Classification of Phytochemicals in Plants with Herbal Value

In the past decade, there has been an increased concern about the effects of medicinal plants. Traditional medicinal herbs from diverse habitats and locations can be evaluated as novel treatment and prevention methods for injuries and diseases. Natural products, especially secondary metabolites in medicinal herbs, including those utilized in conventional and ethnic health care systems, provide prospective components for developing novel drug candidates. Phytochemicals have many potential roles as they can protect plants from enemies and act as antimicrobial, anti-inflammatory, antidiabetic, and chemopreventive agents. Their identification and classification are usually according to the chemical formula, such as flavonoids, terpenoids, alkaloids, saponins, phytosterols, carotenoids, essential oils, nonessential amino acids, and aromatic and aliphatic acids. Each group has characteristics, including anticancer, anthelmintic, and antigenotoxic. Additionally, they can offer direct/indirect protection against pathogens or hazardous conditions. Due to their potency and cost-effectiveness, phytochemicals have recently received considerable interest in this area. The impact of medicinal plant utilization is international and has been developing in many countries. Notably, as a potential source of alternative treatments, traditional medicine has attracted attention worldwide. This chapter will focus on classifying phytochemicals (primary and secondary metabolites), identifying some active secondary metabolites (such as flavonoids, alkaloids, terpenoids, phytosterols, and phenolic compounds), studying their potentiality in the treatment of some disorders, and the modern research advances in herbal medicine field.