Ricinine is a piperidine alkaloid that has been found inR. communisand has diverse biological activities.^1,2,3,4It is an inhibitor of acetylcholinesterase (AChE; IC₅₀= 54.5 µg/ml).²It scavenges ABTS radicals and chelates iron (IC₅₀s = 102.65 and 104.32 µg/ml, respectively). Ricinine is toxic to adultA. gambiaewhen used at a concentration of 0.04 mg/ml in a feeding assay.³It is also toxic to mice with an intraperitoneal LD₅₀value of 340 mg/kg but an oral LD₅₀value of 3,000 mg/kg.¹It has been used as a biomarker of ricin poisoning.⁴

1.Franke, H., Scholl, R., and Aigner, A.Ricin and Ricinus communis in pharmacology and toxicology-from ancient use and "Papyrus Ebers" to modern perspectives and "poisonous plant of the year 2018"Naunyn Schmiedebergs Arch. Pharmacol.392(10)1181-1208(2019) 2.Khan, B.R., Ghous, T., Rasheed, A., et al.Evaluation of anti-acetylcholinesterase activity and antioxidant potential of ricinine (a central nervous system stimulant) isolated from Ricinius communis L.J. Chem. Soc. Pak.38(2)326-332(2016) 3.Wachira, S.W., Omar, S., Jacob, J.W., et al.Toxicity of six plant extracts and two pyridone alkaloids from Ricinus communis against the malaria vector Anopheles gambiaeParasit. Vectors7312(2014) 4.Johnson, R.C., Lemire, S.W., Woolfitt, A.R., et al.Quantification of ricinine in rat and human urine: A biomarker for ricin exposureJ. Anal. Toxicol.29(3)149-155(2005)