Search results for "cholinesterase"

Chemical composition, antioxidant and anticholinesterase activity of the essential oil of algerian cachrys sicula L

2021

In this work, in order to explore a new Algerian medicinal plant used in traditional medicine, the essential oil of the leaves of Cachrys sicula L. (Apiaceae) collected from Algeria, obtained by hydrodistillation, was analyzed by GC/MS. Thirty-two compounds were identified accounting for 98.6% of the total oil, which is characterized by a high content of monoterpene hydrocarbons (74.8%). The main constituents of the essential oil were β-pinene (17.9%), sabinene (17.8%), myrcene (12%), and α-pinene (11.4%). In vitro antioxidant activity of the essential oil was assayed by three methods, namely ABTS•+, metal chelating, and DPPH• assays. The antioxidant activity of the oil was higher in the AB…

THE EFFECTS OF MUSCARINIC AGONISTS AND ANTAGONISTS ON ACETYLCHOLINE RELEASE FROM PERIPHERAL CHOLINERGIC NERVES IN THE ABSENCE AND PRESENCE OF A CHOLI…

1980

Uptake of Acetylcholine by Bean Hypocotyl Hooks

1978

Summary The uptake of acetylcholine by etiolated hypocotyl hooks of beans ( Phaseolus vulgaris L.) is influenced by light and the pH-value of the incubation medium. Acetylcholine is hydrolysed up to 90 % during the uptake. The hydrolysis is inhibited by pH-value lower than 6.0 and by eserine, an inhibitor of the acetylcholinesterase. The high amount of hydrolysis is a serious problem in experiments involving acetylcholine and necessitates the inclusions of adequate controls without which direct effects of acetylcholine cannot be distinguished from reactions of its metabolic products.

Elimination of Parathion by Hemoperfusion in Severe E 605 ForteR Intoxication in Vivo

1978

Severe parathion (P) intoxication results in complete inhibition of cholinesterase activity and toxic accumulation of acetylcholine. Besides these well known biochemical changes, there is evidence of direct toxic effects on the cardio-vascular system which may prove fatal due to an excess of P.

Chapter 17: The cholinesterases: a discussion of some unanswered questions

1993

Publisher Summary During the past three decades, a vast body of specificity and kinetic data relating to the cholinesterases has accumulated, which must now be explained by the extremely interesting new sequence and X-ray crystallographic results presented by MassouliC et al. As this chapter shows, the cholinesterases are remarkable among enzymes in having a broad specificity embracing both charged and uncharged substrates but with a clearly expressed preference, at any rate in the aliphatic series, for the acylcholine configuration: a classical example of the principle of complementariness between substrate and active site as the basis for enzyme action. It is well known that AChE exists i…

Chemie an starren Grenzflächen, 10. Kinetisches Verhalten einiger an „Isothiocyanato-Aerosil” immobilisierter Esterasen – Analogversuche mit Insulin

1988

Amino-Aerosil wird mit Thiophosgen nach Gl. (1) in Isothiocyanato-Aerosil 2 (NCS-Aerosil) ubergefuhrt. Trypsin, Cholinesterase und Acetylcholinesterase werden an 2 nach Gl. (2) immobilisiert. Die Aktivitat der immobilisierten Esterasen wird untersucht auf (a) Lagerstabilitat, (b) Temperaturbestandigkeit und (c) pH-Abhangigkeit. Das kinetische Verhalten der immobilisierten Enzyme wird verglichen mit dem der freien, aber mit n-Butylisothiocyanat behandelten Esterasen. Am Beispiel der Cholinesterase, die uber unterschiedliche Ankergruppen mit Aerosil verknupft wurde, wird der Einflus unterschiedlicher Spacergruppen auf die Hydrolysegeschwindigkeit studiert. Aerosile, die mit Acetylcholin-Analo…

Acetylcholine esterase: the structure.

1991

Biochemical Characterization of an Acetylcholine-hydrolyzing Enzyme from Bean Seedlings.

1980

An acetylcholine hydrolyzing enzyme was prepared and purified (40 times) from dwarf bean hypocotyl hooks. The purity of the enzyme was proved by polyacrylamide gel electrophoresis. The molecular weight of the enzyme was determined to be 65,000 daltons. Enzyme activity was the highest at pH 8.0 and between 30 and 36 C. The enzyme had an apparent affinity constant (K(m)) for acetylcholine of 460/micromolar. The affinity for substrate analogs increased from butyrylthiocholine to propionylthiocholine to acetylthiocholine. The enzyme activity was inhibited by choline, neostigmine, physostigmine, manganese, and calcium. Magnesium had no influence on the enzyme activity. We conclude that the enzym…

ChemInform Abstract: Synthetic Approaches Towards Huperzine A and B

2015

Huperzine A and B are potent acetylcholinesterase inhibitors and promising against Alzheimer's disease. Completed and formal total syntheses of these medically relevant alkaloids are presented and discussed.

(±)- BIGI-3h: Pentatarget-Directed Ligand combining Cholinesterase, Monoamine Oxidase, and Glycogen Synthase Kinase 3β Inhibition with Calcium Channe…

2021

Multitarget-directed ligands (MTDLs) are considered a promising therapeutic strategy to address the multifactorial nature of Alzheimer's disease (AD). Novel MTDLs have been designed as inhibitors of human acetylcholinesterases/butyrylcholinesterases, monoamine oxidase A/B, and glycogen synthase kinase 3β and as calcium channel antagonists via the Biginelli multicomponent reaction. Among these MTDLs, (±)-BIGI-3h was identified as a promising new hit compound showing in vitro balanced activities toward the aforementioned recognized AD targets. Additional in vitro studies demonstrated antioxidant effects and brain penetration, along with the ability to inhibit the aggregation of both τ protein…