Comparison of anti amoebic activity of stereoisomeric diamino and monoamino pregnene alkaloids and their N-methylated analogs

The steroidal alkaloid 3β, 20α-diamino-pregn-5-ene (kurchamine) obtained from the stem bark of Holarrhena antidysenterica is reported to have appreciable amoebicidal activity. Its three stereoisomers namely 3α, 20β-diamino-pregn-5-ene, 3β, 20β-diamino-pregn-5-ene and 3α,20α-diamino-pregn-5-ene and their intermediate stereoisomeric monoamino pregnene alkaloids namely 3β-amino-pregn-5-ene-20-one, 3α-amino-pregn-5-ene-20-one, 20α -amino-pregn-5-ene-3β-ol, 20β-amino-pregn-5-ene-3β-ol were synthesized. The natural stereoisomer and synthesized diamino and monoamino stereoisomers were N-methylated and all the compounds were evaluated for amoebicidal activity comparison. The natural stereoisomer 3β,20α-diamino-pregn-5-ene (kurchamine) was found to be superior than other stereoisomers and N-methylation was found to have insignificant effect on amoebicidal activity of stereoisomers.