Β-glucuronidase Inhibitory Activity Research Articles

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.

Novel benzoxazole-based thiosemicarbazide derivatives as new inhibitors of urease and β-Glucuronidase: Synthesis, in vivo anti-nematodal activity and ADMET prediction along with in silico study

Here, we discuss the synthesis of thiosemicarbazide derivatives based on benzoxazole. These compounds were obtained via sequence of reactions. The targeted products wereconfirmed using a number of spectroscopic methods, including NMR (1H and 13C) and EI-MS. After spectral confirmation all the synthesized compounds were evaluated for urease and β-Glucuronidase inhibitory activity in order to explore their biological significances in the presence of standard drug thiourea (IC50 = 21.86 ± 0.40) and D-saccharic acid 1,4-lactone (IC50 value 22.00 ± 1.10 µM) respectively. Among the evaluated series, compounds 14 and 15 (1.10 and 0.01 and 2.20 and 0.60) were shown to have slightly greater potential than standard drugs. Anti-nematodal activity was also employed to explore the cytotoxic nature of synthesized analogs. In order to establish the binding relationship with enzyme active sites, molecular docking experiments were done and directions for compound modification based on SAR features were addressed. In addition, ADMET prediction study also investigated to found drug like properties of the potential analogs.

Synthesis, β-Glucuronidase Inhibitory Activity, and Molecular Docking Study of Oxazole Derivatives

Synthesis, β-Glucuronidase Inhibitory Activity, and Molecular Docking Study of Oxazole Derivatives

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.

Acylated secoiridoid glucosides isolated from the fruit extract of Symplocos lucida inhibit β-glucuronidase

Two new acylated secoiridoid glucosides, designated symplolucidins A and B, were isolated from the fruit extract of Symplocos lucida (Thunb.) Siebold & Zucc. Their structures, including their absolute configurations, were elucidated by extensive spectroscopic analyses and chemical reactions. They were found to exhibit β-glucuronidase inhibitory effect. • Two new secoiridoid glucosides were isolated from the fruits of Symplocos lucida. • The structures were characterized by spectroscopic methods. • β-Glucuronidase inhibitory activity was evaluated.

Exploring gabosine and chlorogentisyl alcohol derivatives from a marine-derived fungus as EcGUS inhibitors with informatic assisted approaches

β-Glucuronidase catalyzes the cleavage of glucuronosyl-O-bonds, whose inhibitors reduce the level of toxic substances present in the intestine caused by anti-cancer and anti-inflammatory therapies. Herein, we presented a new tool, Bioactive Fractions Filtering Platform (BFFP), which is able to reliably discern active candidate node from crude extracts. The source code for the BFFP is available on GitHub (https://github.com/BioGavin/msbff). With the assistant of BFFP, 25 gabosine and chlorogentisyl alcohol derivatives including 19 new compounds were isolated from a marine-derived fungus Epicoccum sp. GST-5. Compounds 7, 9–15 possessed an unusual hybrid skeleton of gabosine and chlorogentisyl alcohol units. Compounds 9–12, 16 and 17 possessed a novel three-membered spiral ring skeleton with one/two gabosine and one/two chlorogentisyl alcohol units. Compound 25 represented new gabosine-derived skeleton possessing an unusual 6/6/6/5/6 condensed ring system. All isolates were evaluated for in vitro E. coli β-glucuronidase (EcGUS) inhibitory activity. 14 Compounds demonstrated superior inhibitory activity (IC50 = 0.24–4.61 μM) to that of standard d-saccharic acid 1,4-lactone (DSL, IC50 = 56.74 ± 4.01 μM). Compounds with chlorogentisyl alcohol moiety, such as 17 (IC50 = 0.24 ± 0.02 μM) and 1 (IC50 = 0.74 ± 0.03 μM), exhibited the most potent inhibitory activity. Furthermore, literature based QSAR profiling by applying PCA and OPLS analysis was carried out to analyze the features of compounds against EcGUS, revealing that the introduction of substituents able to form polar interactions with binding sites of receptor would lead to more active structures.

Synthesis of Oxadiazole-Based-Thiourea, Evaluation of Their β-Glucuronidase Inhibitory Potential, and Molecular Docking Study

Oxadiazole-based-thiourea analogs (1–18) were synthesized and evaluated for their β-glucuronidase inhibitory activity. All analogs showed extensive β-glucuronidase inhibitory potential ranging between (IC50 = 2.20 ± 0.01 µM) to (IC50 = 52.25 ± 1.20 µM) by comparing with the standard D-Saccharic acid 1,4-lactone (IC50 = 48.30 ± 1.25 µM). Among the series, analogue 7 having IC50 value (IC50 = 2.20 ± 0.01 µM)), 16 (IC50 = 4.40 ± 0.10 µM) and 4 (IC50 = 9.20 ± 0.20 µM) showed an excellent inhibitory potential greater than that of standard D-saccharic acid-1,4- lactone. Analogue 7 (IC50 = 2.20 ± 0.01 µM) of this series having flouro group at ortho-position of phenyl ring was recognized to be most active analogue due to involvement of flouro group in hydrogen bonding with the enzyme active site. In addition, all synthesized derivatives characterized by using High Resolution Mass Spectrometry (HR-MS), 13C-NMR and Nuclear Magnetic Resonance Spectroscopy (1H-NMR proton). For better understanding of binding mode of interactions of these active analogs molecular docking study was performed. Structure Activity relationship (SAR) was also discussed.

Synthesis of new 1,2-disubstituted benzimidazole analogs as potent inhibitors of β-Glucuronidase and in silico study

New benzimidazole analogues (1–18) were synthesized and characterized through different spectroscopic techniques such as 1H NMR, 13C NMR and HREI-MS. All analogues were screened for β-glucuronidase inhibitory potential. All analogues showed varied degree of inhibitory potentials with IC50 values ranging between 1.10 ± 0.10 to 39.60 ± 0.70 μM when compared with standard D-saccharic acid-1,4- lactone having IC50 value 48.30 μM. Analogues 17, 11, 9, 6, 1 and 13 having IC50 values 1.10 ± 0.10, 1.70 ± 0.10, 2.30 ± 0.10, 5.30 ± 0.20, 6.20 ± 0.20 and 8.10 ± 0.20 μM respectively, showed excellent β-glucuronidase inhibitory potential many folds better than the standard. All other analogues also showed good inhibitory potential better as compared to standard. Structure activity relationships (SAR) has been established for all compounds. The results from molecular docking studies supports the established SAR and developed a strong correlation with the results from in to vitro assay. The molecular docking results clearly highlighted how substituents like nitro and chloro affect the binding position of the active compounds in the active site. The docking results were also used to properly establish the effect of bulky substituents of least active compounds on reduced β-glucuronidase inhibitory activity. Compounds 1–18 were found non-toxic.

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.

Synthesis, β-glucuronidase inhibition and molecular docking studies of cyano-substituted bisindole hydrazone hybrids.

The β-glucuronidase, a lysosomal enzyme, catalyzes the cleavage of glucuronosyl-O-bonds. Its inhibitors play a significant role in different medicinal therapies as they cause a decrease in carcinogen-induced colonic tumors by reducing the level of toxic substances present in the intestine. Among those inhibitors, bisindole derivatives had displayed promising β-glucuronidase inhibition activity. In the current study, hydrazone derivatives of bisindolymethane (1-30) were synthesized and evaluated for in vitro β-glucuronidase inhibitory activity. Twenty-eight analogs demonstrated better activity (IC50 = 0.50-46.5µM) than standard D-saccharic acid 1,4-lactone (IC50 = 48.4 ± 1.25µM). Compounds with hydroxyl group like 6 (0.60 ± 0.01µM), 20 (1.50 ± 0.10µM) and 25 (0.50 ± 0.01µM) exhibited the most potent inhibitory activity, followed by analogs with fluorine 21 (3.50 ± 0.10µM) and chlorine 23 (8.20 ± 0.20µM) substituents. The presence of hydroxyl group at the aromatic side chain was observed as the main contributing factor in the inhibitory potential. From the docking studies, it was predicted that the active compounds can fit properly in the binding groove of the β-glucuronidase and displayed significant binding interactions with essential residues.

Synthesis and evaluation of antioxidant and β-glucuronidase inhibitory activity of hesperidin glycosides

Synthesis and evaluation of antioxidant and β-glucuronidase inhibitory activity of hesperidin glycosides

Synthesis and evaluation of antioxidant and β-glucuronidase inhibitory activity of hesperidin glycosides

Synthesis and evaluation of antioxidant and β-glucuronidase inhibitory activity of hesperidin glycosides

Phytochemical composition, β-glucuronidase inhibition, and antioxidant properties of two fractions of Piper betle leaf aqueous extract.

Piper betle leaf, used as masticatory in South Asia, is also medicinally important. This work was done to analyze phytochemical composition of two solvent fractions (chloroform and ethyl acetate) of the aqueous extracts obtained from eight varieties of P. betle leaves and to identify the active components against β-glucuronidaseby chemometric analysis. Twenty-four phenolic compounds, in addition to different organic acids, fatty acids, amino acids, sugars, and polyols, were identified from the solvent fractions. The extracts inhibited the enzyme β-glucuronidase. Piceatannol was the most active constituent against the enzyme (activity 12 times higher than that of silymarin), Chlorogenic acid also inhibited β-glucuronidase (activity 4.4 times higher when compared to silymarin). 2,2'-Diphenyl-1-picrylhydrazyl and superoxide free radical scavenging activities of both the fractions of eight varieties of P. betle leaf extracts showed very strong antioxidant potentiality. The findings validated some medicinal properties of the said leaves. Edible leaves of Piper betle are medicinally and economically important. Leaves of different local varieties are reported to be used for the treatment of different diseases. The leaves have many biological properties, hepatoprotection being one of them. A large number of rural population is economically dependent on the cultivation of betel vine. But with a rapid change in lifestyle, the chewing habit of P. betle is decreasing ultimately affecting the livelihood of farmers dependent on betel cultivation. Knowledge on β-glucuronidase inhibitory activity and the mechanism for hepatoprotection of different P. betle varieties may validate the medicinal properties of betel, which would increase consumption of these leaves.

Synthesis of Chromen-4-One-Oxadiazole Substituted Analogs as Potent β-Glucuronidase Inhibitors

Chromen-4-one substituted oxadiazole analogs 1–19 have been synthesized, characterized and evaluated for β-glucuronidase inhibition. All analogs exhibited a variable degree of β-glucuronidase inhibitory activity with IC50 values ranging in between 0.8 ± 0.1–42.3 ± 0.8 μM when compared with the standard d-saccharic acid 1,4 lactone (IC50 = 48.1 ± 1.2 μM). Structure activity relationship has been established for all compounds. Molecular docking studies were performed to predict the binding interaction of the compounds with the active site of enzyme.

Bioinformatics: A rational combine approach used for the identification and in-vitro activity evaluation of potent β-Glucuronidase inhibitors

Identification of hotspot drug-receptor interactions through in-silico prediction methods (Pharmacophore mapping, virtual screening, 3DQSAR, etc), is considered as a key approach in drug designing and development process. In the current design study, advanced in-silico based computational techniques were used for the identification of lead-like molecules against the targeted receptor β-glucuronidase. The binding pattern of a potent inhibitor in the ligand-receptor X-ray co-crystallize complex was used to identify and extract the structure-base Pharmacophore features. Based on these observations; five structure-based pharmacophore models were derived to conduct the virtual screening of ICCBS in-house data-base. Top-ranked identified Hits (33 compounds) were selected to subject for in-vitro biological activity evaluation against β-glucuronidase enzyme; out of them, twenty compounds (61% of screened compounds) evaluated as actives, however eleven compounds were found to have significantly higher inhibitory activity, including compounds 1, 5–8, 10, 12–13, and 17–19 with IC50 values ranging from 1.2 μM to 34.9 μM. Out of the eleven potent inhibitors, seven compounds 1, 5, 6, 7, 8, 13, and 19 were found new, and evaluated first time for the β-glucuronidase inhibitory activity. Compounds 1, 5 and 19 exhibited a highly potent inhibition in uM of β-glucuronidase enzyme with non-cytotoxic behavior against the mouse fibroblast (3T3) cell line. Our combined in-silico and in-vitro results revealed that the binding pattern analysis of the eleven potent inhibitors, showed almost similar non-covalent interactions, as observed in case of our validated pharmacophore model. The obtained results thus demonstrated that the virtual screening minimizes false positives, and provide a template for the identification and development of new and more potent β-glucuronidase inhibitors with non-toxic effects.

2-Oxo-1,2,3,4-tetrahydropyrimidines Ethyl Esters as Potent β- Glucuronidase Inhibitors: One-pot Synthesis, In vitro and In silico Studies.

Glucuronidation is essential for the metabolism and excretion of toxic substances. β-Glucuronidase enzyme slows down the process of glucuronidation, and thus plays an important role in the on-set of colorectal carcinoma, and many other diseases. Inhibition of β- glucuronidase activity is thus identified as an important approach for the treatment of several diseases. Current study was aimed to synthesize a library of 2-oxo-1,2,3,4-tetrahydropyrimidine and to evaluate their β-glucuronidase inhibitory activity, and their mode of enzyme inhibition. We synthesized a series of 2-oxo-1,2,3,4-tetrahydropyrimidines 1-25 by fusing urea, ethyl acetoacetate, and a variety of aldehydes using copper nitrate trihydrate as catalyst. All synthesized compounds were evaluated for their in vitro β-glucuronidase inhibitory activity. In addition, molecular docking studies were also performed by using MOE docking tools. Eighteen compounds showed inhibitory activity better than the standard D-saccharic acid 1,4-lactone, a well known β-glucuronidase inhibitor (IC50 = 45.75 ± 2.16 µM). Compound 20 (IC50 = 1.36 ± 0.03 µM) showed an excellent inhibitory activity, thirty-five folds superior to the standard. Docking results highlighted the role of various chemical moieties at different positions on 2- oxo-1,2,3,4-tetrahydropyrimidine skeleton in enzyme inhibitory activity. This study has identified a class of potent β-glucuronidase inhibitors with the potential to be investigated further.

Synthesis of indole analogs as potent β-glucuronidase inhibitors

Natural products are the main source of motivation to design and synthesize new molecules for drug development. Designing new molecules against β-glucuronidase inhibitory is utmost essential. In this study indole analogs (1–35) were synthesized, characterized using various spectroscopic techniques including 1H NMR and EI-MS and evaluated for their β-glucuronidase inhibitory activity. Most compounds were identified as potent inhibitors for the enzyme with IC50 values ranging between 0.50 and 53.40μM, with reference to standard d-saccharic acid 1,4-lactone (IC50=48.4±1.25μM). Structure-activity relationship had been also established. The results obtained from docking studies for the most active compound 10 showed that hydrogen bond donor features as well as hydrogen bonding with (Oε1) of nucleophilic residue Glu540 is believed to be the most importance interaction in the inhibition activity. It was also observed that hydroxyl at fourth position of benzylidene ring acts as a hydrogen bond donor and interacts with hydroxyl (OH) on the side chain of catalysis residue Tyr508. The enzyme-ligand complexed were being stabilized through electrostatic π-anion interaction with acid-base catalyst Glu451 (3.96Å) and thus preventing Glu451 from functioning as proton donor residue.

Synthesis and in silico studies of novel sulfonamides having oxadiazole ring: As β-glucuronidase inhibitors

Novel sulfonamides having oxadiazole ring were synthesized by multistep reaction and evaluated to check in vitro β-glucuronidase inhibitory activity. Luckily, except compound 13, all compounds were found to demonstrate good inhibitory activity in the range of IC50=2.40±0.01–58.06±1.60μM when compared to the standard d-saccharic acid 1,4-lactone (IC50=48.4±1.25μM). Structure activity relationship was also presented. However, in order to ensure the SAR as well as the molecular interactions of compounds with the active site of enzyme, molecular docking studies on most active compounds 19, 16, 4 and 6 was carried out. All derivatives were fully characterized by 1H NMR, 13C NMR and EI-MS spectroscopic techniques. CHN analysis was also presented.

Synthesis, in vitro β-glucuronidase inhibitory activity and in silico studies of novel (E)-4-Aryl-2-(2-(pyren-1-ylmethylene)hydrazinyl)thiazoles

Current research is based on the synthesis of novel (E)-4-aryl-2-(2-(pyren-1-ylmethylene)hydrazinyl)thiazole derivatives (3–15) by adopting two steps route. First step was the condensation between the pyrene-1-carbaldehyde (1) with the thiosemicarbazide to afford pyrene-1-thiosemicarbazone intermediate (2). While in second step, cyclization between the intermediate (2) and phenacyl bromide derivatives or 2-bromo ethyl acetate was carried out. Synthetic derivatives were structurally characterized by spectroscopic techniques such as EI-MS, 1H NMR and 13C NMR. Stereochemistry of the iminic double bond was confirmed by NOESY analysis. All pure compounds 2–15 were subjected for in vitro β-glucuronidase inhibitory activity. All molecules were exhibited excellent inhibition in the range of IC50=3.10±0.10–40.10±0.90μM and found to be even more potent than the standard d-saccharic acid 1,4-lactone (IC50=48.38±1.05μM). Molecular docking studies were carried out to verify the structure-activity relationship. A good correlation was perceived between the docking study and biological evaluation of active compounds.

Biology-oriented drug synthesis (BIODS): In vitro β-glucuronidase inhibitory and in silico studies on 2-(2-methyl-5-nitro-1H-imidazol-1-yl)ethyl aryl carboxylate derivatives

Current study is based on the biology-oriented drug synthesis (BIODS) of 2-(2-methyl-5-nitro-1H-imidazol-1-yl)ethyl aryl carboxylate derivatives 1–26, by treating metronidazole with different aryl and hetero-aryl carboxylic acids in the presence of 1,1′-carbonyl diimidazole (CDI) as a coupling agent. Structures of all synthetic derivatives were confirmed with the help of various spectroscopic techniques such as EI-MS, 1H -NMR and 13C NMR. CHN elemental analyses were also found in agreement with the calculated values. Synthetic derivatives were evaluated to check their β-glucuronidase inhibitory activity which revealed that except few derivatives, all demonstrated good inhibition in the range of IC50 = 1.20 ± 0.01–60.30 ± 1.40 μM as compared to the standard d-saccharic acid 1,4-lactone (IC50 = 48.38 ± 1.05 μM). Compounds 1, 3, 4, 6, 9–19, and 21–24 were found to be potent analogs and showed superior activity than standard. Limited structure-activity relationship is suggested that the molecules having electron withdrawing groups like NO2, F, Cl, and Br, were displayed better activity than the compounds with electron donating groups such as Me, OMe and BuO. To verify these interpretations, in silico study was also performed, a good correlation was observed between bioactivities and docking studies.