ABSTRACT
A novel series of coumarin derivatives linked to the N-benzyl triazole group were synthesized and evaluated against 15-lipoxygenase (15-LOX), and acetyl- and butyrylcholinesterase (AChE and BuChE) to find the most potent derivative against Alzheimer's disease (AD). Most of the compounds showed weak to moderate activity against ChEs. Among the most active BuChE and 15-LOX inhibitors, 8l and 8n exhibited an excellent neuroprotective effect, higher than the standard drug (quercetin) on the PC12 cell model injured by H2O2 and significantly reduced aggregation of amyloid Aß1-42, with potencies of 1.44 and 1.79 times higher than donepezil, respectively. Compound 8l also showed more activity than butylated hydroxytoluene (BHT) as the reference antioxidant agent in reducing the levels of H2O2 activated by amyloid ß in BV2 microglial cells. Kinetic and ligand-enzyme docking studies were also performed for better understanding of the mode of interaction between the best BuChE inhibitor and the enzyme. Considering the acceptable BuChE and 15-LOX inhibition activities as well as significant neuroprotection, and anti-amyloid aggregation activities, 8l and 8n could be considered as potential MTDLs for further modification and studies against AD.
ABSTRACT
A series of tacrine-based pyrazolo[4',3':5,6]pyrano[2,3-b]quinolines and related compounds were designed and synthesized for targeting AChE, BuChE and 15-LOX enzymes in the field of Alzheimer's disease therapy. Most of compounds showed potent activity against cholinesterases and mild potency toward 15-LOX enzyme. In particular, compounds 29, 32 and 40 displayed inhibition at nano-molar level against AChE and BuChE (IC50s = 0.005-0.08 µM), being more potent than reference drug tacrine. Moreover, compound 32 with IC50 value of 31 µM was the most potent compound against 15-LOX. The cytotoxicity assay on HepG2 cells revealed that compounds 29 and 32 showed no significant cytotoxic activity even at concentration of 50 µM. The cytotoxicity of compounds 29 and 32 was significantly less than that of tacrine at higher concentrations.
Subject(s)
Butyrylcholinesterase/metabolism , Cholinesterase Inhibitors/chemistry , Cholinesterase Inhibitors/pharmacology , Pyrazoles/chemistry , Tacrine/chemistry , Tacrine/pharmacology , Acetylcholinesterase/chemistry , Acetylcholinesterase/metabolism , Arachidonate 15-Lipoxygenase/metabolism , Blood-Brain Barrier/metabolism , Cell Survival/drug effects , Chemistry Techniques, Synthetic , Cholinesterase Inhibitors/chemical synthesis , Cholinesterase Inhibitors/metabolism , Hep G2 Cells , Humans , Lipoxygenase Inhibitors/chemical synthesis , Lipoxygenase Inhibitors/chemistry , Lipoxygenase Inhibitors/metabolism , Lipoxygenase Inhibitors/pharmacology , Molecular Docking Simulation , Protein Conformation , Structure-Activity Relationship , Tacrine/chemical synthesis , Tacrine/metabolismABSTRACT
A crude phenolic glycolipid extract from Mycobacterium bovis BCG was fractionated by column chromatography. A reversed-phase high performance liquid chromatography (HPLC) method with UV detection at 275 nm was developed for simultaneous detection and separation of phenolic glycolipids (PGLs) in Mycobacterium bovis BCG. This analysis provides a good resolution. Different solvent systems and columns for HPLC were compared. A system composed of acetonitrile-water in the ratio of 0-->80% at a flow rate of 0.8 mL/min and C8 analytical column were found to be optimum for HPLC of the phenolic glycolipids. This simple method is therefore appropriate to purify these compounds present in M. bovis extract.