beta-Hydroxy beta-methylbutyric acid

From Wikipedia, the free encyclopedia - View original article

β-Hydroxy β-methylbutyric acid[1]
Identifiers
CAS number625-08-1 YesY
PubChem69362
ChemSpider62571 YesY
ChEBICHEBI:37084 YesY
Jmol-3D imagesImage 1
Properties
Molecular formulaC5H10O3
Molar mass118.131 g/mol
Density0.938 g/mL
Melting point−80 °C; −112 °F; 193 K
Boiling point88 °C at 1 mmHg
 YesY (verify) (what is: YesY/N?)
Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
Infobox references
 
Jump to: navigation, search
β-Hydroxy β-methylbutyric acid[1]
Identifiers
CAS number625-08-1 YesY
PubChem69362
ChemSpider62571 YesY
ChEBICHEBI:37084 YesY
Jmol-3D imagesImage 1
Properties
Molecular formulaC5H10O3
Molar mass118.131 g/mol
Density0.938 g/mL
Melting point−80 °C; −112 °F; 193 K
Boiling point88 °C at 1 mmHg
 YesY (verify) (what is: YesY/N?)
Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
Infobox references

β-Hydroxy β-methylbutyric acid (HMB), or β-hydroxy β-methylbutyrate, is a metabolite of the essential amino acid leucine and is synthesized in the human body. It plays a part in protein synthesis and was discovered by Steven L. Nissen at Iowa State University. It has been used in scientific studies to purportedly increase muscle mass and decrease muscle breakdown. Nissen held the original patent on the metabolite as a nutritional supplement. It was discovered in pigs and small quantities can also be found in grapefruit, alfalfa, and catfish. As a supplement it is usually sold as the calcium salt calcium beta-hydroxy-beta-methylbutyrate.

Research published in the Journal of Applied Physiology has shown that HMB may have an effect on increasing muscle weight and strength.[2] A review in Nutrition & Metabolism provides an in depth and objective analysis of HMB research. [3] The same study lists as HMB's proposed mechanisms of action the following:

The human body produces about 0.2-0.4 grams per day. Standard doses in research studies have been 1.5 to 3.0 grams per day, usually divided into two doses.

Multiple carboxylase disorders[edit]

In multiple carboxylase deficiency, individuals have low or non-existent activity in one or more of the enzymes that facilitate recycling of biotin, a nutrient referred to as vitamin B7 or vitamin H. In such individuals, hydroxyisovaleric acid (or hydroxyisovalerate) accumulates as a consequence of incomplete leucine metabolism. The presence of hydroxyisovalerate is therefore a sensitive marker of biotin deficiency and may indicate the presence of a genetic disorder such as biotinidase deficiency or holocarboxylase synthetase deficiency.

References[edit]

  1. ^ β-Hydroxyisovaleric acid at Sigma-Aldrich
  2. ^ Nissen S, Sharp R, Ray M, et al. (November 1996). "Effect of leucine metabolite beta-hydroxy-beta-methylbutyrate on muscle metabolism during resistance-exercise training". J. Appl. Physiol. 81 (5): 2095–104. PMID 8941534. 
  3. ^ Wilson GJ, Wilson JM, Manninen AH. (2008). "Effects of beta-hydroxy-beta-methylbutyrate (HMB) on exercise performance and body composition across varying levels of age, sex, and training experience: A review.". Nutrition & Metabolism 5: 1. doi:10.1186/1743-7075-5-1. PMC 2245953. PMID 18173841.