*2.6.2 Soxhlet extraction*

*Bioactive Compounds - Biosynthesis, Characterization and Applications*

It involves many enzymes where the genes encoding of these enzymes need to be uniformly communicate. Lignin is a complex polymer obtained from the oxidizing the coupling of monolignol radicals. The plant*'*s cell wall contains the polymerization of lignin, thus the monolignols has to be transferred from the cytosol and get

By the action of 4CL as well as the corresponding CoA-esters, the biosynthesis of the hydroxycinnamic acids caffeic acid, ferulic acid, 5-hydroxyferulic acid, and sinapic acid from p-coumaric acid, the hydroxycinnamic acids are synthesized through the oxidation of aldehydes, instead of ring substitutions of the free acids. It suggests that the glucosides are messenger of th Coenzme A ester and the ring appears at the level of free acid in the lignin biosynthetic pathway [8, 11].

In the phenylpropanoid pathway, Sinapaldehyde is acquired from the amino acid phenylalanine which is followed by a number of reactions of the hydroxylation and

The coumarins and hydroxycoumarins are synthesized from trans-p-coumaric acid and trans-cinnamic acid in plants respectively, but the complete mechanism of its synthesis is still unknown. The possible way to biosynthetic route that coumarin is through hydroxylation to give coumaric acid, followed by glycosylation to result

It has been a target for genetic engineering of disease resistance in plants, which appears similar to chalcone synthase and it is derived from the condensation of

They are inventing from the hydrolysable tannins and 1,2,3,4,6-penta-O-galloylβ-D-glucopyranose. Gallotannins consist of 10-12 gallic acid moieties per molecule. Ellagitannins are construct from the oxidative of gallic acid residues in pentagalloylglucose molecules which gives in the formation of C-C coupled 3,4,5,3′,4′,5′-hexahy-

By using aqueous organic solvents from solids, the soluble constituents are removed. The selection of solvents should be accurate so that chemical or physical intervention should be within the matrix. In this method, variable such as

*2.5.6 Lignin biosynthesis*

synthesized in the cell wall [10, 11].

*2.5.8 Biosynthesis of sinapoyl esters*

methylation [10, 11].

*2.5.9 Coumarin biosynthesis*

*2.5.10 Stilbene biosynthesis*

*2.6.1 Solid–liquid extraction*

in trans-coumaric acid-2-O-glucoside [8, 11].

*2.5.11 Biosynthesis of gallotannins and ellagitannins*

droxydiphenoyl (HHDP) residues [10, 11].

**2.6 Extraction technologies for phenolic compounds**

p-coumaroyl-CoA with three malonyl-CoA residues [10, 11].

*2.5.7 Hydroxycinnamic acid biosynthesis*

**230**

It usually contains the matrix with pure and hot solvent. In this way the extracted will be greater in the substance. This method is inexpensive related to energy, time and reactant. Soxhlet extraction were done in small scales in batches and can be adapted to continuously in industrial procedure. The main privilege than novel method, such as ultrasound assisted, microwave-assisted, fastidious fluid, and accelerated solvent extractions in terms of industrial implementation, consistency, effectiveness, and extract manipulation. The main disadvantage was the sensitivity of some compounds to the temperature conditions of extraction. The variants of this technique are: high-pressure, automated, ultrasound-assisted, and microwave-assisted Soxhlet extraction [4, 20].
