Reference Compounds Research Articles

Online Comprehensive Two-Dimensional Liquid Chromatography/Quadrupole Time-of-Flight Mass Spectrometry-Based Metabolic Profiling and Comparison Enabling the Characterization of 1146 Ginsenosides and More Explicit Differentiation of Ginseng.

This work was designed for the in-depth characterization and holistic comparison of up to 12 ginseng varieties, which can benefit the development of functional foods and ensure their authenticity in the food industry. An online comprehensive two-dimensional liquid chromatography/quadrupole time-of-flight mass spectrometry (2D-LC/QTOF-MS) approach was established by configurating the XCharge C18 and HSS Cyano columns. Under the optimal conditions, we characterized a total of 1146 ginsenosides (including 876 potentially new compounds) from 12 ginseng varieties by reference to an in-house library of 573 known ginsenosides and 70 reference compounds. The online 2D-LC/QTOF-MS-based untargeted metabolomics workflows were developed, by which 126 potential ginsenoside markers were unveiled and utilized to establish the key identification points for each ginseng species. Compared with the conventional liquid chromatography/mass spectrometry metabolomics, our multidimensional chromatography approach performed better in discriminating multiple ginseng varieties. This work demonstrates a potent and practical methodology to identify easily confused functional plants.

Development of novel CDK9 and CYP3A4 inhibitors for cancer therapy through field and computational approaches

Cyclin-dependent kinase 9 (CDK9) and cytochrome P450 3A4 (CYP3A4) have emerged as promising targets in the development of anticancer drugs, presenting a consistent challenge in the quest for potent inhibitors. CDK9 inhibitors can selectively target fast-growing cancer cells by disrupting transcription elongation, which in turn hinders the production of proteins essential for cell cycle progression and survivaŚ. Understanding how CYP3A4 metabolizes specific chemotherapy drugs allows for personalized treatment plans, optimizing drug dosages according to a patient’s metabolic profile. Since many cancer patients undergo combination therapies, and CYP3A4 is vital in drug metabolism, its inhibition or induction by one drug can alter the plasma levels of others, potentially leading to treatment failure or increased toxicity. Therefore, managing CYP3A4 activity is critical for effective cancer treatment. Employing a range of computational methodologies, this study systematically investigated the binding mechanisms of pyrimidine derivatives against CDK9 and CYP3A4. The field-based model demonstrated high R2 values (0.99), with Q2 (0.66), demonstrating its ability to predict in silico inhibitory activity against the target of this study. The screening process followed in this work led to the discovery of powerful new inhibitor compounds. Of the 15 new compounds designed, three have a high affinity with the target (ranging from −8 to −9 kcal/mol kcal/mol) and were singled out through docking filtration for more detailed investigation. As well as, a reference compound with a substantial pIC50 value of 8.4, serving as the foundation for the development of the new compounds, was included for comparative analysis. To elucidate the essential features of CDK9 and CYP3A4 inhibitor design, a comparative analysis was conducted between 3D-QSAR-generated contours and molecular docking conformations of ligands. Molecular dynamics simulations were carried out for a duration of 100 ns on selected docked complexes, specifically those involving novel compounds with CDK9 and CYP3A4 enzymes. Additionally, the binding free energy for these complexes was assessed using the MM/PBSA method, which evaluates the free energy landscape of protein-ligand interactions. The results of MM/PBSA highlighted the strength of the new compounds in enhancing interactions with the target protein, which favors the results of molecular docking and MD simulation. These insights contribute to a deeper understanding of the mechanisms underlying CDK9 and CYP3A4 inhibition, offering potential avenues for the development of innovative and effective CDK9 inhibitors.

Synthesis, Urease Inhibition, Molecular Docking, and Optical Analysis of a Symmetrical Schiff Base and Its Selected Metal Complexes.

Designing and developing small organic molecules for use as urease inhibitors is challenging due to the need for ecosystem sustainability and the requirement to prevent health risks related to the human stomach and urinary tract. Moreover, imaging analysis is widely utilized for tracking infections in intracellular and in vivo systems, which requires drug molecules with emissive potential, specifically in the low-energy region. This study comprises the synthesis of a Schiff base ligand and its selected transition metals to evaluate their UV/fluorescence properties, inhibitory activity against urease, and molecular docking. Screening of the symmetrical cage-like ligand and its metal complexes with various eco-friendly transition metals revealed significant urease inhibition potential. The IC50 value of the ligand for urease inhibition was 21.80 ± 1.88 µM, comparable to that of thiourea. Notably, upon coordination with transition metals, the ligand-nickel and ligand-copper complexes exhibited even greater potency than the reference compound, with IC50 values of 11.8 ± 1.14 and 9.31 ± 1.31 µM, respectively. The ligand-cobalt complex exhibited an enzyme inhibitory potential comparable with thiourea, while the zinc and iron complexes demonstrated the least activity, which might be due to weaker interactions with the investigated protein. Meanwhile, all the metal complexes demonstrated a pronounced optical response, which could be utilized for fluorescence-guided targeted drug delivery applications in the future. Molecular docking analysis and IC50 values from in vitro urease inhibition screening showed a trend of increasing activity from compounds 7d to 7c to 7b. Enzyme kinetics studies using the Lineweaver-Burk plot indicated mixed-type inhibition against 7c and non-competitive inhibition against 7d.

First TPymT-Ln complexes (TPymT = 2,4,6-Tris(2-pyrimidyl)-1,3,5-triazine; Ln = Eu, Gd, Tb, Dy): Solvothermal synthesis, structure, magnetic and photoluminescent properties

Four novel mononuclear lanthanide complexes, [Ln(TPymT)(NO3)3(H2O)2] (Ln: Eu3+ (1), Gd3+ (2), Tb3+ (3) and Dy3+ (4)), have been solvothermally synthesized using multidentate 2,4,6-tris(2-pyrimidyl)-1,3,5-triazine (TPymT). Compounds 1–3 have been characterized by means of elemental analysis, FT-IR, and single-crystal/powder X-ray diffraction analysis. Compound 4 was structurally characterized. The Ln3+ ion in 1–4 is ten-coordinated, where TPymT serves as an N3 donor in an isostructural series. The alternating-current magnetic studies showed frequency dependence below ca. 10 K for 3, as an indication of a single-ion magnet. The activation energy for the magnetization reorientation was estimated as Ueff/kB = 95(9) K after applying a dc bias field 2000 Oe for 3. The photoluminescent studies clarified that 1 and 3 behaved as red and green light emitters with quantum yields as high as 17 and 39 %, respectively. The TD-DFT calculation supports the energy level scheme of ground and excited states of TPymT together with the reference compound 4′-phenyl-2,2’:6′,2″-terpyridine. The present work suggests a broad chance and motivation to apply TPymT to the field of 4f coordination chemistry.

Determination of the pKa Value of a Brønsted Acid by 19F NMR Spectroscopy.

Brønsted acids, such as phosphoric acids derived from chiral 1,1'-bi-2-naphthol (BINOL), are important catalysts in the formation of carbon-carbon and carbon-heteroatom bonds, for example. The catalytic activity of these Brønsted acids is strongly linked to their acidity, and as such, the evaluation of compounds to determine pKa values provides insight into their catalytic activity. Herein, a 19F{1H} NMR methodology is detailed to determine the pKa of a fluorinated binaphthyl-derived phosphinic acid, rac-1, in acetonitrile and in the presence of a fluorinated sulfonamide reference compound (2-4). The approach was tested initially using 2 and 3, with the ΔpKa (0.08) in strong agreement with previously reported values (6.6 for 2 and 6.68/6.73 for 3). Sigmoidal curves of normalised chemical shift change (Δδ) against equivalents of the base phosphazene P1-tBu added overlapped for 2 and 3, but in the case of rac-1 and either 2, 3 or 4, there was significant separation. A variety of different approaches for determining the ΔpKa were compared. Values of pKa determined when the normalised Δδ was 90% were optimal for 2 and 3, whereas a normalised Δδ of 75% was optimal for 4, resulting in the pKa of rac-1 being determined to be 8.47-8.71.

Identification of Specific Hemoglobin Adduct Patterns in Users of Different Tobacco/nicotine Products by Nontargeted GC-MS/MS Analysis.

Tobacco smoke contains several electrophilic constituents which are capable of forming adducts with nucleophilic sites in DNA and proteins like hemoglobin (Hb) and albumin. New nicotine and tobacco products are discussed as less harmful forms of tobacco use compared to smoking combustible cigarettes (CC) due to reduced exposure to harmful constituents. Hence, the adduct profile in users of various tobacco/nicotine products is expected to differ characteristically. In this article, we present a novel nontargeted screening strategy using GC-MS/MS for Hb adducts based on the analysis of the respective derivatized N-terminal valine adducts after modified Edman degradation. We analyzed blood samples from a clinical study with habitual users of CCs, electronic cigarettes, heated tobacco products (HTPs), oral tobacco, nicotine replacement therapy products and nonusers of any tobacco/nicotine products. Our nontargeted approach revealed significant differences in the Hb adduct profiles of the investigated tobacco/nicotine product user groups. Adduct identification was performed by means of an internal database, retention time estimations based on the theoretical boiling points, as well as in-house synthesized reference compounds. Several chemicals that form adducts with Hb could be identified: methylating and ethylating agents, ethylene oxide, acrylonitrile, acrylamide, glycidamide and 4-hydroxybenzaldehyde. Levels were elevated in smokers compared to all other groups for Hb adducts from methylating agents, ethylene oxide, acrylonitrile, acrylamide and glycidamide. Our approach revealed higher concentrations of Hb adducts formed by ethylation, acrylamide and glycidamide in users of HTPs compared to nonusers. However, concentrations for the latter two were still lower than in smokers. Due to their long half-lives, Hb adducts related to acrylonitrile, acrylamide (glycidamide), and ethylene oxide exposure may be useful for the biochemical verification of subjects̀ compliance in longitudinal and cross-sectional studies with respect to smoking and HTP use/abstinence.

Hypoglycemic Properties of Leccinum scabrum Extracts-An In Vitro Study on α-Glucosidase and α-Amylase Inhibition and Metabolic Profile Determination.

Type-2 diabetes affects an increasing percentage of the world's population and its control through dietary management, involving the consumption of health-promoting foods or their derived supplements, is a common strategy. Several mushroom species have been demonstrated to be endowed with antidiabetic properties, resulting from their ability in improving insulin sensitivity and production, or inhibiting the carbohydrate-hydrolyzing enzymes α-amylase and α-glucosidase. This study aimed to investigate for the first time the hypoglycemic properties of the edible mushroom Leccinum scabrum (Bull.) Gray. Mushroom extracts were prepared through the microwave-assisted extraction (MAE) technique using green solvents with different polarity degrees. The inhibition activity of all the obtained extracts on both α-glucosidase and α-amylase was evaluated and the highest activity was observed for the EtOAc extract which showed an IC50 value about 60-fold lower than the reference compound 1-deoxynojirimycin (DNJ) on α-glucosidase (0.42 ± 0.02 and 25.4 ± 0.6 µg/mL, respectively). As expected on the basis of the literature data concerning both α-glucosidase and α-amylase inhibition, a milder inhibition activity on pancreatic α-amylase was observed. Preliminary in vivo tests on Drosophila melanogaster carried out on the most active obtained extract (EtOAc) confirmed the in vitro observed hypoglycemic activity. Finally, the EtOAc extract metabolic profile was determined through GC-MS and HRMS analyses.

Exploring the impact of end-capped benzothiazine-based acceptors to lead the photovoltaic properties of solar cells: A DFT/TD-DFT approach

To improve the solar cells performance, usually end-capped acceptors are used in designing of new molecules. Therefore, in this study, the side-chain and end-capped moieties were modified in reference compound (BTZR) and proposed new compounds (BTZD1-BTZD6) to augment their photovoltaic and optoelectronic properties. The density functional method was employed at the M06/6-311G(d,p) level to optimize and interpret their frontier molecular orbitals (FMOs), density of states (DOS), transition density matrix (TDM), exciton binding energy (Eb), light absorption and open circuit voltage (Voc) characteristics. Their global reactivity parameters (GRPs) were calculated via the HOMO-LUMO energy band gap. Further, it was observed that all the investigated compounds showed lower band gaps (2.975–3.160 eV) and bathochromic shifts in the visible region (482.501–504.223 nm). Various plots such as the DOS, TDM and hole-electron further confirmed the efficiency of designed chromophores. Additionally, an interface of model donor–acceptor was constructed by considering the donor polymer (PBDB-T) and designed NFAs. Significant results were obtained for Voc (1.538–1.772 V). Among the selected candidates, BTZD3 and BTZD5 were obtained as high-performance non-fullerene acceptors (NFAs). They exhibited least band gaps (2.988 and 2.975 eV) and highest λmax (504.223 and 498.606, respectively). These compounds also demonstrated the least exciton binding energy values as 0.529 and 0.488 eV, respectively. Besides this, comparative study with the standard hole transport material (HTM) spiro-OMeTAD showed a reasonable agreement, suggesting that the entitled compounds could serve as effective HTMs. Overall, the findings suggested the crucial role of end-capped modification in elevating the charge mobility and photovoltaic characteristics of BTZD1-BTZD6. This study provides a valuable insight in the development of good photovoltaic materials.

Synthesis, α-Glucosidase, α-Amylase, and Aldol Reductase Inhibitory Activity with Molecular Docking Study of Novel Imidazo[1,2-a]pyridine Derivatives.

Inhibition ofaldose reductase (AR), α-glycosidase (α-GLY), and α-amylase (α-AMY) are some of the essential targets in diabetes mellitus (DM). Here, a series of imidazo[1,2-a]pyridine-based 1,3,4-thiadiazole derivatives (8a-k) were successfully synthesized and characterized using 1H NMR, 13C NMR, and HRMS spectroscopic techniques. The inhibition effects of the synthesized derivatives against AR, α-GLY, and α-AMY were evaluated using both in vitro and in silico methods. In vitro studies revealed that the derivatives (8a-k) showed significant inhibition activity. The results showed that the novel derivatives (8a-k) demonstrated potential inhibitory activity, with K I values covering the following ranges: 23.47 ± 2.40 to 139.60 ± 13.33 nM for AR and 6.09 ± 0.37 to 119.80 ± 12.31 μM for α-GLY, with IC50 values 81.14 to 153.51 μM for α-AMY. Furthermore, many of these compounds exhibited high inhibition activity, while some of them showed higher potency than the reference compounds. Molecular docking of the target compounds was carried out in the active sites of AR (PDB ID: 4JIR) and α-GLY (PDB ID: 5NN8).

Ionising and ultraviolet radiation induce the secretion of melanin in Tetrahymena pyriformis

ABSTRACT The objective of this study was to determine the effect of ionising and ultraviolet radiation on stimulating melanin secretion in Tetrahymena pyriformis. Cell cultures were exposed to different doses of radiation for 48, 72 and 96 h. After incubation, melanin was extracted and analysed. Our results showed that melanin concentration increased with increasing irradiation dose and exposure duration. Melanin was insoluble in water and organic solvents but soluble in alkaline and acidic solutions. A linear correlation between the logarithm of melanin absorbance and wavelength ranging from 400 to 600 nm was observed. The HPLC chromatograms of melanin degradation products by the alkaline hydrogen peroxide oxidation method revealed the existence of four peaks. The natural melanin standard extracted from the cuttlefish Sepia officinalis was used as a reference compound of eumelanin markers. These markers were detected in control cells, irradiated cells and black human hair but with different intensities.

Probing the role of BrCl in benzotriazole transformation during seawater chlorination

A common understanding attributes the formation of brominated disinfection by-products (Br-DBPs) in seawater chlorination to the conversion of hypochlorous acid to hypobromous acid (HOBr) by bromide. In this study, we reveal that bromine chloride (BrCl), mediated by both chloride and bromide in seawater, plays a dominant role in the transformation of 1H-benzotriazole (BTA) and 5-methyl-1H-benzotriazole (MBTA) and in the formation of brominated DBPs. Using anisole as a reference compound, the second-order rate constant for the reaction of BrCl with BTA was determined to be (2.65 ± 0.13) × 105 L mol−1 s−1, which is over 30,000 times higher than that for the reaction between HOBr and BTA. Ten brominated products were identified and showed a successive bromination pattern. The bromination reaction mechanism was elucidated through theoretical calculations, and the pathways were proposed. The concentrations of brominated BTA and MBTA in seawater were 5.7 and 7.9 times higher than in bromide-only solutions, respectively. BrCl significantly promoted brominated product generation and increased the toxicity of blended DBPs. These results suggest that focusing solely on bromide's effect on brominated product generation may significantly underestimate the potential for DBP formation during seawater chlorination.

The novel selective inhibitors of cyclin-dependent kinase 4/6: in vitro and in silico study.

One of the main regulators in the cell cycle is cyclin-dependent kinase 4 and 6 (CDK4/6). FDA has approved CDK4/6 inhibitors for the treatment of patients with metastatic breast cancer. However, the development of selective agents remains problematic due to the conservation of their ATP binding sites. In the previous in silico study, ZINC585292724, ZINC585292587, ZINC585291674, and ZINC585291474 have been identified as potential inhibitors. Therefore, the present study aimed to analyze the selectivity and inhibitory activity of the four compounds against CDK4/6 in vitro as well as determine the potential for their further development in silico. The in vitro results showed that the four compounds had good selectivity towards both kinases, due to their similar structure. In agreement with the in silico results, ZINC585291674 produced the best inhibitory activity against CDK4 and CDK6, with IC50 of 184.14nM and 111.78nM, respectively. Their ADMET profile were also similar to reference compound of Palbociclib. Based on this, ZINC585291674 can be used as a lead compound for further inhibitor development.

Comprehensive Computational Screening and Analysis of Natural Compounds Reveals Promising Estrogen Receptor Alpha Inhibitors for Breast Cancer Therapy.

Breast cancer remains a leading cause of death among women, with estrogen receptor alpha (ERα) overexpression playing a pivotal role in tumor growth and progression. This study aimed to identify novel ERα inhibitors from a library of 561 natural compounds using computational techniques, including virtual screening, molecular docking, and molecular dynamics simulations. Four promising candidates-Protopine, Sanguinarine, Pseudocoptisine, and Stylopine-were selected based on their high binding affinities and interactions with key ERα residues. Molecular dynamics simulations conducted over 500 nanoseconds revealed that Protopine and Sanguinarine exhibited more excellent stability with minimal fluctuations, suggesting strong and stable binding. In contrast, Pseudocoptisine and Stylopine showed higher flexibility, indicating less stable interactions. Binding free energy calculations further supported the potential of Protopine and Sanguinarine as ERα inhibitors, though their binding strength was slightly lower than that of the reference compound. These findings highlight Protopine and Sanguinarine as leading candidates for further investigation, and in vitro and in vivo studies are recommended to evaluate their therapeutic potential in breast cancer treatment.

Truncated NPY-based NPY(Y1)R-specific radiopeptides: Improved in vivo PET tumor imaging by application of peptidase inhibitors

The neuropeptide Y receptor subtype 1 (NPY(Y1)R) exhibits high expression rates on human breast cancer and is therefore an important target structure for the sensitive and specific visualization and characterization of the disease by Positron Emission Tomography (PET). However, imaging of this receptor type has been of limited success so far due to the low stability of peptide-based NPY-derived NPY(Y1)R-specific radiotracer candidates due to in vivo degradation. Given the challenges in stabilizing these agents, our study sought to explore whether the stability of NPY(Y1)R-specific radiopeptides could be enhanced. We aimed to achieve this by either modifying the peptide structure with various molecular scaffolds or by applying peptidase inhibitors. This evaluation aimed to identify the optimal approach for achieving effective NPY(Y1)R-specific imaging in the following. To validate our approach, we systematically investigated four new truncated 68Ga-labeled analogs of NPY and the reference compound [68Ga]Ga-[Lys4(Nε-DOTA)]BVD15, bearing different molecular scaffolds such as a DOTA or NODA-GA chelator, a 4-APipAc linker, a Bip unit, and an N-terminal Lys(lauryl) group. The four new radiotracers as well as the reference compound were obtained in high chemical and radiochemical yields with molar activities of 33–39 GBq/μmol. The radiopeptides exhibited varying logD7.4 values, ranging from −3.37 ± 0.09 to +0.35 ± 0.11, and showed different levels of stability in human serum and liver microsomes, depending on their molecular structure. Subsequently, the influence of the peptidase inhibitors actinonin, phosphoramidon, captopril and E−64 on the in vitro stability of the radiotracers was investigated. In these studies, only actinonin demonstrated a positive effect on the stability of all radiopeptides. In contrast, phosphoramidon yielded variable results, and neither captopril nor E−64 showed a significant stabilizing effect.Consequently, the effect of actinonin administration on the in vivo PET/CT imaging results of the most promising ligand [68Ga]Ga-[Lys4(Nε-NODA-GA)]BVD15 ([68Ga]Ga-2) was investigated in a T47D tumor-bearing xenograft mouse model, followed by ex vivo biodistribution studies. In these experiments, the administration of 250 μg actinonin resulted in a significantly increased uptake of [68Ga]Ga-2 in the T47D tumor (5.9 ± 1.0 % ID/g (with actinonin) instead of 3.1 ± 0.9 % ID/g (without actinonin) at 2h p.i.), and an increase in tumor-to-muscle ratios from 1.8 to 4.0 upon co-administration of the inhibitor.The results impressively demonstrate the positive influence of actinonin on the in vivo stability of the NPY(Y1)R-specific radiopeptide [68Ga]Ga-2, resulting in an increased tumor accumulation and improved tumor-to-background ratios. These findings thus provide important incentive for further advancement of NPY(Y1)R-specific tumor imaging using PET.

Synthesis and investigation of selective human carbonic anhydrase IX, XII inhibitors using coumarins bearing a sulfonamide or biotin moiety

The role of carbonic anhydrases isoforms (CAs) IX and XII in the pathogenesis and progression of many types of solid tumors is well known. In this context, selective CA inhibitors (CAIs) towards the mentioned isoforms is a validated strategy for the development of agents to target cancer. For this purpose, novel coumarin derivatives based on the hybridization with arylsulfonamide or biotin scaffolds were synthesized and tested as inhibitors of four different human carbonic anhydrases isoforms: hCA I, II, IX and XII. Coumarin-sulfonamide derived 27, with a thiourea moiety and triazole as linker, showed the highest inhibition activity against hCA XII with an inhibition constant (KI) of 7.5 nM and afforded a very good selectivity over hCA I. Compound 32 was the most potent inhibitor against hCA IX (KI = 6.3 nM), 4-fold stronger than the drug acetazolamide AAZ (KI = 25 nM), used herein as a reference compound, and showed remarkable selectivity over hCA I and II. The coumarin-biotin derivatives 37-39 showed outstanding selectivity towards on-target enzymes (hCA IX and XII) and appear as plausible leads for designing of CAIs.

LIN28-Targeting Chromenopyrazoles and Tetrahydroquinolines Induced Cellular Morphological Changes and Showed High Biosimilarity with BRD PROTACs.

The probing of small molecules with heterocyclic scaffolds covering unexplored chemical space and the evaluation of their biological relevance are essential parts of forward chemical genetics approaches and for the development of potential small-molecule therapeutics. In this study, we profiled sets of chromenopyrazoles (CMPs) and tetrahydroquinolines (THQs), originally developed to target the protein-RNA interaction of LIN28-let-7, in a cell painting assay (CPA) measuring cellular morphological changes. Selected LIN28-inactive CMPs and THQs induced cellular morphological changes to different extents. The most CPA-active CMPs 2 and 3 exhibited high bio-similarity with the LCH and BET clusters, while the most CPA-active THQs 13 and 20 indicated a mechanism of action beyond the currently established biosimilarity clusters. Overall, this work demonstrated that CPA is useful in revealing "hidden" biological targets and mechanisms of action for biologically inactive small molecules, which are CMPs and THQs targeting the RNA-binding protein LIN28 in this case, evaluated in target-based strategies. When compared with annotated reference compounds, CMP 3 exhibited a high biosimilarity with the dual BRD7/9 degrading PROTAC VZ185, suggesting that CPA could potentially function as a new phenotypic approach to identify degrader molecules.

Synthesis, Molecular Docking Studies and Biological Evaluation of Thiazolyl Hydrazone Derivatives of Chromone-3-carbaldehyde as Potent Anti-Oxidant and Anti-Inflammatory Agents.

A series of 15 thiazolyl hydrazone derivatives of chromone-3- carbaldehyde have been designed and synthesized by the cyclization of thiosemicarbazone derivatives of chromone-3-carbaldehydes with 4'-substituted-2-bromo acetophenones. All these derivatives were evaluated for antioxidant activity by their direct scavenging activity objects to reactive oxygen species such as DPPH, and nitric oxide, as well as in vitro antiinflammatory activity by a protein denaturation method. Most of these synthesized compounds have shown significant antioxidant activity, among which the compounds 5b, 5c, 5e, 5g, and 5j showed very good antioxidant activities in comparison with the standard ascorbic acid. The in vitro anti-inflammatory activity revealed that the compounds 5b, 5g, and 5h possessed significant activity compared to standard diclofenac sodium. Additionally, molecular docking studies of these molecules using ovalbumin as the protein showed remarkable interactions with its active site residues, and the results indicated that the binding mode of these compounds closely resembled that of the reference compound, diclofenac sodium. Thus, these compounds represent an attractive template for the evaluation of new antiinflammatory and antioxidant agents and might be useful for exploring new therapeutic tools.

Synergistic charge-transfer dynamics of novel benzothiadiazole-based donor materials for higher power conversion efficiency: From structural engineering to efficiency assessment in non-fullerene organic solar cells

In the realm of organic solar cell technology, current research is dedicated to enhancing the photovoltaic properties of donor-π-acceptor (D-π-A) materials to achieve higher power conversion efficiencies (PCE). This optimization focuses particularly on fine-tuning the conduction band and electrolytic characteristics to maximize performance. Addressing the growing demand for novel materials with enhanced optoelectronic properties in organic photovoltaic research, our proposed compound BT05, one of nine new benzothiadiazole-based D-π-A donor molecules (BT01-BT09), exhibits a power conversion efficiency (PCE) of 25%, surpassing the 18% PCE of the reference compound BTD-OMe. TD-DFT and DFT simulations illuminate how donor modifications enhance the photovoltaic characteristics of the proposed molecules. Higher open-circuit voltage (VOC) of 1.74-2.26 V, increase in binding energy (∼1.997), λmax (470-476 nm), reduction in energy gap (4.25-4.65 eV), also validates the PCE results and confirm the usefulness of designed molecules (BT01-BT09). Moreover, DHOMO and ALUMO, TDM, reorganization energy λe (0.0124-0.0134) and λh (0.0094-0.0098), and NPA results also confirm that BT01-BT09 molecules unlock the organic solar cell's potential and advance sustainable energy solutions through innovative technology. Among all developed compounds, BT05 displays higher VOC (2.26 V), 87% fill-factor, and 25% PCE; hence, it is recommended in future solar cell applications.

Rationale design and synthesis of new roflumilast analogues as preferential selective and potent PDE-4B inhibitors

In this study, we designed and synthesized novel analogues of roflumilast that exhibit selective inhibition of PDE-4B. To accomplish this target; synthesis of novel series (4a-u, 5a-i, and 6) was done, aiming at obtaining new PDE-4B inhibitors hits based on the proposed pharmacophore, 1-(cyclopropylmethoxy)-2-(difluoromethoxy) benzene moiety. Enzyme assay was used to measure the IC50 values for the PDE-4B inhibition of all the synthesized compounds along with roflumilast as a reference drug. The results demonstrated that most of the examined candidates exhibited considerable inhibitory activity against the PDE-4B enzyme. The four compounds (4i, 4k, 4p, and 4q) exhibited the highest potency (IC50 = 7.25, 7.15, 5.50, 7.19 nM, respectively) with no significant inhibition difference from roflumilast (no statistical difference at p < 0.05). Interestingly, compound 4p with 3-OH and 4-OCH3 substituents was found to be the most potent against PDE-4B enzyme (IC50 = 5.50 nM), compared to that of roflumilast (IC50 = 2.36 nM). Moreover, the most potent derivatives 4i, 4k, 4p, and 4q were further tested for PDE-4D inhibitory activity to investigate their PDE-4D/PDE-4B selectivity ratio. Compound 4k showed the highest selectivity towards PDE-4B isozyme more than the reference drug roflumilast (PDE-4D/4B IC50 ratio for compound 4k and roflumilast = 3.22 and 3.02, respectively). Additionally, compound 4p was chosen to test its selectivity for PDE-4B over PDE-8A, PDE-11A, and PDE-1B compared to thereference drug roflumilast. Compound 4p showed approximately 6-fold selectivity for PDE-4B over PDE-8A, about 5-fold selectivity for PDE-4B over PDE-11A, and 11-fold selectivity of PDE-4B over PDE-1B. Compound 4p showed a higher selectivity towards PDE-4B than PDE-1B, more than the reference compound roflumilast. Furthermore, the most potent compounds (4i, 4k, 4p, 4q) were subjected to further investigation, and their effects on the cAMP level and percentage of inhibition of tumor necrosis factor-alpha (TNF-α) were studied and compared with reference drug roflumilast. Compound 4q showed the highest increase in the level of intracellular cAMP (6.55 ± 0.37 pmol/mL) and compound 4i showed the highest % of TNF-α inhibition (77.22 %). On the other side, a molecular docking study against PDE-4B clarified that all the examined candidates achieved nearly similar binding modes with similar orientations to that of the native roflumilast ligand and showed higher docking scores than roflumilast.

A Novel Approach for Apical Periodontitis Prevention Through RIPK3 Inhibition Using Organic Flavonoids

Background: Apical periodontitis (AP) entails inflammatory bone resorption facilitated by the induction of necroptosis through receptor-interacting protein kinase 3 (RIPK3). Consequently, the inhibition of RIPK3 holds the potential for favorable effects in addressing AP. A comprehensive investigation, encompassing 44 flavonoids, was undertaken to identify potential inhibitors of RIPK3. Methods: The crystal structure of the RIPK3 catalytic domain (PDB ID: 7MON) underwent meticulous preparation through the removal of ligands and energy optimization. Overall, 44 flavonoids were examined in this study. Utilizing AutoDock 4.0, molecular docking analyses were performed to evaluate the binding energies within the active site of RIPK3 concerning the examined herbal isolates, with subsequent comparison to the results obtained from a positive control inhibitor. Furthermore, the BIOVIA Discovery Studio Visualizer played a crucial role in elucidating the interactions between the top-ranked flavonoids and the residues of RIPK3. Results: Five distinct flavonoids—orientin, rutin, vicenin-2, amentoflavone, and nicotiflorin—manifested notable inhibitory effects on RIPK3, boasting inhibition constant values at either the femtomolar or picomolar scale. Notably, the first three members of this set showcased superior binding affinity to the active site of RIPK3 compared to the reference compound. Conclusion: The proposition arises that flavonoid, particularly orientin, rutin, vicenin-2, amentoflavone, and nicotiflorin, stand as promising herbal isolates for the therapeutic management of AP.