Molecular Docking Methods Research Articles

Deciphering the intriguing molecular recognition of a novel indene-phloroglucinol tethered compound with human serum albumin using multi-spectroscopy and molecular docking studies

A new indene-phloroglucinol tethered compound IPC1 was synthesized in our laboratory in three steps. The interaction of the final compound IPC1 with human serum albumin (HSA) was studied using multi-spectroscopic and molecular docking methods. UV–vis and fluorescence studies confirmed the spontaneous formation of ground state complex and the values of the binding constants were found to be in the order of 104 M−1 (4.727×104 M−1 at 290.15 K). Positive ΔS° (+112.797 J K−1 mol−1) and ΔH° (+6.756 KJ mol−1) indicate the involvement of hydrophobic interaction as the major contributing force in the complex formation process. Site marker studies suggested that the compound IPC1 binds near the subdomain IIIA of HSA, which was further supported by fluorescence spectroscopic and molecular docking analysis.

Binding of Nucleotide Inhibitors to the NS5 RdRp of the ZIKA Virus in the Replication Initiation State.

The bindings of several ribonucleoside triphosphate (NTP) inhibitors to the RNA-dependent RNA polymerase (RdRp) of the Zika virus (ZIKV) are studied herein to identify potential drug-like candidates that can inhibit the replication of the viral genome by RdRp. In this study, a guanosine triphosphate (GTP) bound RdRp structure is generated to model the replication initiation state of RdRp. Subsequently, the bindings of 30 NTP inhibitors to the GTP binding site of RdRp are studied in detail by using the molecular docking method. Based on the docking scores, four NTP inhibitors, such as 2'-Cmethyl- adenosine-5'-triphosphate (mATP), 7-deaza-2'-C-methyladenosine-TP (daza-- mATP), 1-N6-Ethenoadenosine-5'-triphosphate (eATP), and Remdesivir-5'-triphosphate (RTP) are shortlisted for further analysis by employing molecular dynamics simulations and binding free-energy methods. These inhibitors are found to bind to RdRp quite strongly, as evident from their relative binding free energies that lie between -31.54±4.54 to -89.46±4.58 kcal/- mol. As the binding of RTP to the GTP site of RdRp generates the most stable complex, which is about 45 kcal/mol more stable than the binding of GTP to RdRp, it is most likely that RTP may inhibit the replication of the Zika viral genome efficiently. However, experimental studies are required to measure the potency of RTP and other drugs before their clinical use.

Tripterygium wilfordii Hook.f induced kidney injury through mediating inflammation via PI3K-Akt/HIF-1/TNF signaling pathway: A study of network toxicology and molecular docking.

We intend to explore potential mechanisms of Tripterygium wilfordii Hook.f (TwHF) induced kidney injury (KI) using the methods of network toxicology and molecular docking. We determined TwHF potential compounds with its targets and KI targets, obtained the TwHF induced KI targets after intersecting targets of TwHF and KI. Then we conducted protein-protein interaction (PPI) network, gene expression analysis, gene ontology (GO) function and Kyoto encyclopedia of genes and genomes (KEGG) pathway enrichment analysis to explore the mechanism of TwHF-induced KI. Finally we conducted molecular docking to verify the core toxic compounds and the targets. We obtained 12 TwHF toxic compounds and 62 TwHF-induced KI targets. PPI network, gene expression analysis and GO function enrichment analysis unveiled the key biological process and suggested the mechanism of TwHF-induced KI might be associated with inflammation, immune response, hypoxia as well as oxidative stress. KEGG pathway enrichment analysis indicated PI3K-Akt signaling pathway, HIF-1 signaling pathway and TNF signaling pathway were key signaling pathways of TwHF induced KI. Molecular docking showed that the binding energy of core targets and toxic compounds was all less than -6.5 kcal/mol that verified the screening ability of network pharmacology and provided evidence for modifying TwHF toxic compounds structure. Through the study, we unveiled the mechanism of TwHF induce KI that TwHF might activate PI3K-Akt signaling pathway as well as TNF signaling pathway to progress renal inflammation, mediate hypoxia via HIF-1 signaling pathway to accelerate inflammatory processes, and also provided a theoretical basis for modifying TwHF toxic compounds structure as well as supported the follow-up research.

The interaction mechanisms analysis of shikonin with α-glucosidase by multi-spectroscopic and molecular docking methods

This study aimed to investigate the binding mechanism of shikonin with α-glucosidase by multi-spectroscopic and molecular docking technologies. These data suggested that shikonin spontaneously interacted with α-glucosidase primarily through hydrogen bonds (H-bond) and van der Waals forces (vdW), the quenching mechanism was static quenching. At 298 K, the quenching rate constant and binding constant were (1.00 ± 0.06) × 1012 L mol−1 s−1 and (2.32 ± 0.04) × 104 L mol−1, respectively. Molecular docking analysis also confirmed the results of the spectroscopic method. These results are helpful in understanding the interaction mechanism between shikonin and α-glucosidase.

Neuroprotection of Truncated Peptide IIAVE from Isochrysis zhanjiangensis: Quantum Chemical, Molecular Docking, and Bioactivity Studies.

Parkinson's disease (PD) is a progressive neurodegenerative disorder of the elderly for which there is no cure or disease-modifying therapy. Mitochondrial dysfunction and oxidative stress play a central role in dopaminergic neurodegeneration in PD. Therefore, antioxidants are considered a promising neuroprotective approach. In in vivo activity studies, 6-OHDA-induced oxidative stress in SH-SY5Y cells was established as a model of PD for cellular experiments. IIAVE (Ile-Ile-Ala-Val-Glu) was derived from Isochrysis zhanjiangensis octapeptide (IIAVEAGC), which has a small molecular weight. The structure and antioxidant activity of IIAVE were tested in a previous study and proved to have good antioxidant potential. In this study, the chemical properties of IIAVE were calculated using quantum chemical methods, including frontier molecular orbital (FMO), molecular electrostatic potential (MEP), natural population analysis (NPA), and global reactivity properties. The interaction of IIAVE with Bcl-2 and DJ-1 was investigated using the molecular docking method. The results showed that IIAVE promoted the activation of the Keap1/Nrf2 pathway and up-regulated the expression of the superoxide dismutase 1 (SOD-1) protein by inhibiting the level of reactive oxygen species (ROS) in cells. In addition, IIAVE inhibits ROS production and prevents 6-OHDA-induced oxidative damage by restoring mitochondrial membrane potential. Furthermore, IIAVE inhibited cell apoptosis by increasing the Bcl-2/Bax ratio and inhibiting the activation of Caspase-9 and Caspase-3. Thus, IIAVE may become a potential drug for the treatment and prevention of PD.

Underlying Mechanism of Traditional Herbal Formula Chuang-Ling-Ye in the Treatment of Diabetic Foot Ulcer through Network Pharmacology and Molecular Docking.

Chuang-Ling-Ye (CLY) has been clinically proven to be an effective Chinese medicine for the treatment of diabetic foot ulcers (DFU). This study aimed to investigate the possible mechanism of CLY in relation to DFU using network pharmacology and molecular docking. Firstly, relevant targets of CLY against DFU were obtained from TCMSP, Swiss Target Prediction database and GEO database. Then, topological analysis was employed by Cytoscape to screen the top 6 core active ingredients and the top 8 hub targets. Furthermore, the OmicShare Tools were applied for gene ontology (GO) functional enrichment analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) signaling pathway enrichment analysis. Finally, the results of network pharmacology were verified by molecular docking method. CLY has 61 active compounds and 361 targets after de-duplication, and the top 8 hub targets were EGFR, TP53, CCND1, IL-1B, CREBBP, AR, PTGS2 and PGR. GO enrichment analysis is mainly related to signal transducer activity, receptor activity, and molecular transducer activity. KEGG pathway analysis indicated that these shared targets were primarily focused on AGE-RAGE signaling pathway in diabetic complications, HIF-1 signaling pathway, IL-17 signaling pathway, and JAK-STAT signaling pathway. Molecular docking results showed that physciondiglucoside, 2-cinnamoyl-glucose and kinobeon A were well bound with EGFR, IL-1B, AR and PTGS2. This study demonstrated that CLY has anti-oxidative stress and anti-inflammatory effects in the treatment of DFU through various constituents, multiple targets, and multiple pathways, which provides a valuable point of reference for future investigations on CLY.

Molecular docking and molecular dynamics approach to identify EGFR and HER2 receptors inhibitory effect of compounds in Zanthoxylum simulans Hance

AbstractEpidermal growth factor receptor (EGFR) and human epithelium receptor‐2 (HER2) are members of the epidermal growth factor receptor (EGFR/ErbB) family implicated in the development of many types of carcinoma. Zanthoxylum simulans Hance has the effect of inhibiting growth and causing the death of many types of cancer cells. In this study, the molecular docking method and molecular dynamics simulations were used to evaluate the inhibition abilities of EGFR and HER2 receptors of 120 compounds in Zanthoxylum simulans Hance. The results showed two compounds that inhibit both EGFR and HER2 targets including simulanoquinoline and 6‐acetonyldihydroavicine. Therefore, in vivo and in vitro studies of these potential compounds should be carried out to become anti‐cancer drugs in the future.

Clustering of atoms relative to vector space in the Z-matrix coordinate system and 'graphical fingerprint' analysis of 3D pharmacophore structure.

The behavior of a molecule within its environment is governed by chemical fields present in 3D space. However, beyond local descriptors in 3D, the conformations a molecule assumes, and the resulting clusters also play a role in influencing structure-activity models. This study focuses on the clustering of atoms according to the vector space of four atoms aligned in the Z-Matrix Reference system for molecular similarity. Using 3D-QSAR analysis, it was aimed to determine the pharmacophore groups as interaction points in the binding region of the β2-adrenoceptor target of fenoterol stereoisomers. Different types of local reactive descriptors of ligands have been used to elucidate points of interaction with the target. Activity values for ligand-receptor interaction energy were determined using the Levenberg-Marquardt algorithm. Using the Molecular Comparative Electron Topology method, the 3D pharmacophore model (3D-PhaM) was obtained after aligning and superimposing the molecules and was further validated by the molecular docking method. Best guesses were calculated with a non-output validation (LOO-CV) method. Finally, the data were calculated using the 'graphic fingerprint' technique. Based on the eLKlopman (Electrostatic LUMO Klopman) descriptor, the Q2 value of this derivative set was calculated as 0.981 and the R2ext value is calculated as 0.998.

Naturally occurring caffeic acid phenethyl ester from chestnut honey-based propolis and virtual screening towards DYRK1A

Neurodegenerative diseases (NDDs) are disorders with dysfunction and ongoing loss of neurons, glial cells and the neural networks in the brain and spinal cord. DYRK1A protein was reported to modulate to the cytoskeletal fraction in human and mouse brain, and the remaining protein is located in the cytosolic and nuclear fractions. Caffeic acid phenethyl ester (CAPE) is a natural derivative of caffeic acid and found in propolis, a bee product. In this study, we focused on isolation and characterisation of CAPE from chestnut honey-based propolis by HPLC-MS/MS technique and virtual screening of CAPE towards DYRK1A by molecular docking methods. Results revealed that CAPE might be a beneficial option to treat Alzheimer disease (AD) by suppressing DYRK1A protein.

Identification and assessment of new PIM2 inhibitors for treating hematologic cancers: A combined approach of energy-based virtual screening and machine learning evaluation.

PIM2, part of the PIM kinase family along with PIM1 and PIM3, is often overexpressed in hematologic cancers, fueling tumor growth. Despite its significance, there are no approved drugs targeting it. In response to this challenge, we devised a thorough virtual screening workflow for discovering novel PIM2 inhibitors. Our process includes molecular docking and diverse scoring methods likemolecular mechanics generalized born surface area, XGBOOST, and DeepDock to rank potential inhibitors by binding affinities and interaction potential. Ten compounds were selected and subjected to an adequate evaluation of their biological activity. Compound 2 emerged as the most potent inhibitor with an IC50 of approximately 135.7 nM. It also displayed significant activity against various hematological cancers, including acute myeloid leukemia, mantle cell lymphoma, and anaplastic large cell lymphoma (ALCL). Molecular dynamics simulations elucidated the binding mode of compound 2 with PIM2, offering insights for drug development. These results highlight the reliability and efficacy of our virtual screening workflow, promising new drugs for hematologic cancers, notably ALCL.

Proposing of fungal endophyte secondary metabolites as a potential inhibitors of 2019-novel coronavirus main protease using docking and molecular dynamics

In this study, the inhibitory potential of 99 fungal derived secondary metabolites was predicted against SARS-CoV-2 main protease by using of computational approaches. This protein plays an important role in replication and is one of the important targets to inhibit viral reproduction. Among the 99 reported compounds, the 9 of them with the highest binding energy to Mpro obtained from the molecular docking method were selected for the molecular dynamic simulations. The compounds were then investigated by using the SwissADME serve to evaluate the compounds in terms of pharmacokinetic and druglikness properties. The overall results of different analysis show that the compound RKS-1778 is potentially more effective than others and form strong complexes with viral protease. It also had better pharmacokinetic properties than other metabolites, so predicted to be a suitable candidate as anti SARS-CoV-2 bioactive. Communicated by Ramaswamy H. Sarma

Discovery of novel Akt1 inhibitors by an ensemble-based virtual screening method, molecular dynamics simulation, and in vitro biological activity testing.

Akt1, as an important member of the Akt family, plays a controlled role in cancer cell growth and survival. Inhibition of Akt1 activity can promote cancer cell apoptosis and inhibit tumor growth. Therefore, in this investigation, a multilayer virtual screening approach, including receptor-ligand interaction-based pharmacophore, 3D-QSAR, molecular docking, and deep learning methods, was utilized to construct a virtual screening platform for Akt1 inhibitors. 17 representative compounds with different scaffolds were identified as potential Akt1 inhibitors from three databases. Among these 17 compounds, the Hit9 exhibited the best inhibitory activity against Akt1 with inhibition rate of 33.08% at concentration of 1μM. The molecular dynamics simulations revealed that Hit9 and Akt1 could form a compact and stable complex. Moreover, Hit9 interacted with some key residues by hydrophobic, electrostatic, and hydrogen bonding interactions and induced substantial conformation changes in the hinge region of the Akt1 active site. The average binding free energies for the Akt1-CQU, Akt1-Ipatasertib, and Akt1-Hit9 systems were - 34.44, - 63.37, and - 39.14kJ mol-1, respectively. In summary, the results obtained in this investigation suggested that Hit9 with novel scaffold may be a promising lead compound for developing new Akt1 inhibitor for treatment of various cancers with Akt1 overexpressed.

AI-based Virtual Screening of Traditional Chinese Medicine and the Discovery of Novel Inhibitors of TCTP.

Translationally controlled tumour protein (TCTP) is associated with tumor diseases, such as breast cancer, and its inhibitor can reduce the growth of tumor cells. Unfortunately, there is currently no effective medication available for treating TCTP-related breast cancer. The objective of this study was to explore the inhibitor candidates among natural compounds for the treatment of breast cancer related to TCTP protein. To explore the potential inhibitors of TCTP, we first screened out four potential inhibitors in the Traditional Chinese Medicine (TCM) for cancer based on AI virtual screening using the docking method, and then revealed the interaction mechanism of TCTP and four candidate inhibitors from TCM with molecular docking and molecular dynamics (MD) methods. Based on the conformational characteristics and the MD properties of the four leading compounds, we designed the new skeleton molecules with the AI method using MolAICal software. Our MD simulations have revealed that different small molecules bind to different sites of TCTP, but the flexible regions and the signaling pathways are almost the same, and the VDW and hydrophobic interactions are crucial in the interactions between TCTP and ligands. We have proposed the candidate inhibitor of TCTP. Our study has provided a potential new method for exploring inhibitors from Traditional Chinese Medicine (TCM).

Investigating the mechanism and efficacy material basis of Xiehuo Xiaoying decoction for treating Graves' disease via thyroid cell apoptosis based on proteomics and molecular docking techniques

Ethnopharmacological relevanceFor numerous years, the Xiehuo Xiaoying decoction (XHXY), a traditional Chinese medicine formula, has demonstrated substantial promise in treating Graves' disease (GD) in clinical settings, showcasing significant potential. However, the therapeutic mechanism and efficacy material basis of XHXY remains obscure. Aim of the studyThis work aims to investigate the underlying mechanisms and to study the efficacy material basis of XHXY in anti-GD effect using a combination of TMT quantitative proteomics and molecular docking method. Materials and methodsGD model was initiated by administering Ad-TSH289. Subsequently, the mice underwent a four-week regimen that included oral gavage of XHXY at doses of 17 g/kg·d and 34 g/kg·d, along with intraperitoneal injections of Gentiopicroside (GPS). Utilizing the principles of pharmacological chemistry in traditional Chinese medicine, we employed high-performance liquid chromatography quadrupole time-of-flight mass spectrometry (HPLC-QTOF/MS) to discern prescribed prototype composition of XHXY in serum samples from mouse. TMT proteomics research provided evidence of XHXY's putative targets and important pathways in vivo. The binding activity of probable action targets and prototype composition was detected by molecular docking. Finally, Immunohistochemistry (IHC) and TUNEL staining were used to verify the mechanism of XHXY and GPS in anti-GD. ResultsXHXY and GPS alleviated GD by ameliorating the pathological changes and reducing thyroxine and TRAb levels. In mouse serum, a total of 31 prototypical XHXY ingredients were detected, and the majority of these components were from monarch and minister medicine. Proteomics study results indicated that the XHXY may mainly regulate targets including FAS-associated death domain protein (FADD), Apolipoprotein C-III, etc. and main pathways are Apoptosis, Cholesterol metabolism, TNF signalling pathway, etc. Strong binding activity of the prototypical active ingredient and GPS towards FADD, Caspase 8, and Caspase 3 was demonstrated by molecular docking. XHXY and its primary component, GPS, elevated the expression of FADD, Caspase 8, and Caspase 3, and enhance apoptosis in thyroid cells, as lastly validated by TUNEL and IHC staining. ConclusionsXHXY exhibits a favorable therapeutic effect in treating GD by promoting apoptosis in thyroid cells through the upregulation of FADD, Caspase 8, and Caspase 3 expression. And GPS is the main efficacy material basis for its therapeutic effect in anti-GD.

Development of novel ALOX15 inhibitors combining dual machine learning filtering and fragment substitution optimisation approaches, molecular docking and dynamic simulation methods

The oxidation of unsaturated lipids, facilitated by the enzyme Arachidonic acid 15-lipoxygenase (ALOX15), is an essential element in the development of ferroptosis. This study combined a dual-score exclusion strategy with high-throughput virtual screening, naive Bayesian and recursive partitioning machine learning models, the already established ALOX15 inhibitor i472, and a docking-based fragment substitution optimisation approach to identify potential ALOX15 inhibitors, ultimately leading to the discovery of three FDA-approved drugs that demonstrate optimal inhibitory potential against ALOX15. Through fragment substitution-based optimisation, seven new inhibitor structures have been developed. To evaluate their practicality, ADMET predictions and molecular dynamics simulations were performed. In conclusion, the compounds found in this study provide a novel approach to combat conditions related to ferroptosis-related injury by inhibiting ALOX15.

Exploring the potential mechanism and molecular targets of Taohong Siwu Decoction against deep vein thrombosis based on network pharmacology and analysis docking.

This study aims to investigate the mechanism of Taohong Siwu Decoction (THSWD) against deep vein thrombosis (DVT) using network pharmacology and molecular docking technology. We used the Traditional Chinese Medicine Systems Pharmacology database and reviewed literature to identify the main chemical components of THSWD. To find targets for DVT, we consulted GeneCards, Therapeutic Target Database, and PharmGKB databases. We used Cytoscape 3.8.2 software to construct herb-disease-gene-target networks. Additionally, we integrated drug targets and disease targets on the STRING platform to create a protein-protein interaction network. Then, we conducted Kyoto Encyclopedia of Genes and Genomes and gene ontology analysis. Finally, We employed the molecular docking method to validate our findings. We identified 56 potential targets associated with DVT and found 61 effective components. beta-sitosterol, quercetin, and kaempferol were the most prominent among these components. Our analysis of the protein-protein interaction network revealed that IL6, L1B, and AKT1 had the highest degree of association. Gene ontology analysis showed that THSWD treatment for DVT may involve response to inorganic substances, negative regulation of cell differentiation, plasma membrane protein complex, positive regulation of phosphorylation, and signaling receptor regulator activity. Kyoto Encyclopedia of Genes and Genomes analysis indicated that lipid and atherosclerosis, pathways in cancer, as well as the PI3K-Akt pathway are the main signal pathways involved. Molecular docking results demonstrated strong binding affinity between beta-sitosterol, quercetin, kaempferol, and AKT1 proteins as well as IL1B and IL6 proteins. The main targets for THSWD treatment of DVT may include AKT1, IL1B, and IL6. Beta-sitosterol, quercetin, and kaempferol may be the active ingredients responsible for producing this effect. These compounds may slow down the progression of DVT by regulating the inflammatory response through the PI3K/Akt pathway.

Advancing Pyrrole Synthesis through DDQ Catalysis: A Comprehensive Research Incorporating DFT, ADMT, and Molecular Docking Analysis

AbstractThe construction of pyrroles is an important heterocyclic group comprising many compounds with interesting properties that have led to numerous applications in various fields. We delineate a new synthetic method for the rapid construction of tree‐substituted pyrroles from readily available ketoximes as starting materials and also a new mechanism and method has been proposed. It is presented that substituted pyrroles were efficiently synthesized in high yields (up to 81 % yield) through the cyclization reaction of starting ketoximes mediated by 2,3‐dichlor‐5,6‐dicyanobenzoquinone (DDQ). Utilizing this protocol various pyrrole derivatives were synthesized from diethyl acetylene dicarboxylate (DEAD). We then developed the dehydrogenation reaction mechanism of this formation, also studied in detail, also all synthesized compounds were analyzed in detail by spectroscopic techniques (FT‐IR, 1H NMR, 13CNMR) which were compared with the computational data estimated at B3LYP/6‐311G** level. The thermochemical and electronic properties of the pyrroles were evaluated after optimizing and then confirming the equilibrium structures. ADMT scores were also considered to estimate/elucidate the possible bioavailability tendencies as well as the toxicity. In addition, the interactions of the optimized molecules were evaluated by molecular docking methods against BSA “Bovine Serum Albumin” and LIF “Leukemia Inhibitory Factor”. The results obtained from this study will ideally provide a fundamental source in contemporary drug design in terms of both the key electronic properties underlying the possible reactivity features and toxicity.

Effects and mechanisms of Zhizi Chuanxiong herb pair against atherosclerosis: an integration of network pharmacology, molecular docking, and experimental validation

BackgroundThe Zhizi Chuanxiong herb pair (ZCHP) can delay pathological progression of atherosclerosis (AS); however, its pharmacological mechanism remains unclear because of its complex components. The purpose of current study is to systematically investigate the anti-AS mechanism of ZCHP.MethodsThe databases of TCMSP, STITCH, SwissTargetPrediction, BATMAN-TCM, and ETCM were searched to predict the potential targets of ZCHP components. Disease targets associated with AS was retrieved from the GEO database. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes (KEGG) signaling pathway analyses were executed using DAVID 6.8. Molecular docking method was employed to evaluate the core target binding to blood components, and animal experiments were performed to test action mechanism.ResultsA ZCHP-components-targets-AS network was constructed by using Cytoscape, included 11 main components and 52 candidate targets. Crucial genes were shown in the protein–protein interaction network, including TNF, IL-1β, IGF1, MMP9, COL1A1, CCR5, HMOX1, PTGS1, SELE, and SYK. KEGG enrichment illustrated that the NF-κB, Fc epsilon RI, and TNF signaling pathways were important for AS treatment. These results were validated by molecular docking. In ApoE−/− mice, ZCHP significantly reduced intima-media thickness, pulse wave velocity, plaque area, and serum lipid levels while increasing the difference between the end-diastolic and end-systolic diameters. Furthermore, ZCHP significantly decreased the mRNA and protein levels of TNF-α and IL-1β, suppressed NF-κB activation, and inhibited the M1 macrophage polarization marker CD86 in ApoE−/− mice.ConclusionThis study combining network pharmacology, molecular biology, and animal experiments showed that ZCHP can alleviate AS by suppressing the TNF/NF-κB axis and M1 macrophage polarization.Graphical

Virtual screening and multi-synergism of inhibitory compounds against pancreatic lipase

In response to the adverse effects associated with chemically synthesized pancreatic lipase (PL) inhibitors and the limited efficacy of individual natural functional compounds, this investigation aims at virtually screening potential PL inhibitors from natural plant-sourced materials and evaluating their multi-synergism through molecular docking, SynergyFinder tool and spectroscopic methods. Luteolin (LUT), quercetin (QUE), and apigenin (API) have been virtually screened out as outstanding PL inhibitors with the IC50 values being 109.7, 190.0 and 276.9 μg/mL. Synergistic score analysis of the PL inhibition rates by SynergyFinder Plus showed that the tri-component synergistic scores were more significant than one- and two-component synergy scores and the inhibition rate could reach 96.8% with LUT: QUE: API of 2 : 3: 12. The inhibitory mechanism of the complex (L-Q-A) on PL is mixed inhibition. L-Q-A exhibits a more potent quenching effect on PL and exerts a more pronounced influence on the secondary structure of PL. The simultaneous muti-ligand molecule docking results further demonstrate the existence of multiple binding pockets of L-Q-A on the PL that can form more hydrogen bonding, hydrophobic interactions and π-π interactions. In conclusion, LUT, QUE, and API exhibit synergistic effects in inhibiting PL activity, holding promise as innovative dietary supplements for mitigating obesity-related symptoms.

Investigating the binding of caffeic acid to human hemoglobin using multispectroscopic and molecular docking approaches

Caffeic acid (CA) is a hydroxycinnamic acid derivative that possess a wide variety of biological properties and is non-toxic to humans. The binding mechanism of CA with human hemoglobin (HHb) was studied for the first time using multispectroscopic and molecular docking methods. The UV–visible absorption spectra showed that CA interacts with HHb through the formation of ground state complex. The fluorescence studies revealed that CA quenches HHb fluorescence by the static mechanism and confirmed the presence of a single CA binding site on the HHb molecule. The negative values of thermodynamics parameters (ΔH,ΔSand ΔG) showed that the binding of CA to HHb is a spontaneous and exothermic process. Hydrogen bonds and van der Waal interactions are the major intermolecular forces that stabilize the HHb-CA complex. Synchronous fluorescence experiments showed that binding of CA altered the microenvironment around tryptophan residues of HHb. Fluorescence resonance energy transfer studies indicated a high propensity of energy transfer from tryptophan residues of HHb to CA. Circular dichroism spectra and catalytic esterase activity confirmed that only minor changes occur in the secondary structure of HHb in the presence of CA. Molecular docking study identified the HHb amino acid residues involved in binding to CA. Analysis of the binding mode of CA with HHb represents an important step in elucidating the molecular mechanism of the protection of HHb from oxidative damage. This will help in understanding the potential role of CA and related antioxidants as therapeutic agents in various blood-related diseases.