Acetylcholinesterase Inhibitory Properties Research Articles

Chemical composition of γ-irradiated German chamomile (Matricaria recutita L.) flower essential oils, acetylcholinesterase inhibitory activity and effects on growth inhibition of Staphylococcus aureus and Candida albicans

Radiation-induced mutations have been the most commonly used technique for the development of mutant varieties. The primary aim has been to upgrade the existing plant varieties by varying a few major traits responsible for limiting metabolite productivity. The increasing regulations on protected plant varieties and germplasms have restricted their use. The induced mutants have played a vital role in strengthening the plant breeding program. The medicinal and aromatic plants have been poorly explored for mutation breeding. CSIR-CIMAP has initiated a mutation breeding program on some of the high-value plants, like Matricaria. As a result, we could develop gamma-rays-induced stable accessions. Genus Matricaria is well known for the biosynthesis of diverse bioactive plant secondary metabolites as well as for its traditional and healthcare benefits documented in Ph. Eur. In the present work, gamma-irradiated stable accessions of German chamomile, Matricaria recutita L., have been investigated for their essential oil composition and biological assessment. After a thorough investigation for a two-year cropping period, we have observed that some accessions contain the highest α-bisabolol oxide B proportions (24.3–55.3%), while quite a few showed chamazulene (2.9–5.8%), α-bisabolone oxide A (6.5–38%), and α-bisabolol oxide A (30.1–55.3%). A few accessions were marked by the presence of lavandulol, an irregular monoterpenoid of high fragrance value. The antibacterial, anti-inflammatory, and acetylcholinesterase (AChE) inhibitory properties of these gamma-irradiated accessions were also evaluated. The accessions G6-R5-5 and G2-R1-6 exhibited maximum inhibition against S. aureus whereas G2-R1-1 arrested the growth of C. albicans. Furthermore, G2R1-3 composition is responsible for reducing AChE and inflammation in cell lines. These results may open up ways to develop plant-derived consumer products from Matricaria recutita L.

A Novel Tetrahydroacridine Derivative with Potent Acetylcholinesterase Inhibitory Properties and Dissociative Capability against Aβ42 Fibrils Confirmed by In Vitro Studies.

Alzheimer's disease (AD) is one of the most common causes of dementia, accounting for more than 60% of all cases. It is a neurodegenerative disease in which symptoms such as a decline in memory, thinking, learning, and organizing skills develop gradually over many years and eventually become more severe. To date, there is no effective treatment for the cause of Alzheimer's disease, and the existing pharmacological options primarily help manage symptoms. Treatment is mainly based on acetylcholinesterase (AChE) inhibitors such as donepezil, rivastigmine, and galantamine, which exhibit numerous adverse cardiovascular and gastrointestinal effects due to excessive stimulation of peripheral cholinergic activity involving muscarinic receptors. Therefore, in addition to the obvious drugs that act on the cause of the disease, new drugs based on AChE inhibition that show the fewest side effects are needed. One potential drug could be a new compound under study, tetrahydroacridine derivative (CHDA), which showed significant potential to inhibit the AChE enzyme in previous in vitro studies. The present study shows that while having very potent AChE inhibitory properties, CHDA is a compound with low toxicity to nerve cell culture and living organisms. In addition, it exhibits dissociative activity against amyloid β fibrils, which is extremely important for applications in Alzheimer's disease therapy.

Synthesis, characterization of novel mannich bases and their acetylcholinesterase and glutathione S-transferase inhibitory properties: An in vitro and in silico mechanism research

In this study, 4-((3,4-Dimethoxybenzylidene)amino)-5-alkyl(aryl)-2,4-dihydro-3H-1,2,4-triazol-3-ones (4a-g) reacted with formaldehyde and 2,6-dimethylmorpholine to obtain seven novel potential biologically active 4-((3,4-Dimethoxybenzylidene)amino)-2-((2,6-dimethylmorpholino)methyl)-5-alkyl(aryl)-2,4-dihydro-3H-1,2,4-triazol-3-ones (5a-g). The structures (5a-g) of newly synthesized compounds were characterized using FT-IR, 1H-NMR, and 13C-NMR spectral data. The synthesized compounds (5a-g) were investigated for it is in vitro enzyme inhibition properties. Results demonstrated that the newly synthesized compounds had valuable enzyme inhibition activities against acetylcholinesterase (AChE) and glutathione S-transferase (GST) enzymes. Their Ki values were calculated in the range of 0.96 ± 0.0557- 9.7967 ± 5.3105 µM, while their IC50 values were calculated in the range of 1.333–3.551 µM. Tacrine was used for AChE, Ethacrynic acid was used for GST as positive standard. Molecular docking studies revealed that compound 5b binds to AChE and compound 5f binds to GST with high affinity (−10.2 and −9.1 kcal/mol) in protein-ligand complexes. The stability of the ligand-protein complexes was confirmed by 100 ns molecular dynamics simulations.

Phytochemical Analysis, Biological Activities, and Docking of Phenolics from Shoot Cultures of Hypericum perforatum L. Transformed by Agrobacterium rhizogenes.

Hypericum perforatum transformed shoot lines (TSL) regenerated from corresponding hairy roots and non-transformed shoots (NTS) were comparatively evaluated for their phenolic compound contents and in vitro inhibitory capacity against target enzymes (monoamine oxidase-A, cholinesterases, tyrosinase, α-amylase, α-glucosidase, lipase, and cholesterol esterase). Molecular docking was conducted to assess the contribution of dominant phenolic compounds to the enzyme-inhibitory properties of TSL samples. The TSL extracts represent a rich source of chlorogenic acid, epicatechin and procyanidins, quercetin aglycone and glycosides, anthocyanins, naphthodianthrones, acyl-phloroglucinols, and xanthones. Concerning in vitro bioactivity assays, TSL displayed significantly higher acetylcholinesterase, tyrosinase, α-amylase, pancreatic lipase, and cholesterol esterase inhibitory properties compared to NTS, implying their neuroprotective, antidiabetic, and antiobesity potential. The docking data revealed that pseudohypericin, hyperforin, cadensin G, epicatechin, and chlorogenic acid are superior inhibitors of selected enzymes, exhibiting the lowest binding energy of ligand-receptor complexes. Present data indicate that H. perforatum transformed shoots might be recognized as an excellent biotechnological system for producing phenolic compounds with multiple health benefits.

Induction of Three New Secondary Metabolites by the Co-Culture of Endophytic Fungi Phomopsis asparagi DHS-48 and Phomopsis sp. DHS-11 Isolated from the Chinese Mangrove Plant Rhizophora mangle.

Co-cultivation is a powerful emerging tool for awakening biosynthetic gene clusters (BGCs) that remain transcriptionally silent under artificial culture conditions. It has recently been used increasingly extensively to study natural interactions and discover new bioactive metabolites. As a part of our project aiming at the discovery of structurally novel and biologically active natural products from mangrove endophytic fungi, an established co-culture of a strain of Phomopsis asparagi DHS-48 with another Phomopsis genus fungus DHS-11, both endophytes in mangrove Rhizophora mangle, proved to be very efficient to induce the production of new metabolites as well as to increase the yields of respective target metabolites. A detailed chemical investigation of the minor metabolites produced by the co-culture of these two titled fungal strains led to the isolation of six alkaloids (1-6), two sterols (7, 8), and six polyketides (9-14). In addition, all the compounds except 8 and 10, as well as three new metabolites phomopyrazine (1), phomosterol C (7), and phomopyrone E (9), were not present in discrete fungal cultures and only detected in the co-cultures. The structures were elucidated on the basis of spectroscopic analysis, and the absolute configurations were assumed by electronic circular dichroism (ECD) calculations. Subsequently, the cytotoxic, immunosuppressive, and acetylcholinesterase inhibitory properties of all the isolated metabolites were determined in vitro. Compound 8 exhibited moderate inhibitory activity against ConA-induced T and LPS-induced B murine splenic lymphocytes, with IC50 values of 35.75 ± 1.09 and 47.65 ± 1.21 µM, respectively.

In silico and in vitro inhibition abilities of novel benzene sulfonamides on carbonic anhydrase and choline esterases

Compounds that possess a benzene sulfonamide structure are utilized in a wide range of fields. It is reported in the literature that many compounds belonging to this class of compounds exhibit various pharmacological properties such as antibacterial, antifungal, antiviral, anticancer, inflammatory, antiglaucoma, and anticholinergic effects. Carbonic anhydrase (CA) enzymes play a critical role in pH regulation, long-term synaptic turnover and are therefore thought to be associated with such diseases as mental retardation, Alzheimer’s disease (AD) and Down syndrome. Studies have reported that there is an increase in the levels of hCA-I and hCA-II isoenzymes in AD. AD is a complex, multifactorial disorder, so therapy should probably address not only the cholinergic system but also additional systems. Based on these features, a series of novel substituted benzene sulfonamides were synthesized from 1,2,3-trimethoxy-5-methylbenzene. Sulfonyl chloride 9 was synthesized from the reaction of 1,2,3-trimethoxy-5-methylbenzene and excess chlorosulfonic acid. The reaction of the obtained sulfonyl chloride with NH3 and N-alkyl amines, aniline, and phenethylamine gave substituted benzene sulfonamide derivatives 10–16. The synthesized compounds were evaluated for their carbonic anhydrase (hCA I-II), acetyl cholinesterase (AChE) and butyryl cholinesterase (BChE) inhibitory properties. Some of the substituted benzene sulfonamide derivatives 10–16 showed inhibitory effect on hCA isoenzymes. The Ki values determined for the hCA I enzyme are in the range of 102.01–147.19 µM. Benzene sulfonamide derivatives 10–16 showed an inhibitory effect on AChE and BChE. The Ki values determined for AChE and BChE enzymes are in the range of 28.76–308.08 µM and 42.80–445.60 µM, respectively. It was determined that sulfonamides 15–16 were selective inhibitors for the hCA I and 10 showed 11-fold more selectivity on AChE than BChE. In addition, the in-silico SAR and ADME properties of the synthesized compounds were also investigated.

Anthemis tricolor Containing Unusual Totarol with Cytotoxic and Acetylcholinesterase-Inhibitory Activity.

Anthemis tricolor is an endemic species of Cyprus, and there is very limited information on its chemistry and pharmacological activities. The study aims to identify the in-vitro cytotoxic and acetylcholinesterase activities of Anthemis tricolor. The compounds responsible for the activities were also identified. Potent extracts of A. tricolor were subjected to preparative isolation and spectral structure determination studies. The chloroform extract contained many components, and due to the small quantity of extract available, enough pure compound(s) cannot be obtained for structure determination studies, though the n-hexane extract afforded two known compounds, totarol (1) and taraxasterol (2). The structures of the compounds (1 and 2) were determined by 1 H and 13 C NMR experiments. The pure compounds were also tested for their acetylcholinesterase inhibitory properties. For compound 1, the IC50 value was found to be 87.88 μg/mL. However, no inhibition was seen for 2. Anthemis tricolor was established to be a valuable source of pharmacologically active compounds and requires further studies.

Anticholinesterase and Antityrosinase Secondary Metabolites from the Fungus Xylobolus subpileatus.

Xylobolus subpileatus is a widely distributed crust fungus reported from all continents except Antarctica, although considered a rare species in several European countries. Profound mycochemical analysis of the methanol extract of X. subpileatus resulted in the isolation of seven compounds (1-7). Among them, (3β,22E)-3-methoxy-ergosta-4,6,814,22-tetraene (1) is a new natural product, while the NMR assignment of its already known epimer (2) has been revised. In addition to a benzohydrofuran derivative fomannoxin (3), four ergostane-type triterpenes 4-7 were identified. The structure elucidation of the isolated metabolites was performed by one- and two-dimensional NMR and MS analysis. Compounds 2-7 as well as the chloroform, n-hexane, and methanol extracts of X. subpileatus were evaluated for their tyrosinase, acetylcholinesterase, and butyrylcholinesterase inhibitory properties. Among the examined compounds, only fomannoxin (3) displayed the antityrosinase property with 51% of inhibition, and the fungal steroids proved to be inactive. Regarding the potential acetylcholinesterase (AChE) inhibitory activity of the fungal extracts and metabolites, it was demonstrated that the chloroform extract and compounds 3-4 exerted noteworthy inhibitory activity, with 83.86 and 32.99%, respectively. The butyrylcholinesterase (BChE) inhibitory assay revealed that methanol and chloroform extracts, as well as compounds 3 and 4, exerted notable activity, while the rest of the compounds proved to be only weak enzyme inhibitors. Our study represents the first report on the chemical profile of basidiome of the wild-growing X. subpileatus, offering a thorough study on the isolation and structure determination of the most characteristic biologically active constituents of this species.

Green synthesis, biological and molecular docking of some novel sulfonamide thiadiazole derivatives as potential insecticidal against Spodoptera littoralis

Although crop plants provide the majority of human food, pests and insects frequently cause huge economic losses. In order to develop innovative insecticidal compounds with low toxicity and a positive environmental impact, we developed new N-(4-sulfamoylphenyl)-1,3,4-thiadiazole-2-carboxamide derivatives (2–12). With the use of spectroscopic techniques and elemental data, the chemical structure of these new compounds was meticulously clarified. The toxicological and biological effects of the synthesized compound of the cotton leafworm Spodoptera littoralis (Boisduval, 1833) under laboratory conditions were also investigated. Regarding the determined LC50 values, compounds 3, 7, 8, and 10 showed the most potent toxic effect with LC50 values of 29.60, 30.06, 27.65 and 29.01 ppm, respectively. A molecular docking investigation of twelve synthetic compounds (from compound 2 to compound 12) was performed against AChE (Acetylcholinesterase). There was a wide range of binding affinities shown by these compounds. This work suggests that these substances may have insecticidal and AChE inhibitory properties, and it may be possible to further explore them in the process of creating pesticides that target AChE.

In vitro antioxidant, anti-inflammatory activities and acetylcholinesterase inhibition properties of selected plant extracts

Plant extracts remain an infinite source of bioactive chemicals and an inexhaustible resource for discovering new drugs of natural origin. Thus, in this study, we focused on analysing 29 ethanolic extracts (E1-E29) from selected plants of flora of Poland to assess their antioxidant, anti-inflammatory and acetylcholinesterase inhibitory properties in relation to the chemical profiles of phenolic compounds. The results show that the investigated samples differed in terms of their chemical compositions and biological activities. The extract from Cirsium palustre leaves (E13) possesses the highest phenolic and flavonoid contents as well as antiradical activity in the DPPH (2,2-diphenyl-1-picrylhydrazyl) test (415.28 ± 2.22 µM of Trolox equivalent). On the other hand, the most potent anti-inflammatory agents (at 125 µg/mL) were extracts from Odontites vulgaris herbs (E24), with a COX-2 (cyclooxygenase-2) inhibition percentage of 74.54 ± 0.77, and Erigeron acris flower heads (E22), with a 15-sLOX (soybean 15-lipooxygenase) inhibition percentage of 42.45 ± 3.32. All extracts exhibited moderate acetylcholinesterase inhibitory activity. Moreover, to the best of our knowledge, the present study is the first to report phytochemical and pharmacological analyses of extracts from Anthericum ramosum and Lysimachia europaea.

Arbutin aids in the recovery of dyskinesia in Alzheimer's zebrafish by decreasing the function of acetylcholinesterase

Alzheimer’s disease (AD) is a neurodegenerative disease characterized by oxidative stress, neuroinflammation and decreased levels of neurotransmitters (acetylcholine). AD is a complex pathogenesis disease; currently, no efficient drugs are available to treat Alzheimer’s disease. Several AD drug targets have been identified for the last two decades including acetylcholinesterase (AchE), beta-secretase, gamma-secretase and monoamine oxidase. Most of the FDA-approved drugs are acetylcholinesterase inhibitors. Hence acetylcholinesterase is an important drug target for AD. Arbutin is the active glycosylated hydroquinone with acetylcholinesterase (AChE) inhibitory property isolated from the Arctostaphylos uvaursi. Our current aim is to explore arbutin's anti- Alzheimer’s potential. In this study, molecular docking simulations were done with various AD targets to assess the anti-Alzheimer’s possibilities of arbutin. Furthermore, the zebrafish AD model was established with the help of aluminium chloride (AlCl3). Anti- Alzheimer’s efficiency and dyskinesia potentials of arbutin were assessed with the arbutin-treated zebrafish compared with the positive control drug Rivastigmine. Results of molecular docking simulations exhibited that arbutin plays a crucial role in Alzheimer’s disease progression. Arbutin significantly increased the dyskinesia recovery in the AD zebrafish model and it can be developed into an AD drug by inhibiting the acetylcholinesterase and other AD targets.

Acetylcholinesterase inhibitory activity of Ferula plants and their potential for treatment of Alzheimer's disease.

One of the current strategies in the treatment of Alzheimer's disease is using drugs with acetylcholinesterase (AChE) inhibitory property. The existence of various compounds in plants as a potential source for finding new compounds to treat Alzheimer's disease is a scientific fact. Many secondary metabolites and plant extracts have been reported with the ability to inhibit the AChE activity and improve memory and learning. These compounds can increase the concentration of acetylcholine in the brain and improve cholinergic function in individuals with Alzheimer's disease and reduce the symptoms of this neurological disorder. Plants of Ferula genus are a good source ofbiologically active compounds such as sesquiterpene derivatives, coumarin derivatives and sulfur-containing compounds. Numerous studies on various extracts or purified compounds of Ferula genus have shown that members of this genus have the inhibitory properties on acetylcholinesterase and can also be effective in improving Alzheimer's and amnesia. This review article summarizes studies on plants of Ferula extracts and their derived compounds to find AChE inhibitors.

Acetylcholinesterase Inhibition Properties and Docking Studies of Compounds Based on 6-Hydrazinyl-1,3,4-Trimethyl-1H-Pyrazolo[3,4-b]Pyridine

New compounds based on 6-hydrazinyl-1,3,4-trimethyl-1H-pyrazolo[3,4-b]pyridine (3a and 3b) were synthesized and characterized by FTIR and 1H/13C NMR spectroscopic methods and their in vitro acetylcholinesterase (AChE) inhibition studies were evaluated. Compound 3b (IC50 value 104.4 µM) exhibited stronger AChE inhibitory activity than the reference galantamine compound (IC50 value 139.4 µM). Molecular docking studies were performed to determine the key interactions and possible binding modes between AChE of compounds. The most active one, 3b, showed a binding affinity of -10.28 kcal/mol.

Carboxylate‐ and Sulfonate‐Containing Quinazolin‐4(3H)‐one Rings: Synthesis, Characterization, and Carbonic Anhydrase I–II and Acetylcholinesterase Inhibition Properties

AbstractQuinazolines are a group of bioactive heterocyclic compounds with a wide range of biological activities and have gained an important place in the design of active drugs with various targets due to their pharmacological properties. Carbonic anhydrase (CA) and acetylcholinesterase (AChE) inhibitors are very important pharmacologically. In this study, inhibition effects of newly synthesized quinazolin‐4(3H)‐one derivatives on human erythrocyte CA‐I (hCA‐I) and CA‐II (hCA‐II) isoenzyme and AChE activity were investigated. The structures of the novel compounds were characterized by fourier‐transform infrared (FTIR), nuclear magnetic resonance (NMR), and high‐resolution mass spectroscopy (HRMS). All molecules showed strong inhibitory effect in all three enzymes. 4‐[(4‐Oxo‐2‐(phenoxymethyl)quinazolin‐3(4H)‐ylimino)methyl]phenyl furan‐2‐carboxylate for hCA‐I (IC50: 205 nM), 4‐[(4‐oxo‐2‐(phenoxymethyl)quinazolin‐3(4H)‐ylimino)methyl]phenyl isobutyrate for hCA‐II (IC50: 209 nM), and 4‐[(4‐oxo‐2‐(phenoxymethyl)quinazolin‐3(4H)‐ylimino)methyl]phenyl propionate for AChE (IC50: 14.2 nM) were the molecules that showed the strongest inhibitory effect. Molecular docking studies were carried out to elucidate the possible interaction mechanism of the molecules in the active site of the enzymes. The affinity scores of the most active compounds for hCA‐I, hCA‐II, and AChE were determined as −134.765, −147.423, and −175.354 MolDock Score, respectively.

Synthetic Studies on Tetracyclic Diquinane Lycopodium Alkaloids Magellanine, Magellaninone and Paniculatine.

(-)-Magellanine, (+)-magellaninone, and (+)-paniculatine are three natural products isolated from the Lycopodium family that share a unique 6-5-5-6-fused tetracyclic diquinane core skeleton. Several members of this family have potent s anti-inflammatory and acetylcholinesterase-inhibitory properties and are under development for the treatment of Alzheimer's and other neurodegenerative diseases. Several research groups have undertaken the formal and total syntheses of this class of natural products. This review highlights over 20 reported total syntheses of these three alkaloids and the development of synthetic methods for the assembly of their core skeletons.

A tetrahydroacridine derivative and its conjugate with gold nanoparticles: promising agents for the treatment of Alzheimer's disease.

A new tetrahydroacridine derivative (CHDA) with acetylcholinesterase inhibitory properties was synthesized. Using a range of physicochemical techniques, it was shown that the compound strongly adsorbs onto the surface of planar macroscopic or nanoparticulate gold, forming a nearly full monolayer. The adsorbed CHDA molecules reveal well-defined electrochemical behavior, being irreversibly oxidized to electroactive species. The CHDA also exhibits strong fluorescence, which is effectively quenched after adsorption onto gold via a static quenching mechanism. Both CHDA and its conjugate reveal considerable inhibitory properties against acetylcholinesterase activity, which is promising from the perspective of therapeutic application in the treatment of Alzheimer's disease. Moreover, both agents appear to be non-toxic as demonstrated using in vitro studies. On the other hand, conjugation of CHDA with nanoradiogold particles (Au-198) offers new potential diagnostic perspectives in medical imaging.

One-pot three-component synthesis of novel pyrazolo-acridine derivatives and assessment of their acetylcholinesterase inhibitory properties: An in vitro and in silico study

In this study, the synthesis and characterization of newly designed compounds containing pyrazole, acridine, and benzothiazole groups with their biological activity potentials were evaluated. For this purpose, the starting compound of our study, 1-(benzo[d]thiazol-2-yl)-3-(4-chlorophenyl)-1H-pyrazole-4-carbaldehyde (4), was synthesized according to the Vilsmeier-Haack method. Afterward, a series of new pyrazolo-acridine derivatives (7a-l) were obtained as a result of one-pot three-component reaction of compound 1 with 5,5-dimethyl cyclohexane-1,3‑dione and various aromatic amines. The structures of the synthesized compounds were characterized using FT-IR, 1H NMR, 13C NMR, Mass spectroscopy techniques, and elemental analysis. Then, the enzyme inhibition effects of these compounds on acetylcholinesterase (AChE) were investigated. According to the in vitro AChE enzyme activity studies, the most effective inhibitions of the compounds 7f (0.76±0.19 µM), 7d (0.82±0.33 µM), and 7e (1.70±1.66 µM) were determined from their low Ki values. On the other hand, in silico molecular docking interactions of the respective compounds with AChE (pdb id: 4EY9) were carried out by using AutoDock Vina software. The molecular docking analyses showed the effective molecular interactions of all compounds (7a-7l) with the AChE enzyme from their low binding energy values.

Chemical Composition, Antibacterial, Antiviral, Antioxidant, and Acetylcholinesterase Inhibitory Properties of Essential Oils from Carlina acanthifolia All. roots

The investigation aimed to reveal the chemical composition, antioxidant activities, antibacterial, antiviral, and acetylcholinesterase inhibitory properties of the essential oil of Carlina acanthifolia All. roots. Essential oil was produced by hydrodistillation and analyzed by gas chromatography-mass spectrometry (GC/MS). In the essential oil eight compounds were found. Polyacetylene benzyl-2-furylacetylene (carlina oxide (89.36%) was found as the main constituent. There were also found sesquiterpenes farnezol (Z,E), farnezol (Z,Z), trans-β-farnesene, α-curcumene, γ-curcumene, β-sesquiphellandrene, and benzaldehyde. The Carlinae radix essential oil possessed a strong radical scavenging ability IC50 86.20 μg/mL (ABTS method). Essential oil showed antimicrobial activity against Bacillus cereus (MIC 0.313 μg/mL), Staphylococcus aureus (MIC 1.25 μg/mL), Listeria monocytogenes (MIC-5.0 μg/mL), Proteus vulgaris (MIC 0.625 μg/mL), Salmonella enteritidis (MIC-5.0 μg/mL), Candida albicans (MIC 1.25 μg/mL) and Escherichia coli (MIC 5.0 μg/mL). Investigated essential oil showed significant acetylcholinesterase inhibitory activity (IC50 0.28 μg/mL) in comparison to galanthamine. An essential oil from Carlina acanthifolia demonstrated antiviral effect on human poliovirus-1 (LSc-2ab) by inhibiting the adsorption of the viral particles on the cell lines (Human epithelial type 2). The pharmacological activities demonstrated by the essential oil from C. acanthifolia radix showed its potential application as a remedy or its impact on human health and nutrition.

Analysis of Antioxidant, Acetylcholinesterase Inhibitory Properties and Chemical Composition of Some Indian Himalayan Species of Berberis: A Comparative Study

Background: Methanolic extracts of the stems of six species of Berberis e.g., Berberis umbellata, B. vulgaris (Syn: B. nepalensis), B. insignis, B. asiatica, and B. aristata were studied for their antioxidant properties and acetylcholinesterase inhibitory properties. Materials and Methods : Antioxidant property was studied in different systems of assay e.g., DPPH radical scavenging assay, superoxide radical scavenging assay, nitric oxide scavenging assay, assay to chelate metal. Acetylcholinesterase (AChE) inhibitory property was measured using AChE from electric eel. Results: It was observed that all the extracts scavenged DPPH, superoxide and nitric oxide radical and chelated metal ion in a dose dependent manner. The antioxidant properties were correlated with total phenol content, total flavonoid content, berberine and palmatine content. The AChE inhibitory activities of the extracts were also correlated well with berberine, palmatine, total phenol and total flavonoid content. A few phenolic compounds were detected by GC-MS. Highest activity in all respect was observed in B. aristata. Conclusion: Methanolic extracts of the stems of B. aristata exhibited the highest antioxidant activity.

A General Electro-Synthesis Approach to Amaryllidaceae Alkaloids.

Amaryllidaceae alkaloids appeal to organic chemists with their attractive structures and their impressive antitumor and acetylcholinesterase inhibitory properties. We demonstrate a highly versatile access to this family of natural products. A general protocol with high yields in a sustainable electro‐organic key transformation on a metal‐free anode to spirodienones facilitates functionalization to the alkaloids. The biomimetic syntheses start with the readily available, inexpensive biogenic starting materials methyl gallate, O‐methyl tyramine, and vanillin derivatives. Through known dynamic resolutions, this technology provides access to both enantiomeric series of (epi‐)martidine, (epi‐)crinine, siculine, and galantamine, clinically prescribed for the treatment of Alzheimer's disease.