Abstract

VARGAS, David; FISCHER, Nikolaus H.  and  YOUNATHAN, Ezzat S.. Inhibition of Phosphofructokinase by Molluscicidal Sesquiterpene Lactones. Rev. Soc. Quím. Méx [online]. 2001, vol.45, n.4, pp.159-162. ISSN 0583-7693.

The effect of ten molluscicidal sesquiterpene lactones was tested on the enzyme phosphofructokinase (PKF) from rabbit muscle. PFK was inhibited irreversibly by all the sesquiterpene lactones tested. 7α-Hydroxy-3-desoxyzaluzanin C (2) exhibited the highest efficacy of inhibition with a K_i value of 90 nM. This is also the lowest K_i reported for inactivation of this enzyme by sesquiterpene lactones. The molluscicidal action of the sesquiterpene lactones tested in this study correlates closely with their potency as PFK inhibitors. Preincubation of 2 with dithiothreitol resulted in loss of inhibitory power of the lactone. The substrates adenosine-5'-triphospate and fructose-6-phosphate protected phosphofructokinase against inhibition by 2. The PFK inhibitory action and molluscicidal activity are most significant when a hydroxyl group is in proximity of the nucleophile receptor site, the α-methylene-γ-lactone moiety.

Keywords : Sesquiterpene lactones; phosphofructokinase inhibitors; molluscicidal activity.