# Challenge of Utilization Vegetal Extracts as Natural Plant Protection Products
## 4 Plant Extracts as Natural Plant Protection Products
### Methods of Vegetal Extracts Preparation
Vegetal products may be used in the following forms: (i) natural state: whole, fragments, powders or as influenza/infusion, decoction products, macerate, or (ii) phyto-sanitary preparations (extracts, tinctures, syrups) which are easier to administer and not very expensive. Solvent extraction has been shown to be the most commonly used bioactive compound extraction method/technique for plants, involving the extraction of components from a solid or semi-solid sample \begin{table}
\begin{tabular}{c c c} \hline \hline
**Plant/Common Name** & **Extraction/Analysis Method** & **Extract Composition/Pharmacological and Phytosanitary Effects** & **Ref.** \\ \hline \multirow{7}{*}{_Hypericum perfortum_} & Alcoholic extraction (80\% ethanol solution) & \multirow{2}{*}{_Main representative constituents_: polyosaccharides (carbohydrates)} \\  & by by reflux distillation (8 h, 60 \({}^{\circ}\)C water bath) using only dried leaves (60-mesh); & \\  & separation of soluble/insoluble extracts by & and monosaccharides, \\  & centrifugation (4000 rpm)/filtration/drying/ & L-arabine (40.68\%), & \\  & Extracts/EOs were analyzed by GC-MS & D-galactose (36.72\%), mannose (3.58\%), & \\  & system (e.g. Agilent GC-MS system & ramnose (14.38\%), glucose (2.54\%), & \\  & equipped HP-SMS column (30 m x 0.25 m), & xylose (1.83\%), piranose, uronic acid, etc. & \\  & t = 150–300 \({}^{\circ}\)C, 6 \({}^{\circ}\)C/min & \\ \hline \hline \end{tabular}
\end{table} 
Table 2: _Cont._  
Figure 2: Schematic representation of the extraction of active principles from different plants [32]. in a suitable solvent [62; 63; 64; 65; 66]. It can be practiced in several variants depending on the type of compound to be obtained and the cost-benefit criterion: (a) the classical variant, (b) the supercritical fluid variant, (c) with natural deep eutectic solvents or as vegetal oil, and (d) with alternative heating source (ultrasounds and microwaves) [44; 46; 47; 52; 53; 67]. In the extraction technique, the choice of solvent (water, organic solvent (ethanol, methanol), or mixtures of organic solvents (ethyl acetate, hexane, etc.) is essential and depends on the nature of the substance to be extracted and the subsequent treatment to be applied further to the obtained extract [46; 48; 52; 53]. The development of extraction techniques to obtain highly effective separation of all-natural ingredients, irrespective of their concentrations, has prompted numerous comparative studies on the advantages and disadvantages of these separation techniques currently practiced [42; 45; 63]. Numerous restrictions on organic solvents, linked to toxicity and environmental impact, have boosted the identification of new extraction opportunities with modern or \"green\" solvents. Green technologies (e.g., sonoextraction, microwave extraction) have emerged and developed [42; 47; 49; 51; 67; 68] due to a few appreciable advantages: (a) short extraction time, (b) low energy consumption, (c) use of non-toxic environmental solvents (environmentally friendly ones). Also, another direction in solvent extraction is the use of non-polluting \"green solvents\" that are non-volatile organic compounds with high dissolution, low toxicity, low environmental impact, which are usually obtained from renewable resources [46; 48; 49; 52].