Benzothiazole and its natural or synthetic derivatives have been used as precursors for several pharmacological agents for neuroprotective, anti-bacterial, and anti-allergic activities. The objective of the present study was to evaluate effects of benzothiazole analogs (compounds 1-26) for their immunomodulatory activities. Eight compounds (2, 4, 5, 8-10, 12, and 18) showed potent inhibitory activity on PHA-activated peripheral blood mononuclear cells (PBMCs) with IC50 ranging from 3.7 to 11.9 μM compared to that of the standard drug, prednisolone <1.5 μM. Some compounds (2, 4, 8, and 18) were also found to have potent inhibitory activities on the production of IL-2 on PHA/PMA-stimulated PBMCs with IC50 values ranging between <4.0 and 12.8 μM. The binding interaction of these compounds was performed through silico molecular docking. Compounds 2, 8, 9, and 10 significantly suppressed oxidative burst ROS production in phagocytes with IC50 values between <4.0 and 15.2 μM. The lipopolysaccharide (LPS)-induced nitrites in murine macrophages cell line J774 were found to be inhibited by compounds 4, 8, 9, and 18 at a concentration of 25 μg/mL by 56%, 91%, 58%, and 78%, respectively. Furthermore, compounds 5, 8, 12, and 18 showed significant (P<0.05) suppressive activity on Th-2 cytokine, interleukin 4 (IL-4) with an IC50 range of <4.0 to 40.3 μM. Interestingly compound 4 has shown a selective inhibitory activity on IL-2 and T cell proliferation (naïve T cell proliferation stage) rather than on IL-4 cytokine, while compound 12 displayed an interference with T-cell proliferation and IL-4 generation. Moreover compound 8 and 18 exert non-selective inhibition on both IL-2 and IL-4 cytokines, indicating a better interference with stage leading to humoral immune response and hence possible application in autoimmune diseases.
In our effort directed toward the discovery of new anti-diabetic agent for the treatment of diabetes, a library of biscoumarin derivative 1-18 was synthesized and evaluated for α-glucosidase inhibitory potential. All eighteen (18) compounds displayed assorted α-glucosidase activity with IC50 values 16.5-385.9 μM, if compared with the standard acarbose (IC50 = 906 ± 6.387 μM). In addition, molecular docking studies were carried out to explore the binding interactions of biscoumarin derivatives with the enzyme. This study has identified a new class of potent α-glucosidase inhibitors.
Thirty-three 4-amino-1,2,4-triazole derivatives 1-33 were synthesized by reacting 4-amino-1,2,4-triazole with a variety of benzaldehydes. The synthetic molecules were characterized via1H NMR and EI-MS spectroscopic techniques and evaluated for their anti-hyperglycemic potential. Compounds 1-33 exhibited good to moderate in vitro α-amylase and α-glucosidase inhibitory activities in the range of IC50 values 2.01 ± 0.03-6.44 ± 0.16 and 2.09 ± 0.08-6.54 ± 0.10 µM as compared to the standard acarbose (IC50 = 1.92 ± 0.17 µM) and (IC50 = 1.99 ± 0.07 µM), respectively. The limited structure-activity relationship suggested that different substitutions on aryl part of the synthetic compounds are responsible for variable activity. Kinetic study predicted that compounds 1-33 followed mixed and non-competitive type of inhibitions against α-amylase and α-glucosidase enzymes, respectively. In silico studies revealed that both triazole and aryl ring along with different substitutions were playing an important role in the binding interactions of inhibitors within the enzyme pocket. The synthetic molecules were found to have dual inhibitory potential against both enzymes thus they may serve as lead candidates for the drug development and research in the future studies.
On the basis of previous report on promising α-glucosidase inhibitory activity of 5-bromo-2-aryl benzimidazole derivatives, these derivatives were further screened for urease inhibitory and cytotoxicity activity in order to get more potent and non-cytotoxic potential dual inhibitor for the patients suffering from diabetes as well as peptic ulcer. In this study, all compounds showed varying degree of potency in the range of (IC50=8.15±0.03-354.67±0.19μM) as compared to standard thiourea (IC50=21.25±0.15μM). It is worth mentioning that derivatives 7 (IC50=12.07±0.05μM), 8 (IC50=10.57±0.12μM), 11 (IC50=13.76±0.02μM), 14 (IC50=15.70±0.12μM) and 22 (IC50=8.15±0.03μM) were found to be more potent inhibitors than standard. All compounds were also evaluated for cytotoxicity towards 3T3 mouse fibroblast cell line and found to be completely non-toxic. Previously benzimidazole 1-25 were also showed α-glucosidase inhibitory potential. In silico studies were performed on the lead molecules i.e.2, 7, 8, 11, 14, and 22, in order to rationalize the binding interaction of compounds with the active site of urease enzyme.
Dihydropyrimidones 1-37 were synthesized via a 'one-pot' three component reaction according to well-known Biginelli reaction by utilizing Cu(NO3)2·3H2O as catalyst, and screened for their in vitro β-glucuronidase inhibitory activity. It is worth mentioning that amongst the active molecules, compounds 8 (IC50=28.16±.056μM), 9 (IC50=18.16±0.41μM), 10 (IC50=22.14±0.43μM), 13 (IC50=34.16±0.65μM), 14 (IC50=17.60±0.35μM), 15 (IC50=15.19±0.30μM), 16 (IC50=27.16±0.48μM), 17 (IC50=48.16±1.06μM), 22 (IC50=40.16±0.85μM), 23 (IC50=44.16±0.86μM), 24 (IC50=47.16±0.92μM), 25 (IC50=18.19±0.34μM), 26 (IC50=33.14±0.68μM), 27 (IC50=44.16±0.94μM), 28 (IC50=24.16±0.50μM), 29 (IC50=34.24±0.47μM), 31 (IC50=14.11±0.21μM) and 32 (IC50=9.38±0.15μM) found to be more potent than the standard d-saccharic acid 1,4-lactone (IC50=48.4±1.25μM). Molecular docking study was conducted to establish the structure-activity relationship (SAR) which demonstrated that a number of structural features of dihydropyrimidone derivatives were involved to exhibit the inhibitory potential. All compounds were characterized by spectroscopic techniques such as (1)H, (13)C NMR, EIMS and HREI-MS.
A series of thiobarbituric acid derivatives 1-27 were synthesized and evaluated for their urease inhibitory potential. Exciting results were obtained from the screening of these compounds 1-27. Compounds 5, 7, 8, 11, 16, 17, 22, 23 and 24 showed excellent urease inhibition with IC50 values 18.1 ± 0.52, 16.0 ± 0.45, 16.0 ± 0.22, 14.3 ± 0.27, 6.7 ± 0.27, 10.6 ± 0.17, 19.2 ± 0.29, 18.2 ± 0.76 and 1.61 ± 0.18 μM, respectively, much better than the standard urease inhibitor thiourea (IC₅₀=21 ± 0.11 μM). Compound 3, 4, 10, and 26 exhibited comparable activities to the standard with IC₅₀ values 21.4 ± 1.04 and 21.5 ± 0.61 μM, 22.8 ± 0.32, 25.2 ± 0.63, respectively. However the remaining compounds also showed prominent inhibitory potential The structure-activity relationship was established for these compounds. This study identified a novel class of urease inhibitors. The structures of all compounds were confirmed through spectroscopic techniques such as EI-MS and (1)H NMR.
The synthetic indole Mannich bases 1-13 have been investigated for their ability to modulate immune responses measured in vitro. These activities were based on monitoring their affects on T-lymphocyte proliferation, reactive oxygen species (ROS), IL (interleukin)-2, IL-4, and nitric oxide production. Compound 5 was found to be the most potent immunomodulator in this context. Four of the synthesized compounds, 5, 11, 12, and 13, have significant potent inhibitory effects on T-cell proliferation, IL-4, and nitric oxide production. However, none of the thirteen indole compounds exerted any activity against ROS production.
One of the most prevailing metabolic disorder diabetes mellitus has become the global health issue that has to be addressed and cured. Different marketed drugs have been made available for the treatment of diabetes but there is still a need of introducing new therapeutic agents that are economical and have lesser or no side effects. The current study deals with the synthesis of indole acrylonitriles (3-23) and the evaluation of these compounds for their potential for α-glucosidase inhibition. The structures of these synthetic molecules were deduced by using different spectroscopic techniques. Acarbose (IC50 = 2.91 ± 0.02 μM) was used as standard in this study and the synthetic molecules (3-23) have shown promising α-glucosidase inhibitory activity. Compounds 4, 8, 10, 11, 14, 18, and 21 displayed superior inhibition of α-glucosidase enzyme in the range of (IC50 = 0.53 ± 0.01-1.36 ± 0.04 μM) as compared to the standard acarbose. Compound 10 (IC50 = 0.53 ± 0.01 μM) was the most effective inhibitor of this library and displayed many folds enhanced activity in contrast to the standard. Molecular docking of synthetic compounds was performed to verify the binding interactions of ligand with the active site of enzyme. This study had identified a number of potential α-glucosidase inhibitors that can be used for further research to identify a potent therapeutic agent against diabetes.
Despite of a diverse range of biological activities associated with chalcones and bis-chalcones, they are still neglected by the medicinal chemist for their possible α-amylase inhibitory activity. So, the current study is based on the evaluation of this class for the identification of new leads as α-amylase inhibitors. For that purpose, a library of substituted chalcones 1-13 and bis-chalcones 14-18 were synthesized and characterized by spectroscopic techniques EI-MS and 1H NMR. CHN analysis was carried out and found in agreement with the calculated values. All compounds were evaluated for in vitro α-amylase inhibitory activity and demonstrated good activities in the range of IC50 = 1.25 ± 1.05-2.40 ± 0.09 µM as compared to the standard acarbose (IC50 = 1.04 ± 0.3 µM). Limited structure-activity relationship (SAR) was established by considering the effect of different groups attached to aryl rings on varying inhibitory activity. SMe group in chalcones and OMe group in bis-chalcones were found more influential on the activity than other groups. However, in order to predict the involvement of different groups in the binding interactions with the active site of α-amylase enzyme, in silico studies were also conducted.
A variety of dihydroquinazolin-4(1H)-one derivatives (1-37) were synthesized via "one-pot" three-component reaction scheme by treating aniline and different aromatic aldehydes with isatoic anhydride in the presence of acetic acid. Chemical structures of compounds were deduced by different spectroscopic techniques including EI-MS, HREI-MS, 1H-, and 13C-NMR. Compounds were subjected to α-amylase and α-glucosidase inhibitory activities. A number of derivatives exhibited significant to moderate inhibition potential against α-amylase (IC50 = 23.33 ± 0.02-88.65 ± 0.23 μM) and α-glucosidase (IC50 = 25.01 ± 0.12-89.99 ± 0.09 μM) enzymes, respectively. Results were compared with the standard acarbose (IC50 = 17.08 ± 0.07 μM for α-amylase and IC50 = 17.67 ± 0.09 μM for α-glucosidase). Structure-activity relationship (SAR) was rationalized by analyzing the substituents effects on inhibitory potential. Kinetic studies were implemented to find the mode of inhibition by compounds which revealed competitive inhibition for α-amylase and non-competitive inhibition for α-glucosidase. However, in silico study identified several important binding interactions of ligands (synthetic analogues) with the active site of both enzymes.
Over-expression of α-amylase enzyme causes hyperglycemia which lead to many physiological complications including oxidative stress, one of the most commonly associated problem with diabetes mellitus. Marketed α-amylase inhibitors such as acarbose, voglibose, and miglitol used to treat type-II diabetes mellitus, but also linked to several harmful effects. Therefore, it is essential to explore new and nontoxic antidiabetic agents with additional antioxidant properties. In this connection, a series of new N-sulfonohydrazide substituted indazoles 1-19 were synthesized by multistep reaction scheme and assessed for in vitro α-amylase inhibitory and radical (DPPH and ABTS) scavenging properties. All compounds were fully characterized by different spectroscopic techniques including 1H, 13C NMR, EI-MS, HREI-MS, ESI-MS, and HRESI-MS. Compounds showed promising α-amylase inhibitory activities (IC50 = 1.23 ± 0.06-4.5 ± 0.03 µM) as compared to the standard acarbose (IC50 1.20 ± 0.09 µM). In addition to that all derivatives were found good to moderate scavengers of DPPH (IC50 2.01 ± 0.13-5.3 ± 0.11) and ABTS (IC50 = 2.34 ± 0.07-5.5 ± 0.07 µM) radicals, in comparison with standard ascorbic acid having scavenging activities with IC50 = 1.99 ± 0.09 µM, and IC50 2.03 ± 0.11 µM for DPPH and ABTS radicals. In silico molecular docking study was conducted to rationalize the binding interaction of α-amylase enzyme with ligands. Compounds were observed as mixed type inhibitors in enzyme kinetic characterization.
Bisindole analogs 1-17 were synthesized and evaluated for their in vitro β-glucuronidase inhibitory potential. Out of seventeen compounds, the analog 1 (IC50=1.62±0.04 μM), 6 (IC50=1.86±0.05 μM), 10 (IC50=2.80±0.29 μM), 9 (IC50=3.10±0.28 μM), 14 (IC50=4.30±0.08 μM), 2 (IC50=18.40±0.09 μM), 19 (IC50=19.90±1.05 μM), 4 (IC50=20.90±0.62 μM), 7 (IC50=21.50±0.77 μM), and 3 (IC50=22.30±0.02 μM) showed superior β-glucuronidase inhibitory activity than the standard (d-saccharic acid 1,4-lactone, IC50=48.40±1.25 μM). In addition, molecular docking studies were performed to investigate the binding interactions of bisindole derivatives with the enzyme. This study has identified a new class of potent β-glucouronidase inhibitors.
Diabetes being a chronic metabolic disorder have attracted the attention of medicinal chemists and biologists. The introduction of new and potential drug candidates for the cure and treatment of diabetes has become a major concern due to its increased prevelance worldwide. In the current study, twenty-seven azachalcone derivatives 3-29 were synthesized and evaluated for their antihyperglycemic activities by inhibiting α-amylase and α-glucosidase enzymes. Five compounds 3 (IC50 = 23.08 ± 0.03 µM), (IC50 = 26.08 ± 0.43 µM), 5 (IC50 = 24.57 ± 0.07 µM), (IC50 = 27.57 ± 0.07 µM), 6 (IC50 = 24.94 ± 0.12 µM), (IC50 = 27.13 ± 0.08 µM), 16 (IC50 = 27.57 ± 0.07 µM), (IC50 = 29.13 ± 0.18 µM), and 28 (IC50 = 26.94 ± 0.12 µM) (IC50 = 27.99 ± 0.09 µM) demonstrated good inhibitory activities against α-amylase and α-glucosidase enzymes, respectively. Acarbose was used as the standard in this study. Structure-activity relationship was established by considering the parent skeleton and different substitutions on aryl ring. The compounds were also subjected for kinetic studies to study their mechanism of action and they showed competitive mode of inhibition against both enzymes. The molecular docking studies have supported the results and showed that these compounds have been involved in various binding interactions within the active site of enzyme.
Novel ibuprofen derivatives 1-19 including ibuprofen hydrazide 1, and substituted thiourea derivatives 2-19 were synthesized and characterized by EI-MS, FAB-MS, HREI-MS, HRFAB-MS, 1H-, and 13C-NMR spectroscopic techniques. The synthetic molecules 1-19 were examined for their in vitro urease inhibition and were found to display a diversified degree of inhibitory potential in the range of IC50 = 2.96-178 μM as compared to the standard thiourea (IC50 = 21.32 ± 0.22 μM). Out of nineteen, thirteen derivatives 2-4, 6, 7, 9, 11-15, 17, and 18 demonstrated remarkable inhibitory activity with IC50 values of 2.96 ± 1.11 to 16.1 ± 1.07 μM, compound 5 exhibited moderate inhibition with IC50 value of 37.3 ± 0.41 μM, whereas, compounds 1, 8, and 10 demonstrated weak inhibition against urease enzyme. Almost all structural features are participating in the activity; however, limited structure-activity relationship was discussed on the basis of different structural features, i.e., different functional groups and their positions at aryl part. In addition, molecular docking study was performed in order to understand the ligands binding interactions with the active site of urease enzyme.
Current study based on the synthesis of new thiazole derivatives via "one pot" multicomponent reaction, evaluation of their in vitro α-glucosidase inhibitory activities, and in silico studies. All synthetic compounds were fully characterized by (1)H NMR, (13)C NMR and EIMS. CHN analysis was also performed. These newly synthesized compounds showed activities in the range of IC50=9.06±0.10-82.50±1.70μM as compared to standard acarbose (IC50=38.25±0.12μM). It is worth mentioning that most of the compounds such as 1 (IC50=23.60±0.39μM), 2 (IC50=22.70±0.60μM), 3 (IC50=22.40±0.32μM), 4 (IC50=26.5±0.40μM), 6 (IC50=34.60±0.60μM), 7 (IC50=26.20±0.43μM), 8 (IC50=14.06±0.18μM), 9 (IC50=17.60±0.28μM), 10 (IC50=27.16±0.41μM), 11 (IC50=19.16±0.19μM), 12 (IC50=9.06±0.10μM), 13 (IC50=12.80±0.21μM), 14 (IC50=11.94±0.18μM), 15 (IC50=16.90±0.20μM), 16 (IC50=12.60±0.14μM), 17 (IC50=16.30±0.29μM), and 18 (IC50=32.60±0.61μM) exhibited potent inhibitory potential. Molecular docking study was performed in order to understand the molecular interactions between the molecule and enzyme. Newly identified α-glucosidase inhibitors except few were found to be completely non-toxic.
Coumarin sulfonates 4-43 were synthesized by reacting 3-hydroxy coumarin 1, 4-hydroxy coumarin 2and6-hydroxy coumarin 3 with different substituted sulfonyl chlorides and subjected to evaluate for their in vitro immunomodulatory potential. The compounds were investigated for their effect on oxidative burst activity of zymosan stimulated whole blood phagocytes using a luminol enhanced chemiluminescence technique. Ibuprofen was used as standard drug (IC50=54.2±9.2μM). Eleven compounds 6 (IC50=46.60±14.6μM), 8 (IC50=11.50±6.5μM), 15 (IC50=21.40±12.2μM), 19 (IC50=5.75±0.86μM), 22 (IC50=10.27±1.06μM), 23 (IC50=33.09±5.61μM), 24 (IC50=4.93±0.58μM), 25 (IC50=21.96±14.74μM), 29 (IC50=12.47±9.2μM), 35 (IC50=20.20±13.4μM) and 37 (IC50=14.47±5.02μM) out of forty demonstrated their potential suppressive effect on production of reactive oxygen species (ROS) as compared to ibuprofen. All the synthetic derivatives 4-43 were characterized by different available spectroscopic techniques such as 1H NMR, 13C NMR, EIMS and HRMS. CHN analysis was also performed.
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.
Acarbose and voglibose are well-known α-amylase inhibitors used for the management of type-II diabetes mellitus. Unfortunately, these well-known and clinically used inhibitors are also associated with several adverse effects. Therefore, there is still need to develop the safer therapy. Despite of a broad spectrum of biological significances of pyrazolone, it is infrequently evaluated for α-amylase inhibition. Current study deals with the synthesis and biological screening of aryl and arylidene substituted pyrazolones 1-18 for their potential α-amylase inhibitory activity. Structures of synthetic derivatives 1-18 were identified by different spectroscopic techniques. All compounds 1-18 (IC50 = 1.61 ± 0.16 μM to 2.38 ± 0.09 μM) exhibited significant to moderate inhibitory potential when compared to standard acarbose (IC50 = 1.46 ± 0.26 μM). A number of derivatives including 8-12 (IC50 = 1.68 ± 0.1 μM to 1.97 ± 0.07 μM) and 14-16 (IC50 = 1.61 ± 0.16 μM to 1.93 ± 0.07 μM) were found to be significantly active. Limited SAR suggested that different substitutions on compounds do not have any significant effect on the inhibitory potential. Compounds were found to be mixed-type inhibitors revealed by kinetic studies. However, in silico study was identified a number of key features participating in the interaction with the binding site of α-amylase enzyme.
Novel derivatives of flurbiprofen 1-18 including flurbiprofen hydrazide 1, substituted aroyl hydrazides 2-9, 2-mercapto oxadiazole derivative 10, phenacyl substituted 2-mercapto oxadiazole derivatives 11-15, and benzyl substituted 2-mercapto oxadiazole derivatives 16-18 were synthesized and characterized by EI-MS, 1H and 13C NMR spectroscopic techniques. All derivatives 1-18 were screened for α-amylase inhibitory activity and demonstrated a varying degree of potential ranging from IC50 = 1.04 ± 0.3 to 2.41 ± 0.09 µM as compared to the standard acarbose (IC50 = 0.9 ± 0.04 µM). Out of eighteen compounds, derivatives 2 (IC50 = 1.69 ± 0.1 µM), 3 (IC50 = 1.04 ± 0.3 µM), 9 (IC50 = 1.25 ± 1.05 µM), and 13 (IC50 = 1.6 ± 0.18 µM) found to be excellent inhibitors while rest of the compounds demonstrated comparable inhibition potential. A limited structure-activity relationship (SAR) was established by looking at the varying structural features of the library. In addition to that, in silico study was conducted to understand the binding interactions of the compounds (ligands) with the active site of α-amylase enzyme.