VEGFR-2 inhibiting effect and molecular modeling of newly synthesized coumarin derivatives as anti-breast cancer agents

Twenty five newly synthesized coumarin scaffold based derivatives were assayed for their in vitro anticancer activity against MCF-7 breast and PC-3 prostate cancer cell lines and were further assessed for their in vitro VEGFR-2 kinase inhibitory activity. The in vitro cytotoxic studies revealed that most of the synthesized compounds possessed very promising cytotoxicity against MCF-7, particularly; compounds 4a (IC₅₀ = 1.24 µM) and 3d (IC₅₀ = 1.65 µM) exhibited exceptional activities superior to the positive control staurosporine (IC₅₀ = 8.81 µM). Similarly, the majority of the compounds exhibited higher antiproliferative activities compared to the reference standard with IC₅₀ values ranging from 2.07 to 8.68 µM. The two cytotoxic derivatives 4a and 3d were selected to evaluate their inhibitory potencies against VEGFR-2 kinase. Remarkably, compound 4a, exhibited significant IC₅₀ of 0.36 µM comparable to staurosporine (IC₅₀; 0.33 µM). Moreover, it was capable of inducing preG1 apoptosis, cell growth arrest at G2/M phase and activating caspase-9. On the other hand, insignificant cytotoxic activity was observed for all compounds towards PC-3 cell line. Molecular docking study was carried out for the most active anti-VEGFR-2 derivative 4a, which demonstrated the ability of the tested compound to interact with the key amino acids in the target VEGFR-2 kinase binding site. Additionally, the ADME parameters and physicochemical properties of compound 4a were examined in silico.     

Design,synthesis, in vitro evaluation,molecular docking and ADME properties studies of hybrid bis-coumarin with thiadiazole as a new inhibitor of Urease

Hybrid bis-coumarin derivatives 1–18 were synthesized and evaluated for their in vitro urease inhibitory potential. All compounds showed outstanding urease inhibitory potential with IC₅₀ value (The half maximal inhibitory concentration) ranging in between 0.12 SD 0.01 and 38.04 SD 0.63 µM (SD standard deviation). When compared with the standard thiourea (IC₅₀ = 21.40 ± 0.21 µM). Among these derivatives, compounds 7 (IC₅₀ = 0.29 ± 0.01), 9 (IC₅₀ = 2.4 ± 0.05), 10 (IC₅₀ = 2.25 ± 0.05) and 16 (IC₅₀ = 0.12 ± 0.01) are better inhibitors of the urease compared with thiourea (IC₅₀ = 21.40 ± 0.21 µM). To find structure–activity relationship molecular docking as well as absorption, distribution, metabolism, and excretion (ADME) studies were also performed. Various spectroscopic techniques like ¹H NMR, ¹³C NMR, and EI-MS were used for characterization of all synthesized analogs. All compounds were tested for cytotoxicity and found non-toxic.     

Proliferation inhibition of novel diphenylamine derivatives

Nonsteroidal anti-inflammatory drugs (NSAIDs) are the most widely used drugs in the world but some NSAIDs such as diclofenac and tolfenamic acid display levels of cytotoxicity, an effect which has been attributed to the presence of diphenylamine contained in their structures. A novel series of diphenylamine derivatives were synthetised and evaluated for their cytotoxic activities and proliferation inhibition. The most active compounds in the cytotoxicity tests were derivative 6g with an IC₅₀ value of 2.5 ± 1.1 × 10⁻⁶ M and derivative 6f with an IC₅₀ value of 6.0 ± 3.0 × 10⁻⁶ M (L1210 cell line) after 48 h incubation. The results demonstrate that leukemic L1210 cells were much more sensitive to compounds 6f and 6g than the HEK293T cells (IC₅₀ = 35 × 10⁻⁶ M for 6f and IC₅₀ > 50 × 10⁻⁶ M for 6g) and NIH-3T3 (IC₅₀ > 50 × 10⁻⁶ M for both derivatives). The IC₅₀ values show that these substances may selectively kill leukemic cells over non-cancer cells. Cell cycle analysis revealed that a primary trend of the diphenylamine derivatives was to arrest the cells in the G₁-phase of the cell cycle within the first 24 h. UV–visible, fluorescence spectroscopy and circular dichroism were used in order to study the binding mode of the novel compounds with DNA. The binding constants determined by UV–visible spectroscopy were found to be in the range of 2.1–8.7 × 10⁴ M⁻¹. We suggest that the observed trend for binding constant K is likely to be a result of different binding thermodynamics accompanying the formation of the complexes.     

Design and synthesis of some new carboxamide and propanamide derivatives bearing phenylpyridazine as a core ring and the investigation of their inhibitory potential on in-vitro acetylcholinesterase and butyrylcholinesterase

A series of new carboxamide and propanamide derivatives bearing phenylpyridazine as a core ring were designed, synthesized and evaluated for their ability to inhibit both cholinesterase enzymes. In addition, a series of carboxamide and propanamide derivatives bearing biphenyl instead of phenylpyridazine were also synthesized to examine the inhibitory effect of pyridazine moiety on both cholinesterase enzymes. The inhibitory activity results revealed that compounds 5b, 5f, 5h, 5j, 5l pyridazine-3-carboxamide derivative, exhibited selective acetylcholinesterase (AChE) inhibition with IC₅₀ values ranging from 0.11 to 2.69 µM. Among them, compound 5h was the most active one (IC₅₀ = 0.11 µM) without cytotoxic effect at its effective concentration against AChE. Additionally, pyridazine-3-carboxamide derivative 5d (IC₅₀ for AChE = 0.16 µM and IC₅₀ for BChE = 9.80 µM) and biphenyl-4-carboxamide derivative 6d (IC₅₀ for AChE = 0.59 µM and IC₅₀ for BChE = 1.48 µM) displayed dual cholinesterase inhibitory activity. Besides, active compounds were also tested for their ability to inhibit Aβ aggregation. Theoretical physicochemical properties of the compounds were calculated by using Molinspiration Program as well. The Lineweaver-Burk plot and docking study showed that compound 5 h targeted both the catalytic active site (CAS) and the peripheral anionic site (PAS) of AChE.     

Design,synthesis and biological evaluation of coumarin derivatives as novel acetylcholinesterase inhibitors that attenuate H2O2-induced apoptosis in SH-SY5Y cells

A novel series of coumarin derivatives were designed, synthesized and investigated for inhibition of cholinesterase, including acetyl cholinesterase (AChE) and butyrylcholinesterase (BuChE). This biological study showed that these compounds containing piperazine ring had significant inhibition activities on AChE rather than BuChE. Further study suggested that 9x, as one of this kind of structure derivative, showed the strongest inhibition activity on AChE with an IC₅₀ value of 34 nM. Moreover, molecular docking, flow cytometry (FCM), and western blot assay suggested that 9x could induce cytoprotective autophagy to attenuate H₂O₂-induced cell death in human neuroblastoma SH-SY5Y cells. These findings highlight a new approach for the development of a novel potential neuroprotective compound targeting AChE with autophagy-inducing activity in future Alzheimer’s disease (AD) therapy.     

Alkynyl–coumarinyl ethers as MAO-B inhibitors

In this study, alkynyl–coumarinyl ethers were developed as inhibitors of human monoamine oxidase B (MAO-B). A series of 31 new, ether-connected coumarin derivatives was synthesized via hydroxycoumarins, whose phenolic group at position 6, 7 or 8 was converted by means of the Mitsunobu reaction. The majority of the final products were produced from primary alcohols with a terminal alkyne group. The inhibitors were optimized with respect to the structure of the alkynyloxy chain and its position at the fused benzene ring as well as the residue at position 3 of the pyran-2H-one part. A hex-5-ynyloxy chain at position 7 was found to be particular advantageous. Among the 7-hex-5-ynyloxy-coumarins, the 3-methoxycarbonyl derivative 36 was characterized as a dual-acting inhibitor with IC₅₀ values of less than 10 nM towards MAO-A and MAO-B, and the 3-(4-methoxy)phenyl derivative 44 was shown to combine strong anti-MAO-B potency (IC₅₀ = 3.0 nM) and selectivity for MAO-B over MAO-A (selectivity >3400-fold).     

Novel 5,6-disubstituted pyrrolo[2,3-d]pyrimidine derivatives as broad spectrum antiproliferative agents: Synthesis,cell based assays,kinase profile and molecular docking study

Two new series of 5-subtituted and 5,6-disubstituted pyrrolo[2,3-d]pyrimidine octamides (4a–o and 6a–g) and their corresponding free amines 5a–m and 7a–g have been synthesized and biologically evaluated for their antiproliferative activity against three human cancer cell lines. The 5,6-disubstituted octamides 6d–g as well as the amine derivative 7b have shown the best anticancer activity with single digit micromolar GI₅₀ values over the tested cancer cells, and low cytotoxic effects (GI₅₀?>?10.0?µM) against HFF-1 normal cell. A structure activity relationship (SAR) study has been established and disclosed that terminal octamide moiety at C2 as well as disubstitution with fluorobenzyl piperazines at C5 and C6 of pyrrolo[2,3-d]pyrimidine are the key structural features prerequisite for best antiproliferative activity. Moreover, the most active member 6f was tested for its antiproliferative activity over a panel of 60 cancer cell lines at NCI, and exhibited distinct broad spectrum anticancer activity with submicromolar GI₅₀ and TGI values over multiple cancer cells. Kinase profile of compound 6f over 53 oncogenic kinases at 10?µM concentration showed its highly selective inhibitory activity towards FGFR4, Tie2 and TrkA kinases. The observed activity of 6f against TrkA (IC₅₀?=?2.25?µM), FGFR4 (IC₅₀?=?6.71?µM) and Tie2 (IC₅₀?=?6.84?µM) was explained by molecular docking study, which also proposed that 6f may be a type III kinase inhibitor, binding to an allosteric site rather than kinase hinge region. Overall, compound 6f may serve as a promising anticancer lead compound that could be further optimized for development of potent anticancer agents.     

Anti-inflammatory drug approach: Synthesis and biological evaluation of novel pyrazolo[3,4-d]pyrimidine compounds

In this study, the acid chlorides of pyrazolo[3,4-d]pyrimidine compounds were prepared and reacted with a number of nucleophiles. The novel compounds were experimentally tested via enzyme assay and they showed cyclooxygenase-2 inhibition activity in the middle micro molar range (4b had a COX-1 IC₅₀ of 26 µM and a COX-2 IC₅₀ of 34 µM, 3b had a COX-1 IC₅₀ of 19 µM and a COX-2 IC₅₀ of 31 µM, 3a had a COX-2 IC₅₀ of 42 µM). These compounds were analyzed via docking and were predicted to interact with some of the COX-2 key residues. Our best hit, 4d (COX-1 IC₅₀ of 28 µM, COX-2 IC₅₀ of 23 µM), appears to adopt similar binding modes to the standard COX-2 inhibitor, celecoxib, proposing room for possible selectivity. Additionally, the resultant novel compounds were tested in several in vivo assays. Four compounds 3a (COX-2 IC₅₀ of 42 µM), 3d, 4d and 4f were notable for their anti-inflammatory activity that was comparable to that of the clinically available COX-2 inhibitor celecoxib. Interestingly, they showed greater potency than the famous non-steroidal anti-inflammatory drug, Diclofenac sodium. In summary, these novel pyrazolo[3,4-d]pyrimidine analogues showed interesting anti-inflammatory activity and could act as a starting point for future drugs.     

Novel tacrine-coumarin hybrids linked to 1,2,3-triazole as anti-Alzheimer’s compounds: In vitro and in vivo biological evaluation and docking study

A new series of tacrine-coumarin hybrids linked to 1,2,3-triazole were designed, synthesized, and tested as potent dual binding site cholinesterase inhibitors (ChEIs) for the treatment of Alzheimer’s disease (AD). Among them, compound 8e was the most potent anti-AChE derivative (IC₅₀ = 27 nM) and compound 8m displayed the best anti-BChE activity (IC₅₀ = 6 nM) much more active than tacrine and donepezil as the reference drugs. Compound 8e was also evaluated for its BACE1 inhibitory activity and neuroprotectivity against PC12 cells exposed to Aβ_25-35 which indicated low activity. Finally, in vivo studies by Morris water maze task showed that compound 8e significantly reversed scopolamine-induced memory deficit in rats.     

Synthesis and anti-proliferative activity of allogibberic acid derivatives containing 1,2,3-triazole pharmacophore

Sixty novel allogibberic acid derivatives containing 1,2,3-triazole pharmacophore were designed and synthesized. The key chemical processes include aromatization of the A ring in gibberellins, formation of allogibberic azides and its copper mediated Huisgen 1,3-dipolar cycloaddition with alkynes. A number of hybrids containing α,β-unsaturated ketone moiety exhibited excellent in vitro cytotoxic activities. Some of the hybrids were more selective to MCF-7 and SW480 cell lines with IC₅₀ values at least 8-fold more cytotoxic than cisplatin (DDP). The most potent compounds C43 and C45 are more cytotoxic than cisplatin (DDP) against all tested five tumor cell lines, with IC₅₀ values of 0.25–1.72?µM. Mechanism of action studies indicated that allogibberic-triazole derivative C45 could induce the S phase cell cycle arrest and apoptosis in SMMC-7721 cell lines.     

Novel quinoline-3-carboxamides (Part 2): Design,optimization and synthesis of quinoline based scaffold as EGFR inhibitors with potent anticancer activity

EGFR has a key role in cell growth. Its mutation and overexpression share in epithelial malignancies and tumor growth. Quinazoline and quinoline derivatives are common anticancer intracellular inhibitors of EGFR kinase, and their optimization is an important issue for development of potent targeted anticancer agents. Based on these facts, different strategies were used for optimizing our reported quinoline-3-carboxamide compound III (EGFR IC₅₀ = 5.283 µM and MCF-7 IC₅₀ = 3.46 µM) through different molecular modeling techniques. The optimized compounds were synthesized and subjected to EGFR binding assay and accordingly some more potent inhibitors were obtained. The most potent quinoline-3-carboxamides were the furan derivative 5o; thiophene derivative 6b; and benzyloxy derivative 10 showing EGFR IC₅₀ values 2.61, 0.49 and 1.73 μM, respectively. Furthermore, the anticancer activity of compounds eliciting potent EGFR inhibition (5o, 5p, 6b, 8a, 8b, and 10) was evaluated against MCF-7 cell line where they exhibited IC₅₀ values 3.355, 3.647, 5.069, 3.617, 0.839 and 10.85 μM, respectively. Compound 6b was selected as lead structure for further optimization hoping to produce more potent EGFR inhibitors.     

Identification of the fused bicyclic 4-amino-2-phenylpyrimidine derivatives as novel and potent PDE4 inhibitors

2-Phenyl-4-piperidinyl-6,7-dihydrothieno[3,4-d]pyrimidine derivative (2) was found to be a new PDE4 inhibitor with moderate PDE4B activity (IC₅₀ = 150 nM). A number of derivatives with a variety of 4-amino substituents and fused bicyclic pyrimidines were synthesized. Among these, 5,5-dioxo-7,8-dihydro-6H-thiopyrano[3,2-d]pyrimidine derivative (18) showed potent PDE4B inhibitory activity (IC₅₀ = 25 nM). Finally, N-propylacetamide derivative (31b) was determined as a potent inhibitor for both PDE4B (IC₅₀ = 7.5 nM) and TNF-α production in mouse splenocytes (IC₅₀ = 9.8 nM) and showed good in vivo anti-inflammatory activity in the LPS-induced lung inflammation model in mice (ID₅₀ = 18 mg/kg). The binding mode of the new inhibitor (31e) in the catalytic site of PDE4B is presented based on an X-ray crystal structure of the ligand–enzyme complex.     

Aspernolides F and G,new butyrolactones from the endophytic fungus Aspergillus terreus

Two new butyrolactones: aspernolides F (6) and G (7), together with three stigmasterol derivatives: (22E,24R)-stigmasta-5,7,22-trien-3-β-ol (1), stigmast-4-ene-3-one (2), and stigmasta-4,6,8(14), 22-tetraen-3-one (3), two meroterpenoids: terretonin A (4) and terretonin (5), and a butyrolactone derivative: butyrolactone VI (8) have been isolated from the endophytic fungus Aspergillus terreus isolated from the roots of Carthamus lanatus (Asteraceae). Their structures were determined by spectroscopic means (1D, 2D NMR, and HRESIMS), as well as optical rotation measurement and comparison with literature data. The isolated compounds were evaluated for their anti-microbial, anti-malarial, anti-leishmanial, and cytotoxic activities. Compound 1 displayed a potent activity against MRSA and C. neoformans with IC₅₀ values of 0.96 μg/mL and 4.38 μg/mL, respectively compared to ciprofloxacin (IC₅₀ 0.07 μg/mL) and amphotericin B (IC₅₀ 0.34 μg/mL), respectively. While, 6 showed good activity against C. neoformans (IC₅₀ 5.19 μg/mL) and mild activity against MRSA (IC₅₀ 6.39 μg/mL). Moreover, 1 and 2 exhibited very good anti-leishmanial activity towards L. donovani with IC₅₀ values of 4.61 and 6.31 μg/mL, respectively and IC₉₀ values of 6.02 and 16.71 μg/mL, respectively.     

Design,synthesis, cholinesterase inhibition and molecular modelling study of novel tacrine hybrids with carbohydrate derivatives

A series of hybrids containing tacrine linked to carbohydrate-based moieties, such as d-xylose, d-ribose, and d-galactose derivatives, were synthesized by the nucleophilic substitution between 9-aminoalkylamino-1,2,3,4-tetrahydroacridines and the corresponding sugar-based tosylates. All compounds were found to be potent inhibitors of both acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) in the nanomolar IC₅₀ scale. Most of the d-xylose derivatives (6a-e) were selective for AChE and the compound 6e (IC₅₀?=?2.2?nM for AChE and 4.93?nM for BuChE) was the most active compound for both enzymes. The d-galactose derivative 8a was the most selective for AChE exhibiting an IC₅₀ ratio of 7.6 for AChE over BuChE. Only two compounds showed a preference for BuChE, namely 7a (d-ribose derivative) and 6b (d-xylose derivative). Molecular docking studies indicated that the inhibitors are capable of interacting with the entire binding cavity and the main contribution of the linker is to enable the most favorable positioning of the two moieties with CAS, PAS, and hydrophobic pocket to provide optimal interactions with the binding cavity. This finding is reinforced by the fact that there is no linear correlation between the linker size and the observed binding affinities. The majority of the new hybrids synthesized in this work do not violate the Lipinski's rule-of-five according to FAF-Drugs4, and do not demonstrated predicted hepatotoxicity according ProTox-II.     

Development of 6-arylcoumarins as nonsteroidal progesterone antagonists. Structure–activity relationships and fluorescence properties

Progesterone is involved in multiple physiological processes, including female reproduction, via binding to the progesterone receptor (PR). We have developed 6-arylcoumarins such as 5 and 6 as non-steroidal PR antagonists with receptor-binding-dependent fluorescence. In this study, we investigated the structure–activity relationships and fluorescence properties of coumarin derivatives bearing a heterocyclic aromatic moiety. Among these derivatives, 7c (IC₅₀: 34 nM) and 10b (IC₅₀: 24 nM) showed more potent PR-antagonistic activity than lead compounds 5 (IC₅₀: 500 nM) and 6 (IC₅₀: 65 nM) in alkaline phosphatase (AP) assay. Compound 9b showed solvent-dependent fluorescence intensity, exhibiting strong fluorescence in the presence of PR LBD only in buffer solution. On the other hand, 10b showed a solvent-dependent shift of the fluorescence maximum wavelength in the presence of PR LBD. These results indicate that 6-arylcoumarin will be a useful scaffold for PR antagonists and fluorescent probes targeting PR.     

Synthesis, β-haematin inhibition,and in vitro antimalarial testing of isocryptolepine analogues: SAR study of indolo[3,2-c]quinolines with various substituents at C2, C6, and N11

A series of indolo[3,2-c]quinolines were synthesized by modifying the side chains of the ω-aminoalkylamines at the C6 position and introducing substituents at the C2 position, such as F, Cl, Br, Me, MeO and NO₂, and a methyl group at the N11 position for an SAR study. The in vitro antiplasmodial activities of the derivative agents against two different strains (CQS: NF54 and CQR: K1) and the cytotoxic activity against normal L6 cells were evaluated. The test results showed that compounds 6k and 6l containing the branched methyl groups of 3-aminopropylamino at C6 with a Cl atom at C2 exhibited a very low cytotoxicity with IC₅₀ values above 4000 nM, high antimalarial activities with IC₅₀ values of about 11 nM for CQS (NF54), IC₅₀ values of about 17 nM for CQR (K1), and RI resistance indices of 1.6. Furthermore, the compounds were tested for β-haematic inhibition, and QSAR revealed an interesting linear correlation between the biological activity of CQS (NF54) and three contributing factors, namely solubility, hydrophilic surface area, and β-haematin inhibition for this series. In vivo testing of 6l showed a reduction in parasitaemia on day 4 with an activity of 38%.     

Selective cyclooxygenase inhibition and ulcerogenic liability of some newly prepared anti-inflammatory agents having thiazolo[4,5-d]pyrimidine scaffold

Novel candidates of thiazolo[4,5-d]pyrimidines (9a-l) were synthesized and their structures were elucidated by spectral and elemental analyses. All the novel derivatives were screened for their cyclooxygenase inhibitory effect, anti-inflammatory activity and ulcerogenic liability. All the new compounds exhibited anti-inflammatory activity, especially 1-(4-[7-(4-nitrophenyl)-5-thioxo-5,6-dihydro-3H-thiazolo[4,5-d]pyrimidin-2-ylideneamino]phenyl)ethanone (9g) was the most active derivative with 57%, 88% and 88% inhibition of inflammation after 1, 3 and 5h, respectively. Furthermore, this derivative 9g recorded higher anti-inflammatory activity than celecoxib which showed 43%, 43% and 54% inhibition after 1, 3 and 5h, sequentially. Moreover, the target derivatives 9a-l demonstrated moderate to high potent inhibitory action towards COX-2 (IC₅₀ = 0.87–3.78 µM), in particular, the derivatives 9e (IC₅₀ = 0.92 µM), 9g (IC₅₀ = 0.87 µM) and 9k (IC₅₀ = 1.02 µM) recorded higher COX-2 inhibitory effect than the selective COX-2 inhibitor drug celecoxib (IC₅₀ = 1.11 µM). The in vivo potent compounds (9e, 9g and 9k) caused variable ulceration effect (ulcer index = 5–12.25) in comparison to that of celecoxib (ulcer index = 3). Molecular docking was performed to the most potent COX-2 inhibitors (9e, 9g and 9k) to explore the binding mode of these derivatives with Cyclooxygenase-2 enzyme.     

Design,synthesis and biological evaluation of coumarin alkylamines as potent and selective dual binding site inhibitors of acetylcholinesterase

Acetylcholinesterase inhibitors (AChEIs) are currently the drugs of choice, although only symptomatic and palliative, for the treatment of Alzheimer’s disease (AD). Donepezil is one of most used AChEIs in AD therapy, acting as a dual binding site, reversible inhibitor of AChE with high selectivity over butyrylcholinesterase (BChE). Through a combined target- and ligand-based approach, a series of coumarin alkylamines matching the structural determinants of donepezil were designed and prepared. 6,7-Dimethoxycoumarin derivatives carrying a protonatable benzylamino group, linked to position 3 by suitable linkers, exhibited fairly good AChE inhibitory activity and a high selectivity over BChE. The inhibitory potency was strongly influenced by the length and shape of the spacer and by the methoxy substituents on the coumarin scaffold. The inhibition mechanism, assessed for the most active compound 13 (IC₅₀ 7.6 nM) resulted in a mixed-type, thus confirming its binding at both the catalytic and peripheral binding sites of AChE.     

Novel pyridazinone derivatives as butyrylcholinesterase inhibitors

In the current study, forty-four new [3-(2/3/4-methoxyphenyl)-6-oxopyridazin-1(6H)-yl]methyl carbamate derivatives were synthesized and evaluated for their ability to inhibit electric eel acetylcholinesterase (EeAChE) and equine butyrylcholinesterase (eqBuChE) enzymes. According to the inhibitory activity results, [3-(2-methoxyphenyl)-6-oxopyridazin-1(6H)-yl]methyl heptylcarbamate (16c, eqBuChE, IC₅₀ = 12.8 μM; EeAChE, no inhibition at 100 μM) was the most potent eqBuChE inhibitor among the synthesized compounds and was found to be a moderate inhibitor compared to donepezil (eqBuChE, IC₅₀ = 3.25 μM; EeAChE, IC₅₀ = 0.11 μM). Kinetic and molecular docking studies indicated that compounds 16c and 14c (hexylcarbamate derivative, eqBuChE, IC₅₀ = 35 μM; EeAChE, no inhibition at 100 μM) were mixed-type inhibitors which accommodated within the catalytic active site (CAS) and peripheral anionic site (PAS) of hBuChE through stable hydrogen bonding and π-π stacking. Furthermore, it was determined that [3-(2-methoxyphenyl)-6-oxopyridazin-1(6H)-yl]methyl (4-methylphenyl)carbamate 7c (eqBuChE, IC₅₀ = 34.5 μM; EeAChE, 38.9% inhibition at 100 μM) was the most active derivative against EeAChE and a competitive inhibitor binding to the CAS of hBuChE. As a result, 6-(2-methoxyphenyl)pyridazin-3(2H)-one scaffold is important for the inhibitory activity and compounds 7c, 14c and 16c might be considered as promising lead candidates for the design and development of selective BuChE inhibitors for Alzheimer’s disease treatment.     

Synthesis, α-glucosidase inhibition and molecular docking study of coumarin based derivatives

We have synthesized seventeen Coumarin based derivatives (1–17), characterized by ¹HNMR, ¹³CNMR and EI-MS and evaluated for α-glucosidase inhibitory potential. Among the series, all derivatives exhibited outstanding α-glucosidase inhibition with IC₅₀ values ranging between 1.10 ± 0.01 and 36.46 ± 0.70 μM when compared with the standard inhibitor acarbose having IC₅₀ value 39.45 ± 0.10 μM. The most potent derivative among the series is derivative 3 having IC₅₀ value 1.10 ± 0.01 μM, which are many folds better than the standard acarbose. The structure activity relationship (SAR) was mainly based upon by bring about difference of substituent’s on phenyl part. Molecular docking studies were carried out to understand the binding interaction of the most active compounds.