Alzheimer Disease and Acetylcholinesterase Inhibitors

Alzheimer\u27s disease (AD) or Alzheimer\u27s is a is a chronic neurodegenerative disorder. It\u27s characterized by loss of neurons and synapses in the cerebral cortex and certain subcortical regions. AD patients are identified by problems with memory and language, getting lost and desorientation. AD affects about 6% of people 65 years and older but 4% to 5% of cases are younger.1 It is one of the most costly diseases in the world. In 2015, there were about 48 million people worldwide with AD. To prevent AD, intellectual activities such as reading and playing chess are recommended. In muslim countries, learning quran is linked to a reduced risk of AD. The cause for most Alzheimer\u27s cases is still mostly unknown except for 1% to 5% of cases linked to genetic factors AD has been identified as a protein misfolding disease (proteopathy), caused by plaque accumulation of abnormally folded amyloid beta protein in the brain.2 However, there is another hypothesis which proposes that AD is caused by reduced synthesis of the neurotransmitter acetylcholine.3 The enzyme Acetylcholinesterase breaks acetylcholine down after acetylcholine is used in the brain. Galanthamine, a natural product isolated from Galanthus nivalis, G. woronowii and some other Amaryllidaceae plants and rivastigmine which is a natural derived compound and Donepezil which is a synthetic compound are used as cholinesterase inhibitors. Polyphenols which have been shown to possess antioxidant activity are the principal constituants of the mediterranean diet which is known to decrease the risk of AD. Antioxidants may slow the progression of AD and minimise neuronal degeneration.4 The compounds that exhibit anticholinesterase activity are also related to radical scavenging activity.5 Polyphenols and terpenoids from Lamiaceae plants possess antioxidant and anticholinesterase activitie

Antibacterial Activity and Chemical Composition of Essential Oil of Athamanta sicula L. (Apiaceae) from Algeria

Essential oil extracted from fresh aerial parts of Athamanta sicula L. (syn. Tingara sicula) was analysed by gas phase chomatography coupled to mass spectrometry (GC-MS). The main constituents were: germacrene B (88.5%) and apiol (4.9%). Comparing with the tested bacteria, the growth of Escherichia coli and Klebsiella pneumoniae strains was more inhibited by the essential oil of A. sicula

Antibacterial activity and chemical composition of essential oil of Ammi visnaga L. (Apiaceae) from Constantine, Algeria.

Abstract: Essential oil extracted from fresh aerial parts of Athamanta sicula L. (syn. Tingara sicula) was analysed by gas phase chomatography coupled to mass spectrometry (GC-MS). The main constituents were: germacrene B (88.5%) and apiol (4.9%). Comparing with the tested bacteria, the growth of Escherichia coli and Klebsiella pneumoniae strains was more inhibited by the essential oil of A. sicula

Ene‐yne cross‐metathesis for the preparation of 2,3‐diaryl‐1,3‐dienes

International audienc

Components and antioxidant, anti-inflammatory, anti-ulcer and antinociceptive activities of the endemic species Stachys mialhesi de Noé

One diterpenoid, horminone 1, two flavonoid glycosides, apigenin-7-O-(6″-E-p-coumaroyl)-β-d-glucopyranoside 2, isoscutellarein-7-O-(6″′-O-acetyl-β-d-allopyranosyl-(1 → 2)-β-d-glucopyranoside) 3, were isolated from n-butanolic extract of the aerial parts of Stachys mialhesi de Noé (BESM). Their structures were established on the basis of physical and spectroscopic analysis, and by comparison with the literature data. Antioxidant activity of this extract and the compound 3 was evaluated by the use of the Electron Spin Resonance method in order to visualize the inhibition of the DPPH radical. In this study, we also investigated the anti-inflammatory, anti-ulcer and antinociceptive activities of the BESM in experimental animal models at different doses. Our results showed that the BESM showed a strongest antioxidant activity. It decreased acetic acid induced writhing times; inhibited carrageenan-induced hind paw edema. All of these results suggested that the BESM possesses significant antioxidant, antinociceptive and anti-inflammatory activities

Secondary metabolites, evaluation of the DPPH Free-Radical Scavenging Effect by electron spin resonance and antibacterial activity of the endemic species Stachys circinata

The genus Stachys (Lamiaceae), widely known in folk medicine, contains about 200–300 species in the world [1]. In the Flora of Algeria, this genus is represented by 14 species of which four are endemic [2]. In continuation of our work on Stachys genus [3, 4, 5, 6], we report here the chemical constituents of the n-butanolic and dichloromethane extracts of the aerial parts of the Algerian species Stachys circinata L′Her. which has not been the subject of any previous study. Fifteen known compounds have been identified. We also report here the antibacterial and antioxidant activity of the n-butanolic extract by using disk diffusion and eletron spin resonance methods (ESR).The authors are grateful to the ATRSS and DGRSDT-MESRS (Algeria) for financial support.Peer Reviewe

Isoquinoline derivatives via stepwise regioselective sp2 and sp3C-H bond functionalization

International audienceEfficient and practically attractive stepwise ruthenium- and palladium-catalyzed regioselective C−H bond functionalizations were achieved to produce 4- substituted tetrahydroisoquinoline derivatives featuring various heteroaromatic substructures in moderate to good yields. Both ruthenium- and palladium-based catalytic processes generated nontoxic and easily separable side products