Potent Β-glucuronidase Inhibitors Research Articles

Synthesis, in vitro β-glucuronidase inhibition of benzoxazole bearing thiosemicarbazide derivatives along with in silico molecular docking study

This study was aimed to design and synthesize hybrid analogues of benzoxazole bearing thiosemicarbazide analogues 1–15 as promising β-Glucuronidase inhibitory activity using D-saccharic acid 1,4-lactone as the reference inhibitor. The newly afforded benzoxazole-thiosemicarbazide compounds 1–15 displayed a broad range of inhibitory potential with IC50 values ranging from 20.58 ± 2.46 to 87.89 ± 8.43 μM, as compared to D-saccharic acid 1,4-lactone (IC50 = 59.5 ± 5.36 μM). Among the synthesized series, the compounds 14, 2, and 5 demonstrated outstanding β-Glucuronidase inhibitory potential with IC50 values of 20.58 ± 2.46, 25.24 ± 2.34 and 24.53 ± 2.53 μM respectively. Further, the precise structures of synthesized analogues were confirmed using 1H NMR, 13C NMR and HREIMS. Additionally, the molecular docking approach was employed to correlate the in vitro β-Glucuronidase inhibitory activity well with in silico study and result obtained corroborated that active analogues established several key interactions with the active sites of β-Glucuronidase enzyme.

Synthesis, in vitro β-glucuronidase inhibitory potential and molecular docking study of benzimidazole analogues

Synthesis, in vitro β-glucuronidase inhibitory potential and molecular docking study of benzimidazole analogues

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.

Benzimidazole bearing thiourea analogues: Synthesis, β-glucuronidase inhibitory potential and their molecular docking study

Sixteen benzimidazole-bearing thiourea analogues (1-16) were synthesized and tested for their β-glucuronidase inhibitory potential. All analogues showed varying degrees of activity having an IC50 value ranging between 1.9 ± 0.1 to 29.3 ± 0.6 µM as compared to standard drug D-saccharic acid 1,4-lactone (IC50 value = 48.1 ± 1.2 µM). Three of the compounds such as 7, 3 and 16 stand 1st, 2nd and 3rd ranked with IC50 values 1.9 ± 0.1, 3.6 ± 0.1, 5.7 ± 0.2 µM respectively and all other analogues showed many-fold better potency as compared to standard drug. It was observed that the number, nature, position and electron donating/withdrawing effect of substituent/s on both phenyls rings greatly affect inhibitory potential. Structure-activity relationships were established and through molecular docking study binding interactions were confirmed.

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.

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.

Advances in In-Silico based Predictive In-Vivo Profiling of Novel Potent β-Glucuronidase Inhibitors.

Intestinal β-glucuronidase enzyme has a significant importance in colorectal carcinogenesis. Specific inhibition of the enzyme helps prevent immune reactivation of the glucuronide- carcinogens, thus protecting the intestine from ROS (Reactive Oxidative Species) mediatedcarcinogenesis. Advancement in In-silico based techniques has provided a broad range of studies to carry out the drug design and development process smoothly using SwissADME and BOILED-Egg tools. In our designed case study, we used SwissADME and BOILED-Egg predictive computational tools to estimate the physicochemical, human pharmacokinetics, drug-likeness, medicinal chemistry properties and membrane permeability characteristics of our recently In-vitro evaluated novel β-Glucuronidase inhibitors. Out of the eleven screened potent inhibitors, compound (8) exhibited excellent bioavailability radar against the six molecular descriptors, good (ADME) Absorption, Distribution, Metabolism and Excretion along with P-glycoprotein, CYP450 isozymes and membranes permeability profile. On the basis of these factual observations, it is to be predicted that compound (8) can achieve in-vivo experimental clearance efficiently, Therefore, in the future, it can be a drug in the market to treat various disorders associated with the overexpression of β-Glucuronidase enzyme such as various types of cancer, particularly hormone-dependent cancer such as (breast, prostate, and colon cancer). Moreover, other compounds (1-7, & 9-11), have also shown good predictive pharmacokinetics, medicinal chemistry, BBB and HIA membranes permeability profiles with slight lead optimization to obtain improved results. In consequence, in-silico based studies are considered to provide robustness for a rational drug design and development approach to avoid the possibility of failures of drug candidates in the later stages of drug development phases. The results of this study effectively reveal the possible attributes of potent β-Glucuronidase inhibitors, for further experimental evaluation.

2,5-Disubstituted thiadiazoles as potent β-glucuronidase inhibitors; Synthesis, in vitro and in silico studies

Twenty-five thiadiazole derivatives 1–25 were synthesized from methyl 4-methoxybenzoate via hydrazide and thio-hydrazide intermediates, and evaluated for their potential against β-glucuronidase enzyme. Most of the compounds including 1 (IC50 = 26.05 ± 0.60 μM), 2 (IC50 = 42.53 ± 0.80 μM), 4 (IC50 = 38.74 ± 0.70 μM), 5 (IC50 = 9.30 ± 0.29 μM), 6 (IC50 = 6.74 ± 0.26 μM), 7 (IC50 = 18.40 ± 0.66 μM), and 15 (IC50 = 18.10 ± 0.53 μM) exhibited superior activity potential than the standard d-saccharic acid-1,4-lactone (IC50 = 48.4 ± 1.25 μM). Molecular docking studies were conducted to correlate the in vitro results and to identify possible mode of interaction with enzyme active site.

Extraction of phenolic antioxidants from Pyrus elaeagrifolia Pallas: process optimization, investigation of the bioactivity and β-glucuronidase inhibitory potential

This study aimed to develop a mathematical model for the extraction of Pyrus elaeagrifolia Pallas leaves using the Box–Behnken design, to investigate bioactivity and bacterial β-glucuronidase (GUS) inhibitory potential of the extracts obtained under optimum conditions. Results showed that the mathematical models using extraction temperature, time and ethanol concentration as effective parameters fit the real data well. The optimum extraction conditions to maximize phenolic content and antioxidant activity were found 79.7 and 78.4% ethanol, 74.9 °C, and 45.0 and 35.9 min, respectively. The chlorogenic acid was detected as the major phenolic compound in the chromatographic analysis. The highest antibacterial activity achieved against Staphylococcus aureus. The extracts (150 μg/mL) showed 67.9%, and 75.2% cytotoxic effect on the MCF-7 and A549 cells, respectively, and displayed inhibitory potential against GUS. The antioxidant property together bioactivity makes Pyrus elaeagrifolia Pallas leaves potent source for functional food/food ingredient applications and nutraceutical development.

Synthesis of oxadiazole-coupled-thiadiazole derivatives as a potent β-glucuronidase inhibitors and their molecular docking study.

A new series of oxadiazole with thiadiazole moiety (6-27) were synthesized, characterized by different spectroscopic techniques and evaluated for β-glucuronidase inhibitory potential. Sixteen analogs such as 6, 7, 8, 9, 10, 12, 13, 14, 17, 18, 20, 23, 24, 25, 26 and 27 showed IC50 values in the range of 0.96 ± 0.01 to 46.46 ± 1.10 μM, and hence were found to have excellent inhibitory potential in comparison to standard d-saccharic acid 1,4-lactone (IC50 = 48.4 ± 1.25 μM). Two analogs such as 16 and 19 showed moderate inhibitory potential while analogs 11, 15, 21 and 22 were found inactive. Our study identifies new series of potent β-glucuronidase inhibitors for further investigation. Structure activity relationships were established for all compounds which showed that the activity is varied due to different substituents on benzene ring. The interaction of the compounds with enzyme active site were confirmed with the help of docking studies, which reveals that the electron withdrawing group and hydroxy group make the molecules more favorable for enzyme inhibition.

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.

Synthesis, Molecular Docking and β-Glucuronidase Inhibitory Potential of Indole Base Oxadiazole Derivatives.

β-glucuronidase is a lysosomal glycosidase enzyme which catalyzes the extracellular matrix of cancer and normal cells and the glycosaminoglycans of the cell membrane, which is important for cancer cell proliferation, invasion, and metastasis. Liver cancer, colon carcinoma, and neoplasm bladder are triggered by the increase of the level of β-glucuronidase activity. The most valuable structures are indole and oxadiazole which has gain immense attention because of its pharmacological behavior and display many biological properties. Twenty-two (1–22) analogs of indole based oxadiazole were synthesized and screened for their inhibitory potential against β-glucuronidase. Majority of the compounds showed potent inhibitory potential with IC50 values ranging between 0.9 ± 0.01 to 46.4 ± 0.9 µM, under positive control of standard drug d-saccharic acid 1,4 lactone (IC50 = 48.1 ± 1.2 µM). Structural activity relationship (SAR) has been established for all synthesized compounds. To shed light on molecular interactions between the synthesized compounds and β-glucuronidase, 1, 4, and 6 compounds were docked into the active binding site of β-glucuronidase. The obtained results showed that this binding is thermodynamically favorable and β-glucuronidase inhibition of the selected compounds increases with the number of hydrogen bonding established in selected compound-β-glucuronidase complexes.

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: Small library of hybrid scaffolds of benzothiazole having hydrazone and evaluation of their β-glucuronidase activity

Due to the great biological importance of β-glucuronidase inhibitors, here in this study, we have synthesized a library of novel benzothiazole derivatives (1–30), characterized by different spectroscopic methods and evaluated for β-glucuronidase inhibitory potential. Among the series sixteen compounds i.e.1–6, 8, 9, 11, 14, 15, 20–23 and 26 showed outstanding inhibitory potential with IC50 value ranging in between 16.50 ± 0.26 and 59.45 ± 1.12 when compared with standard d-Saccharic acid 1,4-lactone (48.4 ± 1.25 µM). Except compound 8 and 23 all active analogs showed better potential than the standard. Structure activity relationship has been established.

Synthesis of bis-indolylmethanes as new potential inhibitors of β-glucuronidase and their molecular docking studies

Thirty-two (32) bis-indolylmethane-hydrazone hybrids 1–32 were synthesized and characterized by 1HNMR, 13CNNMR and HREI-MS. All compounds were evaluated in vitro for β-glucuronidase inhibitory potential. All analogs showed varying degree of β-glucuronidase inhibitory potential ranging from 0.10 ± 0.01 to 48.50 ± 1.10 μM when compared with the standard drug d-saccharic acid-1,4-lactone (IC50 value 48.30 ± 1.20 μM). Derivatives 1–32 showed the highest β-glucuronidase inhibitory potentials which is many folds better than the standard drug d-saccharic acid-1,4-lactone. Further molecular docking study validated the experimental results. It was proposed that bis-indolylmethane may interact with some amino acid residues located within the active site of β-glucuronidase enzyme. This study has culminated in the identification of a new class of potent β-glucuronidase inhibitors.

Synthesis, in vitro β-glucuronidase inhibitory potential and molecular docking studies of quinolines

In this study synthesis and β-glucuronidase inhibitory potential of 3/5/8 sulfonamide and 8-sulfonate derivatives of quinoline (1–40) are discussed. Studies reveal that all the synthetic compounds were found to have good inhibitory activity against β-glucuronidase. Nonetheless, compounds 1, 2, 5, 13, and 22–24 having IC50 values in the range of 1.60–8.40 μM showed superior activity than the standard saccharic acid 1,4-lactone (IC50 = 48.4 ± 1.25 μM). Moreover, molecular docking studies of selected compounds were also performed to see interactions between active compounds and binding sites. Structures of all the synthetic compounds were confirmed through 1H NMR, EI-MS and HREI-MS spectroscopic techniques.

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, β-glucuronidase inhibition and molecular docking studies of hybrid bisindole-thiosemicarbazides analogs

Hybrid bisindole-thiosemicarbazides analogs (1–18) were synthesized and screened for β-glucuronidase activity. All compounds showed varied degree of β-glucuronidase inhibitory potential when compared with standard d-saccharic acid 1,4-lactone (IC50=48.4±1.25μM). Compounds 4, 7, 9, 6, 5, 12, 17 and 18 showed exceptional β-glucuronidase inhibition with IC50 values ranging from 0.1 to 5.7μM. Compounds 1, 3, 8, 16, 13, 2 and 14 also showed better activities than standard with IC50 values ranging from 7.12 to 15.0μM. The remaining compounds 10, 11, and 15 showed good inhibitory potential with IC50 values 33.2±0.75, 21.4±0.30 and 28.12±0.25μM respectively. Molecular docking studies were carried out to confirm the binding interaction of the compounds.