The investigation into human butyrylcholinesterase (hBChE) inhibitors as therapeutic agents for Alzheimer's disease (AD) holds significant promise, addressing both symptomatic relief and disease progression. In the pursuit of novel drug candidates with a selective BChE inhibition pattern, we focused on naturally occurring template structures, specifically Amaryllidaceae alkaloids of the carltonine-type. Herein, we explored a series of compounds implementing an innovative chemical scaffold built on the 3- and 4-benzyloxy-benzylamino chemotype. Notably, compounds 28 (hBChE IC50 = 0.171 ± 0.063 μM) and 33 (hBChE IC50 = 0.167 ± 0.018 μM) emerged as top-ranked hBChE inhibitors. In silico simulations elucidated the binding modes of these compounds within hBChE. CNS availability was predicted using the BBB score algorithm, corroborated by in vitro permeability assessments with the most potent derivatives. Compound 33 was also inspected for aqueous solubility, microsomal and plasma stability. Chemoinformatics analysis validated these hBChE inhibitors for oral administration, indicating favorable gastrointestinal absorption in compliance with Lipinski's and Veber's rules. Safety assessments, crucial for the chronic administration typical in AD treatment, were conducted through cytotoxicity testing on human neuroblastoma (SH-SY5Y) and hepatocellular carcinoma (HepG2) cell lines.

• Publication type
• Journal Article MeSH

Excessive use of pesticides could potentially harm the environment for a long time. The reason for this is that the banned pesticide is still likely to be used incorrectly. Carbofuran and other banned pesticides that remain in the environment may also have a negative effect on human beings. In order to provide a better chance for effective environmental screening, this thesis describes a prototype of a photometer tested with cholinesterase to potentially detect pesticides in the environment. The open-source portable photodetection platform uses a color-programmable red, green and blue light-emitting diode (RGB LED) as a light source and a TSL230R light frequency sensor. Acetylcholinesterase from Electrophorus electricus (AChE) with high similarity to human AChE was used for biorecognition. The Ellman method was selected as a standard method. Two analytical approaches were applied: (1) subtraction of the output values after a certain period of time and (2) comparison of the slope values of the linear trend. The optimal preincubation time for carbofuran with AChE was 7 min. The limits of detection for carbofuran were 6.3 nmol/L for the kinetic assay and 13.5 nmol/L for the endpoint assay. The paper demonstrates that the open alternative for commercial photometry is equivalent. The concept based on the OS3P/OS3P could be used as a large-scale screening system.

• Keywords
• affordable, cholinesterase, field-analysis, open-source, pesticide, photometry, point-of-care test,
• MeSH
• Acetylcholinesterase MeSH
• Cholinesterase Inhibitors MeSH
• Cholinesterases MeSH
• Carbofuran * MeSH
• Humans MeSH
• Pesticides * MeSH
• Check Tag
• Humans MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Acetylcholinesterase MeSH
• Cholinesterase Inhibitors MeSH
• Cholinesterases MeSH
• Carbofuran * MeSH
• Pesticides * MeSH

2,5-Disubstituted 1,3,4-oxadiazoles are privileged versatile scaffolds in medicinal chemistry that have exhibited diverse biological activities. Acetyl- (AChE) and butyrylcholinesterase (BChE) inhibitors are used, e.g., to treat dementias and myasthenia gravis. 5-Aryl-1,3,4-oxadiazoles decorated with dodecyl linked via nitrogen, sulfur or directly to this heterocycle have been designed as potential inhibitors of AChE and BChE. They were prepared from commercially available or in-house prepared hydrazides by reaction with dodecyl isocyanate to form hydrazine-1-carboxamides 2 (yields 67-98%) followed by cyclization using p-toluenesulfonyl chloride and triethylamine in 41-100% yields. Thiadiazole isostere was also synthesized. The derivatives were screened for inhibition of AChE and BChE using Ellman's spectrophotometric method. The compounds showed a moderate dual inhibition with IC50 values of 12.8-99.2 for AChE and from 53.1 µM for BChE. All the heterocycles were more efficient inhibitors of AChE. The most potent inhibitor, N-dodecyl-5-(pyridin-4-yl)-1,3,4-thiadiazol-2-amine 3t, was subjected to advanced reversibility and type of inhibition evaluation. Structure-activity relationships were identified. Many oxadiazoles showed lower IC50 values against AChE than established drug rivastigmine. According to molecular docking, the compounds interact non-covalently with AChE and BChE and block entry into enzyme gorge and catalytic site, respectively.

• Keywords
• 1,3,4-oxadiazole, 1,3,4-thiadiazole, acetylcholinesterase, butyrylcholinesterase, enzyme inhibition, molecular docking,
• Publication type
• Journal Article MeSH

This article describes acetylcholinesterase (AChE), an enzyme involved in parasympathetic neurotransmission, its activity, and how its inhibition can be pharmacologically useful for treating dementia, caused by Alzheimer's disease, or as a warfare method due to the action of nerve agents. The chemical concepts related to the irreversible inhibition of AChE, its reactivation, and aging are discussed, along with a relationship to the current international legislation on chemical weapons.

• Keywords
• Alzheimer’s disease, Chemical Weapons Convention, acetylcholinesterase, nerve agents,
• MeSH
• Acetylcholinesterase * metabolism   MeSH
• Alzheimer Disease * drug therapy   enzymology   MeSH
• Chemical Warfare legislation & jurisprudence   MeSH
• Cholinesterase Inhibitors therapeutic use   MeSH
• GPI-Linked Proteins antagonists & inhibitors   metabolism   MeSH
• Humans MeSH
• Nerve Agents * MeSH
• Aging metabolism   MeSH
• Check Tag
• Humans MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Review MeSH
• Names of Substances
• Acetylcholinesterase * MeSH
• ACHE protein, human MeSH Browser
• Cholinesterase Inhibitors MeSH
• GPI-Linked Proteins MeSH
• Nerve Agents * MeSH

This paper deals with the innovation of the Czech colorimetric biosensor Detehit designed for the simple, fast, and sensitive detection of nerve agents. The innovation is based on the use of an indicator consisting of a mixture of two triphenylmethane dyes, Guinea green B and a basic fuchsin, on a glass nanofiber filter paper carrier. The advantage of this solution is the blue-red color transition, which is much more visible than the white-yellow transition of other Detehit biosensors. The newly designed biosensor allows the users to visually detect (with the naked eye) the presence of the most significant paralytic substances (sarin, soman, cyclosarin, tabun, VX) in water at concentrations of at least 0.001 μg/mL. This biosensor design also enables one to detect these substances in air or on contaminated surfaces.

• Publication type
• Journal Article MeSH

Lipases are enzymes responsible for the conversion of triglycerides and other esterified substrates, they are involved in the basic metabolism of a wide number of organisms, from a simple microorganism and to mammals. They also have broad applicability in many fields from which industrial biotechnology, the production of cleaning agents, and pharmacy are the most important. The use of lipases in analytical chemistry where it can serve as a part of biosensors or bioassays is an application of growing interest and has become another important use. This review is focused on the description of lipases chemistry, their current applications and the methods for their assay measurement. Examples of bioassays and biosensors, including their physical and chemical principles, performance for specific substrates, and discussion of their relevance, are given in this work.

• Keywords
• amperometry, bioassay, biorecognition, biosensor, catalysis, enzyme, ester, lipase, nanoparticle, nanostructure, potentiometry, voltammetry,
• MeSH
• Enzyme Activation MeSH
• Biosensing Techniques methods   standards   MeSH
• Biological Assay methods   standards   MeSH
• Electrochemical Techniques MeSH
• Hydrolysis MeSH
• Catalysis MeSH
• Lipase chemistry   metabolism   MeSH
• Publication type
• Journal Article MeSH
• Review MeSH
• Names of Substances
• Lipase MeSH

Acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) are two enzymes sensitive to various chemical compounds having ability to bind to crucial parts of these enzymes. Boldine is a natural alkaloid and it was mentioned in some older works that it can inhibit some kinds of AChE. We reinvestigated this effect on AChE and also on BChE using acetyl (butyryl) thiocholine and Ellman's reagents as standard substances for spectrophotometric assay. We found out IC50 of AChE equal to 372 μmol/l and a similar level to BChE, 321 μmol/l. We conclude our experiment by a finding that boldine is cholinesterase inhibitor; however we report significantly weaker inhibition than that suggested in literature. Likewise, we tried to investigate the mechanism of inhibition and completed it with in silico study. Potential toxic effect on cholinesterases in real conditions is also discussed.

• MeSH
• Acetylcholinesterase metabolism   MeSH
• Aporphines chemistry   pharmacology   MeSH
• Butyrylcholinesterase chemistry   metabolism   MeSH
• Cholinesterase Inhibitors chemistry   pharmacology   MeSH
• HEK293 Cells MeSH
• Humans MeSH
• Models, Molecular MeSH
• Secondary Metabolism * MeSH
• Substrate Specificity drug effects   MeSH
• Check Tag
• Humans MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Acetylcholinesterase MeSH
• Aporphines MeSH
• boldine MeSH Browser
• Butyrylcholinesterase MeSH
• Cholinesterase Inhibitors MeSH

Biperiden is a drug used in Parkinson disease treatment and it serves also as an antiseizures compound in organophosphates poisoning. It acts as antagonist of muscarinic receptor activated by acetylcholine while the enzyme acetylcholinesterase (AChE) cleaves acetylcholine in synaptic junction into choline and acetic acid. This enzyme is inhibited by various compounds; however there has not been proposed evidence about interaction with biperiden molecule. We investigated this interaction using standard Ellman's assay and experimental findings were critically completed with an in silico prediction by SwissDock docking software. Uncompetitive mechanism of action was revealed from Dixon plot and inhibition constant (Ki ) was calculated to be 1.11 mmol/l. The lowest predicted binding energy was -7.84 kcal/mol corresponding to H-bond between biperiden molecule and Tyr 341 residuum in protein structure of AChE. This interaction seems to be further stabilized by π-π interaction with Tyr 72, Trp 286, and Tyr 341. In conclusion, biperiden appears as a very weak inhibitor but it can serve as a lead structure in a pharmacological research.

• MeSH
• Acetylcholinesterase metabolism   MeSH
• Biperiden chemistry   pharmacology   therapeutic use   MeSH
• Cholinesterase Inhibitors chemistry   pharmacology   therapeutic use   MeSH
• Enzyme Assays MeSH
• Humans MeSH
• Models, Molecular MeSH
• Parkinson Disease drug therapy   enzymology   MeSH
• Substrate Specificity drug effects   MeSH
• Check Tag
• Humans MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Acetylcholinesterase MeSH
• Biperiden MeSH
• Cholinesterase Inhibitors MeSH

Magnetic particles (MPs) have been widely used in biological applications in recent years as a carrier for various molecules. Their big advantage is in repeated use of immobilized molecules including enzymes. Acetylcholinesterase (AChE) is an enzyme playing crucial role in neurotransmission and the enzyme is targeted by various molecules like Alzheimer's drugs, pesticides and warfare agents. In this work, an electrochemical biosensor having AChE immobilized onto MPs and stabilized through glutaraldehyde (GA) molecule was proposed for assay of the neurotoxic compounds. The prepared nanoparticles were modified by pure AChE and they were used for the measurement anti-Alzheimer's drug galantamine and carbamate pesticide carbofuran with limit of detection 1.5 µM and 20 nM, respectively. All measurements were carried out using screen-printed sensor with carbon working, silver reference, and carbon auxiliary electrode. Standard Ellman's assay was used for validation measurement of both inhibitors. Part of this work was the elimination of reversible inhibitors represented by galantamine from the active site of AChE. For this purpose, we used a lower pH to get the original activity of AChE after inhibition by galantamine. We also observed decarbamylation of the AChE-carbofuran adduct. Influence of organic solvents to AChE as well as repeatability of measurement with MPs with AChE was also established.

• Keywords
• acetylcholinesterase, carbofuran, electrochemistry, galantamine, magnetic particles, nanomaterial, nanoparticles, screen-printed sensor,
• MeSH
• Acetylcholinesterase MeSH
• Biosensing Techniques MeSH
• Cholinesterase Inhibitors MeSH
• Enzymes, Immobilized MeSH
• Nanoparticles * MeSH
• Organophosphorus Compounds MeSH
• Pesticides MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Acetylcholinesterase MeSH
• Cholinesterase Inhibitors MeSH
• Enzymes, Immobilized MeSH
• Organophosphorus Compounds MeSH
• Pesticides MeSH

Smartphones are widely spread and their usage does not require any trained personnel. Recently, smartphones were successfully used in analytical chemistry as a simple detection tool in some applications. This paper focuses on immobilization of acetylcholinesterase (AChE) onto commercially available pH strips with stabilization in the gelatin membrane. AChE degrades acetylcholine into choline and acetic acid which causes color change of acid-base indicator. Smartphone served as a tool for measurement of indicator color change from red to orange while inhibitors blocked this process. AChE inhibitors were measured with limits of detection, 149 nM and 22.3 nM for galanthamine and donepezil, respectively. Organic solvents were measured for method interferences. Measurement procedure was performed on 3D printed holder and digital photography was evaluated using red-green-blue (RGB) channels. The invented assay was validated to the standard Ellman's test and verified on murine plasma samples spiked with inhibitors. We consider that the assay is fully suitable for practical performance.

• Publication type
• Journal Article MeSH