Bioactive Small Molecules Research Articles

Geranylation of Cyclic Dipeptides and Naphthols by the Fungal Prenyltransferase CdpC3PT_F253G.

Prenyl modification often improves the biological activities of compounds.Prenyltransferases have attracted attention as environmentally friendly biocatalysts for catalyzing prenyl modification of compounds. Compared to dimethylallyl modifications, research on geranyl modifications is relatively limited. To enrich biocatalytic toolboxes for generating potentially bioactive geranylated derivatives, this study developed methodologies to synthesize two types of geranylated compounds, i.e., geranylated tryptophan-containing cyclic dipeptides and geranylated naphthols, employing the F253G mutant of CdpC3PT, a cyclic dipeptide prenyltransferase from Neosartorya fischeri. The cyclic dipeptides (1-3) were transformed into C7-geranylated products (1G1-3G1), whereas 1-naphthol (4) and derivatives (5-6) yielded C4-geranylated products (4G1-6G1) and 2,7-dihydroxynaphthalene (7) generated a C3-geranylated product (7G1). All seven substrates and their geranylated products underwent antibacterial efficacy testing against Bacillus subtilis. Among them, five geranylated compounds (2G1 and 4G1-7G1) demonstrated antibacterial efficacies against Bacillus subtilis, with MIC values ranging from 4 to 32 μg/mL, surpassing their non-geranylated precursors. This research broadens the tools of geranyl-modifying biocatalysts, illustrates a case for developing highly efficient or function-altered biocatalysts and showcases the potential of prenyltransferases in the biosynthesis of bioactive small molecules.

Micro-thin hydrogel coating integrated in 3D printing for spatiotemporal delivery of bioactive small molecules

Three-dimensional (3D) printing incorporated with controlled delivery is an effective tool for complex tissue regeneration. Here, we explored a new strategy for spatiotemporal delivery of bioactive cues by establishing a precise-controlled micro-thin coating of hydrogel carriers on 3D-printed scaffolds. We optimized the printing parameters for three hydrogel carriers, fibrin cross-linked with genipin, methacrylate hyaluronic acid, and multidomain peptides, resulting in homogenous micro-coating on desired locations in 3D printed polycaprolactone microfibers at each layer. Using the optimized multi-head printing technique, we successfully established spatial-controlled micro-thin coating of hydrogel layers containing profibrogenic small molecules (SMs), Oxotremorine M and PPBP maleate, and a chondrogenic cue, Kartogenin. The delivered SMs showed sustained releases up to 28 d and guided regional differentiation of mesenchymal stem cells, thus leading to fibrous and cartilaginous tissue matrix formation at designated scaffold regionsin vitroandin vivo. Our micro-coating of hydrogel carriers may serve as an efficient approach to achieve spatiotemporal delivery of various bioactive cues through 3D printed scaffolds for engineering complex tissues.

Unraveling the molecular interactions and antioxidant mechanism of β-lactoglobulin with aloe’s hydroxyanthracene derivatives: A focus on aloin and aloe-emodin

Aloe dairy products have occupied a certain market share, and the interaction between the small bioactive molecules contained in aloe and milk proteins during product processing profoundly affects the performance of dairy products. In this study, two typical and potentially dangerous bioactive small molecules of aloe, aloin (AA) and aloe-emodin (AE), were selected to investigate their interaction mechanism with β-lactoglobulin (β-La). Computer simulations showed that AA/AE had the potential to form complexes with β-La, and the β-La-AA system exhibited a stronger binding affinity than the β-La-AE system. Fluorescence analysis showed that the binding affinity values of AA to β-La at 298 K were deduced to be (4.184 ± 1.06) × 104 M−1, meaning medium-strength interactions, comparatively, AE to β-La was weaker, were deduced to be (3.15 ± 1.25) × 103 M−1. In addition, the thermodynamic analysis found that ΔH0 and ΔS0 were positive in both the β-La-AA system and the β-La-AE system, which implies that the main driving force for the combination of AA/AE and β-La to form the ground state complex is the hydrophobic force. The conformation changes in β-La brought about by binding to AA/AE may alter the properties and functions of the protein, such as surface hydrophobicity and oxidation resistance. Analysis shows that β-La is potentially present in whey as an AA/AE carrier during the production of aloe milk.

3DSTarPred: A Web Server for Target Prediction of Bioactive Small Molecules Based on 3D Shape Similarity.

Target identification plays a critical role in preclinical drug development. The in silico approach has been developed and widely applied to assist medicinal chemists and pharmacologists in drug target identification. There are many target prediction web servers available today that have revealed both advantages and shortcomings in practical applications. Here, we present 3DSTarPred, a web server for three-dimensional (3D) shape similarity-based target prediction of small molecules. A benchmark study showed that 3DSTarPred achieved a target prediction success rate of 76.27%, which was higher than that of existing target prediction web servers. In addition, the performance of 3DSTarPred in the target prediction of diverse substructures/superstructures was also better than that of the existing target prediction web servers. In case studies, 3DSTarPred was used to identify the potential targets of two small molecules, one being kaempferol, a natural lead compound for the treatment of Alzheimer's disease (AD), and the other being sildenafil, a candidate for drug repurposing in AD. The case studies further demonstrated the reliability and success of 3DSTarPred in practice. The 3DSTarPred server is freely available at http://3dstarpred.pumc.wecomput.com.

An Axially CBD‐Containing Novel Pt(IV) Prodrug Designed to Synergistically Enhance Antitumor Activity by Inducing Mitochondrial Dysfunction

ABSTRACTIn recent years, significant attention has been given to the strategy of linking novel active molecules with different biological targets and antitumor mechanisms to the axial positions of Pt(IV) complexes, aiming to synthesize new Pt(IV) antitumor complexes with excellent properties. In this study, Satraplatin analogs and the highly lipophilic bioactive molecule cannabidiol (CBD) were chosen as the main research subjects. By combining these two and introducing other bioactive small molecules, we aimed to enrich the functionalities of Pt(IV) antitumor complexes. Five new multifunctional Pt(IV) antitumor complexes, P1–P5, were prepared. All Pt(IV) prodrugs demonstrated antitumor effects in various tumor cell lines. Notably, compound P1 exhibited significant inhibitory effects, with half‐maximal inhibitory concentration (IC50) values that were 2.1, 1.5, and 1.3 times higher than those of satraplatin in HCT‐116, A549, and HeLa cell lines, respectively, and 2.4, 1.5, and 2.0 times higher than those of the combination of satraplatin and CBD. The cytotoxicity of P1 toward cancer cell lines is significantly higher than that of the combination therapy group, providing preliminary evidence that the strategy of combining CBD and platinum‐based antitumor drugs into a complex is highly effective in simultaneously enhancing the cytotoxicity of both, resulting in a good synergistic antitumor effect. Further research shows that after treating cells with P1, the induced ROS generation increases in a dose‐dependent manner, disrupting the cell's redox homeostasis, leading to oxidative stress, and ultimately causing cell apoptosis. This strategy of introducing the bioactive molecule CBD into platinum‐based drug formation complexes to improve efficacy has been shown to be feasible and deserves further study.

SChemNET: a deep learning framework for predicting small molecules targeting microRNA function

MicroRNAs (miRNAs) have been implicated in human disorders, from cancers to infectious diseases. Targeting miRNAs or their target genes with small molecules offers opportunities to modulate dysregulated cellular processes linked to diseases. Yet, predicting small molecules associated with miRNAs remains challenging due to the small size of small molecule-miRNA datasets. Herein, we develop a generalized deep learning framework, sChemNET, for predicting small molecules affecting miRNA bioactivity based on chemical structure and sequence information. sChemNET overcomes the limitation of sparse chemical information by an objective function that allows the neural network to learn chemical space from a large body of chemical structures yet unknown to affect miRNAs. We experimentally validated small molecules predicted to act on miR-451 or its targets and tested their role in erythrocyte maturation during zebrafish embryogenesis. We also tested small molecules targeting the miR-181 network and other miRNAs using in-vitro and in-vivo experiments. We demonstrate that our machine-learning framework can predict bioactive small molecules targeting miRNAs or their targets in humans and other mammalian organisms.

Identification of Novel Target DCTPP1 for Colorectal Cancer Therapy with the Natural Small-Molecule Inhibitors Regulating Metabolic Reprogramming.

Colorectal cancer (CRC) is one of the most common malignant tumors. Identification of new effective drug targets for CRC and exploration of bioactive small-molecules are clinically urgent. The human dCTP pyrophosphatase 1 (DCTPP1) is a newly identified pyrophosphatase regulating the cellular nucleotide pool but remains unexplored as potential target for CRC treatment. Here, twelve unprecedented chemical architectures terpene-nonadride heterodimers (1-12) and their monomers (13-20) were isolated from endophyte Bipolaris victoriae S27. Compounds 1-12 represented the first example of terpene-nonadride heterodimers, in which nonadride monomers of 1 and 2 were also first example of 5/6 bicyclic nonadrides. A series of assays showed that 2 could repress proliferation and induce cell cycle arrest, apoptotic and autophagic CRC cell death in vitro and in vivo. Clinical cancer samples data revealed that DCTPP1 was a novel target associated with poor survival in CRC. DCTPP1 was also identified as a new target protein of 2. Mechanically, compound 2 bound to DCTPP1, inhibited its enzymatic activity, intervened with amino acid metabolic reprogramming, and exerted anti-CRC activity. Our study demonstrates that DCTPP1 was a novel potential biomarker and therapeutic target for CRC, and 2 was the first natural anti-CRC drug candidate targeting DCTPP1.

Multiplexed Target Profiling with Integrated Chemical Genomics and Chemical Proteomics.

Target identification is crucial for elucidating the mechanisms of bioactive molecules in drug discovery. However, traditional methods assess compounds individually, making it challenging to efficiently examine multiple compounds in parallel, especially for structurally diverse compounds. This study reports a novel strategy called chemical genomics-facilitated chemical proteomics (CGCP) for multiplexing the target identification of bioactive small molecules. CGCP correlates compounds' perturbation of global transcription, or chemical genomic profiles, with their reactivity toward target proteins, enabling simultaneous identification of targets. We demonstrated the utility of CGCP by studying the targets of celastrol (Cel) and four other electrophilic compounds with varying levels of similarity to Cel based on their chemical genomic profiles. We identified multiple novel targets and binding sites shared by the compounds in a single experiment. CGCP enabled multiplexity and improved the efficiency of target identification for structurally distinct compounds, indicating its potential to accelerate drug discovery.

Intermedin Alleviates Diabetic Cardiomyopathy by Up-Regulating CPT-1β through Activation of the Phosphatidyl Inositol 3 Kinase/Protein Kinase B Signaling Pathway.

Diabetic cardiomyopathy (DCM), one of the most serious long-term consequences of diabetes, is closely associated with myocardial fatty acid metabolism. Carnitine palmitoyltransferase-1β (CPT-1β) is the rate-limiting enzyme responsible for β-oxidation of long-chain fatty acids. Intermedin (IMD) is a pivotal bioactive small molecule peptide, participating in the protection of various cardiovascular diseases. However, the role and underlying mechanisms of IMD in DCM are still unclear. In this study, we investigated whether IMD alleviates DCM via regulating CPT-1β. A rat DCM model was established by having rats to drink fructose water for 12 weeks. A mouse DCM model was induced by feeding mice a high-fat diet for 16 weeks. We showed that IMD and its receptor complexes levels were significantly down-regulated in the cardiac tissues of DCM rats and mice. Reduced expression of IMD was also observed in neonatal rat cardiomyocytes treated with palmitic acid (PA, 300 μM) in vitro. Exogenous and endogenous IMD mitigated cardiac hypertrophy, fibrosis, dysfunction, and lipid accumulation in DCM rats and IMD-transgenic DCM mice, whereas knockout of IMD worsened these pathological processes in IMD-knockout DCM mice. In vitro, IMD alleviated PA-induced cardiomyocyte hypertrophy and cardiac fibroblast activation. We found that CPT-1β enzyme activity, mRNA and protein levels, and acetyl-CoA content were increased in T2DM patients, rats and mice. IMD up-regulated the CPT-1β levels and acetyl-CoA content in T2DM rats and mice. Knockdown of CPT-1β blocked the effects of IMD on increasing acetyl-CoA content and on inhibiting cardiomyocyte hypertrophy and cardiac fibroblast activation. IMD receptor antagonist IMD17-47 and the phosphatidyl inositol 3 kinase (PI3K)/protein kinase B (Akt) inhibitor LY294002 reversed the effects of IMD on up-regulating CPT-1β and acetyl-CoA expression and on inhibiting cardiomyocyte hypertrophy and cardiac fibroblast activation. We revealed that IMD alleviates DCM by up-regulating CPT-1β via calcitonin receptor-like receptor/receptor activity-modifying protein (CRLR/RAMP) receptor complexes and PI3K/Akt signaling. IMD may serve as a potent therapeutic target for the treatment of DCM.

Research progress on exosomes and their non-coding RNAs in the diagnosis of neurodegenerative diseases

Neurodegenerative diseases, originating from irreversible progressive loss of neuronal structure or function, are difficult to diagnose and treat. They vary widely in scope and have poor prevention and prognosis. Therefore, research on their early diagnosis is particularly important. Exosomes are small vesicles of cellular origin that contain various bioactive small molecules, such as proteins, RNAs, and DNAs, and play important roles in intercellular communication. Recent studies have shown that exosomes and their non-coding RNAs are key factors in the pathogenesis of various neurodegenerative diseases. Therefore, exosomes and their non-coding RNAs may provide a breakthrough for the early diagnosis of neurodegenerative diseases. This review summarizes the biology of exosomes and the current research progress of exosomes and their non-coding RNAs in diagnosing neurodegenerative diseases and further explores the challenges and prospects they face.

A screen for cell envelope stress uncovers an inhibitor of prolipoprotein diacylglyceryl transferase, Lgt, in Escherichia coli

The increasing prevalence of antibiotic resistance demands the discovery of antibacterial chemical scaffolds with unique mechanisms of action. Phenotypic screening approaches, such as the use of reporters for bacterial cell stress, offer promise to identify compounds while providing strong hypotheses for follow-on mechanism of action studies. From a collection of ∼1,800 Escherichia coli GFP transcriptional reporter strains, we identified a reporter that is highly induced by cell envelope stress-pProm rcsA -GFP. After characterizing pProm rcsA -GFP induction, we assessed a collection of bioactive small molecules for reporter induction, identifying 24 compounds of interest. Spontaneous suppressors to one compound in particular, MAC-0452936, mapped to the gene encoding the essential prolipoprotein diacylglyceryl transferase, lgt. Lgt inhibition by MAC-0452936 inhibition was confirmed through genetic, phenotypic, and biochemical approaches. The oxime ester, MAC-0452936, represents a useful small molecule inhibitor of Lgt and highlights the potential of using pProm rcsA -GFP as a phenotypic screening tool.

Entrapment of antimicrobial compounds in a metal matrix for crop protection.

Agricultural yields are often limited by damage caused by pathogenic microorganisms, including plant-pathogenic bacteria. The chemical control options to cope with bacterial diseases in agriculture are limited, predominantly relying on copper-based products. These compounds, however, possess limited efficacy. Therefore, there is an urgent need to develop novel technologies to manage bacterial plant diseases and reduce food loss. In this study, a new antimicrobial agent was developed using a doping method that entraps small bioactive organic molecules inside copper as the metal matrix. The food preservative agent lauroyl arginate ethyl ester (ethyl lauroyl arginate; LAE) was chosen as the doped organic compound. The new composites were termed LAE@[Cu]. Bactericidal assays against Acidovorax citrulli, a severe plant pathogen, revealed that LAE and copper in the composites possess a synergistic interaction as compared with each component individually. LAE@[Cu] composites were further characterised in terms of chemical properties and in planta assays demonstrated their potential for further development as crop protection agents.

Integrated gene-metabolite association network analysis reveals key metabolic pathways in gastric adenocarcinoma

Gastric adenocarcinoma is one of the most death cause cancers worldwide. Metabolomics is an effective approach for investigating the occurrence and progression of cancer and detecting prognostic biomarkers by studying the profiles of small bioactive molecules. To fully decipher the functional roles of the disrupted metabolites that modulate the cellular mechanism of gastric cancer, integrated gene-metabolite association network methods are critical to map the associations between metabolites and genes. In this study, we constructed a knowledge-based gene-metabolite association network of gastric cancer using the dysregulated metabolites and genes between gastric cancer patients and control group. The topological pathway analysis and gene-protein-metabolite-disease association analysis revealed four key gene-metabolite pathways which include eleven metabolites associated with modulated genes. The integrated gene-metabolite association network enables mechanistic investigation and provides a comprehensive overview regarding the investigation of molecular mechanisms of gastric cancer, which facilitates the in-depth understanding of metabolic biomarker roles in gastric cancer.

Temporal dynamics of N-hydroxypipecolic acid and salicylic acid pathways in the disease response to powdery mildew in wheat

Wheat (Triticum aestivum) is a major staple crop worldwide, and its yields are significantly threatened by wheat powdery mildew (Blumeria graminis f. sp. tritici). Enhancing disease resistance in wheat is crucial for meeting global food demand. This study investigated the disease response in wheat, focusing on the bioactive small molecules salicylic acid (SA), pipecolic acid (Pip), and N-hydroxypipecolic acid (NHP), to provide new insights for molecular breeding. We found that endogenous levels of SA, Pip, and NHP significantly increased in infected plants, with Pip and NHP levels rising earlier than those of SA. Notably, the rate of increase of NHP was substantially higher than that of SA. The gene expression levels of SARD1 and CBP60g, which are transcription factors for SA, Pip, and NHP biosynthesis, increased significantly during the early stages of infection. We also found that during the later stages of infection, the expression of ALD1, SARD4, and FMO1, which encode enzymes for Pip and NHP biosynthesis, dramatically increased. Additionally, ICS1, which encodes a key enzyme involved in SA biosynthesis, also showed increased expression during the later stages of infection. The temporal changes in ICS1 transcription closely mirrored the behavior of endogenous SA levels, suggesting that the ICS pathway is the primary route for SA biosynthesis in wheat. In conclusion, our results suggest that the early accumulation of Pip and NHP cooperates with SA in the disease response against wheat powdery mildew infection.

Mito-LND and (E)-Akt inhibitor-IV: novel compounds inducing endoplasmic reticulum stress and ROS accumulation against hepatocellular carcinoma.

Hepatocellular carcinoma (HCC) is one of the leading causes of cancer-related mortality. Although multi-kinase inhibitors can prolong the overall survival of late-stage HCC patients, the emergence of drug resistance diminishes these benefits, ultimately resulting in treatment failure. Therefore, there is an urgent need for novel and effective drugs to impede the progression of liver cancer. This study employed a concentration gradient increment method to establish acquired sorafenib or regorafenib-resistant SNU-449 cells. Cell viability was assessed using the cell counting kit-8 assay. A library of 793 bioactive small molecules related to metabolism screened compounds targeting both parental and drug-resistant cells. The screened compounds will be added to both the HCC parental cells and the drug-resistant cells, followed by a comprehensive assessment. Intracellular adenosine triphosphate (ATP) levels were quantified using kits. Flow cytometry was applied to assess cell apoptosis and reactive oxygen species (ROS). Real-time quantitative PCR studied relative gene expression, and western blot analysis assessed protein expression changes in HCC parental and drug-resistant cells. A xenograft model in vivo evaluated Mito-LND and (E)-Akt inhibitor-IV effects on liver tumors, with hematoxylin and eosin staining for tissue structure and immunohistochemistry staining for endoplasmic reticulum stress protein expression. From the compound library, we screened out two novel compounds, Mito-LND and (E)-Akt inhibitor-IV, which could potently kill both parental cells and drug-resistant cells. Mito-LND could significantly suppress proliferation and induce apoptosis in HCC parental and drug-resistant cells by upregulating glycolytic intermediates and downregulating those of the tricarboxylic acid (TCA) cycle, thereby decreasing ATP production and increasing ROS. (E)-Akt inhibitor-IV achieved comparable results by reducing glycolytic intermediates, increasing TCA cycle intermediates, and decreasing ATP synthesis and ROS levels. Both compounds trigger apoptosis in HCC cells through the interplay of the AMPK/MAPK pathway and the endoplasmic reticulum stress response. In vivo assays also showed that these two compounds could significantly inhibit the growth of HCC cells and induce endoplasmic reticulum stress. Through high throughput screening, we identified that Mito-LND and (E)-Akt inhibitor-IV are two novel compounds against both parental and drug-resistant HCC cells, which could offer new strategies for HCC patients.

The evaluation of the interaction of baicalein (5,6,7-trihydroxyflavone) with human IgG and a glioblastoma multiforme (GBM) cell line

Baicalein, a nutritional phenolic bioactive small molecule present in the roots of Scutellaria baicalensis and Scutellaria lateriflora, shows promising therapeutic effects against a wide range of cancer cells. However, its potential binding with blood carrier proteins and its anticancer mechanisms have not been well investigated. In this study, the interaction between baicalein and immunoglobulin G (IgG) was analyzed by analyzing intrinsic fluorescence, ellipticity changes, as well as molecular docking. The anticancer effects of baicalein against a glioblastoma multiforme (GBM) cell line, U87MG, and one normal immortalized human astrocytes were assessed by MTT, real-time PCR, caspase assay, and western blot. It was shown that the fluorescence quenching mechanism of human IgG by baicalein was based on a static quenching, where one binding site was responsible for the formation of baicalein-IgG complex derived by the formation of hydrogen bonds and van der Waals forces. A molecular docking study indicated that tyrosine residues (Tyr 91 and Tyr 98) were mostly involved in the binding site of baicalein to IgG. The cellular assay demonstrated that baicalein induced U87MG cell line death with an IC50 concentration of 73.19 µM, whereas normal astrocytes depicted over 82.94% portion of viability at 100 µM baicalein. The Bax mRNA overexpression, Bcl-2 mRNA downexpression, as well as the elevation of caspase-9 and caspase-3 activities confirmed that baicalein could effectively trigger the apoptosis of U87MG cells. Moreover, it was explored that baicalein downregulated the expression of the Axl/STAT3 signaling pathway in the U87MG cells, which is responsible for cellular proliferation and growth. In conclusion, these data may provide useful information regarding the pharmaceutical application of baicalein.

IDENTIFICATION OF NEW CHEMICAL ENTITIES AS VHL INHIBITORS FOR DIABETIC WOUND HEALING

Diabetes is a kind of endocrine disease that impacts around 6% of the world's population. Globally, 68% of amputations were performed in persons with diabetes. Hypoxia-inducible factor 1-alpha (HIF-1) is a crucial regulator of wound healing in diabetic patients, which includes epithelialization, angiogenesis, granulation, tissue development, and wound contraction. Even though diabetic wounds are hypoxic, HIF-1 levels are decreased during diabetic conditions. Diabetic wound healing necessitates the modulation of hypoxia-induced responses by VHL–HIF-1 protein-protein inhibition (PPI). Our proposed hypothesis is to increase HIF-1 levels by inhibiting VHL and HIF-1 interactions by small bioactive molecules, accelerating diabetic wound healing. Three features (Two hydrogen bond acceptors and One hydrogen bond donor) pharmacophore model was generated from the existing VHL inhibitors. Virtual screening was done based on the generated pharmacophore, and a library of 700 compounds was selected using ZINCPharmer. Based on the docking analysis the Top 15 HITs were selected & after performing ADMET studies, the Top 2 HITs (ZINC04214700 and ZINC12529886) were identified as potential VHL inhibitors. From this finding, we demonstrated that inhibiting the VHL and HIF-1 connection is a promising strategy for treating diabetic wounds.

Development of uniform ribosome display technology enabling easy and efficient identification of full-length proteins that interact with bioactive small and large molecules.

Identifying target proteins that interact with bioactive molecules is indispensable for understanding their mechanisms of action. In this study, we developed a uniform ribosome display technology using equal-length DNAs and mRNAs to improve molecular display principle for target identification. The equal-length DNAs were designed to contain various coding sequences for full-length proteins with molecular weights of up to 130 kDa and were used to synthesize equal-length mRNAs, which allowed the formation of full-length protein-ribosome-equal-length mRNA complexes. Uniform ribosome display selections of dihydrofolate reductase and haloalkane dehalogenase mutant were performed against methotrexate and chlorohexane, respectively. Quantitative changes of proteins after each selection indicated that the target protein-displaying ribosomal complexes were specifically selected through non-covalent or covalent interactions with the corresponding bioactive molecules. Furthermore, selection of full-length proteins interacting with methotrexate or anti-DDX46 antibody from protein pools showed that only the target proteins could be precisely identified even though the molar amounts of equal-length mRNAs encoding them were adjusted to 1/20,000 of the total equal-length mRNAs. Thus, the uniform ribosome display technology enabled efficient identification of target proteins that interact with bioactive small and large molecules through simplified operations without deep sequencing.

A simple and universal approach for fabricating bioactive self-stacked hydrogels with enhanced therapeutic efficacy

Despite significant advancements in self-stacked hydrogels of herbal small molecules in recent years, the emergence of new pharmacological small molecule self-stacked hydrogel systems remains largely reliant on serendipity and painstaking efforts. To address this challenge, we proposed a ‘bioactive bivalent metal ions-coordinated pharmacological small molecules’ strategy. This approach enabled the preparation of triterpenoid betulinic acid-based self-stacked hydrogels with excellent injectable and self-healing properties via a simple two-step method. We extended this strategy to self-stacking hydrogels based on other pentacyclic triterpene small molecules, anthraquinone small molecules, flavonoid small molecules and synthetic steroid small molecules. This universal strategy is capable of extracting hydrophobic pharmacological small molecules to construct novel self-stacked biomaterials in a cost-effective, efficient, large-scale, and environmentally friendly manner. Importantly, we successfully synthesized Mg2+-coordinated betulinic acid (BA-Mg) self-stacked hydrogel at low concentrations in the bacterial cellulose (termed BC) hydrogel network, overcoming the mechanical limitations of self-stacked hydrogels for biomedical applications. The BA-Mg/BC hybrid hydrogel demonstrated exceptional biocompatibility, anti-inflammatory, and angiogenic properties, significantly accelerating the skin wound healing process through the synergistic pharmacological effects of Mg2+ and BA.

Revealing binding mechanism of β-casein to chrysin, apigenin, and luteolin and locating its binding pockets by molecular docking and molecular dynamics

Revealing the interaction mechanism of proteins with bioactive molecules and the location of their binding pockets is crucial for predicting the structure-function relationship of proteins in drug discovery and design. Despite some published papers on the interaction of β-casein with small bioactive molecules, the ambiguity of the location and constituent amino acids of β-casein binding pockets prompted us to identify them by in silico simulation of its interaction with three polyphenols, chrysin, apigenin, and luteolin. Molecular docking revealed that the primary β-casein binding pocket for chrysin consists of five nonpolar amino acids (Leu73, Phe77, Pro80, Ile89, and Pro196), three polar neutral amino acids (Ser137, Gln138, and Gln197), and two polar charged amino acids (Glu136, and Arg198). For β-casein/apigenin and β-casein/luteolin complexes, Asn83 also contributes to forming the pocket. Molecular dynamics provided more details, such as the relative contribution of determinative amino acids and the role of various forces. For example, we found that Glu210, Glu132, and Glu35 are the most destructive residues in the binding of chrysin, apigenin, and luteolin to β-casein, respectively. Also, we observed that hydrophobic forces mainly stabilize β-casein/chrysin and β-casein/apigenin, and polar solvation (including hydrogen bonds) stabilizes β-casein/luteolin, all by spontaneous processes.