Extraction and characterization of phenolic compounds and their potential antioxidant activities

For thousands of years, plant has been widely applied in the medical area and is an important part of human diet. A high content of nutrients could be found in all kinds of plants, and the most outstanding group of nutrients that attracts scientists' attention is the high level of phenolic compounds. Due to the relationship between high phenolic compound content and high antioxidant capacity, plant extracts are expected to become a potential treatment for oxidation stress diseases including diabetes and cancer. However, according to the instability of phenolic compounds to light and oxygen, there are certain difficulties in the extraction of such compounds. But after many years of development, the extraction technology of phenolic compounds has been quite stable, and the only problem is how to obtain high-quality extracts with high efficiency. To further enhance the value of plant extracts, concentration and separation methods are often applied, and when detailed analysis is required, characterization methods including HPLC and LC/GC-MS will be applied to evaluate the number and type of phenolic compounds. A series of antioxidant assays are widely performed in numerous studies to test the antioxidant capacity of the plant extracts, which is also an important basis for evaluating value of extracts. This paper intends to provide a view of a variety of methods used in plants' phenolic compound extraction, separation, and characterization. Furthermore, this review presents the advantages and disadvantages of techniques involved in phenolic compound research and provides selected representative bibliographic examples.

Automated summary

Plants have been widely used in medicine and are an important part of the human diet. Phenolic compounds, with their high antioxidant capacity, have attracted scientists' attention. Although the extraction of these compounds has certain difficulties due to their instability, the extraction technology has become stable over the years. Concentration and separation methods are applied to enhance the value of plant extracts, and characterization methods are used to evaluate the phenolic compounds. Antioxidant assays are widely performed to test the extracts' antioxidant capacity. This paper provides an overview of methods used in phenolic compound extraction, separation, and characterization, and presents the advantages and disadvantages of these techniques.