• Journal of the Korean Chemical Society
• /
• v.60 no.2
• /
• pp.125-130
• /
• 2016

With the goal of developing Alzheimer’s disease therapeutics, we have designed and synthesized new triazole linked decursinol derivatives having potency inhibitory activities against cholinesterase [acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE)]. Since inhibition of cholinesterase (ChE) is still considered to be one of the most effective targets to treat AD patients, many new classes of ChE inhibitors have been synthesized. In an effort of identifying new type of cholinergic drug, decursinol derivatives 11-17 have been synthesized between decursinol and other biological interesting compounds such as lipoic acid, polyphenols, etc by using the click reaction and then evaluated their biological activities. Compound 12 (IC₅₀ = 5.89 ± 0.31 mM against BuChE) showed more effective inhibitory activity against BuChE than galantamine (IC₅₀ = 9.4 ± 2.5 mM). Decursinol derivatives can be considered a new class inhibitor for BuChE and can be applied to be a novel drug candidate to treat AD patients.

• Bulletin of the Korean Chemical Society
• /
• v.32 no.8
• /
• pp.2593-2598
• /
• 2011

Polyphenols (PPs) are known as antioxidant compounds having benign biological activities. In this paper, a series of hybrid molecules between the free or acetyl protected polyphenol compounds were synthesized and their in vitro antioxidant activity (DPPH assay) and cholinesterase [acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE)] inhibition activities were evaluated. As expected, free phenolic hybrid compounds (6 and 8) showed better antioxidant activity than acetyl protected hybrid compounds (5 and 7) from DPPH assay. But the contrast result was obtained from BuChE inhibition assay. Acetyl protected hybrid compounds (5 and 7) showed better inhibition activity for BuChE than free phenolic hybrid compounds (6 and 8). Specifically, 10 (AcFA-AcFA) were shown as an effective inhibitor of BuChE ($IC_{50}=2.3{\pm}0.3{\mu}M$) and also had a great selectivity for BuChE over AChE (more than 170 fold). Inhibition kinetic studies with acetyl protected compounds (5, 7, 9, and 10) indicated that 5, 7 and 10 are a hyperbolic mixed-type inhibition and 10 is a competitive inhibition type. The binding affinity (Ki) value of 10 to BuChE is $2.32{\pm}0.15{\mu}M$.

• Bulletin of the Korean Chemical Society
• /
• v.32 no.spc8
• /
• pp.2997-3002
• /
• 2011

A series of hybrid molecules between (R)-lipoic acid (ALA) and the acetylated or methylated polyphenol compounds were synthesized and their in vitro cholinesterase [acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE)] inhibition activities were checked. The $IC_{50}$ values of all hybrid molecules for a BuChE inhibition were lower than those of the single parent compounds. Specifically, ALA-acetyl protected caffeic acid (11, ALA-AcCA) was shown as an effective inhibitor of BuChE ($IC_{50}=0.5{\pm}0.2\;{\mu}M$) and also had a great selectivity for BuChE over AChE (more than 800 fold). Inhibition kinetic study indicated that 11 is a mixed inhibition type. Its binding affinity ($K_i$) value to BuChE is $1.52{\pm}0.18\;{\mu}M$.

• Bulletin of the Korean Chemical Society
• /
• v.34 no.4
• /
• pp.1025-1029
• /
• 2013

In the previous paper (Bull. Korean Chem. Soc., 2011, 32, 2997), the hybrid molecules between ${\alpha}$-lipoic acid (ALA) and polyphenols (PPs) connected with neutral 2-(2-aminoethoxy)ethanol linker (linker-1) showed new biological activity such as butyrylcholinesterase (BuChE) inhibition. In order to increase the binding affinity of the hybrid compounds to cholinesterase (ChE), the neutral 2-(2-aminoethoxy)ethanol (linker 1) was switched to the cationic 2-(piperazin-1-yl)ethanol linker (linker 2). The $IC_{50}$ values of the linker-2 hybrid molecules for BuChE inhibition were lower than those of linker-1 hybrid molecules (except 9-2) and they also had the same great selectivity for BuChE over AChE (> 800 fold) as linker-1 hybrid molecules. ALA-acetyl caffeic acid (10-2, ALA-AcCA) was shown as an effective inhibitor of BuChE ($IC_{50}=0.44{\pm}0.24{\mu}M$). A kinetic study using 7-2 showed that it is the same mixed type inhibition as 7-1. Its inhibition constant (Ki) to BuChE is $4.3{\pm}0.09{\mu}M$.

• Bulletin of the Korean Chemical Society
• /
• v.34 no.11
• /
• pp.3322-3326
• /
• 2013

A series of hybrid molecules between (${\alpha}$)-lipoic acid (ALA) and benzyl piperazines were synthesized and their in vitro cholinesterase [acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE)] inhibitory activities were evaluated. Even though the parent compounds did not show any inhibitory activity against cholinesterase (ChE), all hybrid molecules showed BuChE inhibitory activity. Some hybrid compounds also displayed AChE inhibitory activity. Specifically, ALA-1-(3-methylbenzyl)piperazine (15) was shown to be an effective inhibitor of both BuChE ($IC_{50}=2.3{\pm}0.7{\mu}M$) and AChE ($IC_{50}=30.31{\pm}0.64{\mu}M$). An inhibition kinetic study using compound 15 indicated a mixed inhibition type. Its binding affinity ($K_i$) value to BuChE is $2.91{\pm}0.15{\mu}M$.

• Applied Biological Chemistry
• /
• v.38 no.2
• /
• pp.174-178
• /
• 1995

The purpose of this study was to investigate a role of cytochrome $P_{450}$, for the toxicity of the phosalone in in vitro and in vivo bioactivation systems. The bimolecular inhibition rate constants$(k_i)$ of the phosalone to acetylcholinesterase(AChE) and butyrylcholinesterase(BuChE) were approximately $10^2M^{-1}{\cdot}min^{-1}$, respectively, which meant a poor inhibitor. The potency of the phosalone as an inhibitor of AChE and BuChE was increased about 300 and 40 fold, respectively, when the inhibitor and the ChE were incubated with microsomes fortified with NADPH compared with microsome alone. Piperonyl butoxide(PB) addition to these coupled systems greatly reduced the inhibition of both target enzymes by blocking a bioactivation process. The $I_{50}$ value of the Phosalone alone for rat brain AChE was 170 mg/kg. When PB was pretreated, that value was altered to 42.5 mg/kg. PB pretreatment synergized the inhibition of brain AChE with four times. Rat blood erythrocyte AChE and plasma BuChE were similarly inhibited in vivo by the phosalone and PB pretreatment didn't affect significantly the pattern of the inhibition. The in vivo studies showed different results in the role of cytochrome $P_{450}$ from those of the in vitro studies.

• Proceedings of the PSK Conference
• /
• 2002.10a
• /
• pp.377.1-377.1
• /
• 2002

Neuroscience and molecular biology studies show that inappropriate butyrylcholinesterase (BuChE) activity as well as acetylcholinesterase (AChE) activity increases the risk and/or progression of Alzheimer's disease. BuChE may also regarded to participate in the transformation of Abeta (${\beta}$-amyloid) from an initially benign form to an eventually malignant form associated with neuritic tissue degeneration and clinical dementia. (omitted)

• Proceedings of the PSK Conference
• /
• 2003.04a
• /
• pp.259.3-260
• /
• 2003

Alzheimer's disease(AD) is the most common cause of senile dementia in elderly people and the causes of AD are currently not fully understood. However, AD is generally understood to be associated with reduced levels of acetylcholine in the brain as cholinergic neurons are lost and cholinergic neurotransmission declines. There are growing evidences that two types of cholinesterase(ChE), i.e., acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) both play important roles in the regulation of acetylcholine level in brain and thus may have a crucial role in the development and progression of AD. (omitted)

• Bulletin of the Korean Chemical Society
• /
• v.35 no.6
• /
• pp.1681-1686
• /
• 2014

A series of hybrid molecules between (${\alpha}$)-lipoic acid (ALA) and 4-amino-1-benzyl piperidines were synthesized and their in vitro cholinesterase (acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE)) inhibitory activities were evaluated. Even though the parent compounds did not exhibit any inhibitory activity against cholinesterase (ChE) with the exception of compound 14 ($IC_{50}=255.26{\pm}4.41$ against BuChE), all hybrid molecules demonstrated BuChE inhibitory activity. Some hybrid compounds also displayed AChE inhibitory activity. Specifically, compound 17 was shown to be an effective inhibitor against both AChE ($IC_{50}=1.75{\pm}0.30{\mu}M$) and BuChE ($IC_{50}=5.61{\pm}1.25{\mu}M$) comparable to galantamine ($IC_{50}=1.7{\pm}0.9{\mu}M$ against AChE and $IC_{50}=9.4{\pm}2.5{\mu}M$ against BuChE). Inhibition kinetic studies using compound 17 indicated a mixed inhibition type for AChE and a noncompetitive inhibition type for BuChE. Its binding affinity ($K_i$) values to AChE and BuChE were $3.8{\pm}0.005{\mu}M$ and $7.0{\pm}0.04{\mu}M$, respectively.

• Journal of Ginseng Research
• /
• v.35 no.4
• /
• pp.421-428
• /
• 2011

This study evaluated cholineresterase inhibitory activity of Korean white ginseng extract (WGE), red ginseng extract (RGE), and black ginseng extract (BGE) and the cholinergic effect on scopolamine (SCOP)-induced amnesic mice. WGE, RGE, and BGE inhibited acetylcholineserase (AChE), as well as butyrylcholineserase (BuChE) in a concentration-dependent manner. BGE presented strong inhibition of AChE with an $IC_{50}$ value of 1.72 mg/mL, followed by WGE (5.89 mg/mL), RGE (6.30 mg/mL), respectively. The inhibitory activity of the three ginseng extracts on BuChE showed similar values among the groups. To better understand the mechanisms of the possible effect of ginseng extract on the cholinergic function, this study assessed the expression of the cholinergic markers of choline acetyltransferase (ChAT) and AChE using western blot and RT-PCR analysis in the brains of amnesic mice. Treatment with ginseng extracts led to inhibition of AChE expression and, the activation of ChAT expression in the hippocampus and the cerebral cortex of amnesic mice as induced by SCOP. The results suggest that ginseng extracts including BGE, appear to modulate the metabolism of acetylchoine (ACh), which would greatly increase synaptic ACh levels and most potently revert SCOP-induced amnesia.