Butyrylcholinesterase Inhibitory Activity Research Articles

Acetylcholinesterase and butyrylcholinesterase inhibitory activities of antioxidant peptides obtained from enzymatic pea protein hydrolysates and their ultrafiltration peptide fractions.

This study optimized the enzymatic hydrolysis of yellow field pea proteins using alcalase (ACH), chymotrypsin (CHH), flavourzyme (FZH), pancreatin (PCH), pepsin (PEH), and trypsin (TPH) to obtain hydrolysates and ultrafiltered fractions (<1, 1-3, 3-5 and 5-10kDa) that possess antioxidant plus acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) inhibitory activities. The hydrolysates exhibited varying degrees of radical scavenging and inhibition of linoleic acid peroxidation, as well as cholinesterase inhibition activities but the potency generally improved by >10% after UF separation into peptide fractions. ACH, FZH, and PEH exhibited significantly (p< .05) higher (20%-30% increases) radical scavenging activities than the other hydrolysates. The 1 and 3kDa UF fractions of ACH, FZH, and PEH inhibited ~20%-30% AChE activity, while ACH, PCH, TPH, and PEH inhibited ~20%-40% BuChE activity. We conclude that the pea protein hydrolysates and their peptide fractions possess multifunctional properties with potential use against neurodegenerative disorders. PRACTICAL APPLICATIONS: Alzheimer's disease (AD) has multiple pathological pathways in addition to the loss of acetylcholine (ACh) catalyzed by acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE). The presence of severe oxidative stress triggered by lipid peroxidation and formation of free radicals is a common trait in AD patients. The concept of AChE and BuChE inhibition as an approach toward AD amelioration involves the use of compounds with a similar structure to ACh, the natural substrate. Peptides derived from food proteins consist of ester bonds with structural similarity to ACh and theoretically possess the ability to interact with AChE and BuChE. Results from the present study imply that pea protein-derived peptides are potential candidates for use as inhibitors of AChE and BuChE activities, with application in the prevention and management of AD.

Isolation, derivatization, in-vitro, and in-silico studies of potent butyrylcholinesterase inhibitors from Berberis parkeriana Schneid

Seven known isoquinoline alkaloids 1–7 were isolated from the root extracts of Berberis parkeriana Schneid. Nine new derivatives 8–16 of one of the isolated compounds, jatrorrhizine (7), were synthesized. All the isolated as well as derivatized compounds were evaluated for their in-vitro acetylcholinesterase (AChE), and butyrylcholinesterase (BChE) inhibitory activity. Functionalized compounds selectively exhibited a potent-to-moderate activity with IC50 = 5.5 ± 0.3–124.5 ± 0.4 μM against butyrylcholinesterase enzyme. Among them, compound 15 was a potent BChE inhibitor (IC50 = 5.5 ± 0.3 μM), as compared to the standard drug galantamine hydrobromide (IC50 = 40.83 ± 0.37 μM). Active compounds were further subjected to kinetic, and molecular docking studies to predict their modes of inhibition, and interactions with the receptor (BChE), respectively. Enzyme kinetics studies showed that compounds 9 (IC50 = 25.3 ± 0.5 μM), and 14 (IC50 = 23.9 ± 0.5 μM) were non-competitive inhibitors, while compound 15 exhibited a competitive inhibition. In addition, these compounds were found to be non-cytotoxic against human fibroblast (BJ) cell line, except 9 (IC50 = 17.1 ± 1.0 μM), and 10 (IC50 = 18.4 ± 0.3 μM). Inhibition of cholinesterases is an important approach for development of drugs against Alzheimer’s disease, and thus discoveries presented here deserve further investigation.

Comprehensive study of chemical composition and biological activity of Thymus pubescens Boiss. et Kotschy ex Čelak.

The use of Thymus species amongst the public and their importance in the scientific world is increasing day by day. In addition to being consumed as tea and spice, Thymus species are used as folk medicine for respiratory, digestive, skin, circulatory, genital, nervous, visual and urinary diseases. In this study, it was aimed to examine the essential oil and ethanol extract of the root and aerial parts of Thymus pubescens Boiss. et Kotschy ex Celak in the terms of their biological activity and chemical content. The phenolic content of the species was determined by LC-MS/MS, while triterpenoid content, the chemical composition of the essential oil as well as flavour was determined by GC–MS. In addition, their antioxidant and cytotoxic activities, as well as acetyl- (AChE) and butyrylcholinesterase (BChE), urease, tyrosinase, elastase, collagenase, HMG-CoA reductase and angiotensin-converting enzyme (ACE) inhibitory activities were studied. Thymol (53.33%) was determined as the major component in the essential oil, while β-fenchyl alcohol (43.87%) was determined as the major component of the flavour. According to the LC-MS/MS and GC–MS results, it was found that especially the aerial parts of the species have a high amount of rosmarinic acid (3875.76 µg analyte/g extract), quinic acid (2392.55), naringenin (970.39), oleanolic (92785.96) and ursolic (63373.32) acids. The essential oil of T. pubescens species was observed to show high activity in four antioxidant assays, e.g. inhibition of lipid peroxidation, DPPH and ABTS radical scavenging activity as well as CUPRAC, while the ethanol extracts showed moderate antioxidant activity. In enzyme inhibition assays, the aerial parts exerted marked BChE, elastase, and collagenase inhibitory activities (92.43±1.28%, 42.59±0.56, and 48.61±0.39 at 100 µg/mL, respectively). On the other hand, AChE, urease, tyrosinase, HMG-CoA reductase and ACE inhibitory activities of all extracts were from low to moderate levels. In particular, the aerial parts of the species displayed a high cytotoxic effect (vitality%: 6.82±0.01 at 200 µg/mL) in breast cancer (MCF-7) cell line. Due to its remarkable antioxidant capacity, high content of rosmarinic, oleanolic, and ursolic acids and especially BChE, elastase, and collagenase inhibitory activity, T. pubescens has the potential for using in food supplements, food preservatives, cosmetics, and pharmaceutical industries.

Synthesis, characterisation, DNA binding, acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) activities and molecular docking studies of metal(II) complexes with 1,10-phenanthroline scaffold

A series of metal complexes containing Phenanthroline scaffold [ML] (L-1,10-Phenanthroline derivative comprises conjugated aromatic core and selenol group); M = Cu(II), Zn(II), Co(II) and Zn(II) ions were designed and synthesised to obtain effective anti-cholinesterase efficiencies of metal chelates. Analytical and spectroscopic studies were used to determine the structural features. An octahedral structure with moderate distortion was attributed to the above metal chelates based on spectroscopic data. The distorted octahedral geometry of copper(II) complex to DNA (K b = 4.05 × 105 M−1) is stronger than that of ethidium bromide (EB) to DNA (Kb = 3.2 × 105 M−1), other metal complexes, respectively. The synthesised 1,10-Phenanthroline derivative had the best inhibitory effects against acetylcholinesterase (AChE) and butyrylcholinesterase, with IC50 values of 0.45 and 3.6 M, respectively, which were lower than the reference molecules. As a result, nitrogen-containing heterocyclic compounds (H2L) showed significant inhibitory profiles against the metabolic enzymes. Therefore, we believe that these experimental results may contribute to the development of new drug molecules particularly in the treatment of neurological disorders including glaucoma, Alzheimer’s disease (AD) and diabetes. Docking, AChE and BuChE inhibition activities results revealed that ligand may be used for AD. The prepared 1,10-phenanthroline analogue, which has a high selectivity for AChE, may be studied further to find potential candidates for treating early-stage Alzheimer’s symptoms. Communicated by Ramaswamy H. Sarma

In vitro antioxidant, anticholinesterase, tyrosinase activity studies, and LC-MS/MS simultaneous determination of 37 bioactive compounds in Indigofera heterantha

The flowering plant Indigofera heterantha generally known as Indigo of Himalayan, was extracted with n-hexane, ethyl acetate, and methanol by using Soxhlet apparatus. The extracts were studied for their antioxidants and enzyme inhibition activities. Against DPPH free radical-scavenging activity methanol extract was found moderately active (IC 50 : 158.41 ± 1.1.66 µg/mL). The ethyl acetate and n-hexane extracts exhibited the best ABTS radical scavenging activity (IC 50 : 31.32 ± 2.50 and 52.0 ± 0.89 µg/mL respectively). Against the metal chelating activity, n-hexane extract was active IC 50 : 52.36 ± 0.95 µg/mL. The n-hexane and ethyl acetate extracts demonstrated the best β –carotene antioxidant activity (IC 50 : 22.32 ± 0.84 and 60.66 ± 0.35 μg/mL respectively). Against acetylcholinesterase (AChE), ethyl acetate and methanol extracts were moderate active (IC 50 : 133.58 ± 0.870, and 137.97 ± 0.97 µg/mL respectively). The ethyl acetate extract showed Butyrylcholinesterase (BChE) inhibitory activity with IC 50 value of 121.9 ± 1.13 µg/mL. Against tyrosinase activity, ethyl acetate and n-hexane extracts activity with an IC 50 value of 79.25 ± 0.15 and 131.48 ± 0.88 µg/mL respectively. The phenolic contents of the methanolic extract of I. heterantha were also determined by using LC-MS/MS. The major constituents were Quinic acid (57,333.04 μg/g), malic acid (1135.16 μg/g), gallic acid (201.13 μg/g), isoquercitrin (113.63 μg/g), Rutin (92.97 μg/g), and Salicylic acid (40.45 μg/g). Keeping in view the overall biological activities of I. heterantha, it might be used in food industries and pharmaceuticals as a potential functional food ingredient.

A Comparative Study between Conventional and Advanced Extraction Techniques: Pharmaceutical and Cosmetic Properties of Plant Extracts.

This study aimed to compare the influence of extraction methods on the pharmaceutical and cosmetic properties of medicinal and aromatic plants (MAPs). For this purpose, the dried plant materials were extracted using advanced (microwave (MAE), ultrasonic (UAE), and homogenizer (HAE) assisted extractions) and conventional techniques (maceration, percolation, decoction, infusion, and Soxhlet). The tyrosinase, elastase, α-amylase, butyryl, and acetylcholinesterase inhibition were tested by using L-3,4 dihydroxy-phenylalanine, N-Succinyl-Ala-Ala-p-nitroanilide, butyryl, and acetylcholine as respective substrates. Antioxidant activities were studied by ABTS, DPPH, and FRAP. In terms of extraction yield, advanced extraction techniques showed the highest values (MAE > UAE > HAE). Chemical profiles were dependent on the phenolic compounds tested, whereas the antioxidant activities were always higher, mainly in infusion and decoction as a conventional technique. In relation to the pharmaceutical and cosmetic properties, the highest inhibitory activities against α-amylase and acetylcholinesterase were observed for Soxhlet and macerated extracts, whereas the highest activity against tyrosinase was obtained with MAE > maceration > Soxhlet. Elastase and butyrylcholinesterase inhibitory activities were in the order of Soxhlet > maceration > percolation, with no activities recorded for the other tested methods. In conclusion, advanced methods afford an extract with high yield, while conventional methods might be an adequate approach for minimal changes in the biological properties of the extract.

Design, synthesis and in vitro biological activities of coumarin linked 1,3,4-oxadiazole hybrids as potential multi-target directed anti-Alzheimer agents

IntroductionAlzheimer’s disease (AD) is one of the most common and prevalent forms of neurodegenerative diseases. Coumarin is a versatile scaffold that exhibits a wide range of biological properties including cholinesterase inhibitory activity and therefore is an important heterocyclic moiety to develop anti-AD drugs. ObjectivesThis study aimed to design and synthesize coumarin linked 1,3,4-oxadiazole hybrid derivatives as multi-target directed ligands (MTDLs) and to investigate their in vitro anticholinesterase, antioxidant and anti-inflammatory activities. MethodsTwo series (4a-n and 7a-m) of low molecular weight ligands (27 compounds) containing coumarin linked 1,3,4-oxadiazole hybrids were synthesized and their chemical structures were characterized using analytical data. In vitro acetylcholinesterase (AChE), butyrylcholinesterase (BuChE) inhibitory activity, antioxidant activity and cyclooxygenase (COX) inhibitory activity were investigated following standard spectrophotometric methods. Molecular docking studies to predict the binding mode with AChE and BuChE in addition to the pharmacokinetic profile of the synthesized compounds were studied with the help of online cheminformatics software. ResultsAmongst the tested compounds for anticholinesterase activity, 4e and 4g hybrid derivatives were found to be the most potent AChE inhibitors (IC50 values = 29.56 and 28.68 μM), respectively. Compound 4m exhibited the maximum inhibitory activity against BuChE (IC50 value = 23.97 μM). Compounds 4g and 4e also showed higher selectivity index (SI) of 1.652 and 1.552 as compared to standard galantamine (SI = 1.132). Molecular docking studies revealed that 4g and 4e, two most potent AChE inhibitors identified through in vitro assay, binds well to AChE (binding energy scores of −9.7 and −10.1 Kcal/Mol). Synthesized hybrid molecules also exhibited good to excellent in vitro antioxidant and anti-inflammatory activities. ConclusionBased on the results of in vitro and in-silico studies, it could be concluded that coumarin-oxadiazole hybrids acts as MTDLs and are promising source of anti-AD drugs. Further detailed investigations and modification of these compounds can lead to the development of highly potent therapeutics for the treatment of AD.

Antioxidant and Enzymes Inhibitory Activities of Leaf Extracts of Plant Species Traditionally Used for Medicinal and Spiritual Purposes in Nepal

ABSTRACT The flavonoids and phenolics contents, antioxidant potential, and enzymes (α-amylase, lipase, elastase, tyrosinase, acetylcholinesterase, and butyrylcholinesterase) inhibition potential of leaf extracts from Elaeocarpus sphaericus, Santalum album, Pterocarpus santalinus, and Ziziphus budhensis collected from Ramechhap District of Nepal were evaluated. DPPH assay was used to determine the antioxidant potential, and the DNSA method was used to examine α-amylase inhibition activity. P-NPB, L-DOPA, AAAPVN, acetylthiocholine iodide, and butyrylthiocholine iodide were used as respective substrates for the determination of lipase, tyrosinase, elastase, acetylcholinesterase, and butyrylcholinesterase inhibition activities. The crude extract of P. santalinus showed inhibitory potential against all enzymes, whereas E. sphaericus, S. album, and Z. budhensis extracts showed moderate inhibition activity. However, S. album did not inhibit lipase, elastase, and tyrosinase.

An Insight into Salvia haematodes L. (Lamiaceae) Bioactive Extracts Obtained by Traditional and Green Extraction Procedures.

Even though Salvia is one of the most known genera of the Lamiaceae family, some traditionally used Salvia species are still now less investigated. To that end, the present study aims to evaluate the chemical profile and the potential bioactivities of extracts and related fractions obtained from the endemic sage Salvia haematodes L. by applying a traditional extraction method such as Soxhlet apparatus (SHS) and the rapid solid–liquid dynamic extraction (RSLDE) by Naviglio extractor® (SHN), considered among the “green techniques” operating at room temperature and with minimum solvent employment and minimum energy. Acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitory activity was measured by a modified Ellman’s method. The antioxidant activity was investigated by using 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), ferric reducing ability power (FRAP), and β-carotene bleaching tests. The SHN methanol fraction resulted the most active in all assays in particular in inhibiting lipid peroxidation with IC50 of 1.7 and 1.6 μg/mL, respectively, after 30 and 60 min of incubation. The SHN n-hexane fraction exhibited a selective activity against AChE with half-maximal inhibitory concentration (IC50) of 22.9 μg/mL, while the SHS n-hexane extract was more active against BChE (IC50 of 30.9 μg/mL). Based on these results, these fractions were subjected to further bio-fractionation by Medium Pressure Liquid Chromatography (MPLC) and the relative obtained fractions were investigated for their AChE and BChE inhibitory activity. A comparative analysis with bio-activity and chemical profile was performed. The observed biological effects provided us with a good starting point for further studies on S. haematodes extracts and fractions such as agents beneficial for the treatment of AD.

Synthesis and molecular modelling of thiadizole based hydrazone derivatives as acetylcholinesterase and butyrylcholinesterase inhibitory activities

ABSTRACT Some novel substituted thiazolylhydrazine derivatives were designed, synthesized and their inhibitory effects on acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) enzymes and antioxidant activities were investigated. The structures of the synthesized compounds were determined using different spectroscopic techniques such as 1H-NMR, 13C-NMR, and HRMS. According to the enzyme inhibition results, the synthesized compounds showed selectivity against BuChE enzyme inhibition. Compounds 5e, 5g, 5i and 5j displayed significant BuChE inhibition potencies. Among them, compound 5i was found to be the most effective derivative with an IC50 value of 56.01 ± 0.054 µM. In addition, their antioxidant properties were evaluated in vitro through the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay. For compounds 5e, 5g, 5i and 5j in silico molecular docking and 100 ns molecular dynamics simulations studies against the BuChE enzyme were performed to determine possible protein-ligand interactions and stability. DFT-D3 study was performed to stabilize of compounds 5e, 5g, 5i and 5j both in gas and solvent medium and investigated their electronic properties. Of all geometries, that of DMSO is the lowest one.

Structural Insight of New Butyrylcholinesterase Inhibitors Based on Benzylbenzofuran Scaffold.

In the present work, we use a merger of computational and biochemical techniques as a rational guideline for structural modification of benzofuran derivatives to find pertinent structural features for the butyrylcholinesterase inhibitory activity and selectivity. Previously, we revealed a series of 2-phenylbenzofuran compounds that displayed a selective inhibitory activity for BChE. Here, in an effort to discover novel selective BChE inhibitors with favorable physicochemical and pharmacokinetic profiles, 2-benzylbenzofurans were designed, synthesized, and evaluated as BChE inhibitors. The 2-phenylbenzofuran scaffold structure is modified by introducing one methylene spacer between the benzofuran core and the 2-phenyl ring with a hydroxyl substituent in the para or meta position. Either position 5 or 7 of the benzofuran scaffold was substituted with a bromine or chlorine atom. Further assessment of the selected list of compounds indicated that the substituent’s nature and position determined their activity and selectivity. 5-bromo-2-(4-hydroxybenzyl)benzofuran 9B proved to be the most potent butyrylcholinesterase inhibitor (IC50 = 2.93 µM) of the studied series. Computational studies were carried out to correlate the theoretical and experimental binding affinity of the compounds to the BChE protein.

Synthesis, photochemistry and computational study of novel 1,2,3-triazole heterostilbenes: Expressed biological activity of their electrocyclization photoproducts

New 1,2,3-triazolostilbenes were synthesized and photochemically transformed to substituted naphthotriazoles as electrocyclization products in high isolated yields for studying the acetyl- and butyrylcholinesterase inhibitory and anti-inflammatory activity. The best experimental results showed the naphthotriazole photoproducts providing interesting observation on cholinesterase inhibition associated with the inhibition of TNFα cytokine production. The geometries of synthesized triazolostilbenes were computationally examined using Density Functional Theory (DFT), followed by time-dependent DFT calculations to obtain insight into electronic properties observed by UV–Vis spectroscopy. The complexes between selected compounds with the active site of AChE are assessed by docking. A quantum mechanical cluster approach was utilized to optimize their structures, thus providing insight into the stabilizing interactions between the potential inhibitor and the active site.

Survey of New, Small-Molecule Isatin-Based Oxindole Hybrids as Multi-Targeted Drugs for the Treatment of Alzheimer’s Disease

AbstractIn the last decade, our group has been very active at developing and assaying complex libraries of scaffolds with a focus on their potential to identify bioactive drug candidates for neurodegenerative diseases, particularly Alzheimer’s disease (AD). Attention has been focused on isatin-based oxindole scaffolds, for which promising results concerning butyrylcholinesterase (BuChE) inhibitory activity have previously been obtained. Considering some published reports and detailed analysis of the pharmacophores of commercially available drugs for AD (powerful cholinesterase (ChE) inhibitors), we performed a strategic structural modification of the isatin core and generated a new family of isatin-based oxindole hybrids (27 new compounds) possessing crucial key functional units in their framework. The syntheses were accomplished using multiple approaches, including simple N-alkylation reactions, copper-catalyzed amination reactions, and click chemistry. The resulting library was evaluated on ChE and MAO enzymes, both of which are involved in the pathophysiology of neurodegeneration. IC50 values of 1.6 and 2.6 μM (BuChE assays), were achieved for the best inhibitors.

Design, molecular Docking, synthesis and evaluation of xanthoxylin hybrids as dual inhibitors of IL-6 and acetylcholinesterase for Alzheimer's disease

Interleukin-6 (IL-6) and acetylcholinesterase (AChE) are two important targets implicated in progression of Alzheimer's Disease (AD). Simultaneous inhibition of both IL-6 and AChE by a molecule presents an effective strategy for the treatment of AD. In this study, the pharmacophores for inhibition of IL-6 and AChE are identified, and coupled to design novel molecules capable of acting as dual inhibitors of IL-6 and AChE. Literature review reveals that xanthoxylin and a disubstituted or a carbamoyl amine are pharmacophore for IL-6 and AChE inhibition, respectively. Therefore, xanthoxylin is coupled with various disubstituted amines or carbamoyl amines through alkyl linkers of different lengths (1–4 carbon atoms) to design two series of 80 compounds. All designed compounds are docked in AChE. Based on their docking score, 15 compounds are selected for synthesis and evaluation of AChE inhibitory activity. The compounds showing > 45% inhibition of EeAChE are selected for evaluation of IL-6 and butyrylcholinesterase (BuChE) inhibitory activities. Compound Y13g is found to be the most potent inhibitor of EeAChE, BuChE and IL-6. It is further evaluated in vivo using STZ-induced amnesia model in mice at three doses (0.2, 0.4 and 0.8 mg/kg), wherein it shows dose-dependent effects. At 0.8 mg/kg, it reverses the STZ-induced memory deficit, and shows histopathology similarly as in normal animals. The findings suggest that compounds derived from coupling of xanthoxylin with piperazine through a 3-carbon chain provides a useful template for the development of new chemical entities effective against AD.

Design, synthesis, characterization and evaluation of 1,3,5-triazine-benzimidazole hybrids as multifunctional acetylcholinesterases inhibitors

A series of hybrids of benzimidazole and 1,3,5-triazine were designed and synthesized and evaluated as multi-target agents for the treatment of Alzheimer's disease. 24 compounds were designed, synthesized and identified by NMR, IR, HRMS and single-crystal X-ray diffraction studies. The compound 6c had the crystal system of orthorhombic and the space group of P212121. The cholinesterase inhibitory activity of synthesized compounds was measured using colorimetric Ellman's method. Most 1,3,5-triazine-benzimidazole hybrids showed potent acetylcholinesterase-inhibition activities and weak butyrylcholinesterase inhibitory activities. Compound 9f possessed the best acetylcholinesterase inhibitory activity with the IC50 of 0.044 µM, which is better than donepezil (0.052 µM). Molecular docking and molecular dynamics simulations demonstrated that there is a stable interaction between compound 9f and acetylcholinesterase. Simultaneously, experiments have also proved that compound 9f has good metal chelating properties. ADMET in silico prediction results suggest the compound can pass through the blood-brain barrier well and have good drug similarity. So, compound 9f could be a multi-target agent for the treatment of Alzheimer's disease.

Phytochemical Profiling, In Vitro Biological Activities, and In Silico Molecular Docking Studies of Dracaena reflexa.

Dracaena reflexa, a traditionally significant medicinal plant, has not been extensively explored before for its phytochemical and biological potential. The present study was conducted to evaluate the bioactive phytochemicals and in vitro biological activities of D. reflexa, and perform in silico molecular docking validation of D. reflexa. The bioactive phytochemicals were assessed by preliminary phytochemical testing, total bioactive contents, and GC-MS analysis. For biological evaluation, the antioxidant (DPPH, ABTS, CUPRAC, and ABTS), antibacterial, thrombolytic, and enzyme inhibition (tyrosinase and cholinesterase enzymes) potential were determined. The highest level of total phenolic contents (92.72 ± 0.79 mg GAE/g extract) was found in the n-butanol fraction while the maximum total flavonoid content (110 ± 0.83 mg QE/g extract) was observed in methanolic extract. The results showed that n-butanol fraction exhibited very significant tyrosinase inhibition activity (73.46 ± 0.80) and acetylcholinesterase inhibition activity (64.06 ± 2.65%) as compared to other fractions and comparable to the standard compounds (kojic acid and galantamine). The methanolic extract was considered to have moderate butyrylcholinesterase inhibition activity (50.97 ± 063) as compared to the standard compound galantamine (53.671 ± 0.97%). The GC-MS analysis of the n-hexane fraction resulted in the tentative identification of 120 bioactive phytochemicals. Furthermore, the major compounds as identified by GC-MS were analyzed using in silico molecular docking studies to determine the binding affinity between the ligands and the enzymes (tyrosinase, acetylcholinesterase, and butyrylcholinesterase enzymes). The results of this study suggest that Dracaena reflexa has unquestionable pharmaceutical importance and it should be further explored for the isolation of secondary metabolites that can be employed for the treatment of different diseases.

Cholinesterase inhibitors assessment of aporphine alkaloids from Annona crassiflora and molecular docking studies

Annona crassiflora Mart. is an endemic plant from Brazilian Cerrado (savanna) biome, commonly employed in traditional medicine to treat wounds, diarrhea, and scalp infections. The pulp of the fruits is edible and has a characteristic taste, being employed to prepare sweets like jam, cakes, and ice cream by the people who live in the region of the Cerrado, although the peels are discarded. In this way, the A. crassiflora fruit peels ethanol extract was prepared and subjected to liquid–liquid extraction, which yielded the alkaloidal fraction (CH2Cl2). Subjected to high-performance liquid chromatography separations, this fraction allowed the purification of the aporphine alkaloids stephalagine (1), liriodenine (2), and atherospermidine (3), that were structurally characterized by high-resolution mass spectrometry with electrospray ionization, and nuclear magnetic resonance spectroscopy analyses. Aporphine alkaloids are recognized for their acetylcholinesterase (AChE) inhibitory activity, an important target in Alzheimer's disease therapy. Thus, the ethanol extract, alkaloidal fraction, and compounds1,2,and3were evaluated for acetyl- and butyrylcholinesterase (BChE) inhibitory activities. Compound1(IC50 104.2 µmol L–1) exhibited better BChE inhibitory activity than the standard compound galanthamine (IC50 162.7 µmol L–1), while2had a comparable result(and IC50 167.3 µmol L–1). Furthermore, molecular docking was performed to predict the compound's binding mode to the human AChE at a molecular level. Semiempirical calculation results show that the enthalpy interaction energy (ΔHint) between AChE and BChE active sites and all ligands were favorable for both enzymes, with the ligands interacting even more strongly with AChE, corroborating with IC50 results.

Inhibitory potential of nitrogen, oxygen and sulfur containing heterocyclic scaffolds against acetylcholinesterase and butyrylcholinesterase.

Heterocycles are the key structures in organic chemistry owing to their immense applications in the biological, chemical, and pharmaceutical fields. Heterocyclic compounds perform various noteworthy functions in nature, medication, innovation etc. Most frequently, pure nitrogen heterocycles or various positional combinations of nitrogen, oxygen, and sulfur atoms in five or six-membered rings can be found. Inhibition of acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) enzymes is a popular strategy for the management of numerous mental diseases. In this context, cholinesterase inhibitors are utilized to relieve the symptoms of neurological illnesses like dementia and Alzheimer's disease (AD). The present review focuses on various heterocyclic scaffolds and their role in designing and developing new potential AChE and BChE inhibitors to treat AD. Moreover, a detailed structure–activity relationship (SAR) has been established for the future discovery of novel drugs for the treatment of AD. Most of the heterocyclic motifs have been used in the design of new potent cholinesterase inhibitors. In this regard, this review is an endeavor to summarize the biological and chemical studies over the past decade (2010–2022) describing the pursuit of new N, O and S containing heterocycles which can offer a rich supply of promising AChE and BChE inhibitory activities.

Chemical profile, acetylcholinesterase, butyrylcholinesterase, and prolyl oligopeptidase inhibitory activity of Glaucium corniculatum subsp. refractum

Papaveraceae is one of the prominent alkaloid-containing families, and plants of the genus Glaucium (Papaveraceae) are known for their bioactive alkaloids. Glaucium species have been used in traditional medicine in Turkey as an analgesic, narcotic, sedative, and antitussive. In this study, it was planned to evaluate the inhibitory activity of an alkaloidal extract of Glaucium corniculatum subsp. refractum on acetylcholinesterase (AChE), butyrylcholinesterase (BuChE) and prolyl oligopeptidase (POP), as well as exploring the chemical profile of the plant by using Gas Chromatography-Mass Spectrometry (GC-MS). The AChE, BuChE and POP inhibition activities of the alkaloidal extract of G. corniculatum subsp. refractum were determined spectrophotometrically. A rapid GC-MS method was used to identify alkaloids that could be responsible for these inhibition activities. In total, eleven alkaloids were identified in the alkaloid extract of the plant by GC-MS. Allocyptopine (52.92%) and protopine (25.38%) were found as the major constituents. The alkaloidal extract of G. corniculatum subsp. refractum showed potent AChE inhibitory activity (IC50:1.25 µg/mL) and BuChE inhibitory activity (IC50: 7.02 µg/mL). The extract also showed a remarkable inhibitory effect on POP with an IC50 value of 123.69 µg/mL. This study presents the first GC-MS investigation and POP inhibitory activity of G. corniculatum subsp. refractum.

Determination of essential oil and biological activities of Hypericum ternatum Poulter and H. scabrum L. species collected from different localities: is H. scabrum an alternative to multifunctional species ST JOHN'S WORT (H. perforatum)?

The importance of Hypericum L. species, being used in traditional medicine, in the scientific world is increasing day by day. Hypericum species are plants that have been used in the treatment of many diseases for a long time and have healing properties. In the current study, the essential oil compositions of Hypericum scabrum L. and H. ternatum Poulter collected from different localities in Turkey were determined by GC-MS/FID. In addition, their antioxidant, cytotoxic, and antimicrobial activities with their enzyme inhibitory potentials (cholinesterase, urease, tyrosinase, elastase, and collagenase) were investigated. Also, in vitro and in silico studies of the major components of the species have been carried out on the studied enzymes. It was determined that four H. scabrum samples mainly contained α-pinene (55.99%-62.80%) while three H. ternatum samples contained 2-methyloctane (9.45%-22.39%) and α-pinene (12.75%-33.08%). While H. scabrum essential oils possessed significant biological activity potential except for the antimicrobial activity, H. ternatum samples did not. All essential oil samples of H. scabrum exhibited a high cytotoxic effect (IC50 21.67 ± 0.34 to 34.67 ± 0.45 μg/mL) against colon cancer cell line (HT-29) and indicated higher acetyl-(Inhibiton% 83.30 ± 1.90 to 93.08 ± 1.04) and butyryl-cholinesterase (Inhibiton% 80.58 ± 1.19 to 93.28 ± 1.99) inhibitory activity than the standard compound, galantamine. Furthermore, all samples of H. scabrum showed high tyrosinase (Inhibiton% 69.00 ± 1.64 to 95.25 ± 1.42) and elastase (Inhibiton% 27.58 ± 0.34 to 36.69 ± 0.18) inhibitory effects. These biological activity results indicated that H. scabrum essential oil could be used in the cosmetic and pharmaceutical industries.