Pyridoxal phosphate

Types

The vitamin B6 family consists of three compounds, all of which are pyridine derivatives. Pyridoxal phosphate, commonly referred to as PLP, is the coenzyme form for the vitamin B6 family. Most of its functions are primarily enzymatic reactions involving amino acids.

This compound is a result of the phosphorylation and condensation of pyridoxal with alpha-ketoglutarate in the presence of pyridoxal. This vitamin is necessary for brain development, immune system management, and hormone regulation. Due to its important role in the human body, vitamin B6 is known as a vital nutrient.

Other forms of vitamin B6 include:

• Pyridoxine

  This is the type of vitamin B6 that is commonly found in supplements and fortified foods. It has a high biological half-life but is slightly less potent when compared to other types of vitamin B6.

• Pyridoxamine

  Pyridoxamine is often found in kidneys and is considered a good source of protein. Like pyridoxine, this compound has a low potency but a high biological half-life. It is rarely used in supplements since it is constantly broken down to pyridoxal.

• Pyridoxal

  This has a high potency but is often short-lived in the human body. Because of its high bioactivity, pyridoxal is often used in pharmaceutical medicine to treat deficiency in vitamin B6. In mere days, most of the vitamin becomes inactive.

• Pyridoxal phosphate

  This is a coenzyme form of vitamin B6 and is necessary for multiple enzyme reactions in the human body. These include the amino acid racemization, decarboxylation, and transamination reactions. Vitamin B6 deficiency causes depression, confusion, and a weakened immune system.

• Pyridoxine hydrochloride

  This is the most commonly administered form of vitamin B6 in pharmaceutical medicinal supplements. It has a higher stability compared to pyridoxine alone and is often used for vitamin B6 deficiency. This compound is converted to active coenzyme forms in the body.

Uses

The uses of vitamin B6 stem from the unique physiological effects and biochemical properties of its derivatives. Pyridoxal phosphate, for example, is predominantly used in brain therapy to treat CNS conditions. That is because of its ability to help synthesize catecholamines, such as serotonin, norepinephrine, and dopamine.

The importance of vitamin B6 in protein metabolism allows it to be utilized in developing protein-rich functional foods and nutritional supplements. Its anti-inflammatory properties make PLP suitable for developing supplements to help alleviate inflammation in patients with chronic diseases, such as arthritis and cardiovascular disorders.

This vitamin can also be used in germ warfare. This is achieved by combining it with β-lactams, vancomycin, and α-amino acids. These are compounds identified to inhibit vitamin B6 synthesis in bacteria. Pyridoxine can also be used in agriculture to enhance crop yield and nutritional value through foliar application of vitamins.

Here are more precise uses of pyridoxal phosphate in various industries:

• Pharmaceuticals

  Pyridoxal phosphate is used to develop and manufacture various medications, especially those related to neurological conditions. Due to its role in neurotransmitter synthesis, it enhances the efficiency of drugs used to treat depression, seizures, and other mood disorders. PLP is usually used in combination with other medicines to improve treatment outcomes for these conditions.

• Nutritional supplements

  Pyridoxal phosphate is preferred over vitamin B6 because it does not require conversion for biological activity. It is used in supplements targeting nutrient deficiencies, especially for at-risk populations, such as the elderly. PLP is utilized in high-dose formulations to treat clinical deficiencies when ≤ 100% of the daily value is indicated on the label.

• Food fortification

  This vitamin is added to food products to enhance their nutritional profiles. fortified cereals, bakery products, and beverage companies commonly add vitamin B6 as pyridoxine hydrochloride. However, during the food processing timeline, there is degradation of the vitamin, so food manufacturers use PLP instead since it is more stable.

• Clinical diagnostics

  Pyridoxal phosphate is used as a co-factor in clinical diagnostic tests and laboratory procedures. It is mainly used for transaminase assays measuring ALT and AST. These two are important liver function tests. An impaired liver is usually associated with abnormal pyridoxal phosphate concentrations.

• Research and Development

  PLP is a critical component in academic and pharmaceutical research to better understand enzyme reactions and metabolic pathways. This information can be applied in other areas outside pharmaceutical supplements, such as metabolic disorder treatments. It is also used to study the role of vitamin B6 dependent enzymes in health and disease. This might lead to the development of novel therapeutic interventions.

Benefits

• Coenzyme activity

  Pyridoxal phosphate is involved in almost 140 enzyme-catalyzed reactions in the human body, especially in amino acid metabolism. This is mainly due to its ability to form a schiff base with amino acids. PLP acts as a proton acceptor, nitrogen donor, and carbon molecule at the same time. This means it can perform transamination, deamination, and even decarboxylation at the same time.

• Neurotransmitter synthesis

  As coenzyme, PLP is used to synthesize important neurotransmitters like serotonin, dopamine, and norepinephrine. These are achieved through reactions with their corresponding amino acids. Pyridoxal phosphate is useful in brain therapy to manufacture molecules responsible for regulating mood, cognition, and mental state. This makes it useful for treating depression, anxiety, and neurological disorders.

• Amino acid metabolism

  Pyridoxal phosphate's primary function is to assist enzymes in breaking down amino acids. This B vitamin is vital for protein metabolism and for transforming amino acids into useful derivatives. With PLP, the human body can convert dietary proteins into energy and other useful components. It also supports the synthesis of essential biological molecules and prevents amino acid accumulation in the body.

• Enhanced immune function

  Pyridoxal phosphate can also be used to support the immune function of cells such as lymphocytes, T cells, and monocytes. These are the cells that synthesize the aforementioned neurotransmitters, which in turn enhance the overall immune response. This promotes the production of antibodies and is vital for maintaining a healthy immune system. This also helps the body resist infections and diseases.

• Anti-inflammatory effects

  Pyridoxal phosphates are useful in combating chronic systemic inflammation. This is accomplished by suppressing the production of pro-inflammatory cytokines and directly inhibiting their activity. PLP is beneficial for patients with inflammatory conditions such as arthritis. It alleviates the negative effects that come with elevated levels of inflammation, such as joint pain and reduced mobility.

How to choose

Choosing the right vitamin B6 requires one to consider various factors related to its biological, functional, and chemical characteristics. This will help determine which of the vitamin B6 forms will be most suitable for the intended purpose.

Here are the factors to consider when buying:

• Bioactivity and potency

  Different forms of vitamin B6 have varying degrees of bioactivity. For example, pyridoxal phosphate is the most bioactive form of vitamin B6. It is readily available for use in the human body without requiring conversion. On the other hand, pyridoxine must first be converted into pyridoxal phosphate before it can be useful.

• Stability and storage

  Different derivatives of vitamin B6 possess varying degrees of stability under specific conditions. These include temperature, light exposure, and humidity. Pyridoxine hydrochloride, for example, is very stable and can easily be stored under normal room temperatures. Conversely, pyridoxal is very sensitive to light and heat.

• Bioavailability

  The ease with which the human body can absorb and utilize the vitamin will depend on its form. Pyridoxine hydrochloride is more easily digestible when compared to other forms of vitamin B6. This makes it ideal for oral supplementation. On the other hand, PLP is highly bioavailable but requires special handling to prevent degradation during processing and storage.

• Compatibility with formulations

  Different vitamin B6 forms interact uniquely with other compounds in pharmaceutical or food formulations. Pyridoxine hydrochloride is more soluble in water when compared to pyridoxal phosphate. This makes it easier to incorporate into liquid supplements. Conversely, PLP is better for specialized drug delivery systems because of its unique chemical properties.

• Regulatory considerations

  Different countries have different regulations and restrictions regarding the use of various vitamin B6 forms in supplements and foods. For example, pyridoxamine is regulated as a drug in some jurisdictions because of its high bioactivity and potency. This limits its use in dietary supplements and fortified foods.

• Purpose and target audience

  Choosing the right vitamin B6 form depends on the intended audience and goals. Supplements aiming to treat deficiency-related disorders in healthcare facilities target older adults. These should contain PLP since it doesn’t require conversion to be bioactive. Conversely, fortified foods targeting the general population can use pyridoxine. The general populace is not likely to experience vitamin B6 deficiency.

Q & A

Can pyridoxal be used as a drug to treat seizures?

Research has shown that vitamin B6, as PLP, alleviates seizures during infancy. This is especially true for patients with pyridoxine-dependent epilepsy (PDE). PDE is a rare disease characterized by recurrent seizures during infancy. These are caused by mutations in genes responsible for producing the enzymes that convert vitamin B6 into pyridoxal phosphate.

Does PLP cause hyperhidrosis?

Pyridoxal phosphate doesn’t directly cause hyperhidrosis. However, high doses of vitamin B6 can cause excessive sweating as a side effect. This is because high doses are oftenexclusively in supplementing individuals with vitamin B6 deficiency. Such high doses typically have lower half-lives than normal concentrations of the vitamin.

What is the difference between pyridoxine and pyridoxal phosphate?

Pyridoxine and pyridoxal phosphate are both forms of vitamin B6, but they differ in their chemical structures and biological functions. Pyridoxine is a simple alcohol form of vitamin B6. It requires conversion in the body to become pyridoxal phosphate, the active coenzyme form. On the other hand, pyridoxal phosphate is formed by the condensation and phosphorylation of pyridoxal. It is already in the coenzyme form and doesn't require any conversion to be bioactive.

What foods are high in pyridoxal phosphate?

Foods that are high in vitamin B6 are also high in pyridoxal phosphate. These include fish, beef liver, and poultry. Other sources include potatoes and starchy vegetables, non-citrus fruits such as bananas and avocados, as well as fortified cereals.

Is vitamin B6 the same as pyridoxal phosphate?

No, vitamin B6 is not the same as pyridoxal phosphate. Pyridoxal phosphate is just one of the many forms of vitamin B6. Other forms include pyridoxine, pyridoxamine, and pyridoxine hydrochloride.