Historically, natural products have played an important role in drug discovery to combat a variety of diseases. Today natural products remain an important source of drugs and drug leads despite the development of high throughput screening of combinatorial libraries during the past two decades. Recently, as oxidative stress has been increasingly recognized as a significant contributing factor in the pathogenesis of various disorders, numerous studies have been performed to explore the positive role of natural antioxidants in the prevention and treatment of oxidative stress-related diseases, such as pulmonary disorders, neurodegeneration, cardiovascular diseases, and cancer. Oxidative stress results from the imbalance between reactive oxygen or nitrogen species (ROS or RNS) and antioxidants. Phenolic natural compounds such as flavonoids, anthocyanins, stilbenes, tanins, and phenolic acids are well known antioxidants that scavenge and therefore potentially protect against ROS- or RNS-induced in vivo damage. However, a large number of phenolic natural products remain unexplored with respect to their antioxidant properties. Furthermore, substantial evidence is needed to elucidate the molecular mechanisms of different classes of phenolic compounds involved in the potential protective effects against oxidative stress.

The objective of this special issue is to highlight the discovery as well as biochemical and pharmacological evaluation of natural phenolic antioxidants. We cordially invite investigators to contribute original research articles, comprehensive reviews, and perspective articles aiming to provide insights into the identification, evaluation, and quality control of phenolic antioxidants and to ultimately form solid scientific basis for the usage of these chemical constituents to prevent and treat oxidative stress-related diseases.

Potential topics include but are not limited to the following:

• Bioactivity guided isolation and identification of new phenolic compounds from natural sources demonstrating in vivo antioxidant activity
• Quality control of phenolic antioxidants and validation of antioxidant assays
• Elucidation of the molecular mechanisms behind antioxidant activities of phenolic natural products
• Pharmacokinetic profiling and bioavailability studies on phenolic compounds