Antioxidant Profile of 1‐Monocaffeoyl Glycerol in Lipophobic/Lipophilic Media

Oxidative stress has been generally considered as one trigger of organism imbalance, resulting in lipid peroxidation, DNA damage and protein oxidation, which could be relieved by antioxidant supplement or endogenous antioxidant system. In present study, 1‐monocaffeoyl glycerol (1‐MCG), an amphipathic caffeic acid natural derivative, was enzymatically synthesized by Lipozyme 435, and its antioxidant profile in both lipophilic and lipophobic media was evaluated. The 1‐MCG was identified by HPLC‐UV, HPLC‐ESI‐MS, and 1H/13C‐NMR. Subsequently, antioxidant assays in lipophilic (DPPH assay) and lipophobic (ABTS, ORAC, erythrocyte hemolysis, ROS, MDA, and GPx assays) systems were explored. The better and lasting DPPH· and ABTS+· inhibitions of 1‐MCG than caffeic acid (CA) were related to its better solubilities in ethanol/water media and electron transfer ability. ORAC results suggested the radical scavenging activities of 1‐MCG (5 to 40 µM) were higher than Trolox. Furthermore, the effectiveness of 1‐MCG against AAPH‐induced erythrocytes oxidation indicated that 1‐MCG can effectively inhibit hemolysis. ESEM was also applied to verify the hemolysis inhibition and morphology preservation abilities of 1‐MCG. Besides, results showed 1‐MCG was able to prevent ROS from invasion, reduce production of MDA, up‐regulated GPx activity, terminate lipid peroxidation, and maintain the integrity of the structure and function of erythrocytes. Practical Application As an amphiphilic caffeic acid derivative, 1‐monocaffeoyl glycerol was synthesized, purified, and identified. 1‐Monocaffeoyl glycerol could significantly eliminate radicals including DPPH·, ABTS+·, and AAPH in ethanol, water, and PBS system, respectively. 1‐Monocaffeoyl glycerol could protect erythrocyte from AAPH induced hemolysis.