Variation of chemical compounds in wild Heliconiini reveals ecological factors involved in the evolution of chemical defenses in mimetic butterflies.

Evolutionary convergence of color pattern in mimetic species is tightly linked with the evolution of chemical defenses. Yet, the evolutionary forces involved in natural variations of chemical defenses in aposematic species are still understudied. Herein, we focus on the evolution of chemical defenses in the butterfly tribe Heliconiini. These neotropical butterflies contain large concentrations of cyanogenic glucosides, cyanide-releasing compounds acting as predator deterrent. These compounds are either de novo synthesized or sequestered from their Passiflora host plant, so that their concentrations may depend on host plant specialization and host plant availability. We sampled 375 wild Heliconiini butterflies across Central and South America, covering 43% species of this clade, and quantify individual variations in the different CGs using liquid chromatography coupled with tandem mass spectrometry. We detected new compounds and important variations in chemical defenses both within and among species. Based on the most recent and well-studied phylogeny of Heliconiini, we show that ecological factors such as mimetic interactions and host plant specialization have a significant association with chemical profiles, but these effects are largely explained by phylogenetic relationships. Our results therefore suggest that shared ancestries largely contribute to chemical defense variation, pointing out at the interaction between historical and ecological factors in the evolution of Müllerian mimicry

An integrative approach to decipher the chemical antagonism between the competing endophytes paraconiothyrium variabile and Bacillus subtilis

An integrative approach combining traditional natural products chemistry, molecular networking, and mass spectrometry imaging has been undertaken to decipher the molecular dialogue between the fungus Paraconiothyrium variabile and the bacterium Bacillus subtilis, which were isolated as endophytes from the conifer Cephalotaxus harringtonia and are characterized by a strong and mutual antibiosis. From this study, we highlight that bacterial surfactins and a fungal tetronic acid are involved in such competition and that the fungus is able to hydrolyze surfactins to fight against the bacterial partner

Natural product total synthesis: how and why?

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Bioactive natural products: Opportunities for total synthesis at the biological interface

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Bioactive natural products: opportunities for total synthesis at the biological interface

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Natural product synthesis, methods and opportunities at the edge of biology

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Biomimetic total synthesis of hybrid polyketide-alkaloids

International audienceBio-inspiration in total synthesis is a way to study the molecular origin and the chemical reactivity of natural compounds.1 It is also a mean to make them accessible to study their biological role and possible applications. Indeed, natural products are used by living organisms to communicate or compete and may have extremely diverse biological properties with useful medicinal, agrochemical and many other applications. We have been interested by complex PKS-NRPS metabolites as potential drug leads and fascinating synthetic targets. It has resulted in biomimetic synthetic strategies that will be exposed during this presentation. Special attention will be paid to the total synthesis of hybrid polyketides in the cytochalasan series and related fungal compounds (Figure),2 concentrating on the use of key biomimetic intermediates to demonstrate how structural complexity can be installed in polycyclic natural products, in connection with complementary biosynthetic experiments and biological screenings

Making compounds inspired by Nature: from total synthesis to medicinal chemistry

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La synthèse de substances naturelles et supernaturelles: stratégies, méthodes et perspectives biologiques

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Natural product total synthesis: Methods and opportunities at the biological interface

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