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Biotransformation of Sesquiterpenoids, Ionones, Damascones, Adamantanes, and Aromatic Compounds by Green Algae, Fungi, and Mammals
Published in K. Hüsnü Can Başer, Gerhard Buchbauer, Handbook of Essential Oils, 2020
Yoshinori Asakawa, Yoshiaki Noma
(−)-β-Caryophyllene epoxide (453) was incubated with C. aphidicola for 6 days to afford two metabolites (457 l, 457 m), while Macrophomina phaseolina biotransformed the same substrate to 14- (454) and 15-hydroxy derivatives (457k). The same substrate was treated in A. niger, G. fujikuroi, and R. stolonifer for 8 days and F. lini for 10 days to afford the metabolites 457n, 457o, 457p and 457q, and 457r, respectively. All metabolites were estimated for butyrylcholine esterase inhibitory activity, and compound 457k was found to show potency similar activity to galantamine HBr (IC50 10.9 vs. 8.5 mM) (Choudhary et al., 2006b) (Figure 23.133).
Enzymes
Published in S.J. Mulé, Henry Brill, Chemical and Biological Aspects of Drug Dependence, 2019
Like many other CNS active drugs, cocaine also inhibits cholinesterase in erythrocytes, in Electro-phorus electricus, and in plasma.130,131 In plasma an enhancing action has also been observed when butyrylcholine was used as substrate.132 The inhibitory action of cocaine on cholinesterase was about 5,000 times weaker than that of physo-stigmine.131 At extremely high concentrations (> 10–2 M) cocaine inhibits monoamine oxidase.133,134
Physiology, Biochemistry, and Pathology of Neuromuscular Transmission
Published in Marc H. De Baets, Hans J.G.H. Oosterhuis, Myasthenia Gravis, 2019
The Cholinesterase exists in several forms, the true AChE and the pseudo-cholinesterase (or butyry lcholinesterase, BuChE, so named because of its ability to split butyrylcholine). Both enzymes have a widespread location in the body, including blood plasma (BuChE) and red blood cells (AChE).
Fluorosulfate-containing pyrazole heterocycles as selective BuChE inhibitors: structure-activity relationship and biological evaluation for the treatment of Alzheimer’s disease
Published in Journal of Enzyme Inhibition and Medicinal Chemistry, 2022
Huan-Huan Li, Chengyao Wu, Shi-Long Zhang, Jian-Guo Yang, Hua-Li Qin, Wenjian Tang
Potent inhibitor K3 was subjected to enzyme kinetics analysis to determine the kinetics of BuChE inhibition43–45. As shown in Figure 3(A), the plots of the remaining enzyme activity versus the concentration of enzyme (0, 0.01125, 0.0225, 0.045, 0.090 and 0.18 U/mL) in the presence of different concentrations of compound K3 for the catalysis of butyrylcholine gave a series of straight lines. Concentrations of compound K3 (0, 0.4, 0.8, 1.6 μM) were used respectively, for the determination of reversible as well as irreversible binding of inhibitors at enzyme. In case of compound K3, all the lines intersected at the same point. With the inhibitor concentration increased, the slope of the lines decreased, which indicated that compound K3 was reversible BuChE inhibitors. Kinetic studies of eqBuChE inhibition were performed with the same test conditions, using six concentrations of substrate (0.1‒1 mM) and four concentrations of inhibitor (0‒1.6 μM). The concentration effect of compound K3 on the activity or the catalysis of BuChE at 37 °C was also studied. Assay conditions were the same as described in assay protocol except that the final concentration of enzyme was varied (0‒0.18 U/mL). As shown in Figure 3(B), overlaid reciprocal Lineweaver-Burk plots confirmed it is a typical non-competitive inhibitors because all lines intersect in the second quadrant. And the dissociation constant Ki of compound K3 from the Lineweavere-Burk secondary plots was estimated to be 0.77 μM.
Shaddock (Citrus maxima) peels extract restores cognitive function, cholinergic and purinergic enzyme systems in scopolamine-induced amnesic rats
Published in Drug and Chemical Toxicology, 2022
Ayokunle O. Ademosun, Adeniyi A. Adebayo, Temitope V. Popoola, Ganiyu Oboh
Activities of cholinergic neurotransmitters (acetylcholine and butyrylcholine) are regulated by cholinesterases. Cholinergic system in the central nervous system (CNS) are widely known to play crucial roles in the cognition and memory process (Marisco et al.2013, Hashimoto et al.2014). Studies have related impaired cholinergic system to dementia and other cognitive-related disorder, thus implicating the central cholinergic neurons in the cognitive process (Schliebs and Arendt 2006, Marisco et al.2013, Hashimoto et al.2014, Akinyemi et al.2017). A decrease in (essential) neurotransmitters level causes loss of dissemination of information from the brain and to other parts of the body which results in cognitive impairment. The result revealed that shaddock peels extract administration ameliorated memory dysfunction in scopolamine-treated rats as observed by an improvement of the cholinergic neurotransmitters through inhibition of cholinesterase (AChE and BChE) activities. AChE and BChE inactivate the neurotransmitter acetylcholine (ACh) and are thus viable therapeutic targets in cognitive disorder (Schliebs and Arendt 2006). ACh is a neurotransmitter release from cholinergic neurons, and it has been implicated in cognitive and behavioral functions that are widely disturbed in cognitive-related disorders (Soreq and Seidman 2001, Thanvi and Lo 2004).
Antioxidant, antiepileptic, and anticholinergic properties of 4′,5,7-Trihydroxy-3,6-dimethoxyflavone as natural phenolic compound: a toxicology approach
Published in Toxin Reviews, 2021
Alzheimer’s disease (AD) is initiated with short-term memory loss and worsening more with disorientation, impaired communication, behavior changes, swallowing, speaking, and walking difficulties (Gülçin et al.2016; Taslimi et al. 2017a). hCA inhibitors are clinically used as antiglaucoma and diuretic drugs (Çoban et al. 2007; Topal and Gülçin 2014). Cholinesterase (ChE) enzymes hydrolyze the achethycholine or butyrylcholine to choline and achetate or butyrate. In mammalian cells, there are two important kinds of ChEs, namely, butyrylcholineesterase (BChE) and acetylcholinesterase (AChE), characterized by high concentrations in the placental tissue, nerve cells, muscle, erythrocyte cells, and brain. AChE is a special ChE and also is a key enzyme of the serine class. BChE enzyme hydrolyzes choline esters and several esters. It is also called as pseudo ChE. For nervous system, AChE is significant member, so any negative effects on AChE efficiency may cause to neurotoxicity (Bayrak et al.2017; Ozlem and Nimet 2017). BChE is related in many physiological factors, the most exclusive is the hydrolysis of both choline and noncholine esters, such as aspirin, cocaine, and succinylcholine; therefore, it has a significant role in neurotransmission and anesthesia. Some of the BChE and AChE enzyme inhibitors have detected as drugs developed for the therapy of AD and myasthenia gravis (Öztaskın et al. 2015).