2-Hydroxybutyric acid, also known as ''alpha''-hydroxybutyrate and α-hydroxybutyrate, is a
hydroxybutyric acid with the
hydroxyl group on the carbon adjacent to the
carboxyl. It is a
chiral compound having two
enantiomers
In chemistry, an enantiomer ( /ɪˈnænti.əmər, ɛ-, -oʊ-/ ''ih-NAN-tee-ə-mər''; from Ancient Greek ἐνάντιος ''(enántios)'' 'opposite', and μέρος ''(méros)'' 'part') – also called optical isomer, antipode, or optical anti ...
,
D-2-hydroxybutyric acid and
L-2-hydroxybutyric acid.
(R)-2-Hydroxybutanic Acid Structural Formula V1.svg, (''R'')-2-hydroxybutyric acid
(S)-2-Hydroxybutanic Acid Structural Formula V1.svg, (''S'')-2-hydroxybutyric acid
2-Hydroxybutyrate, the
conjugate base of 2-hydroxybutyric acid, is produced in mammalian tissues (principally hepatic) that catabolize
L-threonine or synthesize
glutathione.
Oxidative stress or detoxification demands can dramatically increase the rate of hepatic glutathione synthesis. Under such metabolic stress conditions, supplies of
L-cysteine for glutathione synthesis become limiting, so
homocysteine is diverted from the
transmethylation
Transmethylation is a biologically important organic chemical reaction in which a methyl group is transferred from one compound to another.
An example of transmethylation is the recovery of methionine from homocysteine. In order to sustain suffic ...
pathway forming methionine into the
transsulfuration pathway forming cystathionine. 2-Hydroxybutyrate is released as a byproduct when
cystathionine is cleaved to cysteine that is incorporated into glutathione. Chronic shifts in the rate of glutathione synthesis may be reflected by urinary excretion of 2-hydroxybutyrate.
α-hydroxybutyrate may be useful as an early indicator of
insulin resistance
Insulin resistance (IR) is a pathological condition in which cell (biology), cells fail to respond normally to the hormone insulin.
Insulin is a hormone that facilitates the transport of glucose from blood into cells, thereby reducing blood gluco ...
in
non-diabetic subjects.
Moreover, elevated serum α-hydroxybutyrate predicts worsening
glucose tolerance.
References
{{DEFAULTSORT:Hydroxybutyric acid, 2-
Alpha hydroxy acids