L-Proline was first discovered in 1901 by Richard Willstätter, a German chemist who won the Nobel Prize in Chemistry in 1915 for his research on plant pigments. Willstätter isolated L-Proline from gelatin, a protein-rich substance derived from collagen. Its name, “Proline,” was derived from the Greek word “prolos,” meaning “before glue,” due to its presence in the sticky substance produced when gelatin is heated.

The chemistry of l-proline

L-Proline is an amino acid, a building block of proteins our DNA encodes. Structurally, it is unique among amino acids due to its cyclic side chain, which imparts distinctive properties. The unique properties of L-Proline’s side chain also make it an excellent target for chemical modifications and derivatization. 

L-Proline may act as a catalyst in organic reactions and may help promote asymmetric synthesis, and it can also help facilitate the formation of chiral compounds.*

L-proline in biology

L-Proline may play a role in various biological processes and help support overall health and wellness.* L-Proline may be a component in synthesizing collagen, one of the most abundant proteins in the body. 

Collagen may help provide structural support to connective tissues, including skin, tendons, ligaments, and blood vessels. Collagen might be helpful with wound healing by promoting the production and organization of collagen fibers and may play a part in tissue regeneration.* 

L-Proline may support joint and bone health and promote the integrity and flexibility of joints, which can play a role in overall mobility.* L-Proline may be involved in synthesizing neurotransmitters, such as gamma-aminobutyric acid (GABA). GABA may act as an inhibitory neurotransmitter, which may help support relaxation and calmness.*

L-Proline supplements and diet

L-Proline supplements are available in various forms, including capsules, powders, and liquids. They are commonly used to help support collagen production and joint health.* L-Proline can also be obtained through dietary, plant-based, and animal sources. Plant-based sources include soy products, legumes, nuts, and certain grains. Some animal-based sources include meat, dairy products, and eggs. Maintaining a balanced diet incorporating several sources may help with your L-Proline intake.

Some interesting facts

1. L-Proline’s involvement in collagen synthesis has made it a popular ingredient in skincare products. It might help support skin elasticity and wrinkles and promote a youthful skin appearance.* 
2. L-Proline might also be involved in the cross-linking of collagen fibers, which may help support the structural integrity of connective tissues.* Cross-linking may help to contribute to the resilience and elasticity of tissues like skin, tendons, and blood vessels.
3. In the realm of metabolism, L-Proline may be involved in several metabolic pathways. It may be a precursor for the synthesis of various compounds, including hydroxyproline, a modified form of proline found abundantly in collagen.
4. This amino acid has applications in the food industry as a flavor enhancer and stabilizer. It can help improve the taste of food products and contribute to their texture and shelf life.
5. L-Proline can be metabolized via the Krebs cycle, also known as the citric acid cycle or TCA cycle, to help generate energy in the form of ATP. L-Proline may be a potential energy source for the body during increased demand.* 
6. L-Proline may also act as a stress protectant in plants. During periods of environmental stress, such as drought or extreme temperatures, plants may accumulate L-Proline to help maintain cellular integrity and protect against damage.*

As always, talk to your doctor before taking any supplements. Get professional advice if you think you might need an L- Proline supplement or are already taking one to ensure you’re not exceeding the amounts you may need.