Composition and Anti-Acetylcholinesterase Properties of the Essential Oil of the Ecuadorian Endemic Species Eugenia valvata McVaugh.

Alzheimer's disease is a global health problem due to the scarcity of acetylcholinesterase inhibitors, the basis for symptomatic treatment of this disease; this requires new approaches to drug discovery. In this study, we investigated the chemical composition and anticholinesterase activity of Eugenia valvata McVaugt (Myrtaceae) collected in southern Ecuador, which was obtained as an essential oil (EO) with a yield of 0.124 ± 0.03% (w/w); as a result of the chemical composition analysis, a total of 58 organic compounds were identified-representing 95.91% of the total volatile compounds-using a stationary phase based on 5% phenyl-methylpolysiloxane, as analyzed via gas chromatography coupled to mass spectrometry (GC-MS) and flame ionization detection (GC-FID). The main groups were hydrocarbon sesquiterpenes (37.43%), oxygenated sesquiterpenes (31.08%), hydrocarbon monoterpenes (24.14%), oxygenated monoterpenes (0.20%), and other compounds (3.058%). Samples were characterized by the following compounds: α-pinene (22.70%), α-humulene (17.20%), (E)-caryophyllene (6.02%), citronellyl pentanoate (5.76%), 7-epi-α-eudesmol (4.34%) and 5-iso-cedranol (3.64%); this research was complemented with an enantioselective analysis carried out using 2,3-diethyl-6-tert-butyldimethylsilyl-ß-cyclodextrin as a stationary phase chiral selector. As a result, α-pinene, limonene, and α-cadinene enantiomers were identified; finally, in the search for new active principles, the EO reported strong anticholinesterase activity with an IC50 of 53.08 ± 1.13 µg/mL, making it a promising candidate for future studies of Alzheimer's disease.

Efficient Combination of Complex Chromatography, Molecular Docking and Enzyme Kinetics for Exploration of Acetylcholinesterase Inhibitors from Poria cocos.

Poria cocos (P. cocos) is a traditional Chinese medicinal product with the same origin as medicine and food. It has diuretic, anti-inflammatory and liver protection properties, and has been widely used in a Chinese medicine in the treatment of Alzheimer's disease (AD). This study was conducted to explore the activity screening, isolation of acetylcholinesterase inhibitors (AChEIs), and in vitro inhibiting effect of P. cocos. The aim was to develop a new extraction process optimization method based on the Matlab genetic algorithm combined with a traditional orthogonal experiment. Moreover, bio-affinity ultrafiltration combined with molecular docking was used to screen and evaluate the activity of the AChEIs, which were subsequently isolated and purified using high-speed counter-current chromatography (HSCCC) and semi-preparative high-performance liquid chromatography (semi-preparative HPLC). The change in acetylcholinesterase (AChE) activity was tested using an enzymatic reaction kinetics experiment to reflect the inhibitory effect of active compounds on AChE and explore its mechanism of action. Five potential AChEIs were screened via bio-affinity ultrafiltration. Molecular docking results showed that they had good binding affinity for the active site of AChE. Meanwhile, the five active compounds had reversible inhibitory effects on AChE: Polyporenic acid C and Tumulosic acid were non-competitive inhibitors; 3-Epidehydrotumulosic acid was a mixed inhibitor; and Pachymic acid and Dehydrotrametenolic acid were competitive inhibitors. This study provided a basis for the comprehensive utilization of P. cocos and drug development for the treatment of AD.

Natural Antioxidants, Tyrosinase and Acetylcholinesterase Inhibitors from Cercis glabra Leaves.

Cercis glabra is a plant belonging to the legume family, whose flowers and barks are commonly used as food and traditional Chinese medicines. However, its leaves are usually disposed of as wastes. This research comprehensively investigated the bioactive constituents of C. glabra leaves, and two new phenolic, ceroffesters A-B (1-2) and thirteen known compounds (3-15) were isolated. Their structures were elucidated by spectroscopic methods such as nuclear magnetic resonance (1D NMR and 2D NMR), high-resolution electrospray ionization mass spectra (HR-ESI-MS), optical rotatory dispersion (ORD) and electronic circular dichroism (ECD). All of them were assessed for their antioxidant activities through ABTS, DPPH and PTIO methodologies, and evaluated for inhibitory activities against two enzymes (mushroom tyrosinase and acetylcholinesterase). As a result, compounds 3-6, 10 and 13 exhibited evident antioxidant activities. Meanwhile, compounds 5, 10 and 13 showed the most potent tyrosinase inhibitory activities, with IC50 of 0.64, 0.65 and 0.59 mM, and compared with the positive control of 0.63 mM (kojic acid). In the initial concentration of 1 mg/mL, compounds 3, 5 and 6 demonstrated moderate inhibitory activities against acetylcholinesterase with 85.27 ± 0.06%, 83.65 ± 0.48% and 82.21 ± 0.09%, respectively, compared with the positive control of 91.17 ± 0.23% (donepezil). These bioactive components could be promising antioxidants, tyrosinase and acetylcholinesterase inhibitors.

Polyphenols composition and the biological effects of six selected small dark fruits.

The health-promoting activities of fruits are in the limelight in view of the growing risks posed by civilisational diseases and are connected with polyphenols. The present study examined bilberry, blueberry, blackcurrant, redcurrant, cherry and plum for their polyphenolic content and biological activities. The contents of total polyphenolic compounds and their subclasses were determined. Liquid chromatography high-resolution mass spectrometry was used to characterise the polyphenolic profiles. Small dark fruits' antioxidant, anti-inflammatory, and anti-cholinesterase activities were also extensively determined. Significant qualitative and quantitative differences in the analysed fruits' polyphenols composition and biological activities were demonstrated. The highest polyphenolic contents and antioxidant activities were established in blackcurrant fruit, but bilberry also had our attention due to an additional mild influence on antioxidant enzymes. The condensed tannin content in small dark fruits is developed. All tested fruits exhibit anti-inflammatory and anti-cholinesterase activities.

Anti-diabetic, anti-cholinesterase, and antioxidant potential, chemical composition and sensory evaluation of novel sea buckthorn-based smoothies.

Sea buckthorn berries fit into the strategy of seeking natural factors in the non-communicable diseases prevention, but their sensory qualities are a challenge for consumers and food industry. The study aimed to evaluate anti-cholinesterase (anti-acetylcholinesterase and -butylcholinesterase), anti-diabetic (anti-α-amylase, -α-glucosidase, -pancreatic lipase) and antioxidant potential (FRAP, ORAC), phenolic compounds (UPLC-PDA-FL), basic chemical composition, and sensory quality of sea buckthorn-based smoothies. Eighteen novel products containing sea buckthorn (25-50%) with other fruits and vegetables were analyzed. Sea buckthorn enriched the smoothies in flavonols (25.46-95.13 mg/100 g), and fruits and vegetables provided phenolic acids and procyanidins. The anti-BuChE effect was higher than anti-AChE, while products with apricot, orange, grape and parsley root were strong inhibitors of carbohydrates digesting enzymes. Lipase inhibition by all smoothies was over 50%. Products with 75% fruits or 50% vegetables were the most sensory attractive. The results will be valuable in designing innovative food with rarely used berries.

Ocotea daphnifolia: phytochemical investigation, in vitro dual cholinesterase inhibition, and molecular docking studies

This study aimed to evaluate the anticholinesterase activities of extracts and fractions of Ocotea daphnifolia in vitro and characterize its constituents. The effects of hexane, ethyl acetate, and ethanolic extracts on acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) activity were determined with a spectrophotometry assay. All extracts inhibited cholinesterase activity, and the ethanolic extract (2 mg/mL) exhibited the highest inhibition of both enzymes (99.7% for BuChE and 82.4% for AChE). The ethanolic extract was fractionated by column chromatography resulting in 14 fractions that were also screened for their anticholinesterase effects. Fraction 9 (2 mg/mL) showed the highest activity, inhibiting AChE and BuChE by 71.8% and 90.2%, respectively. This fraction was analyzed by high-performance liquid chromatography high-resolution mass spectrometry which allowed the characterization of seven glycosylated flavonoids (containing kaempferol and quercetin nucleus) and one alkaloid (reticuline). In order to better understand the enzyme-inhibitor interaction of the reticuline toward cholinesterase, molecular modeling studies were performed. Reticuline targeted the catalytic activity site of the enzymes. Ocotea daphnifolia exhibits a dual cholinesterase inhibitory activity and displays the same pattern of intermolecular interactions as described in the literature. The alkaloid reticuline can be considered as an important bioactive constituent of this plant.

A Novel Chemical Profile of a Selective In Vitro Cholinergic Essential Oil from Clinopodium taxifolium (Kunth) Govaerts (Lamiaceae), a Native Andean Species of Ecuador.

A novel chemical profile essential oil, distilled from the aerial parts of Clinopodium taxifolium (Kunth) Govaerts (Lamiaceae), was analysed by Gas Chromatography-Mass Spectrometry (GC-MS, qualitative analysis) and Gas Chromatography with Flame Ionization Detector (GC-FID, quantitative analysis), with both polar and non-polar stationary phase columns. The chemical composition mostly consisted of sesquiterpenes and sesquiterpenoids (>70%), the main ones being (E)-ß-caryophyllene (17.8%), α-copaene (10.5%), ß-bourbonene (9.9%), δ-cadinene (6.6%), cis-cadina-1(6),4-diene (6.4%) and germacrene D (4.9%), with the non-polar column. The essential oil was then submitted to enantioselective GC analysis, with a diethyl-tert-butyldimethylsilyl-ß-cyclodextrin diluted in PS-086 chiral selector, resulting in the following enantiomeric excesses for the chiral components: (1R,5S)-(-)-α-thujene (67.8%), (1R,5R)-(+)-α-pinene (85.5%), (1S,5S)-(-)-ß-pinene (90.0%), (1S,5S)-(-)-sabinene (12.3%), (S)-(-)-limonene (88.1%), (S)-(+)-linalool (32.7%), (R)-(-)-terpinen-4-ol (9.3%), (S)-(-)-α-terpineol (71.2%) and (S)-(-)-germacrene D (89.0%). The inhibition activity against acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) of C. taxifolium essential oil was then tested, resulting in selective activity against BChE with an IC50 value of 31.3 ± 3.0 µg/mL (positive control: donepezil, IC50 = 3.6 µg/mL).

Thiol-suppressed I2-etching of AuNRs: acetylcholinesterase-mediated colorimetric detection of organophosphorus pesticides.

For the first time it is demonstrated that sulfhydryl compounds can suppress longitudinal etching of gold nanorods via consuming oxidizers, which provides a new signaling mechanism for colorimetric sensing. As a proof of concept, a colorimetric assay is developed for detecting organophosphorus pesticides, which are most widely used in modern agriculture to improve food production but with high toxicity to animals and the ecological environment. Triazophos was selected as a model organophosphorus pesticide. In the absence of triazophos, the active acetylcholinesterase can catalyze the conversion of acetylthiocholine iodide to thiocholine whose thiol group can suppress the I2-induced etching of gold nanorods. When triazophos is present, the activity of AchE is inhibited, and I2-induced etching of gold nanorods results in triazophos concentration-dependent color change from brown to blue, pink, and red. The aspect ratio of gold nanorods reduced with gradually blue-shifted longitudinal absorption. There was a linear detection range from 0 to 117 nM (R2 = 0.9908), the detection limit was 4.69 nM, and a good application potential was demonstrated by the assay of real water samples. This method will not only contribute to public monitoring of organophosphorus pesticides but also has verified a new signaling mechanism which will open up a new path to develop colorimetric detection methods. It has been first found that sulfhydryl compounds can suppress longitudinal etching of gold nanorods (AuNRs) via consuming oxidizers, which provides a new signaling mechanism for colorimetric sensing. As a proof of concept, a colorimetric assay is developed for sensitively detecting organophosphorus pesticides (OPs). It will not only contribute to public monitoring of OPs but also has verified a new signaling mechanism which will open up a new path to develop multicolor colorimetric methods.

An Overview on the Mechanisms and Applications of Enzyme Inhibition-Based Methods for Determination of Organophosphate and Carbamate Pesticides.

Acetylcholinesterase inactivating compounds, such as organophosphate (OP) and carbamate (CM) pesticides, are widely used in agriculture to ensure sustainable production of food and feed. As a consequence of their applications, they would result in neurotoxicity, even death. In this essence, the development of enzyme inhibition methods still shows great significance as rapid detection techniques for on-site large-scale screening of OPs and CMs. Initially, mechanisms and applications of various enzyme-inhibition-based methods and devices, including optical colorimetric assay, fluorometric assays, electrochemical biosensors, rapid test card, and microfluidic device, are highlighted in the present overview. Further, to enhance the enzyme sensitivity for detection; alternative enzyme sources or high yield enrichment methods (such as abzyme, artificial enzyme, and recombinant enzyme), as well as enzyme reactivation and identification, are also addressed in this comprehensive overview.

Walnut (Juglans regia L.) Septum: Assessment of Bioactive Molecules and In Vitro Biological Effects.

Walnut (Juglans regia L.) septum represents an interesting bioactive compound source by-product. In our study, a rich phenolic walnut septum extract, previously selected, was further examined. The tocopherol content determined by liquid chromatography-tandem mass spectrometry (LC-MS/MS) revealed higher amounts of α-tocopherol compared to γ- and δ-tocopherols. Moreover, several biological activities were investigated. The in vitro inhibiting assessment against acetylcholinesterase, α-glucosidase, or lipase attested a real management potential in diabetes or obesity. The extract demonstrated very strong antimicrobial potential against Staphylococcus aureus, Pseudomonas aeruginosa and Salmonella enteritidis. It also revealed moderate (36.08%) and strong (43.27%) antimutagenic inhibitory effects against TA 98 and TA 100 strains. The cytotoxicity of the extract was assessed on cancerous (A549, T47D-KBluc, MCF-7) and normal (human gingival fibroblasts (HGF)) cell lines. Flow cytometry measurements confirmed the cytotoxicity of the extract in the cancerous cell lines. Additionally, the extract demonstrated antioxidant activity on all four cell types, as well as anti-inflammatory activity by lowering the inflammatory cytokines (interleukin-6 (IL-6), interleukin-8 (IL-8), interleukin-1 ß (IL-1ß)) evaluated in HGF cells. To the best of our knowledge, most of the cellular model analyses were performed for the first time in this matrix. The results prove that walnut septum may be a potential phytochemical source for pharmaceutical and food industry.

Development of QCM based biosensor for the selective and sensitive detection of paraoxon.

In this study, a quartz crystal microbalance (QCM) based sensor was developed that selectively recognizes and binds the paraoxon molecule. For this purpose, poly (styrene-maleic anhydride) (PSMA) polymer was synthesized to obtain nanofiber. A 30% (wt/wt) PSMA/DMSO solution was prepared for use in the electrospinning process, with operating conditions of 5 kV potential and 1 mL/h flow rate. After obtaining the nanofibers, AChE enzyme was immobilized to nanofiber. The QCM gold electrode surface was coated with AChE immobilized nanofiber. For this purpose, the QCM electrode was first functionalized with 4-aminothiophenol. The quartz electrode coated with the recognition layer was sequentially studied with aqueous solutions containing 50% (v/v) methanol, ranging from 0.1 ppm to 10 ppm of paraoxon. When the electrode interacts with paraoxon, the frequency value decreases. The obtained data were converted to graphs and a calibration graph was obtained. The LOD value was found to be 4.57 × 10-8 and the LOQ value was found to be 1.52 × 10-7 M. These results show us that the developed method can analyze very small quantities of paraoxon samples. The Langmuir adsorption equation was used to study the interaction of the bond between the electrode surface and the paraoxon. For the calculation of the coupling constant Ka, Δm/C (g/M) versus Δm (g) was plotted on the graph. The Ka binding constant of the obtained graphic was found to be 5 × 107 M-1.

UPLC-PDA-Q/TOF-MS profiling of phenolic and carotenoid compounds and their influence on anticholinergic potential for AChE and BuChE inhibition and on-line antioxidant activity of selected Hippophaë rhamnoides L. cultivars.

This study aimed to identify by UPLC-PDA-Q/TOF-MS and quantify by UPLC-PDA phenolic compounds (26 flavonols and 2 phenolic acids) and carotenoids (16) from berries of different cultivars of Hippophaë rhamnoides and determine correlations between these variables and in vitro anticholinergic and on-line antioxidant potential. Isorhamnetin derivatives presented over 65% of total flavonols, but quercetin and kaempferol derivatives were also determined. Carotenes accounted for 19 to 47%, xanthophylls 16 to 81% of total carotenoids. Pearson's correlations between AChE and BuChE inhibition and phenolic acid content were low (r = 0.388 and 0.355), moderate for carotenoids (0.504 and 0.437) and high for flavonols (0.851 and 0.614). The PCA biplot showed the highest correlation between anticholinergic activity and all-trans-ß-cryptoxanthin, quercetin-3-O-glucoside, isorhamnetin-3-O-(2-rhamnosyl)glucoside, kaempferol-3-O-hexoside-7-O-rhamnoside, isorhamnetin-3-O-(6-rhamnosyl)hexoside, isorhamnetin-3-O-rutinoside, and isorhamnetin-3-O-glucoside concentrations. The results obtained can be used to identify sea buckthorn cultivars, develop crops and production, and design functional products rich in flavonols and carotenoids with anticholinergic properties.

Determination of acute median lethal concentration and sublethal effects on AChE activity of Gymnotus carapo (Teleostei: Gymnotidae) exposed to trichlorfon / Determinação da concentração letal média e efeitos subletais da atividade AchE de Gymnotus carapo (Teleostei: Gymnotidae) exposto ao triclorfon

Trichlorfon (TRF) is a pesticide widely used in aquaculture to control fish ectoparasites. This pesticide is an inhibitor of acetylcholinesterase, an essential enzyme for termination of nerve impulses. High rates of TRF use generate risks to the environment and human health. In the environment, pesticides can affect the local fauna and generate an ecological breakdown. There are several studies performed with fish production; however, gaps are created for native fish with other commercial values. The tuvira (Gymnotus carapo) is a fish native to Brazilian fauna and has great commercial importance in sport fishing. The present study aimed to determine the lethal concentration of trichlorfon (Masoten) in Gymnotus carapo and its sublethal effects on the enzyme AChE. In this study, the acute toxicity (the concentrations to kill 50% of the fish LC50) of TRF in tuviras (Gymnotus carapo) and acetylcholinesterase inhibition in liver and muscle tissue of tuviras submitted to sublethal concentrations were evaluated. For the acute assay, concentrations of 0.0, 5.0, 7.5, 15, 22.5, 30, 37.5 and 45 mg L-1 were used for a period of 96 h. After the acute exposure period, a LC50 of 6.38 mg L-1 was determined. In the sublethal assay, concentrations of 0.0, 0.238, 0.438 and 0.638 mg L-1 were used, based on 10% of the LC50, over a period of 14 days. Two collections were performed: one at seven days and the other at the end (day 14). Inhibition of acetylcholinesterase in the liver was only shown (p < 0.05) for the treatment with 0.638 mg L-1 after 14 days of exposure. At seven days, muscle activity showed a significant difference only for the treatments 0.438 and 0.638 mg L-1, compared with the treatment 0.238 mg L-1 and control. At 14 days of exposure, only the treatment 0.638 mg L-1 showed significant differences in relation to the other groups, thus showing that enzyme recovery had occurred. The value found in the acute test allowed the conclusion that TRF presents moderately toxic characteristics to Gymnotus carapo. The toxicity parameter values calculated in the present study assisted in estimation of maximum allowable limits in bodies of water when combined with test data from other non-target organisms.(AU)

O triclorfon (TRC) é um pesticida muito utilizado na aquicultura para o controle de ectoparasitos de peixes. Este pesticida é um inibidor da acetilcolinesterase, uma enzima essencial para a finalização de impulsos nervosos. As altas concentrações utilizadas de TRC geram riscos ao meio ambiente e à saúde humana. No ambiente, os pesticidas podem afetar a fauna local e gerar um colapso ecológico. Existem vários estudos com peixes de produção, no entanto, há lacunas para peixes nativos com outros valores comerciais. A tuvira (Gymnotus carapo) é um peixe nativo da fauna brasileira e possui grande importância comercial na pesca esportiva. O presente trabalho, delineado para determinar a concentração letal de triclorfon (Masoten) em Gymnotus carapo e seus efeitos subletais na enzima AChE, avaliou a toxicidade aguda (concentrações para matar 50% dos peixes CL50) do TRC em tuviras (Gymnotus carapo) e a inibição da acetilcolinesterase no fígado e tecido muscular de tuviras. Para o ensaio agudo, foram utilizadas concentrações de 0,0, 5,0, 7,5, 15, 22,5, 30, 37,5 e 45 mg L-1por um período de 96 horas. Após o período de exposição aguda, foi determinado uma CL50 de 6,38 mg L-1. No ensaio subletal, foram utilizadas concentrações de 0,0, 0,238, 0,438 e 0,638 mg L-1, com base em 10% do CL50, durante um período de catorze dias. Foram realizadas duas colheitas: uma aos sete dias e a outra ao final (décimo quarto dia). A inibição da acetilcolinesterase no fígado foi demonstrada apenas (p <0,05) para o tratamento com 0,638 mg L-1 após catorze dias de exposição. Aos sete dias, a atividade muscular mostrou diferença significativa apenas para os tratamentos 0,438 e 0,638 mg L-1, em comparação com o tratamento 0,238 mg L-1 e controle. Aos catorze dias de exposição, apenas o tratamento 0,638 mg L-1 apresentou diferenças significativas em relação aos demais grupos, demonstrando a recuperação enzimática. O valor encontrado no teste agudo permitiu concluir que o TRC apresenta características moderadamente tóxicas para Gymnotus carapo. Os valores dos parâmetros de toxicidade calculados no presente estudo permitiram o estabelecimento da estimativa dos limites máximos permitidos em corpos d'água quando combinados com dados de testes de outros organismos não-alvo.(AU)

Leek-derived codoped carbon dots as efficient fluorescent probes for dichlorvos sensitive detection and cell multicolor imaging.

A biomass nitrogen and sulfur codoped carbon dots (NS-Cdots) was prepared by a simple and clean hydrothermal method using leek, and was employed as efficient fluorescent probes for sensitive detection of organophosphorus pesticides (OPs). The leek-derived NS-Cdots emitted blue fluorescence, but was quenched by H2O2. Due to acetylcholinesterase/choline oxidase-based cascade enzymatic reaction that produces H2O2 and the inhibition effect of OPs on acetylcholinesterase activity, a NS-Cdots-based fluorescence "off-on" method to detect OPs-dichlorvos (DDVP) was developed. More sensitivity and wider linear detection range were achieved from 1.0 × 10-9 to 1.0 × 10-3 M (limit of detection = 5.0 × 10-10 M). This developed method was applied to the detection of DDVP in Chinese cabbage successfully. The average recoveries were in the range of 96.0~104.0% with a relative standard deviation of less than 3.3%. In addition, the NS-Cdots fluorescent probes were also employed successfully in multicolor imaging of living cells, manifesting that the NS-Cdots fluorescent probes have great application potential in agricultural and biomedical fields. Graphical Abstract.

Phytochemical contents, antioxidant effects, and inhibitory activities of key enzymes associated with Alzheimer's disease, ulcer, and skin disorders of Sideritis albiflora and Sideritis leptoclada.

In this study, urease, tyrosinase, cholinesterase inhibitory, and antioxidant activities of various extracts of Sideritis albiflora and Sideritis leptoclada were determined together with the phytochemical contents. In addition, the fatty acid compositions and phenolic compounds were investigated by gas chromatography (GC), gas chromatography-mass spectrometry (GC-MS), and high performance liquid chromatography-diode array detector (HPLC-DAD). Rosmarinic acid and caffeic acid in both Sideritis species were identified as the most abundant phenolic compounds whereas palmitic acid was found as a major fatty acid. The acetone extract of S. leptoclada indicated the highest antioxidant activity in ß-carotene-linoleic acid (IC50 : 17.23 ± 0.11 µg/ml), DPPH• (IC50 : 28.14 ± 0.05 µg/ml) and ABTS•+ (IC50 : 15.18 ± 0.02 µg/ml) assays. The acetone extract of S. albiflora (A0.50 : 32.71 ± 0.44 µg/ml) was found as the best reductant in cupric reducing antioxidant capacity (CUPRAC) assay. Against acetylcholinesterase (AChE) and butyrylcholinesterase (BChE), only the hexane extracts of Sideritis species showed moderate inhibitory activity. Moreover, all extracts of S. albiflora and the hexane extract of S. leptoclada exhibited significantly higher urease inhibitory activity than that of thiourea. Further, in vivo activity studies on extracts and isolated constituents obtained from these species are needed to understand the activity in biological systems. PRACTICAL APPLICATIONS: Multiple pharmacological studies have proven that Sideritis species is precious with significant bioactive properties. This is the first comprehensive research to determine the enzyme inhibitory and antioxidant activities of various extracts of S. albiflora and S. leptoclada with phytochemical contents. Both Sideritis species were found to be rich in rosmarinic and caffeic acids. The acetone extracts showed the highest activity in terms of antioxidant activity, while the hexane extracts exhibited superior urease inhibitory activity. These results show that Sideritis species could be used as urease inhibitors' agents and source of antioxidants in food, pharmaceutical, and cosmetic industries.

Isolation, characterization, and bioactivities of compounds from Fuscoporia torulosa mushroom.

Chromatographic purification of Fuscoporia torulosa extracts resulted in the isolation and characterization of a new steroid, 5α,8α-epidioxyergosta-6,22-dien-3ß-il-palmitate (1) and 10 known compounds (2-11). The structures of compounds were elucidated by IR, NMR, MS analyses, and comparison with literature data. Cytotoxic activities against MCF-7 (breast cancer), PC-3 (prostate cancer), and 3T3 (nontumor) of the extracts and cytotoxic, antioxidant, cholinesterase, and tyrosinase inhibitory activities of all isolated compounds were evaluated. The methanol extract and Compound 8 showed the best cytotoxicity against MCF-7, whereas the hexane extract and Compound 4 displayed the highest cytotoxicity against PC-3. Compounds 10 and 11 displayed higher antioxidant activity than α-tocopherol and butylated hydroxyanisole (BHA) which are used as standards in ABTS•+ , DPPH• , and cupric reducing antioxidant capacity (CUPRAC) assays. Also, cholinesterase inhibitory activity against acetylcholinesterase (AChE) and butrylcholinesterase (BChE), Compounds 4 and 8 were determined as the most active compounds. Among all isolated compounds, Compound 11 exhibited the highest tyrosinase inhibitory activity. PRACTICAL APPLICATIONS: Mushrooms have various important medicinal properties. A detailed study was made to identify the bioactive constituents of Fuscoporia torulosa mushroom and a new (1) and 10 known compounds (2-11) were isolated. Compounds 10 and 11 showed higher antioxidant activity than standards. The methanol extract and Compound 8 exhibited high cytotoxic activity against MCF-7. Compound 8 indicated potent BChE inhibitory activity. This study suggests that natural compounds isolated from F. torulosa mushroom could be used as promising anticancer, antioxidant, and anticholinesterase agents.

New insights into the chemical profiling, cytotoxicity and bioactivity of four Bunium species.

Bunium species have been reported to be used both as food and in traditional medicines. The scientific community has attempted to probe into the pharmacological and chemical profiles of this genus. Nonetheless, many species have not been investigated fully to date. In this study, we determined the phenolic components, antimicrobial, antioxidant, and enzyme inhibitory activities of aerial parts of four Bunium species (B. sayai, B. pinnatifolium, B. brachyactis and B. macrocarpum). Results showed that B. microcarpum and B. pinnatifolium were strong antioxidants as evidenced in the DPPH, ABTS, CUPRAC, and FRAP assays. B. brachyactis was the most effective metal chelator, and displayed high enzyme inhibition against cholinesterase, tyrosinase, amylase, glucosidase, and lipase. The four species showed varied antimicrobial activity against each microorganism. Overall, they showed high activity against P. mirabilis and E. coli (MIC and MBC <1 mg mL-1). B. brachyactis was more effective against Aspergillus versicolor compared to the standard drug ketoconazole. B. brachyactis was also more effective than both ketoconazole and bifonazole against Trichoderma viride. B. sayai was more effective than ketoconazole in inhibiting A. fumigatus. B. sayai was most non-toxic to HEK 293 (cellular viability = 117%) and HepG2 (cellular viability = 104%). The highest level of TPC was observed in B. pinnatifolium (35.94 mg GAE g-1) while B. microcarpum possessed the highest TFC (39.21 mg RE g-1). Seventy four compounds were detected in B. microcarpum, 70 in B. brachyactis, 66 in B. sayai, and 51 in B. pinnatifolium. Quinic acid, chlorogenic acid, pantothenic acid, esculin, isoquercitrin, rutin, apigenin, and scopoletin were present in all the four species. This study showed that the four Bunium species are good sources of biologically active compounds with pharmaceutical and nutraceutical potential.

Rapid colorimetric determination of the pesticides carbofuran and dichlorvos by exploiting their inhibitory effect on the aggregation of peroxidase-mimicking platinum nanoparticles.

A novel and highly sensitive enzyme inhibition assay was developed for the rapid detection of the organophosphate pesticide dichlorvos and the carbamate pesticide carbofuran. It achieves signal amplification by the secondary catalysis of platinum nanoparticles. Acetylcholinesterase (AChE) is capable of catalyzing the hydrolysis of acetylthiocholine to form thiocholine. Thiocholine causes the aggregation of citrate-capped platinum nanoparticles which then lose their peroxidase-mimicking properties. After addition of pesticides, the activity of AChE is inhibited, less thiocholine is produced, less aggregation occurs, and the peroxidase-mimetic properties are increasingly retained. In the presence of tetramethylbenzidine and H2O2, a deep blue coloration with an absorption maximum at 650 nm will be formed. The assay was applied to the determination of dichlorvos and carbofuran, and detection limits of 2.3 µg·L-1 and 1.4 µg·L-1 were obtained, respectively. Recovery experiments with spiked tap water and pears gave satisfactory relative standard deviations. Graphical abstract The blue product formed by platinum nanoparticle-catalyzed oxidation of 3,3'5,5'-tetramethylbenzidine (TMB) by H2O2 is reduced if acetylthiocholine (ATCh) is hydrolyzed by acetylcholinesterase (AChE) to form thiocholine. However, if AChE is inhibited by pesticides, color formation will recover.

A sensitive fluorescence assay of organophosphorus pesticides using acetylcholinesterase and copper-catalyzed click chemistry.

Organophosphorus pesticides (OPs) are widely used in agricultural fields, but exhibit high toxicity to human beings. A sensitive fluorescence assay for organophosphorus pesticides was developed using the inhibition of acetylcholinesterase (AChE) activity and the copper-catalyzed click chemical reaction. In the click reaction, two hybridized DNA probes can be ligated with copper ions, inducing a fluorescence quenching during the strand displacement reaction. AChE can hydrolyze acetylthiocholine (ATCh) to form thiocholine (TCh) which contains a thiol group. TCh will react with copper ions, blocking the click reaction and a high fluorescence signal is observed. But in the presence of OPs, the activity of AChE is inhibited, releasing a high concentration of copper ions that catalyze the click chemical reaction and resulting in decreased fluorescence signals. Taking advantage of the copper-mediated signal amplification effect, the sensitivity was improved. This assay has also been applied to detect OPs in river water samples with satisfactory results, which demonstrates that the method has great potential for practical applications in environmental protection and food safety fields.

Screening of acetylcholinesterase inhibitors in marine organisms from the Caribbean Sea.

The acetylcholinesterase inhibitory activity of 89 organic extracts from marine organisms was evaluated through a TLC bioautography methodology. Extracts from soft corals (Eunicea and Plexaura) were the most active compared with extracts from sponges. The bioguided chemical study of the most active extract, obtained from Pseudoplexaura porosa, led to the isolation of a diterpene with spectroscopic properties consistent to those published to the cembrane Steylolide. However, further analysis by X-ray diffraction indicated that the compound was the 14-acetoxycrassine (1), correcting the structure reported to the Styelolide. Additionally, the acetylcholinesterase inhibitory activity of fourteen cembranoids (2-15) isolated from soft corals Eunicea knighti and Pseudoplexaura flagellosa was evaluated. Cembranoids 2, 3 and 4 were the most active compounds in the TLC bioassay. Then, the most promising cembranoids, 14-acetoxycrassine (1) and asperdiol (2), were tested quantitatively and they exhibited IC50 values of 1.40 ± 0.113 and 0.358 ± 0.130 µM, respectively.