Altemicidin is a monoterpene alkaloid originally isolated from S. sioyaensis with acaricidal and anticancer activities.1 It is acaricidal to two-spotted spider mites (T. urticae) in a greenhouse pot test at concentrations of 10 and 100 ppm. Altemicidin inhibits the growth of murine L1210 lymphocytic leukemia and IMC carcinoma cells (IC50s = 0.84 and 0.82 µg/ml, respectively). It is toxic to mice with an LD50 value of 0.3 mg/kg.
1.Takahashi, A., Kurasawa, S., Ikeda, D., et al.Altemicidin, a new acaricidal and antitumor substance. I. Taxonomy, fermentation, isolation and physico-chemical and biological propertiesJ. Antibiot. (Tokyo)42(11)1556-1561(1989)