Hydroxytyrosol 1 is a natural polyphenolic antioxidant present in leafs and fruits of olive tree and in small amount in virgin olive oil. It presents high radical scavenging capacity so protecting cells against oxidative stress. Furthermore, it possesses antiatherogenic, anti-inflammatory and anti-platelet aggregation properties, reducing risk for CVD disease. However, 1 is highly hydrophilic and this has hampered its use as nutraceutical or antioxidant additive in oils or fats. Fatty acids hydroxytyrosyl esters has overcome these limitations. Continuing the research on new derivatives of this natural antioxidant, in order to test the effect on the antioxidant activity of the presence of a double hydroxytyrosyl moiety in a single molecule, we have developed the synthesis of a series of dihydroxytyrosyl esters of dicarboxilic acids. To obtain regioselectively the diesters 3 from 1 the catechol hydroxyls in 1 were previously protected as methyl orthoformate 2 and easily deprotected after esterification. Dihydroxytyrosyl esters 3 constitute a new class of antioxidants and were analyzed for their antioxidant activity. Both chemical (ABTS assay) and biological (DCF assay) experiments were carried out. In vitro studies evidenced in all the derivatives 3 a strong and lipophilicity-dependent enhancement of antioxidant capacity (TEAC) in comparison with that of the already known monohydroxytyrosyl esters of carboxylic fatty acids. In cell environment, MTT experiments demonstrated that these compounds do not inhibit cell proliferation, while either with L6 or HTP-1 cells, high antioxidant activities were measured, although not as strong as in in vitro measurements.
Tofani, D., V., B., Gasperi, T., A., G., Incerpi, S., E., M. (2013). Dihydroxytyrosyl Esters Of Dicarboxilic Acids. Synthesis And Structure/Antioxidant Activity Relationships.
Dihydroxytyrosyl Esters Of Dicarboxilic Acids. Synthesis And Structure/Antioxidant Activity Relationships
TOFANI, DANIELA;GASPERI, TECLA;INCERPI, Sandra;
2013-01-01
Abstract
Hydroxytyrosol 1 is a natural polyphenolic antioxidant present in leafs and fruits of olive tree and in small amount in virgin olive oil. It presents high radical scavenging capacity so protecting cells against oxidative stress. Furthermore, it possesses antiatherogenic, anti-inflammatory and anti-platelet aggregation properties, reducing risk for CVD disease. However, 1 is highly hydrophilic and this has hampered its use as nutraceutical or antioxidant additive in oils or fats. Fatty acids hydroxytyrosyl esters has overcome these limitations. Continuing the research on new derivatives of this natural antioxidant, in order to test the effect on the antioxidant activity of the presence of a double hydroxytyrosyl moiety in a single molecule, we have developed the synthesis of a series of dihydroxytyrosyl esters of dicarboxilic acids. To obtain regioselectively the diesters 3 from 1 the catechol hydroxyls in 1 were previously protected as methyl orthoformate 2 and easily deprotected after esterification. Dihydroxytyrosyl esters 3 constitute a new class of antioxidants and were analyzed for their antioxidant activity. Both chemical (ABTS assay) and biological (DCF assay) experiments were carried out. In vitro studies evidenced in all the derivatives 3 a strong and lipophilicity-dependent enhancement of antioxidant capacity (TEAC) in comparison with that of the already known monohydroxytyrosyl esters of carboxylic fatty acids. In cell environment, MTT experiments demonstrated that these compounds do not inhibit cell proliferation, while either with L6 or HTP-1 cells, high antioxidant activities were measured, although not as strong as in in vitro measurements.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
