Β-glucuronidase Inhibitors Research Articles

Design, synthesis, and biological evaluation of (thio)urea derivatives as potent Escherichia coli β-glucuronidase inhibitors

EcGUS has drawn considerable attention for its role as a target in alleviating serious GIAEs. In this study, a series of 72 (thio)urea derivatives were designed, synthesised, and biologically assayed. The bioassay results revealed that E-9 (IC50 = 2.68 μM) exhibited a promising inhibitory effect on EcGUS, surpassing EcGUS inhibitor D-saccharic acid-1,4-lactone (DSL, IC50 = 45.8 μM). Additionally, the inhibitory kinetic study indicated that E-9 (Ki = 1.64 μM) acted as an uncompetitive inhibitor against EcGUS. The structure-activity relationship revealed that introducing an electron-withdrawing group into the benzene ring at the para-position is beneficial for enhancing inhibitory activity against EcGUS. Furthermore, molecular docking analysis indicated that E-9 has a strong affinity to EcGUS by forming interactions with residues Asp 163, Tyr 472, and Glu 504. Overall, these results suggested that E-9 could be a potent EcGUS inhibitor, providing valuable insights and guidelines for the development of future inhibitors targeting EcGUS.

Dissecting molecular mechanisms underlying the inhibition of β-glucuronidase by alkaloids from Hibiscus trionum: Integrating in vitro and in silico perspectives

β-Glucuronidase, a crucial enzyme in drug metabolism and detoxification, represents a promising target for therapeutic intervention due to its potential to modulate drug pharmacokinetics and enhance therapeutic efficacy. Herein, we assessed the inhibitory potential of phytochemicals from Hibiscus trionum against β-glucuronidase. Grossamide and grossamide K emerged as the most potent β-glucuronidase inhibitors with IC50 values of 0.73 ± 0.03 and 1.24 ± 0.03 μM, respectively. The investigated alkaloids effectively inhibited β-glucuronidase-catalyzed PNPG hydrolysis through a noncompetitive inhibition mode, whereas steppogenin displayed a mixed inhibition mechanism. Molecular docking analyses highlighted grossamide and grossamide K as inhibitors with the lowest binding free energy, all compounds successfully docked into the same main binding site occupied by the reference drug Epigallocatechin gallate (EGCG). We explored the interaction dynamics of isolated compounds with β-glucuronidase through a 200 ns molecular dynamics (MD) simulation. Analysis of various MD parameters revealed that grossamide and grossamide K maintained stable trajectories and demonstrated significant energy stabilization upon binding to β-glucuronidase. Additionally, these compounds exhibited the lowest average interaction energies with the target enzyme. The MM/PBSA calculations further supported these findings, showing the lowest binding free energies for grossamide and grossamide K. These computational results are consistent with experimental data, suggesting that grossamide and grossamide K could be potent inhibitors of β-glucuronidase.

Bridging in silico and in vitro perspectives to unravel molecular mechanisms underlying the inhibition of β-glucuronidase by coumarins from Hibiscus trionum

Unraveling the intricacies of β-glucuronidase inhibition is pivotal for developing effective strategies in applications specific to gastrointestinal health and drug metabolism. Our study investigated the efficacy of some Hibiscus trionum phytochemicals as β-glucuronidase inhibitors. The results showed that cleomiscosin A and mansonone H emerged as the most potent inhibitors, with IC50 values of 3.97 ± 0.35 μM and 10.32 ± 1.85 μM, respectively. Mechanistic analysis of β-glucuronidase inhibition indicated that cleomiscosin A and the reference drug EGCG displayed a mixed inhibition mode against β-glucuronidase, while mansonone H exhibited noncompetitive inhibition against β-glucuronidase. Docking studies revealed that cleomiscosin A and mansonone H exhibited the lowest binding affinities, occupying the same site as EGCG, and engaged significant key residues in their binding mechanisms. Using a 30 ns molecular dynamics (MD) simulation, we explored the interaction dynamics of isolated compounds with β-glucuronidase. Analysis of various MD parameters showed that cleomiscosin A and mansonone H exhibited consistent trajectories and significant energy stabilization with β-glucuronidase. These computational insights complemented experimental findings, underscoring the potential of cleomiscosin A and mansonone H as β-glucuronidase inhibitors.

Astraoleanosides E–P, oleanane-type triterpenoid saponins from the aerial parts of Astragalus membranaceus Bunge and their β-glucuronidase inhibitory activity

Historically, Astragalus membranaceus Bunge has been used as a beneficial medicinal plant, particularly in the Asian traditional medical systems, for the treatment of various human diseases such as stomach ulcers, diarrhea, and respiratory issues associated with phlegm. In this study, a phytochemical characterization of the aerial parts of A. membranaceusled to the isolation of 29 oleanane-type triterpenoid saponins, including 11 new compounds named astraoleanosides E–P (6–9, 13, 14, 18–22), as well as 18 known ones. The structures of these compounds were elucidated using nuclear magnetic resonance (NMR) spectroscopy and high-resolution mass spectrometry. Among them, astraoleanoside H (9) and cloversaponin III (15) demonstrated the most potent β-glucuronidase inhibitory activities, with IC50 values of 21.20 ± 0.75 and 9.05 ± 0.47 µM, respectively, compared to the positive control d-saccharic acid 1,4-lactone (IC50 = 20.62 ± 1.61 µM). Enzyme kinetics studies were then conducted to investigate the type of inhibition exhibited by these active compounds. In addition, the binding mechanism, key interactions, binding stability, and dynamic behavior of protein–ligand complexes were investigated through in silico approaches, such as molecular docking and molecular dynamics simulations. These findings highlight the promising potential of triterpenoid saponins from A. membranaceus as lead compounds for β-glucuronidase inhibitors, offering new possibilities for the development of therapeutic agents targeting various diseases where β-glucuronidase plays a crucial role.

Synthesis of 2-Aminopyrimidine Derivatives and Their Evaluation as β-Glucuronidase Inhibitors: In Vitro and In Silico Studies.

Currently the discovery and development of potent β-glucuronidase inhibitors is an active area of research due to the observation that increased activity of this enzyme is associated with many pathological conditions, such as colon cancer, renal diseases, and infections of the urinary tract. In this study, twenty-seven 2-aminopyrimidine derivatives 1-27 were synthesized by fusion of 2-amino-4,6-dichloropyrimidine with a variety of amines in the presence of triethylamine without using any solvent and catalyst, in good to excellent yields. All synthesized compounds were characterized by EI-MS, HREI-MS and NMR spectroscopy. Compounds 1-27 were then evaluated for their β-glucuronidase inhibitory activity, and among them, compound 24 (IC50 = 2.8 ± 0.10 µM) showed an activity much superior to standard D-saccharic acid 1,4-lactone (IC50 = 45.75 ± 2.16 µM). To predict the binding mode of the substrate and β-glucuronidase, in silico study was performed. Conclusively, this study has identified a potent β-glucuronidase inhibitor that deserves to be further studied for the development of pharmaceutical products.

Discovering biological efficacy of new thiadiazole as effective inhibitors of urease, glycation, and (DPPH) scavengers: Biochemical and in silico study

Thiadiazole is a potential class of α-glucosidase, β-glucuronidase, and anti-leishmanial inhibitors. Our aim was to develop thiadiazole based dual inhibitors for urease glycation inhibition and (DDPH) scavenging activity. Pyridine-based-thiadiazole analogs (1–18) were synthesized and characterized through 1H NMR, 13C NMR, EI-HRMS. All synthesized compounds were new and showed good inhibition ranging between IC50 value (0.70 ± 0.010 to 21.10 ± 0.90 μM) when compared with standard thiourea (21.40 ± 0.21 μM). Among the series, analog 13 having IC50 value (0.70 ± 0.010) showed the most potent inhibition. All synthesized compounds screened for their antioxidant and antiglycation inhibitory effect, and they showed good inhibition for both. The binding interactions with urease enzyme with active inhibitors studied via molecular docking studies. The compound 13 showed potent urease, antiglycation and (DPPH) scavenging activity and showed its character as dual inhibitor.

Inhibitory Effect of Coumarins and Isocoumarins Isolated from the Stems and Branches of Acer mono Maxim. against Escherichia coli β-Glucuronidase

We isolated eight known secondary metabolites, including two isocoumarins and six coumarins, from the stems and branches of Acer mono Maxim. Their structures were confirmed using nuclear magnetic resonance spectroscopy and by comparing the data to published reports. The inhibitory effects of all compounds (1−8) on Escherichia coli β-glucuronidase were evaluated for the first time using in vitro assays. 3-(3,4-Dihydroxyphenyl)-8-hydroxyisocoumarin (1) displayed an inhibitory effect against β-glucuronidase (IC50 = 58.83 ± 1.36 μM). According to the findings of kinetic studies, compound 1 could function as a non-competitive inhibitor. Molecular docking indicated that compound 1 binds to the allosteric binding site of β-glucuronidase, and the results corroborated those from kinetic studies. Furthermore, molecular dynamics simulations of compound 1 were performed to identify the behavioral and dynamic properties of the protein–ligand complex. Our results reveal that compound 1 could be a lead metabolite for designing new β-glucuronidase inhibitors.

Characterizing the metabolic effects of the selective inhibition of gut microbial β-glucuronidases in mice

The hydrolysis of xenobiotic glucuronides by gut bacterial glucuronidases reactivates previously detoxified compounds resulting in severe gut toxicity for the host. Selective bacterial β-glucuronidase inhibitors can mitigate this toxicity but their impact on wider host metabolic processes has not been studied. To investigate this the inhibitor 4-(8-(piperazin-1-yl)-1,2,3,4-tetrahydro-[1,2,3]triazino[4′,5′:4,5]thieno[2,3-c]isoquinolin-5-yl)morpholine (UNC10201652, Inh 9) was administered to mice to selectively inhibit a narrow range of bacterial β-glucuronidases in the gut. The metabolomic profiles of the intestinal contents, biofluids, and several tissues involved in the enterohepatic circulation were measured and compared to control animals. No biochemical perturbations were observed in the plasma, liver or gall bladder. In contrast, the metabolite profiles of urine, colon contents, feces and gut wall were altered compared to the controls. Changes were largely restricted to compounds derived from gut microbial metabolism. This work establishes that inhibitors targeted towards bacterial β-glucuronidases modulate the functionality of the intestinal microbiota without adversely impacting the host metabolic system.

Inhibitory Activity of Bioactive Phloroglucinols from the Rhizomes of Dryopteris crassirhizoma on Escherichia coli β-Glucuronidase: Kinetic Analysis and Molecular Docking Studies

Phloroglucinols—one of the major secondary metabolites in Dryopteris crassirhizoma—exhibit various pharmacological effects, such as antiviral, antioxidant, and antidiabetic activities. This study evaluated 30 phloroglucinols isolated from the rhizomes of D. crassirhizoma for their inhibitory activity on β-glucuronidase via in vitro assays. Among them, dimeric phloroglucinols 13–15 moderately inhibited β-glucuronidase, and trimeric phloroglucinols 26–28 showed strong inhibitory effects, with IC50 values ranging from 5.6 to 8.0 μM. Enzyme kinetic analysis confirmed all six active compounds to be in a competitive mode of inhibition. Molecular docking simulations revealed the key binding interactions with the active site of β-glucuronidase protein and the binding mechanisms of these active metabolites. Our results suggest that the rhizomes of D. crassirhizoma and trimeric compounds 26–28 may serve as potential candidates for discovering and developing new β-glucuronidase inhibitors.

Identification of naturally occurring inhibitors in Xian-Ling-Gu-Bao capsule against the glucuronidation of estrogens.

Xian-Ling-Gu-Bao (XLGB) capsule, a well-known traditional Chinese medicine prescription, is widely used for the treatment of osteoporosis. It could significantly increase the levels of estrogen in ovariectomized rats and mice. However, this working mechanism has not been well elucidated. Considering that UDP-glucuronosyltransferase (UGT) enzymes are the important enzymes that inactivate and regulate estrogen activity in vivo, this study aimed to identify the bioactive compounds from XLGB against the glucuronidation of estrogens. First, thirty compounds were considered as candidate bioactive compounds based on our previous studies including pharmacological evaluation, chemical profiles, and metabolic profiles. Second, the characteristics of estrogen glucuronidation by uridine diphosphate glucuronic acid (UDPGA)-supplemented human liver microsomes (HLM), human intestine microsomes (HIM), and expressed UGT enzymes were determined, and the incubation systems of their key UGT enzymes were optimized. Then, inhibitory effects and mechanisms of XLGB and its main compounds toward the key UGT isozymes were further investigated. As a result, estrogen underwent efficient glucuronidation by HLM and HIM. UGT1A10, 1A1, and 2B7 were mainly responsible for the glucuronidation of estrone, β-estradiol, and estriol, respectively. For E1 and E2, UGT1A10 and 1A1 tended to mediate estrogen-3-O-glucuronidation, while UGT2B7 preferred catalyzing estrogen-16-O-glucuronidation. Furthermore, the incubation system for active UGT isoforms was optimized including Tris-HCl buffer, detergents, MgCl2 concentration, β-glucuronidase inhibitors, UDPGA concentration, protein concentration, and incubation time. Based on optimal incubation conditions, eleven, nine, and nine compounds were identified as the potent inhibitors for UGT1A10, 1A1, and 2B7, respectively (IC50 < 4.97 μM and Ki < 3.35 μM). Among them, six compounds (bavachin, isobavachin, isobavachalcone, neobavaisoflavone, corylifol A, and icariside II) simultaneously demonstrated potent inhibitory effects against these three active enzymes. Prenylated flavanols from Epimedium brevicornu Maxim., prenylated flavonoids from Psoralea corylifolia L., and salvianolic acids from Salvia miltiorrhiza Bge. were characterized as the most important and effective compounds. The identification of potent natural inhibitors of XLGB against the glucuronidation of estrogen laid an important foundation for the pharmacodynamic material basis.

Synthesis, Biological Evaluation, and In Silico Studies of Novel Coumarin-Based 4H,5H-pyrano[3,2-c]chromenes as Potent β-Glucuronidase and Carbonic Anhydrase Inhibitors.

The search for novel heterocyclic compounds with a natural product skeleton as potent enzyme inhibitors against clinical hits is our prime concern in this study. Here, a simple and facile two-step strategy has been designed to synthesize a series of novel coumarin-based dihydropyranochromenes (12a–12m) in a basic moiety. The synthesized compounds were thus characterized through spectroscopic techniques and screened for inhibition potency against the cytosolic hCA II isoform and β-glucuronidase. Few of these compounds were potent inhibitors of hCA II and β-glucuronidase with varying IC50 values ranging from 4.55 ± 0.22 to 21.77 ± 3.32 μM and 440.1 ± 1.17 to 971.3 ± 0.05 μM, respectively. Among the stream of synthesized compounds, 12e and 12i were the most potent inhibitors of β-glucuronidase, while 12h, 12i, and 12j showed greater potency against hCA II. In silico docking studies illustrated the significance of substituted groups on the pyranochromene skeleton and binding pattern of these highly potent compounds inside enzyme pockets.

Virtual Screening for the Discovery of Microbiome β-Glucuronidase Inhibitors to Alleviate Cancer Drug Toxicity.

Despite the potency of most first-line anti-cancer drugs, nonadherence to these drug regimens remains high and is attributable to the prevalence of "off-target" drug effects that result in serious adverse events (SAEs) like hair loss, nausea, vomiting, and diarrhea. Some anti-cancer drugs are converted by liver uridine 5'-diphospho-glucuronosyltransferases through homeostatic host metabolism to form drug-glucuronide conjugates. These sugar-conjugated metabolites are generally inactive and can be safely excreted via the biliary system into the gastrointestinal tract. However, β-glucuronidase (βGUS) enzymes expressed by commensal gut bacteria can remove the glucuronic acid moiety, producing the reactivated drug and triggering dose-limiting side effects. Small-molecule βGUS inhibitors may reduce this drug-induced gut toxicity, allowing patients to complete their full course of treatment. Herein, we report the discovery of novel chemical series of βGUS inhibitors by structure-based virtual high-throughput screening (vHTS). We developed homology models for βGUS and applied them to large-scale vHTS against nearly 400,000 compounds within the chemical libraries of the National Center for Advancing Translational Sciences at the National Institutes of Health. From the vHTS results, we cherry-picked 291 compounds via a multifactor prioritization procedure, providing 69 diverse compounds that exhibited positive inhibitory activity in a follow-up βGUS biochemical assay in vitro. Our findings correspond to a hit rate of 24% and could inform the successful downstream development of a therapeutic adjunct that targets the human microbiome to prevent SAEs associated with first-line, standard-of-care anti-cancer drugs.

α-Glucosidase and Bacterial β-Glucuronidase Inhibitors from the Stems of Schisandra sphaerandra Staph.

α-Glucosidase (AGS) is a therapeutic target for Type 2 diabetes mellitus (T2DM) that tends to complicate with other diseases. Some medications for the treatment of T2DM complications have the risk of inducing severe adverse reactions such as diarrhea via the metabolism of intestinal bacterial β-glucuronidase (BGUS). The development of new AGS and/or BGUS inhibitors may improve the therapeutic effects of T2DM and its complications. The present work focused on the isolation and characterization of AGS and/or BGUS inhibitors from the medicinal plant Schisandra sphaerandra. A total of eight compounds were isolated and identified. Sphaerandralide A (1) was obtained as a previously undescribed triterpenoid, which may have chemotaxonomy significance in the authentication of the genus Schisandra and Kadsura. 2′-acetyl-4′,4-dimethoxybiphenyl-2-carbaldehyde (8) was obtained from a plant source for the first time, while compounds 2–7 were isolated from S. sphaerandra for the first time. In the in vitro assay, compounds 1–5 showed potent to moderate activity against AGS. Interestingly, compound 3 also exhibited significant BGUS inhibitory activity, demonstrating the potential of being developed as a bifunctional inhibitor that may find application in the therapy of T2DM and/or the diarrhea induced by medications for the treatment of T2DM complications.

Diverse diterpenoids with α-glucosidase and β-glucuronidase inhibitory activities from Euphorbia milii

Four undescribed regular rosane-type diterpenoids euphominoids M−P and three undescribed rearranged rosane-type diterpenoids euphomilones C-E were isolated from the whole plants of Euphorbia milii Des Moul., along with nine known compounds. Their structures were elucidated by detailed interpretation of the NMR and mass spectroscopy. The absolute configurations were established by single-crystal X-ray diffraction experiments, as well as comparative analyses of calculated and experimental ECD spectra. Euphominoid M featured a highly oxygenated ring A and a rare four-membered oxygen ring while euphomilones C-E possessed 7/5/6 or 5/7/6 fused ring systems, which were rarely occurring in rosane-type diterpenoids. In the in-vitro bioassays, 19-norrosa-1,3,5(10),15-tetraene-2,3-diol and antiquorin showed more potent α-glucosidase inhibitory activity than the positive control acarbose while euphominoid C exhibited significant inhibitory activity against both α-glucosidase and β-glucuronidase. To the best of our knowledge, it was the first time that rosane-type diterpenoids were reported as β-glucuronidase inhibitors.

Is Our Natural Food Our Homeostasis? Array of a Thousand Effect-Directed Profiles of 68 Herbs and Spices.

The beneficial effects of plant-rich diets and traditional medicines are increasingly recognized in the treatment of civilization diseases due to the abundance and diversity of bioactive substances therein. However, the important active portion of natural food or plant-based medicine is presently not under control. Hence, a paradigm shift from quality control based on marker compounds to effect-directed profiling is postulated. We investigated 68 powdered plant extracts (botanicals) which are added to food products in food industry. Among them are many plants that are used as traditional medicines, herbs and spices. A generic strategy was developed to evaluate the bioactivity profile of each botanical as completely as possible and to straightforwardly assign the most potent bioactive compounds. It is an 8-dimensional hyphenation of normal-phase high-performance thin-layer chromatography with multi-imaging by ultraviolet, visible and fluorescence light detection as well as effect-directed assay and heart-cut of the bioactive zone to orthogonal reversed-phase high-performance liquid chromato-graphy−photodiode array detection−heated electrospray ionization mass spectrometry. In the non-target, effect-directed screening via 16 different on-surface assays, we tentatively assigned more than 60 important bioactive compounds in the studied botanicals. These were antibacterials, estrogens, antiestrogens, androgens, and antiandrogens, as well as acetylcholinesterase, butyrylcholinesterase, α-amylase, α-glucosidase, β-glucosidase, β-glucuronidase, and tyrosinase inhibitors, which were on-surface heart-cut eluted from the bioautogram or enzyme inhibition autogram to the next dimension for further targeted characterization. This biological-physicochemical hyphenation is able to detect and control active mechanisms of traditional medicines or botanicals as well as the essentials of plant-based food. The array of 1,292 profiles (68 samples × 19 detections) showed the versatile bioactivity potential of natural food. It reveals how efficiently and powerful our natural food contributes to our homeostasis.

Discovery of a series of 5-phenyl-2-furan derivatives containing 1,3-thiazole moiety as potent Escherichia coli β-glucuronidase inhibitors

Gut microbial β-glucuronidases have drawn much attention due to their role as a potential therapeutic target to alleviate some drugs or their metabolites-induced gastrointestinal toxicity. In this study, fifteen 5-phenyl-2-furan derivatives containing 1,3-thiazole moiety (1–15) were synthesized and evaluated for their inhibitory effects against Escherichia coli β-glucuronidase (EcGUS). Twelve of them showed satisfactory inhibition against EcGUS with IC50 values ranging from 0.25 μM to 2.13 μM with compound 12 exhibited the best inhibition. Inhibition kinetics studies indicated that compound 12 (Ki = 0.14 ± 0.01 μM) was an uncompetitive inhibitor for EcGUS and molecular docking simulation further predicted the binding model and capability of compound 12 with EcGUS. A preliminary structure-inhibitory activity relationship study revealed that the heterocyclic backbone and bromine substitution of benzene may be essential for inhibition against EcGUS. The compounds have the potential to be applied in drug-induced gastrointestinal toxicity and the findings would help researchers to design and develop more effective 5-phenyl-2-furan type EcGUS inhibitors.

Synthesis, in-vitro and in-silico studies of triazinoindole bearing bis-Schiff base as β-glucuronidase inhibitors

Triazinoindole bearing bis-Schiff base analogs (1–20) were synthesized by triazinoindole-thione ring formation, triazinoindole-thiol-phenylethanone, followed by triazinoindole bis-Schiff base formation. Synthesized analogs showed β-glucuronidase potential with IC50 value ranging between 2.60 ± 0.10 to 55.40 ± 1.60 µM as compared to standard d-saccharic acid 1,4-lactone (IC50 = 48.10 ± 1.2 µM). Analog 20 was the most potent one with IC50 value 2.60 ± 0.10 µM. Analogs 17, 4 showed IC50 values 5.20 ± 0.20 and 5.70 ± 0.20 µM respectively and withstand 2nd and 3rd ranked scaffolds among the synthesized analogs. All other sixteen analogs showed many-fold better potency with IC50 values ranging from 7.9 ± 0.2 to 48.1 ± 1.2 µM. The structure-activity relationship was established and confirmed of binding interactions through molecular docking studies.

Beta-Glucuronidase Inhibition by Constituents of Mulberry Bark.

Intestinal bacterial β-glucuronidases, the key enzymes responsible for the hydrolysis of various glucuronides into free aglycone, have been recognized as key targets for treating various intestinal diseases. This study aimed to investigate the inhibitory effects and mechanisms of the Mulberry bark constituents on E. coli β-glucuronidase (EcGUS), the most abundant β-glucuronidases produced by intestinal bacteria. The results showed that the flavonoids isolated from Mulberry bark could strongly inhibit E. coli β-glucuronidase, with IC50 values ranging from 1.12 µM to 10.63 µM, which were more potent than D-glucaric acid-1,4-lactone. Furthermore, the mode of inhibition of 5 flavonoids with strong E. coli β-glucuronidase inhibitory activity (IC50 ≤ 5 µM) was carefully investigated by a set of kinetic assays and in silico analyses. The results demonstrated that these flavonoids were noncompetitive inhibitors against E. coli β-glucuronidase-catalyzed 4-nitrophenyl β-D-glucuronide hydrolysis, with Ki values of 0.97 µM, 2.71 µM, 3.74 µM, 3.35 µM, and 4.03 µM for morin (1: ), sanggenon C (2: ), kuwanon G (3: ), sanggenol A (4: ), and kuwanon C (5: ), respectively. Additionally, molecular docking simulations showed that all identified flavonoid-type E. coli β-glucuronidase inhibitors could be well-docked into E. coli β-glucuronidase at nonsubstrate binding sites, which were highly consistent with these agents' noncompetitive inhibition mode. Collectively, our findings demonstrated that the flavonoids in Mulberry bark displayed strong E. coli β-glucuronidase inhibition activity, suggesting that Mulberry bark might be a promising dietary supplement for ameliorating β-glucuronidase-mediated intestinal toxicity.

Rational Design, Synthesis, In Vitro, and In Silico Studies of Dihydropyrimidinone Derivatives as β-Glucuronidase Inhibitors

In the current study, a series of dihydropyrimidinone derivatives were rationally designed as β-glucuronidase inhibitors. These designed compounds were successfully synthesized and characterized through various spectroscopic techniques such as IR, 1H-NMR, 13C-NMR, and EI-MS. A structure-activity relationship (SAR) of synthesized derivatives to inhibit β-glucuronidase was also established. In vitro biological evaluations revealed that 4i as the most potent compound in this series has an IC50 value of 31.52 ± 2.54 μM compared to the standard D-saccharic acid 1,4-lactone (IC50 = 41.32 ± 1.82 µM). Also, molecular docking and dynamics studies of the most potent compound are performed to evaluate interactions between the active compound and binding site.

2,5-Disubstituted furan derivatives containing 1,3,4-thiadiazole moiety as potent α-glucosidase and E.coli β-glucuronidase inhibitors.

In this paper, the 2,5-disubstituted furan derivatives containing 1,3,4-thiadiazole were synthesized and screened for their inhibitory activity against α-glucosidase and β-glucuronidases to obtain potent α-glucosidase inhibitor 9 (IC50=0.186μM) and E.coli β-glucuronidase inhibitor 26 (IC50=0.082μM), respectively. The mechanisms of the compounds were studied. The kinetic study revealed that compound 9 is a competitive inhibitor against α-glucosidase (Ki=0.05±0.003μM) and molecular docking simulation showed several key interactions between 9 and the target including hydrogen bond and p-π stacking interaction. Derivative 26 (Ki=0.06±0.005μM) displayed uncompetitive inhibition behavior against EcGUS. Furthermore, the result of docking revealed the furan ring of 26 may be a key moiety in obstructing the active domain of EcGUS. In addition, compound 15 exhibited significant inhibitory activity against these two enzymes, with potential therapeutic effects against diabetes and against CPT-11-induced diarrhea. At the same time, their low toxicity against normal liver tissue LO2 cells lays the foundation for invivo studies and the development of bifunctional drug.