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DOI: 10.1055/s-0031-1282706
Anticholinesterase and free-radical scavenging activity of Corydalis cava alkaloids
The tubers of Corydalis cava Schweigg. & Kort. were extracted with ethanol and the summary alkaloid extract was fractionated in silica gel chromatography column using step gradient elution with hexane, chloroform and ethanol. Repeated column chromatography, preparative TLC and crystallization led to the isolation of fifteen isoquinoline alkaloids. The chemical structures of isolated compounds were determined on the basis of spectroscopic techniques and by comparison with literature data. Isolated alkaloids were tested on ability to inhibit human erythrocyte acetylcholinesterase, serum butyrylcholinesterase (IC50) and for its free-radical scavenging activities (EC50).
Cholinesterase inhibitory activities were determined in vitro by modified spectrophotometric Ellman's method [1]. (+)-canadaline inhibited acetylcholinesterase as well as butyrylcholinesterase in a dose-dependent manner with IC50 values 20.1±1.1µM and 85.2±3.2µM, respectively. (+)-canadine with an IC50 value 12.4±0.9µM was the most potent inhibitor of acetylcholinesterase, whilst (±)-corycavidine and (+)-bulbocapnine were effective inhibitors of butyrylcholinesterase with IC50 values 46.2±2.4µM and 67.0±2.1µM. Other isolated alkaloids were considered inactive (IC50 >100µM).
Free-radical scavenging activities of isolated alkaloids were tested in vitro by means of the DPPH test [2]. The highest activities exhibited (-)-scoulerine, (-)-sinoacutine and (+)-bulbocapnine with EC50 values 102±6.2µM, 209±8.1µM and 279±16.7µM, respectively. Other isolated alkaloids were considered inactive (EC50 >1000µM).
Acknowledgement: The study was supported by grants of GA UK No. 122309 and SVV-2010–263–002.
References: 1. Ellman L, Courtney D, Andreas V, Featherstone R (1961) Biochem Pharm 7: 88–95.
2. Polášek M, Skála P, Opletal L, Jahodár L.(2004) Anal Bioanal Chem 379: 754–758.