Selective Acetylcholinesterase Inhibitor Research Articles

LC-MS and GC-MS Analyses on Green Algae Penicillus Capitatus: Cytotoxic, Antimicrobial and Anticholinesterase Activity Screening Enhanced by Molecular Docking & Dynamics and ADME Studies.

In this comprehensive screening study, the chemical composition, and cytotoxic, antimicrobial, and anticholinergic activities of the green algae Penicillus capitatus, collected from Antalya-Türkiye, were determined as in vitro and in silico. GC-MS analysis of the hexane extract revealed a high content of fatty acids, with hexadecanoic acid constituting half of the total fatty acid content. LC-HRMS analysis of the DCM:MeOH extract identified ascorbic acid as the most abundant compound, followed by (-)-epigallocatechin and salicylic acid. The DCM:MeOH extract exhibited potent cytotoxicity against MDA-MB-231 and MCF7 breast cancer cell lines, outperforming doxorubicin with lower IC50 values and a higher selectivity index. Additionally, the extract demonstrated significant antimicrobial activity against Staphylococcus aureus, Escherichia coli, and Candida albicans, along with selective inhibition of acetylcholinesterase (hAChE) over butyrylcholinesterase (hBChE). Molecular docking and dynamics studies revealed that apigenin-7-O-glucoside and epigallocatechin form stable interactions with estrogen receptor alpha (ERα) and hAChE, suggesting their potential as inhibitors. In silico ADME studies indicated favorable pharmacokinetic profiles for the detected compounds, supporting their potential as drug candidates. The promising cytotoxic activity of the P. capitatus extracts, coupled with significant antimicrobial properties and selective hAChE inhibition, highlights their therapeutic potential for breast cancer treatment, infection management, and neurodegenerative disease intervention.

Design, Synthesis, and Evaluation of New Pyrazolines As Small Molecule Inhibitors of Acetylcholinesterase.

In pursuit of identifying small molecule inhibitors of acetylcholinesterase (AChE), the synthesis of new 2-pyrazolines was performed efficiently. A modified spectrophotometric method was used to examine their inhibitory effects on AChE as well as butyrylcholinesterase. Four compounds (2a, 2g, 2j, and 2l) were identified as selective AChE inhibitors. Molecular docking studies were conducted to explore their potential interactions with the active site of AChE (PDB code: 4EY7). 1-(3-Nitrophenyl)-3-(thiophen-3-yl)-5-[4-(4-morpholinyl)phenyl]-2-pyrazoline (2l) exerted significant AChE inhibitory action with an IC50 value of 0.040 μM close to donepezil (IC50 = 0.021 μM). In addition to π-π interactions with Tyr341, Tyr124, and Trp86 residues, compound 2l was also capable of forming two hydrogen bonds and a salt bridge at the active site of AChE thanks to its nitro group at the meta position of the phenyl moiety linked to the N 1 position of the pyrazoline scaffold. The higher inhibitory effect of compound 2l on AChE when compared to other compounds in this series might be explained by these additional interactions. Based on the in vitro parallel artificial membrane permeability assay, compound 2l was found to have high blood-brain barrier permeability. In vitro and in silico studies suggest that compound 2l is a potent inhibitor of AChE, which is an important target for neurodegenerative disorders, particularly Alzheimer's disease.

Design of Promising Thiazoloindazole-Based Acetylcholinesterase Inhibitors Guided by Molecular Docking and Experimental Insights.

Alzheimer's disease is characterized by a progressive deterioration of cognitive function and memory loss, and it is closely associated with the dysregulation of cholinergic neurotransmission. Since acetylcholinesterase (AChE) is a critical enzyme in the nervous system, responsible for breaking down the neurotransmitter acetylcholine, its inhibition holds a significant interest in the treatment of various neurological disorders. Therefore, it is crucial to develop efficient AChE inhibitors capable of increasing acetylcholine levels, ultimately leading to improved cholinergic neurotransmission. The results reported here represent a step forward in the development of novel thiazoloindazole-based compounds that have the potential to serve as effective AChE inhibitors. Molecular docking studies revealed that certain of the evaluated nitroindazole-based compounds outperformed donepezil, a well-known AChE inhibitor used in Alzheimer's disease treatment. Sustained by these findings, two series of compounds were synthesized. One series included a triazole moiety (Tl45a-c), while the other incorporated a carbazole moiety (Tl58a-c). These compounds were isolated in yields ranging from 66 to 87% through nucleophilic substitution and Cu(I)-catalyzed azide-alkyne 1,3-dipolar cycloaddition (CuAAC) reactions. Among the synthesized compounds, the thiazoloindazole-based 6b core derivatives emerged as selective AChE inhibitors, exhibiting remarkable IC50 values of less than 1.0 μM. Notably, derivative Tl45b displays superior performance as an AChE inhibitor, boasting the lowest IC50 (0.071 ± 0.014 μM). Structure-activity relationship (SAR) analysis indicated that derivatives containing the bis(trifluoromethyl)phenyl-triazolyl group demonstrated the most promising activity against AChE, when compared to more rigid substituents such as carbazolyl moiety. The combination of molecular docking and experimental synthesis provides a suitable and promising strategy for the development of new efficient thiazoloindazole-based AChE inhibitors.

Design, synthesis, and biological evaluation of novel tryptanthrin derivatives as selective acetylcholinesterase inhibitors for the treatment of Alzheimer's disease

Two novel series of tryptanthrin (TRYP) derivatives were designed and synthesized as multifunctional agents for the treatment of Alzheimer’s disease (AD). Inhibition assay against cholinesterase (ChE) indicated that these derivatives can act as acetylcholinesterase (AChE) inhibitors with selectivity over butyrylcholinesterase (BuChE). Among them, n1 exhibited the most excellent ChE inhibitory potency (AChE, IC50 = 12.17 ± 1.50 nM; BuChE, IC50 = 6.29 ± 0.48 μΜ; selectivity index = 517). Molecular docking studies indicated that compound n1 can interact with amino acid residues in the catalytic active site and peripheral anionic site of AChE and the molecular dynamics (MD) simulation studies demonstrated that the AChE–n1 complex had good stability. N1 also exhibited anti-amyloid-β (Aβ) aggregation (63.48 % ± 1.02 %, 100 μΜ) and anti-neuroinflammation activity (NO, IL-1β, TNF-α; IC50 = 2.13 ± 0.54 μΜ, 2.21 ± 0.37 μΜ, 2.47 ± 0.07 μΜ, respectively), and n1 had neuroprotective and metal-chelating properties. Further studies indicated n1 had proper blood–brain barrier permeability in the Parallel artificial membrane permeation assay. In vivo studies found that n1 effectively improved learning and memory impairment in scopolamine-induced AD mouse models. Nissl staining ofmice hippocampaltissue sections revealed that n1 restored neuronal cells in the hippocampus CA3 and CA1 regions. These findings suggested that n1 can be a promising compound for further development of multifunctional agents for AD treatment.

Structurally diverse brefeldin A derivatives as potent and selective acetylcholinesterase inhibitors from an endophytic fungus Penicillium brefeldianum F4a

Nine previously undescribed brefeldin A (BFA) derivatives (1–9), together with one known compound 4-epi-brefeldin A (10), were isolated from an endophytic fungus Penicillium brefeldianum F4a. The chemical structures were elucidated using NMR and HRESIMS. ECD analysis and Mosher's method were used to confirm the absolute configurations of 1–9. The inhibitory activity of all isolated BFA derivatives (1–10) on acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) was evaluated in vitro. The bioassay results suggested that neobrefeldin (1) and brefeldin H (2) exhibited higher potent and selective AChE inhibitory activity (IC50 = 0.12 and 0.28 μM) than the therapeutic drug galantamine for Alzheimer's disease (AD) (IC50 = 0.66 µM), whereas only neobrefeldin (1) displayed weak inhibitory activity against BuChE (IC50 = 175.04 µM). Moreover, a molecular docking analyses was performed and showed compounds 1 and 2 were dual binding site AChE inhibitors. It is worth noting that neobrefeldin (1) showed a better binding affinity with the peripheral anionic site through the hydrogen bonding interaction with Tyr124 than brefeldin H (2), resulting in better AChE inhibitory activity. These findings not only provide a promising AChE inhibitor neobrefeldin (1) for developing agents against early AD, but also provide a valuable perspective for better understanding its AChE inhibition activity.

2-Oxoquinoline-based-thiosemicarbazones as multitargeting neurotherapeutics against Alzheimer's disease: In vitro and in silico studies of MAO and ChE inhibitors.

Alzheimer's disease (AD) presents a multifactorial neurological disorder with multiple enzyme involvement in its onset. Conventional monotherapies fall short in providing long-term relief, necessitating the exploration of alternative multitargeting approaches to address the complexity of AD. Therefore, the design, synthesis, and in vitro and in silico evaluation of 2-oxoquinoline-based thiosemicarbazones 9a-r as multipotent analogs, able to simultaneously inhibit the cholinesterase (ChE) and monoamine oxidase (MAO) enzymes for the potential treatment of AD, are reported. In the in vitro experimental evaluation of MAO and ChE inhibition, all tested compounds demonstrated remarkable potency exhibiting nonselective inhibition of both MAO-A and MAO-B, and selective inhibition of acetylcholinesterase (AChE) over butyrylcholinesterase (BChE), with 9d, 9j, and 9m evolving as lead compounds for MAO-A, MAO-B, and AChE, displaying IC50 values of 0.35 ± 0.92, 0.50 ± 0.02, and 0.25 ± 0.13 μM, respectively. Moreover, the kinetic studies revealed that all tested compounds inhibited all three enzymes through a competitive mode of inhibition. Furthermore, the molecular docking studies of the most active compounds revealed several crucial interactions, particularly hydrogen bonding interactions. These interactions were observed between the nitrogen and sulfur atoms of thiosemicarbazone and the nitrogen and oxygen atoms of the quinoline ring with various amino acids, suggesting the strong interactions of these compounds with the enzymes.

In-vitro anti-diabetic, anti-Alzheimer, anti-tyrosinase, antioxidant activities of selected coumarin and dihydroisocoumarin derivatives

Benzo-α-pyrone structured coumarin derivatives are secondary metabolites first obtained from Coumarouna odorata in 1822. Coumarin and its structural isomer dihydroisocoumarin derivatives are found in many different sources in nature. Several different bioactivities of these compounds have been reported. In this study, preliminary activity screening and comparison of four purchased coumarin derivatives (esculetin, esculin monohydrate, umbelliferon, scoparone) and four previously isolated 3-phenyl-3,4-dihydroisocoumarin derivatives (thunberginol C, scorzocreticoside I, scorzocreticoside II, scorzopygmaecoside) from a medicinal plant were carried out by in-vitro methods. α-Glucosidase, acetylcholinesterase, butyrylcholinesterase, tyrosinase inhibitor activities and antioxidant potentials of the compounds were evaluated. Consequently, thunberginol C (free – not glycosylated form of 3,4-dihydroisocoumarin structure) showed better potential in all enzyme inhibitory activities compared to coumarin structure. Particularly, α-glucosidase inhibitory activity of this compound with a very low IC50 value (94.76±2.98 µM) compared to standard acarbose (1036.2±2.70 µM) should be noted. Glycosylation and/or methoxy substitution of 3,4-dihydroisocoumarin structure resulted a significant decrease in all tested enzyme inhibitory activities. The structures of esculin MH, umbelliferone, scoparone, scorzocreticoside I, and scorzopygmaeceoside might be considered in further synthetic studies as selective acetylcholinesterase inhibitors. Thunberginol C has a promising potential in tyrosinase inhibitory activity. Esculetin and thunberginol C showed the best results with high potentials in antioxidant activity via 2,2-diphenyl-1-picryl-hydrazyl-hydrate free radical scavenging, 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid cation radical decolorization, and cupric ion reducing antioxidant capacity assays compared to the standards.

Synthesis andin vitro assessment of anticholinesterase andantioxidant properties of triazineamide derivatives.

Aim: Cholinesterase inhibitors and radical scavengers have been recognized as powerful symptomatic anti-Alzheimer's disease agents. Hence, the present study aimed to develop new triazineamides as potent anticholinesterase and antioxidant agents. Methods: Triazineamide (7a-i) derivatives were synthesized using cyanuric chloride via nucleophilic substitution followed by condensation. Ellman assay, 2,2-azinobis(3-ethylbenzthiazoline-6-sulfonic acid) radical scavenging assay and molecular docking studies with Autodock 4.2.3 program were conducted. Results: Triazineamide 7c was assessed as a potent, selective and mixed-type dual inhibitor of acetylcholinesterase, with and IC50 of 5.306±0.002μM, by binding simultaneously with the catalytic active and peripheral anionic sites of acetylcholinesterase, and it had strong 2,2-azinobis(3-ethylbenzthiazoline-6-sulfonic acid) radical scavenging abilities. Conclusion: These results suggest that triazineamides may be of interest to establish a structural basis for new anti-Alzheimer's disease agents.

New acetylcholinesterase inhibitors isolated from Delphinium uncinatum

The inhibition of acetylcholinesterase (AChE), the key enzyme in the breakdown of acetylcholine, is presently the most common pharmacological approach available for Alzheimer’s disease (AD). Despite research on the molecular bases of AD, potent therapeutic agent against its expansion is still needed. In searching for natural cholinesterase inhibitors, the present study was focused on the isolation of three new norditerpenoid alkaloids, uncinatine B-D together with known virescenine from Delphinium uncinatum. Chemical structures for all the isolated norditerpenoids (1–4) were established using latest spectroscopic techniques. The isolated undescribed compounds along with known virescenine were testified for their acetylcholinesterase inhibitory activity supported by docking analyses. Molecular docking simulation showed that the isolated compounds (1–4) were observed to adhered in the active site of AChE with docking scores − 13.5322 (1), −11.8173 (2), −12.4240 (3) and − 8.9352 (4) respectively. Overall results demonstrated that these natural norditerpenoids compounds were found as selective inhibitors of AChE. This is the first report regarding the use of bioactive ingredients of Delphinium uncinatum in testing against Alzheimer's disease.

Spiroisoxazoline Inhibitors of Acetylcholinesterase from Pseudoceratina verrucosa. Quantitative Chiroptical Analysis of Configurational Heterogeneity, and Total Synthesis of (±)-Methyl Purpuroceratate C.

Examination of the MeOH extract of the sponge, Pseudoceratina cf. verrucosa, Berquist 1995 collected near Ningaloo Reef, Western Australia for selective acetylcholinesterase (AChE) inhibitors, yielded five new bromotyrosine alkaloids, methyl purpuroceratates A and B (1b and 2b), purpuroceratic acid C (3a), and ningalamides A and B (4 and 5). The structures of 1-4 share the dibromo-spirocyclohexadienyl-isoxazoline (SIO) ring system found in purealidin-R, while ketoxime 5 is analogous to ianthelline and purpurealidin I. The planar structures of all five compounds were obtained from analysis of MS, 1D and 2D NMR data, and the absolute configuration of the spiroisoxazoline (SIO) unit was assigned by electronic circular dichroism (ECD) and comparison with standards prepared by total synthesis of methyl purpuroceratate C, (±)-3b. Compound 4 is the most complex SIO described, to date. The configuration of the homoserine module (C) in 4 was ascertained, after acid hydrolysis, by derivatization of an l-tryptophanamide derivative based on Marfey's reagent. Chiral-phase HPLC, with comparison to synthetic standards, revealed that most SIOs isolated from P. cf. verrucosa were configurationally heterogeneous; some, essentially racemic. Chiral-phase HPLC, with UV-ECD detection, is demonstrated as a superlative method for configurational assignment and quantitation of the enantiomeric composition of SIOs. Two SIOs─aerophobin-1 and aplysinamisine II─emerged as selective inhibitors of AChE over butyrylcholinesterase (BuChE, IC50 ratio >10), while aplysamine-2 moderately inhibited both cholinesterases (ChEs, IC50, (AChE) 0.46 μM; IC50, (BuChE) 1.03 μM). SIO alkaloids represent a potential new structural manifold for lead-discovery of new therapeutics for treatment of Alzheimer's disease.

Design, synthesis, in silico and biological evaluations of novel polysubstituted pyrroles as selective acetylcholinesterase inhibitors against Alzheimer’s disease

The objective of this study was to design new polysubstituted pyrrole derivatives as selective acetylcholinesterase (AChE) inhibitors to target Alzheimer's disease. In this context, a highly efficient, one-pot, sequential, multi-component synthesis of a diverse range of polysubstituted pyrroles was developed through a sequential domino strategy by the condensation of amines with 1,1-bis(methylthio)-2-nitroethene (BMTNE), Knovenagle reaction of arylglyoxals with malono derivatives and subsequent Michael addition and intramolecular cyclization reaction in EtOH at reflux. Thirty-nine synthesized compounds were evaluated as AChE and butyrylcholinesterase (BChE) inhibitors. Among the synthesized compounds, compound 4ad (IC50 = 2.95 ± 1.31 µM) was the most potent and selective AChE inhibitor with no significant inhibition against butyrylcholinesterase BChE. A kinetic study of 4ad revealed that this compound inhibited AChE in an uncompetitive mode. Based on a molecular modeling study, compound 4ad due to its small size properly fitted into the active site of AChE compared to BChE and stabilized by H-bond and hydrophobic interactions with the critical residues of the AChE binding pocket. Consequently, it was proposed that the 4ad derivative can be an ideal lead candidate against AD with a simple and practical operation of synthetic procedures.

Synthesis, anticholinesterase activity, molecular docking, and molecular dynamic simulation studies of 1,3,4-oxadiazole derivatives.

Two new series of 1,3,4-oxadiazoles bearing pyridine and thiazole heterocycles (4a-h and 5a-h) were synthesized (2,5-disubstituted-1,3,4-oxadiazoles). The structures of these newly synthesized compounds were confirmed by 1 H nuclear magnetic resonance (NMR), 13 C NMR, high-resolution mass spectrometric and Fourier transform infrared spectroscopic methods. All these compounds were evaluated for their enzyme inhibitory activities against two cholinesterase enzymes, acetylcholinesterase (AChE) and butyrylcholinesterase (BChE). From the studies, we identified compounds 4a, 4h, 5a, 5d, and 5e as selective AChE inhibitors, with IC50 values ranging from 0.023 to 0.037 μM. Furthermore, docking studies of these compounds were performed at the active sites of their target enzymes. The molecular docking study showed that 5e possessed an ideal docking pose with interactions inside AChE.

Synthesis and Exploitation of the Biological Profile of Novel Guanidino Xylofuranose Derivatives.

The synthesis and biological evaluation of novel guanidino sugars as isonucleoside analogs is described. 5-Guanidino xylofuranoses containing 3-O-saturated/unsaturated hydrocarbon or aromatic-containing moieties were accessed from 5-azido xylofuranoses via reduction followed by guanidinylation with N,N'-bis(tert-butoxycarbonyl)-N''-triflylguanidine. Molecules comprising novel types of isonucleosidic structures including 5-guanidino 3-O-methyl-branched N-benzyltriazole isonucleosides and a guanidinomethyltriazole 3'-O-dodecyl xylofuranos-5'-yl isonucleoside were accessed. The guanidinomethyltriazole derivative and a 3-O-dodecyl (N-Boc)guanidino xylofuranose were revealed as selective inhibitors of acetylcholinesterase (Ki =22.87 and 7.49 μM, respectively). The latter also showed moderate antiproliferative effects in chronic myeloid leukemia (K562) and breast cancer (MCF-7) cells. An aminomethyltriazole 5'-isonucleoside was the most potent molecule with low micromolar GI50 values in both cells (GI50 =6.33 μM, 8.45 μM), similar to that of the drug 5-fluorouracil in MCF-7 cells. Moreover, the most bioactive compounds showed low toxicity in human fibroblasts, further indicating their interest as promising lead molecules.

Structure-based design of novel donepezil-like hybrids for a multi-target approach to the therapy of Alzheimer's disease

Alzheimer's disease (AD) is a widespread multifactorial aging-related pathology, which includes cholinergic deficit among its main causes. Following a multi-target design strategy, the structure of the approved drug donepezil was taken as the starting point for generating some new potential multi-functional compounds. Therefore, a series of twenty molecular hybrids were synthesized and assayed against three different enzymes, namely the well-established targets acetylcholinesterase (AChE) and butyrylcholinesterase (BChE), and the innovative one fatty acid amide hydrolase (FAAH). In silico studies confirmed the interaction of benzylpiperidine and the benzylpiperazine isostere with the catalytic anionic site (CAS) of AChE, while the aryloxycarbonyl portion appeared to be important for the interaction with the peripheral site (PAS). A QSAR study was carried out on AChE inhibition data, which revealed that the inhibition potency seems to depend upon the length of the spacer and the number of polar atoms. The docking poses of selected compounds within BChE and FAAH were also calculated. Furthermore, pharmacokinetics and drug-likeness properties were assessed by chemoinformatic tools. Several piperidine derivatives (in particular compound 10) showed interesting profiles as multi-target directed agents, while the lead piperazine derivative 12 (SON38) was found to be a more potent and selective AChE inhibitor (IC50 = 0.8 nM) than donepezil, besides being able to bind bivalent copper cations (pCu = 7.9 at physiological pH). Finally, the selected lead compounds (10 and 12, SON38) did not show significant cytotoxicity on SH-SY5Y and HepG2 cells at the highest tested concentration (100 μM) in a MTT assay.

Development of 5-hydroxyl-1-azabenzanthrone derivatives as dual binding site and selective acetylcholinesterase inhibitors

A series of novel 5-hydroxyl-1-azabenzanthrone derivatives were designed, synthesized and evaluated as dual binding site acetylcholinesterase inhibitors for the treatment of Alzheimer's disease (AD). The most effective Compound 16 showed selective inhibition of acetylcholinesterase (eeAChE IC50 = 0.045 μM; eeBuChE IC50 = 19.68 μM; SI = 437.33). Most of the compounds showed cytoprotective effects on PC12 cells damaged by hydrogen peroxide, which might be related to their antioxidant activity. Further experiments confirmed that 16 exhibited anti-apoptotic effects at low concentrations and reduced the relative level of ROS generation in PC12 cells. The expression level of proteins related to antioxidant stress pathway in PC12 cells was relatively increased after administrated with 16, which may be beneficial to delay the progression of the disease. Moreover, 16 was evaluated to be safe in vivo and in vitro, and showed good overall pharmacokinetic performance and high bioavailability (Foral = 55.5%). Besides, 16 showed comparable performance in ameliorating the scopolamine-induced cognition impairment to donepezil. In addition, in vitro BBB permeability experiments confirmed that 16 had high BBB permeability.

Pharmacokinetics of HupA-PLGA-NPs of different sizes in the mouse blood and brain determined by LC-MS/MS.

Huperzine A, which was extracted from a Chinese herb, is a reversible and selective inhibitor of acetylcholinesterase (AChE), which is used as an anti-Alzheimer's drug that exerts evident pretreatment effects against exposure to organophosphate chemical warfare agents or pesticides. The aims of this study were to establish an LC-MS/MS method for the detection of HupA in biological samples and to investigate the pharmacokinetics of HupA polylactic-co-glycolic acid nanoparticles (HupA-PLGA-NPs) with different diameters in mice. The proposed LC-MS/MS method was established by optimizing the MS conditions and validating the specificity, linear range, lower limit, precision, accuracy, matrix effects, absolute recovery, and sample stability of the method. ICR mice were divided into three treatment groups: the HupA control group, the 46.4-nm HupA-PLGA-NP group and the 208.5-nm HupA-PLGA-NP group. All the mice in the three groups were administered 0.5 mg/kg HupA via the tail vein. The pharmacokinetic parameters in plasma and the brain were detected by LC-MS/MS. Pharmacokinetic parameters were analyzed using PKS pharmacokinetic software, and the relative bioavailability and brain-targeted drug targeting efficiency (DTE) were also calculated. The distributions of HupA-PLGA-NP groups showed marked changes compared with that of HupA in mice in vivo, and the particle size of nanodrugs exerted a significant effect on the pharmacokinetic parameters in mice. The half-life (T1/2) values in plasma of the 46.4- and 208.5-nm HupA-PLGA-NPs were 1.53- and 1.96-fold longer than that of the HupA at the same dose. The bioavailabilities of the two nanoparticles were 1.93- and 2.19-fold higher than that of HupA, respectively. In the brain, the Tmax values of the two HupA-PLGA-NPs of different sizes was 1.25 h, which was clearly longer than that of HupA (0.5 h), and the corresponding T1/2 values were 12.53 h and 8.47 h, which were 1.82- and 1.23-fold higher than that of HupA (6.89 h). In addition, the brain targeting index of the 46.40-nm HupA-PLGA-NPs was 1.48, which revealed an evident brain-targeting effect. The LC-MS/MS method has the advantages of good specificity, high sensitivity and needing a low sample amount and is economical and particularly suitable for determining the drug content in plasma and brain samples. The NP size is associated with the distribution patterns of nanodrugs. Therefore, a particular NP size can be selected to maximize the pharmacodynamics effects and control the toxicity of nanodrugs.

Synthesis of Sulfanoquinoxaline-2,3-Dione Hydrazones Derivatives as a Selective Inhibitor for Acetylcholinesterase and Butyryl Cholinesterase

Some Sulfanoquinoxaline-2,3-diones hydrazone derivatives (1-8) were synthesized from the reactions of 2,3-dioxoquinoxaline-6-sulfonohydrazine with seven substituted benzaldehydes and acetophenone. All the synthesized compounds were biologically evaluated against cholinesterase’s (acetylcholinesterase and butyryl cholinesterase). Compounds 1-8 were found to be a good selective inhibitor for acetylcholinesterase and butyryl cholinesterase. Among the series, compounds 3 (IC50 = 75 ± 10 µg/mL) and 5 (IC50 = 80 ± 10 µg/mL) were found to be the most active inhibitors against acetylcholinesterase, while compounds 6 (IC50 = 110 ± 10 µg/mL), 8 (IC50 = 130 ± 10 µg/mL) and 7 (IC50 = 150 ± 10 µg/mL), were found to be most active inhibitor against butyryl cholinesterase. The IC50 values for all the synthesized compounds were lower than standard, eserine (IC50 = 70 ± 20 µg/mL). Their considerable acetylcholinesterase and butyryl cholinesterase inhibitory activities make them a good candidate for the development of selective acetylcholinesterase and butyryl cholinesterase inhibitors.

Synthesis of Some Phenylisoindoline-1,3-Diones and their Acetylcholinesterase and Butyryl Cholinesterase Inhibitory Activities

Aims: To synthesize some phthalimides derivatives and evaluate the compounds for their possible biological properties.
 Methods: The substituted phenylisoindoline-1,3-dione were synthesized from the reactions of N-phenyl phthalimide with different substituted aromatic aldehyde. The synthesized compounds were characterized using nuclear magnetic resonance spectroscopic analysis. The acetylcholinesterase and butyryl cholinesterase inhibitions were determined by Spectro photochemical analysis of acetylthiocholine and butyryl choline chloride.
 Results: Compounds 6 (IC50 = 30±3 µg/mL) and 4 (IC50 = 141±60 µg/mL) were found to be the most active inhibitors against acetylcholinesterase, while compounds 4 (IC50 = 102±10 µg/mL), 5 (IC50 = 105 ± 20 µg/mL) and 2 (IC50 = 190 ± 10 µg/mL), were found to be most active inhibitor against butyryl cholinesterase.
 Conclusion: The considerable acetylcholinesterase and butyryl cholinesterase inhibitory activities of the synthesized compounds makes them good candidates for the development of selective acetylcholinesterase and butyryl cholinesterase inhibitors.

Diversity of Endophytic Fungi in Huperzia serrata and Their Acetylcholinesterase Inhibitory Activity

Huperzia serrata is a Huperzine A (HupA)-producing herb. HupA is a potent, reversible, highly specific, centrally active and selective acetylcholinesterase inhibitor, and is commonly used to improve Alzheimer’s disease.At present, H. serrata resources have been overexploited and their artificial cultivation has lagged behind the need, so the market demand cannot be met. In this study, the diversity of the endophytic fungi in H. serrata was studied by high-throughput sequencing and traditional culture methods. Furthermore, the ability of the isolated endophytic fungi to produce acetylcholinesterase-inhibiting activity was evaluated. The results related to the diversity of fungi between high-throughput sequencing and traditional culture methods were compared. With high-throughput sequencing, five phyla, 22 classes, 55 orders, 120 families, and 178 genera of fungi were detected in Hubei Province, and five phyla, 22 classes, 54 orders, 124 families, and 196 genera were detected in Fujian Province. After cultivation with traditional culture methods, two phyla, three classes, five orders, six families, and six genera were detected in Hubei, and one phylum, three classes, five orders, five families, and six genera in Fujian. The endophytic fungi of H. serrata are highly diverse, and the results of high-throughput sequencing comprehensively reflect their community compositions. When the acetylcholinesterase-inhibiting activity of the isolated and cultured endophytic fungi was determined, five and three endophytic fungi from Hubei and Fujian Provinces, respectively, had good inhibitory activity (inhibition rate > 50%). Most of them were separated from leaf tissue. The strain HBR-1 and strain FJL-5 had the strongest inhibitory effects on AChE, with inhibition rates of 72.34% and 60.54%, respectively. Although only a proportion of the endophytic fungi was isolated with traditional culture methods, metabolites with broad potential applications can be isolated from these fungal cultures. The combination of high-throughput sequencing and traditional culture methods can be used to isolate and purify endophytic fungi in a targeted manner, gain many endophytic fungi, and enrich the endophytic fungi resource library.

Desorption electrospray ionization (DESI) source coupling ion mobility mass spectrometry for imaging fluoropezil (DC20) distribution in rat brain.

Fluoropezil (DC20) is a new selective acetylcholinesterase inhibitor, and it was developed for the treatment of Alzheimer's disease patients. In this study, a desorption electrospray ionization source coupling ion mobility mass spectrometry imaging (DESI/IMS-MSI) method was developed to explore the distribution of DC20 in brain tissue following oral administration. Rat brain coronal slices obtained 1 h and 3 h following drug dosing were used in the study. D6-DC20 was used as internal standard and sprayed by matrix sprayer on the brain slices to calibrate the matrix effect. Ion mobility separation was used to reduce the interference from background noise and the biological matrix. By optimizing DESI-MSI parameters for improved sensitivity, the limit of quantitation of the method was 1.45 pg/mm2 with a linear range from 1.45 to 72.7 pg/mm2. DESI-MSI data showed that DC20 could quickly enter and diffuse across whole brain and tended to be much more enriched in striatum than cerebral cortex and hippocampus, which was consistent with quantitative analysis using high-performance liquid chromatography-electrospray tandem mass spectrometry to measure DC20 concentration in each homogenized brain sub-region. The workflow of tissue imaging method optimization and strategy were established, and for the first time, the DESI-MSI technique and optimized method were used to explore the distribution characteristics of DC20 in rat brain, which could help elucidate pharmacological effect mechanisms and improve clinical outcomes.