What is L-methionine?

L-methionine is an amino acid, one of the components of protein, and one of the essential amino acids for the human body. It is a sulfur amino acid and contains sulfur atoms, so it plays a vital role in physiological functions in the body. L-methionine must be consumed through food as an essential amino acid because the body cannot synthesize it alone. It is mainly found in high-protein foods such as meat, fish, dairy products, beans, and nuts.

What is Glycine?

Glycine is an amino acid and one of the simplest amino acids in the human body. It is also a non-essential amino acid because the human body can produce it synthetically. It is one of the components of proteins and plays a vital role in many biochemical processes of organisms. Glycine has a variety of critical physiological functions in the human body. It is a protein component and participates in various biochemical reactions and physiological processes essential for maintaining normal biological functions.

Source

L-Methionine:
Protein-rich foods: L-methionine is found primarily in protein-rich foods. Animal foods, such as meat, fish, poultry, and dairy products, are especially rich in protein and provide the L-methionine needed by the human body.

Nuts and seeds: Nuts and seeds are also a good source of methionine. For example, nuts and seeds such as almonds, walnuts, peanuts, pumpkin seeds, and sunflower seeds are rich in protein and contain a certain amount of L-methionine.

Beans and soy products: Beans and soy products are also important plant methionine sources. Soybeans, tofu, soy milk, and other soy products are rich in protein and contain a certain amount of L-methionine.

Whole grains: Whole grains, such as oats, wheat, rice, etc., also contain a certain amount of methionine, especially in the germ part of the grain.

Eggs are one of the best protein sources, especially egg whites, and are rich in L-methionine.

Glycine:
Protein-rich foods: Glycine is widely found in protein-rich foods. Animal foods such as meat (beef, pork, chicken, etc.), fish (salmon, tuna, etc.), and dairy products (milk, cheese, yogurt, etc.) are rich in glycine.

Beans and soy products: Beans (soybeans, tofu, soy milk, etc.) and soy products are also important plant sources of glycine.

Nuts and Seeds: Nuts (almonds, walnuts, peanuts, etc.) and seeds (pumpkin seeds, sesame seeds, etc.) contain some amount of protein, including glycine.

Whole grains: Whole grains, such as oats, wheat, rice, etc., also contain a certain amount of glycine.

Eggs: Eggs (eggs, duck eggs, etc.) are good protein sources, and egg whites are rich in glycine.

Extraction

L-Methionine:
Chemical synthesis: L-methionine can be produced through chemical synthesis. This method typically uses synthetic substrates and reaction conditions to synthesize L-methionine on a laboratory or industrial scale. The synthetic route may involve using suitable starting materials and conducting a series of chemical reactions to obtain L-methionine.

Microbial Fermentation: Another method of producing L-methionine is through microbial fermentation. Usually, a specific microorganism, such as Escherichia coli, is used and allowed to ferment in a culture medium containing appropriate carbon and nitrogen sources. The organisms can produce large amounts of L-methionine by adjusting culture conditions, such as temperature, pH value, and oxygen supply. Subsequently, L-methionine is separated from the fermentation broth through extraction, purification, and crystallization.

Glycine:
Chemical synthesis: Glycine can be produced by chemical synthesis. In this method, common starting materials include ammonia and formaldehyde. These raw materials can be converted into glycine through a series of chemical reactions. This method is often used for industrial-scale glycine production because it can obtain high-purity products in large-scale production.

Hydrolysis of Natural Proteins: Another standard method is to extract glycine through hydrolysis of natural proteins. In this approach, the protein source can be animal-based (such as skin, bones, eggs, etc.) or plant-based (such as soy, wheat, corn, etc.). Hydrolyzing the protein, glycine can be released from the protein and subsequently subjected to extraction, purification, and crystallization.

Effects

L-Methionine:
Protein synthesis: As an essential amino acid, L-methionine is one of the critical components of protein synthesis. It is one of the starting amino acids for protein synthesis and builds new protein molecules with other amino acids.

Methylthio group donor: L-methionine also acts as a methylthio group donor in the body and participates in various biosynthetic reactions. For example, it can provide methylthio groups for synthesizing myoglobin, heparin, and cysteine.

Components of biosynthetic pathways: L-methionine is a component of some essential biochemical synthesis pathways, such as fatty acid and choline.

Antioxidant effect: L-methionine can act as an antioxidant, helping to remove free radicals in the body and reducing oxidative stress damage to cells and tissues.

Liver function support: L-methionine is also thought to have some support for liver function. It promotes fat metabolism in the liver and helps maintain healthy liver function.

Glycine:
Neurotransmitter function: Glycine acts as a neurotransmitter in the central nervous system and has an inhibitory effect. It can transmit signals between neurons, regulate the excitability of neurons, and help maintain the stable state of the nervous system. Glycine is also involved in signal transduction processes in the brain and plays a vital role in sleep, cognitive function, and mood regulation.

Protein synthesis: Glycine is one of the components of protein and participates in the protein synthesis process within cells. It is an amino acid that can be combined with other amino acids to form the building blocks of protein molecules.

Components of biosynthetic pathways: Glycine is a component of some essential biochemical synthesis pathways, including choline synthesis, heparin synthesis, and glutamate synthesis.

Antioxidant effect: Glycine has a particular antioxidant effect, which can help remove free radicals in the body and reduce oxidative stress damage to cells and tissues.

Growth and Repair: Glycine is essential in cell growth and repair processes. It is involved in cell division and proliferation and helps grow and repair tissues and organs.

Applications

L-Methionine:
Protein supplements: L-methionine can be used as part of a protein supplement, along with other amino acids, in powder, tablet, or liquid form. These supplements are often used to increase protein intake or assist athletes with muscle recovery and growth.

Medicinal Uses: L-methionine can also be found as an ingredient in pharmaceuticals. In medicine, L-methionine can treat specific diseases or as a raw material for certain drugs.

Nutritional supplements: L-methionine can also be found in dietary supplements. These supplements can be comprehensive multivitamin and mineral formulas or individual supplements of specific amino acids.

Animal feed: In the agricultural field, L-methionine is also used as an additive in animal feed to increase the protein content of the feed and improve the growth rate and yield of animals.

Glycine:
Food additive: Glycine is usually used as a food additive to improve the taste of food, increase the nutritional value of food, or expand its range of uses. In food processing, glycine is commonly used as a flavor enhancer, humectant, and acidity regulator.

Drugs: Glycine is also used as a raw material or drug additive. It can be used as a component of drugs to treat specific diseases or improve specific physiological states. For example, glycine can be used to prepare antacid drugs, antidepressant drugs, analgesic drugs, etc.

Nutritional supplements: Glycine can be found as an ingredient in dietary supplements, usually available in capsule, powder, or liquid form. It can be combined alone or with other amino acids, vitamins, and minerals to form a comprehensive nutritional supplement.

Cosmetics: Glycine is widely used in cosmetics and personal care products as a moisturizer, antioxidant, and skin conditioner. It helps maintain the skin's moisture balance, enhances its elasticity, and makes the skin smoother and softer.

Animal feed: In the agricultural field, glycine is also used as an additive in animal feed to increase the protein content of the feed and improve the growth rate and yield of animals.

L-Methionine VS Glycine