To enhance the production of oxyprotostemonine, stemocurtisine and stemocurtisinol (the important
insecticidal alkaloids) by root cultures of Stemona curtisii Hook. F. (Thai vernacular, Non Tai Yak, Family
Stemonaceae). The roots were cultured on semi-solid MS medium containing 1 mg/L NAA with different
concentrations of salicylic acid for 16 weeks. The quantity of the individual alkaloids was determined by HPLC.
The highest production of oxyprotostemonine (7.192 mg/g dw), stemocurtisine (0.039 mg/g dw) and
stemocurtisinol (0.197 mg/g dw) occurred when the roots were stimulated by 500 mg/L salicylic acid.