9H-Pyrido[3,4-b]indole-1-carboxylic acid

β-Carboline-1-carboxylic acid is an alkaloid that has been found in P. quassioides and has diverse biological activities.1,2,3 It reduces LPS-induced increases in MCP-1, TNF-α, IL-6, and IL-1β levels in RAW 264.7 cells when used at a concentration of 15 μg/ml and inhibits the epithelial-to-mesenchymal transition (EMT) induced by TGF-β1 in A549 cells.2 β-Carboline-1-carboxylic acid induces cytotoxicity in CT26.WT, K562, and SGC-7901 cells (IC50s = 14.96, 22.11, and 19.7 μg/ml, respectively) but not HepG2 or A549 cells (IC50s = 36.41 and 41.51 μg/ml, respectively).1 It also inhibits cAMP phosphodiesterase with an IC50 value of 96 μM.3

1.Lai, Z.-Q., Liu, W.-H., Ip, S.-P., et al.Seven alkaloids from Picrasma quassioides and their cytotoxic activitiesChem. Nat. Compd.50(5)884-888(2014) 2.Cui, Y., Jiang, L., Yu, R., et al.β-carboline alkaloids attenuate bleomycin induced pulmonary fibrosis in mice through inhibiting NF-kb/p65 phosphorylation and epithelial-mesenchymal transitionJ. Ethnopharmacol.243112096(2019) 3.Sung, Y.-I., Koike, K., Nikaido, T., et al.Inhibitors of cyclic AMP phosphodiesterase in Picrasma quassioides BENNET, and inhibitory activities of related β-carboline alkaloidsChem. Pharm. Bull. (Tokyo)32(5)1872-1877(1984)