Bioactivity of the Alkaloids, Norharman and L-N-Methylcrotonosine/Linearisine

The toxic effects of the alkaloids, Norharman and a mixture of L-N-Methylcrotonosine/Linearisine (M/L mixture), on two organisms, Gambusia puncticulata and Veronicella sloanei were determined. The effect of the alkaloids on the fecundity of Thiara granifera was also investigated. Norharman was harmless to G. puncticulata but the M/L mixture inflicted 55.5% mortality on fish populations. The alkaloids had narcotizing, repellent and anti-feedant effects on V. sloanei. The M/L mixture suppressed the development of hatchlings in the brood pouches of T. granifera. Norharman and the M/L mixture reduced the number of hatchlings released from the brood pouches of T. granifera by 60 and 40%, respectively.