Abstract ................................................................................................. 190 10.1 Introduction .................................................................................. 190 10.2 Materials and Methods ................................................................. 195 10.3 Rotational Viscometry ................................................................. 197 10.4 Conclusion Remarks .................................................................... 203 10.5 Acknowledgment ......................................................................... 204 Keywords .............................................................................................. 205 References ............................................................................................. 205

PREPARATION OF TWO QUERCETIN DERIVATIVES AND EVALUATION OF THEIR ANTIOXIDATIVE ACTIVITY KATARÍNA VALACHOVÁ1,*, TAMER MAHMOUD TAMER1,2, MIROSLAV VEVERKA3, AND LADISLAV SˇOLTÉS1

1Laboratory of Bioorganic Chemistry of Drugs, Institute of Experimental Pharmacology and Toxicology, SK 81404, Bratislava, Slovakia 2Polymer Materials Research Department, Advanced Technologies and New Materials Research Institute (ATNMRI), City of Scientific Research and Technological Applications (SRTA-City), New Borg El-Arab City, Alexandria 21934, Egypt 3EUROFINS Bel/Novamann Ltd., SK 94002, NovéZámky, Slovakia

*Corresponding author. E-mail: [email protected]

ABSTRACT

In this study, we synthesized phosphatidylcholine quercetin (PCQ) and phosphatidylcholine dihydro quercetin (PCDQ) and assessed their antioxidative activities under acidic conditions, which occurs in vivo during inflammation. We determined IC50 values of both derivatives using two standard spectrophotometric methods-the 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) and 2,2-Diphenyl-1-picrylhydrazyl (DPPH) assays. Further, these methods were used to examine the PCQ and PCDQ electron donor properties. An original rotational viscometric method was used to evaluate the ability of both quercetin derivatives to act as a donor of H atom.