{{short description|Sugar molecule with an –OH group at the end(s) of the carbon chain}}
In organic chemistry, a '''sugar acid''' or '''acidic sugar''' is a monosaccharide with a carboxyl group at one end or both ends of its chain.<ref>{{cite book |title=Essentials of carbohydrate chemistry |author=Robyt, J.F. |publisher=Springer |location=New York |year= 1998 | url=https://books.google.com/books?id=l4NfU7_sAZoC&q=%22b.+Aldonic+acids%22&pg=PA366 |isbn=0-387-94951-8}}</ref>
Main classes of sugar acids include: * Aldonic acids, in which the aldehyde group ({{chem2|\sCH\dO}}) located at the initial end (position 1) of an aldose is oxidized. * '''Ulosonic acids''', in which the hydroxymethyl group ({{chem2|\sCH2OH}}) at the initial end of a 2-ketose is oxidized creating an α-ketoacid. * Uronic acids, in which the {{chem2|\sCH2OH}} group at the terminal end of an aldose or ketose is oxidized. * Aldaric acids, in which both ends ({{chem2|\sCH\dO}} and {{chem2|\sCH2OH}}) of an aldose are oxidized.
{| <!--class="wikitable"--> |- | [[File:D-Gluconsäure Keilstrich.svg|thumb|150px|right|Aldonic acid]] || [[File:3-Deoxy-D-manno-oct-2-ulosonic acid linear.png|thumb|150px|right|An ulosonic acid; specifically, 3-Deoxy-D-manno-oct-2-ulosonic acid]] || [[File:Beta D-Glucuronic acid.svg|thumb|150px|right|Uronic acid]] || [[File:Tartaric acid.svg|thumb|150px|right|Aldaric acid]] |}
==Examples== Examples of sugar acids include: * Aldonic acids ** Glyceric acid (3C) ** Xylonic acid (5C) ** Gluconic acid (6C) ** Ascorbic acid<ref>{{Cite book|author1=Davies Michael B.|author2=Austin John|author3=Partridge David A.| title=Vitamin C: Its Chemistry and Biochemistry| publisher=The Royal Society of Chemistry| year=1991| page=48 |isbn = 0-85186-333-7}}</ref> (6C, unsaturated lactone) * Ulosonic acids ** Neuraminic acid (5-amino-3,5-dideoxy-<small>D</small>-''glycero''-<small>D</small>-''galacto''-non-2-ulosonic acid) ** Ketodeoxyoctulosonic acid (KDO or 3-deoxy-<small>D</small>-''manno''-oct-2-ulosonic acid) * Uronic acids ** Glucuronic acid (6C) ** Galacturonic acid (6C) ** Iduronic acid (6C) * Aldaric acids ** Tartaric acid (4C) ** ''meso''-Galactaric acid (Mucic acid) (6C) ** <small>D</small>-Glucaric acid (Saccharic acid) (6C)
{| |[[File:L-Ascorbic acid.svg|thumb|right|Ascorbic acid (Vitamin C)]] |[[File:Beta D-Glucuronic acid.svg|thumb|right|The β-D form of glucuronic acid]] |}
==References== {{reflist|2}}
==External links== * {{MeshName|Sugar+Acids}}
Category:Sugar acids