Introduction to natural products analysis

Abstract Natural products are the chemical compounds or substances produced naturally by a living organism via synthetic process and/or semisynthetic that are present in the nature (includes small molecules and complex structure such as urea and Taxol, respectively). Phytochemicals are originated from Greek word “Phyto” means “Plant” and are basically chemical compounds produced via primary or secondary metabolism which have role in biological activities (growth and defense mechanisms against competitor, pathogen, or predators). Phytochemicals are plant-origin chemicals and some of these are required as essential nutrients, having a key role in the maintenance of the healthy status of organisms. Information on the health effects of natural products including phytochemicals is often obtained from animal experiments, cell and tissue culture, and human data. Some of the most important natural products obtained from plants, so-called phytochemicals, are terpenes, alkaloids, and phenolics such as tannins and flavonoids. Natural products can be extracted from matrices by different methods including solvent extraction, solid-phase extraction (SPE) method, supercritical fluid extraction (SFE), microwave-assisted extraction (MAE), ultrasonic-assisted extraction (UAE), pulsed electric field (PEF) extraction, enzyme-assisted extraction (EAE), and pressurized liquid extraction (PLE). The advanced and modern chromatographic techniques are used to isolate and purify natural products. Different procedures of spectroscopy like ultraviolet-visible (UV) spectroscopy, mass spectrometry (MS), nuclear magnetic resonance (NMR) spectroscopy, and infrared (IR) spectroscopy are used to determine the structure of molecules. A number of natural products, especially phytochemicals, have demonstrated significant biological properties like antiinflammatory and antioxidant activity, allowing to decrease the risk of cardiovascular disease, anticancer, type 2 diabetes, cortical and subcapsular cataract, and progression in Alzheimer’s disease. The purpose of this chapter is to give an overview of the analysis techniques of natural products, with special emphasis on phytochemicals.