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Lignin-modifying enzymes benefit industry as they can break down lignin; a common waste product of the paper and pulp industry. These enzymes have been used in the refinement of poplar as lignin inhibits the enzymatic hydrolysis of treated poplar and Lignin-modifying enzymes can efficiently degrade the lignin thus fixing this problem. [4]
Flax seeds and sesame seeds contain high levels of lignans. [1] [8] The principal lignan precursor found in flaxseeds is secoisolariciresinol diglucoside.[1] [8] Other foods containing lignans include cereals (rye, wheat, oat and barley), soybeans, tofu, cruciferous vegetables, such as broccoli and cabbage, and some fruits, particularly apricots and strawberries. [1]
For example, laccases play a role in the formation of lignin by promoting the oxidative coupling of monolignols, a family of naturally occurring phenols. [1] [2] Other laccases, such as those produced by the fungus Pleurotus ostreatus, play a role in the degradation of lignin, and can therefore be classed as lignin-modifying enzymes. [3]
Secoisolariciresinol diglucoside can be isolated from de-fatted (hexane extraction) flaxseed by extraction of the lignan polymer precursor with a water/acetone mixture, followed by acetone removal and alkaline hydrolysis.
Lignin is a class of complex organic polymers that form key structural materials in the support tissues of most plants. [1] Lignins are particularly important in the formation of cell walls, especially in wood and bark, because they lend rigidity and do not rot easily. Chemically, lignins are polymers made by cross-linking phenolic precursors. [2]
Lignin is a macromolecule formed from the combination of many phenolic aromatic groups via oxidative coupling. Because of its high stability, lignin is incapable of being broken down through simple decomposition. As a result, white-rot fungi employ a series of enzymes that break lignin down into smaller aromatic rings.
Phenylalanine and tyrosine are the precursors used in the phenylpropanoids biosynthesis. The phenylpropanoids are then used to produce the flavonoids , coumarins , tannins and lignin . The first enzyme involved is phenylalanine ammonia-lyase (PAL) that converts L - phenylalanine to trans - cinnamic acid and ammonia .
The lignin content can be defined as the sum of the amount of acid-insoluble matter and acid-soluble matter, absorbing at 205 nm, after sulphuric acid hydrolysis during specified conditions, as determined by gravimetry and spectrophotometry, in milligrams per gram. In the determination, the samples are hydrolyzed with sulphuric acid using a two ...