(–)-Isocorypalmine is an isoquinoline alkaloid and a metabolite of L-tetrahydropalmitine that has been found in Corydalis and has diverse biological activities.1,2,3,4,5 It binds to human dopamine D1-5 receptors with Ki values of 6.2, 41.8, 37.3, 77.4, and 9.5 nM, respectively.2 (–)-Isocorypalmine inhibits Epstein-Barr virus-early antigen (EBV-EA) activation induced by phorbol 12-myristate 13-acetate in Raji cells (IC50 = 300 mol ratio/32 pmol TPA), which is predictive for anti-tumor activity.3 It is cytotoxic to A549, SKOV3, SK-MEL-2, and HCT15 cancer cells (IC50s = 67.32, 47.37, 47.66, and 67.32 μM, respectively).4 (–)-Isocorypalmine is active against clinical strains of C. albicans, C. glabratas, C. krusei, C. parapsilosis, and C. neoformans (MICs = 40-320 μg/ml).5
1.Xiao, W., Zhuang, X., Shen, G., et al.Simultaneous quantification of ?-tetrahydropalmatine and its urine metabolites by ultra high performance liquid chromatography with tandem mass spectrometryJ. Sep. Sci.37(6)696-703(2014) 2.Lee, D.Y.W., Liu, J., Zhang, S., et al.Asymmetric total synthesis of tetrahydroprotoberberine derivatives andevaluation of their binding affinities at dopamine receptorsBioorg. Med. Chem. Lett.27(6)1437-1440(2017) 3.Ito, C., Itoigawa, M., Tokuda, H., et al.Chemopreventive activity of isoquinoline alkaloids from Corydalis plantsPlanta Med.67(5)473-475(2001) 4.Kim, K.H., Piao, C., J., Choi, S.U., et al.New cytotoxic tetrahydroprotoberberine-aporphine dimeric and aporphine alkaloids from Corydalis turtschaninoviiPlanta Med.76(15)1732-1738(2010) 5.Rao, G.-X., Zhang, S., Wang, H.-M., et al.Antifungal alkaloids from the fresh rattan stem of Fibraurea recisa PierreJ. Ethnopharmacol.123(1)1-5(2009)