Synergism between the potato glycoalkaloids α-chaconine and α-solanine in inhibition of snail feeding
Abstract
Snails (Helix aspersa L.) were fed filter paper treated with the potato glycoalkaloids, α-solanine and α-chaconine, singly or together. In pure form, both glycoalkaloids deterred feeding, with chaconine being the more active compound. In combination, authentic solanine and chaconine interacted synergistically in their inhibition of feeding. The antifeedant activities of methanolic extracts of tuber peel of the potato varieties Majestic and Sharpe's Express presented via filter paper discs did not differ significantly from those of authentic glycoalkaloid solutions of comparable concentration and ratio. In contrast, feeding inhibition by diluted tuber peel extracts of the variety Homeguard was greater than that elicited by comparable authentic glycoalkaloid solutions suggesting additional inhibitory compound(s) in the peel of this variety. Comparison of data from peel extracts of all three potato varieties and authentic glycoalkaloids indicated that the level of feeding inhibition by the extracts was, at least in part, a consequence of a synergism between solanine and chaconine.