Irritant potential of some constituents from the seeds of Caesalpinia bonducella (L.) Fleming

The irritant potential of four triterpenoids, isolated for the first time from the seeds of Caesalpinia bonducella , identified as alpha-amyrin [12-ursen-3beta-ol], beta-amyrin [12-oleanex-3beta-ol], lupeol [lup-20(29)-en-3beta-ol] and lupeol acetate [lup-20(29)-en-3beta-yl acetate] was investigated by open mouse ear assay, evaluating their ID50 (irritant dose in 50% animals) after acute effects and by irritant units (IU) after chronic effects. alpha-Amyrin, lupeol acetate and beta-amyrin were the most potent and persistent irritant compounds with red weals of 1.5-2.1 cm diameter areas of the animal skin and with lowest ID50 =0.078, 0.186 and 0.190 mg/10 mul after 1.5, 2.10 and 3.5 h, respectively. Their reactions lasted for 24 h with IU=2.5; 0.312 and 1.25 mg/10 mul, respectively. Lupeol was the least irritant and least persistent compound with ID50 =0.603 mg/10 mul after 4.5 h. Its reaction subsided before 24 h.