Identification of tryptophan and β-carboline as paralysins in larvae of the yellow mealworm, Tenebrio molitor

Effect of different post-feeding intervals on the total time of development of the blowfly Lucilia sericata (Diptera: Calliphoridae)

“…The concentration of these toxins is low in young larvae and increases during development peaking just after pupariation. A possible role of these molecules, with a paralytic effect in the late immature stages, could be the immobilization of the larvae just before pupariation [24]. So it seems that it is not just a behavioral response of the larva to its environment to either continue with dispersal or to start pupariation, but also a chemical process.…”

Crystal structure of the Anopheles gambiae 3-hydroxykynurenine transaminase

“…Indeed, several invertebrate species, which depend on the kynurenine pathway for dietary tryptophan oxidation, are highly sensitive to perturbations in the physiological balance of its intermediate metabolites (13,14). In particular, the exogenous administration of 3-HK in adult insects profoundly affects locomotive activity and can culminate in irreversible paralysis and death (15,16). The biochemical description of the kynurenine pathway from a number of vertebrates revealed that 3-HK can undergo two alternative fates: either (i) it is hydrolyzed by a specific kynureninase to alanine and 3-hydroxyanthranilic acid, feeding the de novo synthesis of the essential cofactor NAD (17), or (ii) it can be directly converted into the more chemically stable compound xanthurenic acid (XA) by irreversible transamination.…”

Isolation and Characterization of Norharmane from <I>Reticulitermes</I> Termites (Isoptera: Rhinotermitidae)

“…Another previously identiÞed ␤-carboline in insects is 1,2,3,4,-tetrahydro-␤-carboline-3-carboxylic acid (THCA), which occurs in larvae of the yellow mealworm, Tenebrio molitor L. (Kotanen et al 2003). THCA is a defensive compound and belongs to a group of molecules termed "paralsins" for their highly toxic effects on adult insects of the same species and other species (Kotanen et al 2003).…”