L - Lysine

Definition and Structure: L - Lysine is an α - amino acid and one of the basic units that make up proteins. Its chemical formula is C₆H₁₄N₂O₂, with a molecular weight of 146.19. Its chemical name is (2S) - 2,6 - Diaminohexanoic acid. It contains an α - amino group (in the protonated - NH₃⁺ form under physiological conditions), an α - carboxyl group (in the deprotonated - COO⁻ form), and a side chain (CH₂)₄NH₂. It belongs to basic, charged (at physiological pH) aliphatic amino acids and is encoded by the codons AAA and AAG.
CAS Number: 56 - 87 - 1.

Appearance: Usually a white or nearly white crystalline powder.
Melting Point: 224 - 225 °C (decomposes, turns black at 210 °C). Some sources also indicate a melting point of 263 - 264 °C with decomposition upon melting.
It is prone to caking under high humidity. It is stable at a relative humidity of less than 60% and forms a dihydrate when the relative humidity is above 60%. It colors when co - existing with vitamin C and vitamin K₃. It decomposes when heated under alkaline conditions or in the presence of reducing sugars directly.

L - Lysine base is relatively stable but will decompose or react under specific conditions. For example, it decomposes when heated under alkaline conditions or in the presence of reducing sugars directly. It undergoes racemization when heated together with phosphoric acid, hydrochloric acid, sodium hydroxide, ion - exchange resins, etc.

Protein Synthesis: It is an essential amino acid for the human body, which cannot be synthesized by itself and must be obtained from food or supplements. It is an important raw material for protein synthesis and plays a key role in the structure of many proteins.
Antiviral Activity: It can inhibit the replication of herpes simplex viruses (HSV - 1 and HSV - 2). It reduces virus propagation by competitively inhibiting arginine absorption, and can reduce the frequency and severity of outbreaks of cold sores, oral ulcers, and shingles. For herpes prevention, the daily intake is 500 - 1000 mg, and during outbreaks, it is 2000 - 3000 mg per day (taken in divided doses).
Promoting Collagen Synthesis: As an essential component of collagen, it helps with skin repair, wound healing, and reducing wrinkles. It is suitable for people recovering from surgery or with skin damage.
Supporting Bone Health: It promotes the absorption of calcium in the small intestine and reduces urinary calcium loss, preventing osteoporosis. It is suitable for the elderly, people in the recovery period from fractures, and those with calcium deficiency.
Promoting Muscle Growth: It helps with muscle recovery and growth and is suitable for fitness enthusiasts, athletes, and vegetarians.
Supporting Immune Function: It enhances the activity of immune cells and helps the body resist infections. It is suitable for people with low immunity and those prone to colds. It may also reduce anxiety and stress responses by regulating GABA receptors.

Food Sources: It is present in a variety of foods, such as meat, dairy products, legumes (e.g., chickpeas, lentils), nuts, soybeans, cod, etc. Plant - based sources include legumes, nuts, quinoa, etc.
Supplements: When dietary intake is insufficient (such as during high - intensity exercise or under stress), it can be obtained by taking supplements containing L - lysine.

Food Industry: As a nutritional fortifier, it enriches the lysine content in foods and improves their nutritional value. It is added to milk powder, children's health products, nutritional tonics, alcohol, soft drinks, bread, starch products, etc.
Feed Industry: Used as a feed additive, it can improve the appetite and disease - resistance of livestock and poultry, promote their growth and development, and improve the quality of meat.
Medical Field: Used in infusions, nutritional drugs, etc. It regulates the metabolic balance in the body and improves the absorption of cereal proteins. It can also be made into relevant drugs or health products to prevent and treat diseases caused by lysine deficiency.