**3.2 Click chemistry and preparation of potential therapeutic agents using natural phenolic compounds**

Search for new compounds, e.g., commonly available phenolic compounds, which can be used by using small molecules (units) to join together as building block with heteroatom links.

A click reactions advantage may include high yield products, and less or no byproducts, simple reaction conditions, simple available starting materials, simple reagents, and environment-friendly solvents (mainly water), which will help in easy and clean isolation, purification, and crystallization. Therefore, click reactions may

#### **Figure 2.**

*Preparation of nano-silver particle using natural phenolic compounds; flavonoids (A), naphthoquinone, gallic acid, and hexagaloyl derivatives (B) via chelation, capping, and stabilized silver ion (C).*

*Research on Natural Phenolic Compounds in FAB-Lab: Nonconventional Industrial… DOI: http://dx.doi.org/10.5772/intechopen.101446*

#### **Figure 3.**

*Curcumin-triazole click reaction product and binding sites between curcumin-triazole click reaction product and alpha amylase.*

offer a good alternative to conventional reactions. This prompted us to use vaniline, eugenol, and curcumin in azide-alkyne cycloaddition (AAC) as a major reaction of click chemistry based on the CuAAC [25].

Curcumin was used as a starting material to prepare three new triazole derivatives via 1,3-dipolar cycloaddition (CuAAC) click reaction to produce three triazole derivatives, which were tested against alpha-amylase, which is an essential metabolic enzyme for carbohydrate metabolism. Curcumin-benzyl triazole derivatives showed effective inhibitory activity against alpha-amylase (83.9% inhibition at concentration 1 mg/ml). In silico studies were also performed to predict the binding affinity of the prepared triazoles toward human α-amylase (PDBID: 1u30) (as presented in **Figure 3**) [25].

#### **3.3 Augmentation of phenolic compounds in edible seed sprouts**

Elicitation and physical stimulation during germination are efficient tools to modulate both chemical and biological contents of many important functional foods and medicinal plants. Elicitors from different origins could be used either alone or with hydroponic sprays during germination and growth or right before harvest. A better knowledge on the effect of certain compounds on biosynthetic pathways in responding to specific treatments with elicitors would be a very useful way to augment the production of secondary metabolites or produce new metabolites. This will help in production of high-quality, healthy, and useful medicinal plants and foods. *Moringa oleifera* (MO) leaves extract contains a several active constituents; alkaloids, carotenoids, glucosinolates, polyphenols, tannins, and saponins and is considered as a good biotic elicitor. It was used in this study to enhance both phenolic and antioxidant contents in germinated alfalfa sprouts. Germination of alfalfa seeds in continuous light and soaking seeds in 0.0625, 0.03125 g/L MO extract before germination significantly increases the levels of total phenolics and their antioxidant activity. The maximum amount of flavonoids was exudated after 8 hours of germination. The optimal concentration to elicit maximum phenolic levels was further used to study the biological activities [26].

#### *3.3.1 Histochemical localization of polyphenolic compounds*

Localization of phenolic compounds in the different organs and tissues of cotton (*Gossypium barbadense* L. var. Giza 86) plant (seeds, stems, leaves, and roots) was conducted in FAB-Lab. The study revealed the presence of polyphenolic compounds as tiny particles in the cytoplasm of some parenchymatous cells surrounding the lysigenous glands. The obtained data shed more light on our previous results on the antimitotic activity of polyphenolic aldehyde gossypol and why does not affect the growing tip of the plant [27].
