Structure-Antioxidant Activity of p-Coumaric Acid Analogs

TCE

The Chemical Educator

ISSN: 1430-4171 (electronic version)

Table of Contents

Abstract Volume 14 Issue 2 (2009) pp 52-54

Structure-Antioxidant Activity of p-Coumaric Acid Analogs

Leticia U. Colmenares,* Shirley Young-Robbins,† and Alfred E. Asato‡

Natural Science Department, University of Hawaii-Windward, Science Department Kaneohe, HI, 96744, leticia@hawaii.edu and Chemistry Department, University of Hawaii-Manoa, Honolulu, HI 96822
Received November 12, 2007. Accepted September 16, 2008.

Published online: 1 April 2009

Abstract. A series of p-coumaric acid analogs, 3-substituted 4-hydroxycinnamic acids with electron-withdrawing (II: 3-NO₂, III: 3-F) and electron-donating (IV: 3-CH₃, V: 3-OCH₃) substituents are utilized to demonstrate the relationship between their chemical structures and antioxidant properties. Using the ABTS/HRP/H₂O₂ method, the relative decolorization concentration DC₅₀ (dose to scavenge 50% of the free radical) for I-V were determined and found to correlate with electronic substituent effects.

Key Words: Laboratories and Demonstrations; first-year undergraduate/general to upper-division undergraduate; organic chemistry; substitutent effect; antioxidant activity; coumaric acids; phenols; spectrophotometry

(*) Corresponding author. (E-mail: leticia@hawaii.edu)

Article in PDF format (118 KB) HTML format

Supporting Materials:

Details of the experiment including safety information are available in the supporting materPreparation and ¹H-NMR data of p-coumaric acid derivatives (I-IV) and detailed student results of antioxidant activity determination are included in the supporting material (120 KB).