94236 - Chemistry of Antioxidants

Learning outcomes

At the end of the course students will be familiar with the radical reactions involved in the oxidation of organic materials and biomolecules, and on the main mechanisms for antioxidant protection. The student will know the main classes of natural and synthetic antioxidants and the structure-activity relationships for antioxidant behavior. He/She will have developed a critical attitude in the evaluation of a potential antioxidant. The student will know the main methods to test the antioxidant activity in model systems, either chemical or biomimetic. The student will possess the body of knowledge necessary to select appropriate antioxidant systems to protect manufactured materials or biomaterials.

Course contents

- Structure and properties of free radicals. Main radical reactions. Radical chain-reactions and the autoxidation reaction. Mechanism of autoxidation of main organic substrates. Kinetic aspects.

- Classification of antioxidants according to the mechanism of interference with autoxidation. Preventive antioxidants, chain-breaking antioxidants, other types of antioxidants. Indirect antioxidant activity in biological systems.

- Kinetic aspects of antioxidant activity: how effective is an antioxidant?

- Main structures of chain-breaking antioxidants: phenols, amines, thiols, enols, hydroxylamines, sulfenic and selenenic acids. Structure-activity relationships.

- Examples of natural antioxidants of special importance in nutrition and human health (vitamin E, vitamin C, bioflavonoids, uric acid, glutathione, allicine, essential oils, etc).

- Synergism in antioxidant activity

- Main methods to study antioxidant and test their efficacy. Model systems.

- How to design novel antioxidant systems

- Examples of antioxidants used in the formulation of cosmetic products as preservatives or as active ingredients.

Readings/Bibliography

- L. Valgimigli, D. A. Pratt; Antioxidants in Chemistry and Biology. In: Encyclopedia of Radicals in Chemistry, Biology and Materials, Wiley 2012, Vol. 3 Chapter 56, pag. 1623-1678

- R. Amorati, M. C. Foti, L. Valgimigli. Antioxidant Activity of Essential Oils. J. Agric. Food Chem. 2013, 61, 10835−10847.

- R. Amorati, L. Valgimigli. Advantages and limitations of common testing methods for antioxidants. Free Radical Research, 2015, 49, 633–649.

- Powerpoint presentations used during classes

Teaching methods

Front teaching in class and discussion of current scientific literature concerning the course topics. The teacher will dedicate special effort toward stimulating a critical attitude by the students.

Assessment methods

Colloquium on the topics presented in the lectures, and discussion by the student of a brief thesis prepared from current scientific literature.

Teaching tools

A copy of the PowerPoint presentations used during classes will be made available through the portal Insegnamenti On Line (https://iol.unibo.it/)

Office hours

See the website of Luca Valgimigli