The conversion of lignocellulosic biomass by pyrolysis or hydrothermal liquefaction gives access to a wide variety of molecules that can be used as fuel or as building blocks in the chemical industry. For such purposes, it is necessary to obtain their detailed chemical composition to adapt the conversion process, including the upgrading steps. Petroleomics has emerged as an integral approach to cover a missing link in the investigation bio-oils and linked products. It relies on ultra-high-resolution mass spectrometry to attempt to unravel the contribution of many compounds in complex samples by a non-targeted approach. The most recent developments in petroleomics partially alter the discriminating nature of the non-targeted analyses. However, a peak referring to one chemical formula possibly hides a forest of isomeric compounds, which may present a large chemical diversity concerning the nature of the chemical functions. This identification of chemical functions is essential in the context of the upgrading of bio-oils. The latest developments dedicated to this analytical challenge will be reviewed and discussed, particularly by integrating ion source features and incorporating new steps in the analytical workflow. The representativeness of the data obtained by the petroleomic approach is still an important issue.

Eleven previously undescribed triterpenoid saponins (19, 22, 27, 38-41 and 47-50) were isolated from the roots of Gypsophila perfoliata L. (Caryophyllaceae), together with four known saponins. Their structures were elucidated by comprehensive NMR spectroscopic analyses (¹H, ¹³C NMR, COSY, TOCSY, ROESY, HSQC, and HMBC), complemented by HR-ESI-MS and ESI-MSⁿ data. In addition, UHPLC-Orbitrap-HRMS profiling of the hydroethanolic root extract (GPR) enabled the annotation of 53 GOTCAB-type saponins, including nine monodesmosides bearing a hydroxymethylglutaryl group within the С-28 oligosaccharide chain. The isolated saponins correspond to annotated compounds 1, 2, 19, 22, 27, 29, 30, 38-41 and 47-50. The oligosaccharide moiety attached to C-28 is further substituted with acetyl and (or) methoxycinnamoyl groups. This distinctive saponin profile, characterized by a high diversity of acetylated and/or methoxycinnamoylated GOTCAB structures, highlights the Gypsophila genus as a rich source of highly glycosylated triterpenoid saponins.

Développement méthodologique en FT-ICR MS pour l'analyse de bio-huiles issue de la pyrolyse de la biomasse lignocellulosique: L'utilisation de combustibles fossiles tels que le gaz et le pétrole n'est pas durable. En réalité, les réserves diminuent alors que la population mondiale augmente ainsi que la demande en énergie. Pour surmonter ce problème, des technologies alternatives et plus durables doivent être développées. Parmi les voies renouvelables existantes, la biomasse ligno-cellulosique est une ressource prometteuse. Ce matériau est principalement composé de cellulose, d'hémicelluloses et de lignine. La biomasse peut être convertie en une bio-huile qui peut ensuite être transformée en un biocarburant ou en produits chimiques pour les industries pétrochimiques. Cette ressource est principalement basée sur les sous-produits de l'industrie du bois ou de l'agriculture et n'a donc pas d'impact sur les denrées alimentaires, tant pour l'homme que pour le bétail, ni d'influence sur les surfaces de culture. Avant d'être considéré au niveau industriel, le procédé de pyrolyse doit être parfaitement compris et optimisé afin de produire des composés valorisables avec une bonne sélectivité. En effet, leur utilisation directe est réduite par la complexité importante des mélanges obtenus et la teneur élevée en oxygène des constituants. En conséquence, il est nécessaire de faire subir à ces bio-huiles des traitements catalytiques de désoxygénation et/ou de craquage. Afin de déterminer quels sont les traitements catalytiques les mieux adaptés, la connaissance aussi précise que possible de la composition de ces bio-huiles est requise. L'approche non ciblée de type pétroléomique est parfaitement adaptée et a montré, notamment dans le cadre de la thèse de Jasmine Hertzog, tout son potentiel en combinant l'utilisation de la spectrométrie de masse à résonance cyclotronique des ions à transformée de Fourier (FT ICR–MS) en association avec les sources d'ionisation par électro-nébulisation (ESI), désorption/ionisation laser (LDI) et photo-ionisation à pression atmosphérique (APPI) pour permettre la détection sensible de composés polaires, aromatiques et apolaires. Cette approche assure une analyse exhaustive de la composition chimique d'un mélange complexe mais souffre néanmoins de certaines faiblesses. Il n'est en effet pas possible d'obtenir d'informations quantitatives ou semi-quantitatives ni d'éléments de structure. Ces informations sont importantes pour pouvoir adapter finement les traitements catalytiques des bio-huiles brutes afin d'en accroitre l'efficacité mais également pour déterminer les espèces réfractaires et en améliorer la conversion. Les obtenir par l'emploi de méthodes de spectrométrie de masse avancées constituent les objectifs principaux de ce projet doctoral.

This study reports the in situ hemisynthesis of two novel dipyrromethanes (DPM-1 and DPM-2) from ethyl 1,2-dimethyl-1H-pyrrole-3-carboxylate and natural aldehydes: perillaldehyde from Ammodaucus leucotrichus and cuminaldehyde from cumin seed essential oil. The compounds were synthesized via a double Friedel-Crafts reaction under two catalytic systems: (i) water/ethanol (1:1 v/v) with 0.18 M HCl, and (ii) iodine-catalyzed chloroform. Structural elucidation was achieved using ¹H NMR,¹³C NMR, HSQC, HMBC, and HR-MS. Both derivatives showed significant inhibitory activity against AChE and BChE. DPM-2 was more active against AChE (IC₅₀ = 22.6 ± 0.06 μM) than DPM-1 (IC₅₀ = 51 ± 1.74 μM), and comparable to Galantamine (IC₅₀ = 21.81 ± 1.15 μM). Regarding BChE, DPM-2 (IC₅₀ = 115 ± 1.91 μM) exhibited greater inhibitory potency than DPM-1 (IC₅₀ = 230.41 ± 0.75 μM), and remained close to Galantamine (IC₅₀ = 120.93 ± 1.99 μM). In silico analysis supported their potential as anti-Alzheimer's agents.

Leishmaniasis and toxoplasmosis are neglected parasitic diseases that remain major global health concerns due to limited therapeutic options, drug toxicity, and emerging resistance. In this context, the development of new antiparasitic agents based on natural product scaffolds is highly relevant. Totarol, a naturally occurring abietane-type diterpene isolated from Tetraclinis articulata, was used as a starting scaffold for hemisynthetic modification. A series of totarol-derived functionalized ketones, including α-bromoketone (4) and chalcone derivatives (5a–g), was synthesized and fully characterized by NMR, IR, and HRMS analyses. The compounds were evaluated for their in vitro antiparasitic activity against Leishmania major and Toxoplasma gondii. Compound 4 showed the highest activity, with half-maximal inhibitory concentration (IC₅₀) values of 3.2–5.3 µM against Leishmania major and 6.1 µM against T. gondii. However, compound 4 showed none strong host–cell selectivity, with selectivity indices of 0.79–1.5. Docking against L. major pteridine reductase 1 (PTR1) gave a Glide XP score of −5.3 kcal/mol, and the modeled complex persisted during a 100 ns molecular dynamics simulation. These computational results generate a hypothesis for antileishmanial activity without demonstrating PTR1 inhibition or explaining T. gondii activity. The active structures require substantial optimization of selectivity before consideration as antiparasitic candidates.