**1.16. Phenols**

Phenols contribute to the prevention of various degenerative diseases that act as an antioxidant [41]. Phenols, phenolics, or polyphenolics are chemical constituents that are commonly present as natural color pigments giving fruits of plants their colors. The action of phenylalanine ammonia lyses (PAL) on phenylalanine leads to the synthesis of phenolics in plants. Among the various functions of phenols is in plant defense against pathogens and predators of herbivores and therefore used in the control of human infections caused by pathogens [43]. The most common of phenolic compounds widespread in plants is caffeic acid which is followed by chlorogenic acid, the causal agent of excessively sensitive inflammation of the skin (dermatitis) among humans [27]. Phenolics are natural antioxidants functioning as nutraceuticals and available in red wine, apples, and green tea. They serve as anticancer and anti-inflammatory agents as well as prevent heart diseases.
