The growing awareness of the adverse health effects of trans‐fats and saturated fats are driving researchers to seek healthy alternatives. A promising strategy to structure liquid oil, called oleogelation, has been a subject of great interest. In the development of oleogels, highly unsaturated oils can be structured through different gelation mechanisms by varying structuring agents (e.g., polymeric or low molecular weight oleogelators). Due to their potential to reduce saturated fat in food products while also providing solid texture without changing the oil's chemical composition and nutritional values, oleogels have been introduced into various products (meat, spread, and confectionary) as alternatives to traditional solid fats. However, the shortcomings of oleogels cannot be ignored, such as the softer texture and the poorer plasticity than traditional solid fat. As the physicochemical properties and functionalities of oleogels are highly dependent on their composition and structuring mechanism, it is possible to obtain a product with desirable functionality by choosing a suitable oleogelator or oil phase. Thus, comprehensive and detailed knowledge regarding the role of oleoglarors, oil phase, and oleogelation mechanism on oleogelation is needed. This review primarily focuses on published information within the last decades addressing how the composition and oleogelation mechanism affect the structure and functionality of oleogels and oleogel‐based products. The factors affecting the oil gelation are summarized concerning three aspects: (i) oleogelator (chemical composition and molecular structure); (ii) oil phase (TAG composition and minor component); and (iii) oleogelation mechanism. Finally, the future perspectives toward oleogels are highlighted. This review aims to deepen the understanding of oleogelation and the rational design of oleogel‐based products.

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Progress in developing synthetic pathways for novel and complex phospholipid species, such as Hemi-bis-(monoacylglycero)phosphates (Hemi-BMPs) and bis-(diacylglycero)phosphates (BDPs), is essential for expanding the knowledge and availability of rare and uncommon phospholipid species. These structurally complex phospholipid species have recently gained more attention with promising applications, as active pharmaceutical ingredient carriers in multiple COVID-19 vaccines, or biomarkers for numerous lysosomal storage disorders and certain types of cancers. The presented work facilitates the production of a range of structurally diverse Hemi-BMP and BDP products intending to increase the availability and thereby the understanding of the underlying chemistry for these high-valuable compounds. The transphosphatidylation of phosphatidylcholine with a variety of structurally diverse monoacylglycerols and diacylglycerols is proceeded by phospholipase D (PLD) catalysis in a biphasic system. Optimization in regard to enzyme loading (5 U), substrate mole ratio (1:5 mol/mol), temperature (30 °C), and aqueous concentration of (18% v/v) afforded the highest conversion for the model transphosphatidylation of phosphatidylcholine with monoolein, yielding 87% in 2 h. The study additionally proposes a reaction mechanism based on molecular simulation, elegantly elaborating the structural constraints (substrate configuration and character of the fatty acid residues) for access to the active site of PLD accordingly for lower yield of BDPs. The successful system designed for the production of high-valuable Hemi-BMP and BDP-analogues demonstrated in this work promises to enhance the understanding of these complex phospholipids, leading to new scientific breakthroughs.

1-Palmitoyl- d 31 -2-oleoyl- d 32 - sn -glycero-3-phosphocholine (POPC- d 63 ) with the palmitoyl and oleoyl chains deuterium-labeled was produced in three steps from 1-palmitoyl-2-hydroxy- sn -glycero-3-phosphocholine, deuterated palmitic acid, and deuterated oleic anhydride. Esterification at the sn -2 position was achieved under standard chemical conditions, using DMAP to catalyze the reaction between the 2-lysolipid and oleic anhydride- d 64 . Complete regioselective sn -1 acyl substitution was achieved in two steps using operationally simple, enzyme-catalyzed regioselective hydrolysis and esterification to substitute the sn -1 chain for a perdeuterated analogue. This method provides chain-deuterated POPC with high chemical purity (>96%) and complete regiopurity, useful for a variety of experimental techniques. This chemoenzymatic semisynthetic approach is a general, modular method of producing highly pure, mixed-acyl phospholipids, where the advantages of both chemical synthesis (efficiency, high yields) and biocatalytic synthesis (specificity, nontoxicity) are realized.

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The fourth enzymatic reaction in the de novo pyrimidine biosynthesis, the oxidation of dihydroorotate to orotate, is catalyzed by dihydroorotate dehydrogenase (DHODH). Enzymes belonging to the DHODH Class II are membrane-bound proteins that use ubiquinones as their electron acceptors. We have designed this study to understand the interaction of an N-terminally truncated human DHODH (HsΔ29DHODH) and the DHODH from Escherichia coli (EcDHODH) with ubiquinone (Q10) in supported lipid membranes using neutron reflectometry (NR). NR has allowed us to determine in situ, under solution conditions, how the enzymes bind to lipid membranes and to unambiguously resolve the location of Q10. Q10 is exclusively located at the center of all of the lipid bilayers investigated, and upon binding, both of the DHODHs penetrate into the hydrophobic region of the outer lipid leaflet towards the Q10. We therefore show that the interaction between the soluble enzymes and the membrane-embedded Q10 is mediated by enzyme penetration. We can also show that EcDHODH binds more efficiently to the surface of simple bilayers consisting of 1-palmitoyl, 2-oleoyl phosphatidylcholine, and tetraoleoyl cardiolipin than HsΔ29DHODH, but does not penetrate into the lipids to the same degree. Our results also highlight the importance of Q10, as well as lipid composition, on enzyme binding.

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