Rational design of a near-infrared fluorescence probe for highly selective sensing butyrylcholinesterase (BChE) and its bioimaging applications in living cell
TALANTA
Authors: Ma, Jianlong; Lu, Xiaofeng; Zhai, Honglin; Li, Qiang; Qiao, Li; Guo, Yong
Abstract
In the current work, a near-infrared (NIR) fluorescent probe (CyClCP) was developed for fast (35 min), highly sensitive (LOD of 3.75 U/L) and selective response to BChE in vitro and in vivo. Upon the addition of BChE, CyClCP could be efficiently activated with remarkable NIR (lambda(em) = 708 nm) fluorescence enhancement and obvious absorbance red shift (581 nm-687 nm). Specifically, according to the subtle differences structural features and substrate preference between BChE and its sister enzyme AChE, CyClCP was constructed by introducing chlorine atom at the ortho-position of the phenolic hydroxyl in the previous reported probe (CyCP). Fortunately, CyClCP exhibited better selectivity towards BChE over AChE compared with CyCP. This molecular design strategy was further rationalized by docking molecular of fluorescence probes (CyClCP and CyCP) and enzymes (BChE and AChE). Finally, CyClCP was membrane permeable and successfully applied to image endogenous BChE level in HepG2 and LO2 cells. Therefore, CyClCP could serve as a promising tool for BChErelated physiological function studies in complex biological systems.
Exploring Structure-Activity Relationship in Tacrine-Squaramide Derivatives as Potent Cholinesterase Inhibitors
BIOMOLECULES
Authors: Svobodova, Barbora; Mezeiova, Eva; Hepnarova, Vendula; Hrabinova, Martina; Muckova, Lubica; Kobrlova, Tereza; Jun, Daniel; Soukup, Ondrej; Luisa Jimeno, Maria; Marco-Contelles, Jose; Korabecny, Jan
Abstract
Tacrine was the first drug to be approved for Alzheimer's disease (AD) treatment, acting as a cholinesterase inhibitor. The neuropathological hallmarks of AD are amyloid-rich senile plaques, neurofibrillary tangles, and neuronal degeneration. The portfolio of currently approved drugs for AD includes acetylcholinesterase inhibitors (AChEIs) and N-methyl-d-aspartate (NMDA) receptor antagonist. Squaric acid is a versatile structural scaffold capable to be easily transformed into amide-bearing compounds that feature both hydrogen bond donor and acceptor groups with the possibility to create multiple interactions with complementary sites. Considering the relatively simple synthesis approach and other interesting properties (rigidity, aromatic character, H-bond formation) of squaramide motif, we combined this scaffold with different tacrine-based derivatives. In this study, we developed 21 novel dimers amalgamating squaric acid with either tacrine, 6-chlorotacrine or 7-methoxytacrine representing various AChEIs. All new derivatives were evaluated for their anti-cholinesterase activities, cytotoxicity using HepG2 cell line and screened to predict their ability to cross the blood-brain barrier. In this contribution, we also report in silico studies of the most potent AChE and BChE inhibitors in the active site of these enzymes.