Interests: Declaration of competing interest The authors declare that there is no conflict of interests regarding the publication of this paper., (Copyright © 2018. Published by Elsevier B.V.)

A series of PROTACs (PROteolysis-TArgeting Chimeras) consisting of bicalutamide analogs and thalidomides were designed, synthesized, and biologically evaluated as novel androgen receptor (AR) degraders. In particular, we found that PROTAC compound 13b could successfully demonstrate a targeted degradation of AR in AR-positive cancer cells and might be a useful chemical probe for the investigation of AR-dependent cancer cells, as well as a potential therapeutic candidate for prostate cancers.

Cartilage is an avascular tissue with low cellularity and insufficient self-repair response. In clinical practice, a large articular cartilage defect is usually fixed by cartilage transplantation. Importantly, the fast repair process has been demanded postoperatively in the area between the host cartilage and the transplanted cartilage. In the past few years, magnetic nanoparticles have drawn great attention due to their biocompatible, biodegradable, and nontoxic properties. In addition, the nanoparticles can easily pass through the cell plasma membrane and increase the cellular uptake efficiency. Here, a therapeutic drug delivery strategy was proposed for cartilage repair. The prepared kartogenin (KGN)-conjugated magnetic nanocarriers (KGN@NCs) promoted the viability of chondrocytes in vitro. In a rat model of cartilage transplantation, intra-articularly delivered KGN@NCs generated cartilage with a flat surface and a high level of aggrecan in vivo. Notably, KGN@NCs were also capable of improving the pain-related motor functions. They promoted the motor functional parameters including the print area and intensity to restore to a normal level compared with the single KGN. Therefore, these therapeutic drug nanocarriers provided the potential for cartilage repair.

Natural product congeners serve a useful role in the understanding of natural product biosynthesis and structure-activity relationships. A minor congener with superior activity, selectivity, and modifiable functional groups could serve as a more effective lead structure and replace even the original lead molecule that was used for medicinal chemistry modifications. Currently, no effective method exists to discover targeted congeners rapidly, specifically, and selectively from producing sources. Herein, a new method based on liquid-chromatography tandem-mass spectrometry combination is evaluated for targeted discovery of congeners of platensimycin and platencin from the extracts of Streptomyces platensis . By utilizing a precursor-ion searching protocol, tandem mass spectrometry not only confirmed the presence of known congeners but also provided unambiguous detection of many previously unknown congeners of platensimycin and platencin. This high-throughput and quantitative method can be rapidly and broadly applied for dereplication and congener discovery from a variety of producing sources, even when the targeted compounds are obscured by the presence of unrelated natural products.

Starting from the N-hydroxy-3-(4-(2-phenylbutanoyl)amino)phenyl)acrylamide (5 b) previously described by us as a HDAC inhibitor, we prepared four aza-analogues, 6-8, 9 b, as regioisomers containing the pyridine nucleus. Preliminary screening against mHDAC1 highlighted the N-hydroxy-5-(2-(2-phenylbutanoyl)amino)pyridyl)acrylamide (9 b) as the most potent inhibitor. Thus, we further developed both pyridylacrylic- and nicotinic-based hydroxamates (9 a, 9 c-f, and 11 a-f) and 2'-aminoanilides (10 a-f and 12 a-f), related to 9 b, to be tested against HDACs. Among them, the nicotinic hydroxamate 11 d displayed sub-nanomolar potency (IC 50 : 0.5 nM) and selectivity up to 34 000 times that of HDAC4 and from 100 to 1300 times that of all the other tested HDAC isoforms. The 2'-aminoanilides were class I-selective HDAC inhibitors, generally more potent against HDAC3, with the nicotinic anilide 12 d being the most effective (IC 50 HDAC3 =0.113 μM). When tested in U937 leukemia cells, the hydroxamates 9 e, 11 c, and 11 d blocked over 80 % of cells in G2/M phase, whereas the anilides did not alter cell-cycle progress. In the same cell line, the hydroxamate 11 c and the anilide 10 b induced about 30 % apoptosis, and the anilide 12 c displayed about 40 % cytodifferentiation. Finally, the most potent compounds in leukemia cells 9 b, 11 c, 10 b, 10 e, and 12 c were also tested in K562, HCT116, and A549 cancer cells, displaying antiproliferative IC 50 values at single-digit to sub-micromolar level., (© 2020 Wiley-VCH GmbH.)

The androgen receptor (AR) is a pivotal target for the treatment of prostate cancer (PC) even when the disease progresses toward androgen-independent or castration-resistant forms. In this study, a series of sulfoxide derivatives were prepared and their antiproliferative activity evaluated in vitro against four different human prostate cancer cell lines (22Rv1, DU-145, LNCaP and VCap). Bicalutamide and enzalutamide were used as positive controls. Compound 28 displayed significant enhancement in anticancer activity across the four PC cell lines with IC 50  = 9.09 - 31.11 µM compared to the positive controls: bicalutamide (IC 50  = 45.20 -51.61 µM) and enzalutamide (IC 50  = 11.47 - 53.04 µM). Sulfoxide derivatives of bicalutamide were prepared efficiently from the corresponding sulfides using only one equivalent of mCPBA, limiting the reaction time to 15-30 min and maintaining the temperature at 0 °C. Interestingly, three pairs of sulfoxide diastereomers were separated and NMR comparison of their diastereotopic methylene (CH 2 ) group is presented. X-ray diffraction crystal structure analysis provided relative configuration assignment at the chiral sulfur and carbon centres. Molecular modelling study of the four diastereoisomers of compound 28 is described., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

AR-15512 (formerly known as AVX-012 and WS-12) is a TRPM8 receptor agonist currently in phase 2b clinical trials for the treatment of dry eye. This bioactive compound with menthol-like cooling activity has three stereogenic centers, and its final structure and absolute configuration, (1 R ,2 S ,5 R ), have been previously solved by cryo-electron microscopy. The route of synthesis of AR-15512 has also been reported, revealing that epimerization processes at the C-1 can occur at specific stages of the synthesis. In order to confirm that the desired configuration of AR-15512 does not change throughout the process and to discard the presence of the enantiomer in the final product due to possible contamination of the initial starting material, both the enantiomer of AR-15512 and the diastereomer at the C-1 were synthesized and fully characterized. In addition, the absolute configuration of the (1 S ,2 S ,5 R )-diastereomer was determined by X-ray crystallographic analysis, and new HPLC methods were designed and developed for the identification of the two stereoisomers and their comparison with the clinical candidate AR-15512.

Deubiquitinase USP28 plays a crucial role in tumorigenesis by enhancing the stabilities of multiple cancer-related proteins including c-Myc, Notch1, and LSD1, and has become an attractive target for anticancer drug development. However, to date, only a few of USP28-targeted active compounds have been developed, and the active compound-binding pocket in USP28 has not been experimentally revealed yet. In this study, bioassay-based high-throughput screening was applied to discover USP28-targeted inhibitors from the commercially available drug library. Vismodegib, an inhibitor of Hedgehog signaling pathway and FDA-approved drug for the treatment of basal cell carcinoma, was found to exhibit inhibition activity against USP28 (IC 50 : 4.41 ± 1.08 μm). Multiple biophysical and biochemical techniques including NMR, ITC, thermal shift assay, HDX-MS, and site-directed mutagenesis analysis were then used to characterize the interaction between Vismodegib and USP28. The binding pocket in USP28 for Vismodegib, which is mainly composed of two helical structures spanning D255-N278 and N286-Y293, was revealed. According to the possible binding pose generated by HDX-MS data-defined molecular docking, the binding cavity occupied by Vismodegib in USP28 aligns well with one of the reported-binding pockets in USP7 for its inhibitors. Furthermore, cellular assays were conducted to confirm that Vismodegib could interact with the evolutionarily related deubiquitinases USP28 and USP25 and downregulate the levels of the two enzymes' substrate proteins c-Myc, Notch1, and Tankyrase-1/2., (© 2020 Federation of European Biochemical Societies.)

NUAK, the member of AMPK (AMP-activated protein kinase) family of protein kinases, is phosphorylated and activated by the LKB1 (liver kinase B1) tumor suppressor protein kinase. Recent work has indicated that NUAK1 is a key component of the antioxidant stress response pathway, and the inhibition of NUAK1 will suppress the growth and survival of colorectal tumors. As a promising target for anticancer drugs, few inhibitors of NUAK were developed. With this goal in mind, based on NUAK inhibitor WZ4003, a series of derivatives has been synthesized and evaluated for anticancer activity. Compound 9q, a derivative of WZ4003 by removing a methoxy group, was found to be the most potential one with stronger inhibitory against NUAK1/2 enzyme activity, tumor cell proliferation and inducing apoptosis of tumor cells. By in vivo efficacy evaluations of colorectal SW480 xenografts, 9q suppresses tumor growth more effectively with an excellent safety profile in vivo and is therefore seen as a suitable candidate for further investigation., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Masson SAS. All rights reserved.)

The androgen receptor (AR) is a pivotal target for the treatment of prostate cancer (PC) even when the disease progresses toward androgen-independent or castration-resistant forms. In this study, a series of 15 bicalutamide analogues (sulfide, deshydroxy, sulfone, and O -acetylated) were prepared and their antiproliferative activity evaluated against four different human prostate cancer cell lines (22Rv1, DU-145, LNCaP, and VCap). Bicalutamide and enzalutamide were used as positive controls. Seven of these compounds displayed remarkable enhancement in anticancer activity across the four PC cell lines. The deshydroxy analogue ( 16 ) was the most active compound with IC 50 = 6.59-10.86 µM. Molecular modeling offers a plausible explanation of the higher activity of the sulfide analogues compared to their sulfone counterparts.

C-Terminally thioesterificated peptides are essential building blocks for chemical protein synthesis. To date, many acyl transfer auxiliaries have been developed to enable facile preparation of peptide thioesters. We previously developed an N-sulfanylethylanilide (SEAlide) auxiliary, which causes an N-S acyl transfer reaction upon addition of phosphate salt to convert a C-terminal amide to a thioester. The mechanism of how phosphate triggers the reaction is speculative, and the details are unknown. In this study, the mechanism by which phosphate promotes acyl transfer is discussed based on density functional theory (DFT) calculations and non-covalent interaction (NCI) analysis. As a result, although the notion that phosphate acts as an acid-base catalyst, as speculated in our previous study, was correct, it became clear that two competing reaction pathways exist: a previously proposed stepwise pathway and a concerted one. Furthermore, calculation was performed in the presence of various additives other than phosphate to uncover the effect of the additives on the stability of transition states.

Inosine-5'-monophosphate dehydrogenase (IMPDH) is a potential target for microorganisms. However, identifying inhibitor design determinants for IMPDH orthologs continues to evolve. Herein, a series of mycophenolic anilide inhibitors of Cryptosporidium parvum and human IMPDHs are reported. Furthermore, molecular docking of 12 (e.g. SH-19; CpIMPDH K i,app  = 0.042 ± 0.015 µM, HsIMPDH2 K i,app  = 0.13 ± 0.05 µM) supports different binding modes with the two enzymes. For CpIMPDH the inhibitor extends into a pocket in an adjacent subunit. In contrast, docking suggests the inhibitor interacts with Ser276 in the NAD binding site in HsIMPDH2, as well as an adjacent pocket within the same subunit. These results provide further guidance for generating IMPDH inhibitors for enzymes found in an array of pathogenic microorganisms, including Mycobacterium tuberculosis., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

It is now 30 years since the first report of a potent zinc-dependent histone deacetylase (HDAC) inhibitor appeared. Since then, five HDAC inhibitors have received regulatory approval for cancer chemotherapy while many others are in clinical development for oncology as well as other therapeutic indications. This Perspective reviews the biological and medicinal chemistry advances over the past 3 decades with an emphasis on the design of selective inhibitors that discriminate between the 11 human HDAC isoforms.

The studies were aimed at formulating tablets containing bicalutamide-PVP K-29/32 solid dispersions and accessing the interrelationships between the properties of obtained binary systems in the form of powder and compacts. The effect of the compression of the solid dispersions obtained by either milling or using the supercritical fluid method on the dissolution and phase transition of the drug was investigated. Mechanical stress induced the amorphization of the drug, while the treatment with supercritical carbon dioxide did not cause any phase transition as confirmed by X-ray diffractometry. Co-processing of the drug substance with the carrier resulted in even a 10-fold improvement of the bicalutamide dissolution from the solid dispersions. The release of the drug from tablets was lower than from the corresponding powder system.

A collaborative study was conducted to understand the correlation between pigments purity profile (primary aromatic amine content of the pigments) and the behaviour of these PAAs during cold water extraction (CWE) tests according to EN 645. From a selection of organic pigments based on seven colour indexes (PR122, PR184, PO13, PY74, PY111, PY138 and PY155), the pigment purity profile was established according to European Resolution AP (89) 1, then mono-pigmented inks were prepared and napkins printed with these inks. In a second step, cold water extraction and PAA determination were performed by two independent laboratories. In one laboratory, an analytical method based on LC-MS/MS was used, whereas in the other laboratory a method based on LC-HRMS using Orbitrap technology was developed for the simultaneous analysis of 35 PAAs. Good qualitative results were obtained if we consider that at significant levels the PAAs were positively detected in both laboratories, except for 3-amino-4-methoxybenzanilide and 8-amino-2-methyl-quinoline, for which inter-laboratory differences were observed. It was also shown that no contamination from unexpected PAAs was detected. The comparison between pigment analysis and CWE results shows that if the pigment purity profile is of major importance, other parameters such as pigment surface treatment, ink grinding process or ink formulation could have an important influence on the CWE results. For such sensitive applications, for example napkins or other Food Contact Materials (FCM), it is therefore recommended not only to select a pigment with a good purity profile but also to test the pigment in the final application. Finally, this work highlights the difficulty of validating a product on a single analysis and shows the importance of a multilevel global assessment on worst case application.

Oral administration of vismodegib for basal cell carcinoma treatment is limited by significant class-specific systemic side effects. We investigated the approach of combining ablative fractional laser-assisted drug delivery with an extended-release microemulsion formulation of vismodegib to provide efficient cutaneous delivery in vivo. The developed formulation consisted of an oil-in-water microemulsion stabilized by Tween-80. Pig skin was exposed to ablative fractional laser followed by topical application of vismodegib microemulsion for 4 hours. At 4 hours, 2 days, 5 days, and 9 days, we evaluated vismodegib biodistribution in superficial, mid, and deep dermis and plasma (n = 189 measurements) and assessed local skin reactions. Sustained topical delivery of vismodegib was detected in all depths of ablative fractional laser-exposed skin over the course of the study, with peak concentrations found at 5 days and 9 days. The highest vismodegib concentrations reached 1,409.7 μmol/liter in superficial dermis and 62.3 μmol/liter in deep dermis, exceeding steady-state plasma concentrations previously reported for oral administration of vismodegib (5.5-56.0 μmol/liter). Ablative fractional laser increased vismodegib uptake up to 16.6-fold compared with intact skin. Only mild local skin responses to vismodegib were observed, and no vismodegib was detected in plasma. We report sustained topical delivery of vismodegib in vivo at high concentrations with favorable skin tolerability, suggesting a future safer vismodegib treatment., (Copyright © 2020 The Authors. Published by Elsevier Inc. All rights reserved.)

Histone deacetylases (HDACs) are an attractive therapeutic target for a variety of human diseases. Currently, all four FDA-approved HDAC-targeting drugs are nonselective, pan-HDAC inhibitors, exhibiting adverse side effects at therapeutic doses. Although selective HDAC inhibition has been proposed to mitigate toxicity, the targeted catalytic domains are highly conserved. Herein, we describe a series of rationally designed, conformationally constrained, benzanilide foldamers which selectively bind the catalytic tunnel of HDAC8. The series includes benzanilides, MMH371 , MMH409 , and MMH410 , which exhibit potent in vitro HDAC8 activity (IC 50 = 66, 23, and 66 nM, respectively) and up to 410-fold selectivity for HDAC8 over the next targeted HDAC. Experimental and computational analyses of the benzanilide structure docked with human HDAC8 enzyme showed the adoption of a low-energy L-shaped conformer that favors HDAC8 selectivity. The conformationally constrained HDAC8 inhibitors present an alternative biological probe for further determining the clinical utility and safety of pharmacological knockdown of HDAC8 in diseased cells.

A simple and sensitive ultra-high-performance liquid chromatography tandem mass spectrometric method was developed and validated for the determination of foretinib in rat plasma. The analyte and internal standard were extracted from the bio-samples with acetonitrile and then separated on an Acquity UPLC BEH C 18 column (50 × 2.1 mm, 1.7 μm) using 0.1% formic acid aqueous and acetonitrile as mobile phase, at a flow rate of 0.4 ml/min. The mass detection was performed in positive selected reaction monitoring mode with precursor-to-product transitions at m/z 317.1 > 128.1 for foretinib and m/z 502.2 > 323.1 for internal standard. The assay was demonstrated to be linear in the concentration range of 0.5-1000 ng/ml, with correlation coefficient >0.999. The mean extraction recovery of foretinib from rat plasma was within the range of 84.55-88.09%, while the matrix effect was in the range of 88.56-99.21%. The intra- and inter-day precisions were <12.95% and the accuracy ranged from -7.55 to 8.57%. Foretinib was stable in rat plasma under the tested storage conditions. The validated assay was successfully applied to the pharmacokinetic study of foretinib in the rats. The results revealed that foretinib showed moderate elimination half-life, low clearance and dose-independent pharmacokinetic profiles inrats., (© 2020 John Wiley & Sons, Ltd.)

Purpose: Cancer immunotherapy has shown huge potential in the fight against cancer, but only a small proportion of patients respond successfully to treatment. Non-invasive methods to stratify responders from non-responders are critically important as immune therapies are often associated with immune-related side effects. Currently, conventional clinical imaging modalities do not provide a useful measure of immune therapy efficacy. Sensitive imaging biomarkers that provide information about the tumoural microenvironment may provide useful insights allowing for improved patient management., Procedures: We have assessed the ability of a number of radiopharmaceuticals to non-invasively measure different aspects of the tumour microenvironment and correlated tumour uptake to immune therapy response in a syngeneic model of colon cancer, CT26-WT. Four radiopharmaceuticals, [ 18 F]FDG (a glucose analogue), [ 18 F]FEPPA (a marker for macrophage activation), [ 18 F]FB-IL2 (a marker for CD25 + cells) and [ 68 Ga] Ga-mNOTA-GZP (a marker for granzyme B, the serine protease downstream effector of cytotoxic T cells), were assessed as potential biomarkers to help stratify response to PD-1 monotherapy or combined anti-PD1 and CLTA4 therapy in vivo correlating tumour uptake with changes in tumour-associated immune cell populations., Results: [ 18 F]FDG, [ 18 F]FEPPA and [ 18 F]FB-IL2 (a marker for CD25 + cells) showed limited ability to determine therapy response and showed little correlation to tumour-associated immune cell changes. However, [ 68 Ga] Ga-mNOTA-GZP showed good predictive ability and correlated well with changes in tumour-associated T cells, especially CD8 + T cells., Conclusions: [ 68 Ga]Ga-mNOTA-GZP uptake correlates well with changes in CD8 + T cell populations supporting continued development of granzyme B-based imaging agents for stratification of response to immunotherapy. Early assessment of immunotherapy efficacy with [ 68 Ga]Ga-mNOTA-GZP may allow for the reduction of unnecessary side effects while significantly improving patient management.

In the present study eighteen inhibitors of the hydrolytic enzymes of the endocannabinoid system were investigated for antioxidant activity using lipid peroxidation (LP) method. Among the assayed compounds ten belong to carbamates with phenyl [1,1'-biphenyl]-3-ylcarbamate (6), reported for the first time, and eight are retro-amide derivatives of palmitamine. Interestingly, results indicated that most of the tested compounds have good antioxidant properties. In particular, 1,3-di([1,1'-biphenyl]-3-yl)urea (3) shows IC 50  = 26 ± 6 μM comparable to ones obtained for standard antioxidants trolox and quercetin (IC 50  = 22 ± 6 μM and 23 ± 6 μM, respectively). Compound 3 was investigated further by means of DFT calculations, to clarify a possible mechanism of the antioxidant action. In order to estimate the capability of 3 to act as radical scavenger the structure was optimized at B3LYP/6-311++G** level and the respective bond dissociation enthalpies were calculated. The calculations in non-polar medium predicted as favorable mechanism a donation of a hydrogen atom to the free radical and formation of N-centered radical, while in polar solvents the mechanism of free radical scavenging by SPLET dominates over HAT H-abstraction. The possible radical scavenging mechanisms of another compound with potent antioxidant properties (IC 50  = 53 ± 12 μM), the retro-amide derivative of palmitamine (compound 18), was estimated computationally based on the reaction enthalpies of a model compound (structural analogue to 18). The computations indicated that the most favorable mechanisms are hydrogen atom transfer from the hydroxyl group in meta-position of the benzamide fragment in nonpolar medium, and proton transfer from the hydroxyl group in ortho-position of the benzamide fragment in polar medium., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier B.V. All rights reserved.)

The feasibility of using activity-directed synthesis to drive antibacterial discovery was investigated. An array of 220 Pd-catalysed microscale reactions was executed, and the crude product mixtures were evaluated for activity against Staphylococcus aureus. Scale-up of the hit reactions, purification and evaluation, enabled expansion of a class of antibacterial quinazolinones. The novel antibacterials had MICs from 0.016 μg mL-1 (i.e. 38 nM) to 2-4 μg mL-1 against S. aureus ATCC29213.