Antifeedant Delphinium Diterpenoid Alkaloids. Structure−Activity Relationships

Abstract

The insect antifeedant and toxic activity of the Delphinium diterpene alkaloids 15-acetylcardiopetamine, cardiopetamine along with its amino alcohol, the beta,gamma unsaturated ketone, and the acetylated ketone derivatives were studied in Spodoptera littoralis and Leptinotarsadecemlineata. Cardiopetamine and 15-acetylcardiopetamine strongly inhibited the feeding activity of S. littoralis and L. decemlineata, respectively. Structure-activity studies with S. littoralis showed that the C13 and C15 hydroxy substituents are essential features of the active molecule, while a C13 hydroxy and/or a C15 acetate determined their effect on L.decemlineata. The C11 benzoate group enhanced the biological effect on both insect species. These alkaloids were not toxic to S. littoralis, while their toxicity on L. decemlineata was inversely correlated with their antifeedant effects, the beta,gamma unsaturated ketone derivative being the most toxic. Cardiopetamine showed little antifungal action against several species of plant pathogens and did not have any mutagenic effects on Salmonella typhimurium by means of the Ames test.

Structural diversity and defensive properties of diterpenoid alkaloids

“…In this article, we present a comparative overview of the insecticidal effects (antifeedant and toxic) on Spodoptera littoralis and Leptinotarsa decemlineata, the cytotoxicity on several tumoral cell lines with varying multidrug resistance mechanisms (CT26, SW480, HeLa, SkMel25 and SkMel28), and the antiparasitic effects against Trypanososma cruzi and Leishmania infantum of 67 diterpenoid alkaloids (44 NDAs, and 23 DAs) from several chemical classes (Gonzá lez-Coloma et al 1998, 2004aGonzá lez et al 2005Gonzá lez et al , 2006De Iné s et al 2006), isolated from Aconitum, Delphinium and Consolida species (citations in Gonzá lez-Coloma et al 1998, 2004aDe la Fuente and Reina 1990). …”

In vitro activity of C20-diterpenoid alkaloid derivatives in promastigotes and intracellular amastigotes of Leishmania infantum

“…The insecticidal and anti-feedant activity of NDAs [8][9][10], suggest a defensive role played by these compounds. However, only a few DAs have been studied for their plant defensive and pharmacological properties, including their effects on Trypanosoma cruzi epimastigote forms [9,[11][12][13][14][15] and their neurotoxic effects are unknown.…”

Antifeedant C20 Diterpene Alkaloids

“…Compound 20, a rearranged hetisine with an adamantane-type skeleton, was the strongest CPB antifeedant tested here. Previous studies have shown that the S. littoralis antifeedant effects of several hetisine-type DAs, including 2 ± 6, depended on the OH group at C(13) and C (15), while the presence of a OH group at C(13) and/or of a AcO group at C(15) affected their activity on CPB [10]. Furthermore, the potency as antiplatelet aggregation agents of several atisine-type DAs was closely affected by the presence of an O-substitution at C(15) [11].…”