Novel polyfunctionalized antioxidants, 5-S-lipoylhydroxytyrosol (1) and its disulfide 2, trisulfide 3, and tetrasulfide 4, were prepd. from tyrosol and dihydrolipoic acid in the presence, when appropriate, of sulfur. Compd. 1 exhibited significant activity in the ferric reducing/antioxidant power (FRAP) assay (1.60 Trolox equiv), whereas polysulfides 2-4 were more efficient in the DPPH redn. assay (88-93% redn. vs 68% by Trolox). At 10 μM concn., all compds. 1-4 proved to be efficient hydroxyl radical scavengers (56-69% inhibition) in a Fenton reaction assay. When administered to human HepG2 cells, 1-4 proved to be nontoxic and exhibited marked protective effects against reactive oxygen species (ROS) generation (60-84% inhibition at 1 μM concn.) and cell damage induced by 400 μM tert-butylhydroperoxide. All compds. 1-4 exhibited overall greater antioxidant activity than hydroxytyrosol.
Synthesis and Bioactivity Profile of 5-S-Lipoylhydroxytyrosol-Based Multidefense Antioxidants with a Sizeable (Poly)sulfide Chain / Panzella, Lucia; Verotta, L.; Goya, L.; Ramos, S.; Martin, M. A.; Bravo, L.; Napolitano, Alessandra; D'Ischia, Marco. - In: JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY. - ISSN 0021-8561. - 61:8(2013), pp. 1710-1717. [10.1021/jf302690c]
Synthesis and Bioactivity Profile of 5-S-Lipoylhydroxytyrosol-Based Multidefense Antioxidants with a Sizeable (Poly)sulfide Chain
PANZELLA, LUCIA;NAPOLITANO, ALESSANDRA;D'ISCHIA, MARCO
2013
Abstract
Novel polyfunctionalized antioxidants, 5-S-lipoylhydroxytyrosol (1) and its disulfide 2, trisulfide 3, and tetrasulfide 4, were prepd. from tyrosol and dihydrolipoic acid in the presence, when appropriate, of sulfur. Compd. 1 exhibited significant activity in the ferric reducing/antioxidant power (FRAP) assay (1.60 Trolox equiv), whereas polysulfides 2-4 were more efficient in the DPPH redn. assay (88-93% redn. vs 68% by Trolox). At 10 μM concn., all compds. 1-4 proved to be efficient hydroxyl radical scavengers (56-69% inhibition) in a Fenton reaction assay. When administered to human HepG2 cells, 1-4 proved to be nontoxic and exhibited marked protective effects against reactive oxygen species (ROS) generation (60-84% inhibition at 1 μM concn.) and cell damage induced by 400 μM tert-butylhydroperoxide. All compds. 1-4 exhibited overall greater antioxidant activity than hydroxytyrosol.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
