[en] Strychnine is unstable under light in chloroformic solution and is partly transformed in pseudostrychnine, genostrychnine (Nb-oxy-strychnine) and chloromethostrychninium (a quaternary derivative). In other respects the curarizing activity of African Strychnos (e.g. Strychnos usambarensis) is not due to isostrychnine as erroneously written by TURKOVIC (J.Pharm Belg. 1976, 31, 277-286) but to quaternary alkaloids like C-dihydrotoxiferine, C-curarine, afrocurarine and C-calebassine (cf L.ANGENOT et al. Arch. Intern. Pharmacodyn. Ther. 1975, 215, 246-258).