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Interactions of Oleanolic Acid, Apigenin, Rutin, Resveratrol and Ferulic Acid with Phosphatidylcholine Lipid Membranes - A Spectroscopic and Machine Learning Study
Biologically active compounds present in the diet can interact with biological membranes (such as cell membranes), changing their properties. Their mutual interactions can influence their respective activities. In this study, we analyzed the interactions of oleanolic acid and phenolic compounds such as apigenin, rutin, resveratrol and ferulic acid with phosphatidylcholine membranes. Spectroscopic methods (fluorescence spectroscopy, dynamic light scattering) and machine learning were applied. The results of structural studies were compared with the antioxidant activity of the investigated substances in lipid membranes. In liposomes loaded with oleanolic acid, the pro-oxidant activity of resveratrol arises from changes in membrane structure, leading to an increased exposure of its hydrophilic region to external radicals. A similar mechanism may be involved in the pro-oxidant action of oleanolic acid. By contrast, apigenin, rutin and ferulic acid are present at the membrane surface. Their presence in this region protects the bilayer from radicals generated in the aqueous phase. Lower antioxidant activity observed in the case of ferulic aid is probably related to weaker interactions of this compound with the membrane, compared to the investigated flavonoids. Appropriate machine learning models for predicting oleanolic acid and phenolic compounds have been developed for the future application of intelligent predictive systems to optimizing manufacturing processes involving liposomes. The most effective regression model turned out to be the MLP 1:1-100-50-50-6:1, identifying resveratrol with a determination index of 0.83.
Phytochemical content of roasted seeds of three white mustard (Sinapis alba L.) varieties differing in their glucosinolate and erucic acid content
Water content, critical micelle concentration of phospholipids and formation of association colloids as factors influencing autoxidation of rapeseed oil
AbstractBACKGROUNDThe exact mechanism of lipid autoxidation in vegetable oils, taking into account physical aspects of this phenomenon, including the role of association colloids, is still not fully understood. The purpose of this study was to consider changes in moisture content and DOPC phospholipid (1,2‐dioleoyl‐sn‐glycero‐3‐phosphocholine) critical micelle concentration (CMC) in rapeseed oil during autoxidation as well as to find the relationship between these parameters and the accumulation of primary and secondary lipid oxidation products.RESULTSThe experiments were performed at initial oil humidity 220 ppm and 700 ppm, with DOPC below and above CMC. The increase in water concentration was favored by the presence of phospholipids above CMC and, at the same time, high initial water level, which favored oxidation processes and the creation of amphiphilic autoxidation products. At relatively high water level and low amphiphilic DOPC concentration, the growth of water content does not affect the concentration of oxidation products.CONCLUSIONAmphiphilic substances play a significant role in increasing the water content of oil. Autoxidation products may reduce CMC of DOPC, but water is able to compensate for the CMC‐reducing effect of oxidation products. The presence of association colloids and initial water content play a crucial role in the oxidation process of rapeseed oil. The increase in water concentration does not cause a sufficiently large increase in the number of micelles or sufficiently significant changes in their structure to effect an increase in the level of oxidation products. The formation of micelles requires an appropriate content of both water and amphiphilic substances derived from seeds (phospholipids). © 2021 Society of Chemical Industry.