{{Chembox <!-- Images --> | ImageFile = | ImageSize = | ImageAlt = <!-- Names --> | IUPACName = | OtherNames = <small>D</small>-Galactan; Galactosan <!-- Sections --> | Section1 = {{Chembox Identifiers | CASNo = 9037-55-2 | ChEBI = 37165 | KEGG = C05796 | PubChem = | SMILES = }} | Section2 = {{Chembox Properties | Formula = (C<sub>6</sub>H<sub>10</sub>O<sub>5</sub>)<sub>n</sub> | MolarMass = Variable | Appearance = | Density = | MeltingPt = | BoilingPt = | Solubility = }} | Section3 = {{Chembox Hazards | MainHazards = | FlashPt = | AutoignitionPt = }} }}
'''Galactan''' ('''galactosan''') is a polysaccharide consisting of polymerized galactose.<ref>{{MeshName|Galactans}}</ref> In general, galactans in natural sources contain a core of galactose units connected by α(1→3) or α(1→6), with structures containing other monosaccharides as side-chains.<ref>{{Cite book|url=https://books.google.com/books?id=GDuy5zL6eRAC&pg=PA78|title=The Antibodies|last1=Zanetti|first1=Maurizio|last2=Capra|first2=Donald J.|date=2003-09-02|publisher= CRC Press |isbn=9780203216514|pages=78|language=en}}</ref>
Galactan derived from ''Anogeissus latifolia'' is primarily α(1→6), but galactan from acacia trees is primarily α(1→3).<ref>{{Cite book | last1 = Zanetti | first1 = Maurizio | title = The antibodies | year = 1995 | publisher = Harwood Academic Publishers | location = Luxembourg | isbn = 0-415-28466-X | pages = 78 }}</ref>
''Halymenia durvillei'' is a red seaweed (algae) that produces a sulfated galactan.<ref>{{cite journal |last1=Fenoradosoa |first1=T. A. |last2=Delattre |first2=C. |last3=Laroche |first3=C. |last4=Wadouachi |first4=A. |last5=Dulong |first5=V. |last6=Picton |first6=L. |last7=Andriamadio |first7=P. |last8=Michaud |first8=P. |title=Highly sulphated galactan from ''Halymenia durvillei'' (Halymeniales, Rhodophyta), a red seaweed of Madagascar marine coasts |journal=Int J Biol Macromol |date=1 August 2009 |volume=45 |issue=2 |pages=140–5 |doi=10.1016/j.ijbiomac.2009.04.015|pmid=19409410 }}</ref> Several other algae species also contain galactans.<ref> {{google books|3ZaKAk4XBxMC|Advances in Carbohydrate Chemistry and Biochemistry Vol. 65 (2011)|page=168}}</ref> Including ''Carpopeltis'' {{Au|F.Schmitz, 1895}}.<ref>I.J. Miller and J. Mollion, Evaluation of the structures of galactans from ''Carpopeltis'' sp. a member of the Halymeniales in the western Indian Ocean, Bot. Mar., 49 (2006) 79-85</ref>
Galactan is found in the side chains of rhamnogalacturonan I (RG-I) and is needed for gel formation in the cell walls of organisms.<ref name=":0">{{Cite journal |last1=Mikshina |first1=Polina V. |last2=Makshakova |first2=Olga N. |last3=Petrova |first3=Anna A. |last4=Gaifullina |first4=Ilzira Z. |last5=Idiyatullin |first5=Bulat Z. |last6=Gorshkova |first6=Tatyana A. |last7=Zuev |first7=Yuriy F. |date=September 2017 |title=Gelation of rhamnogalacturonan I is based on galactan side chain interaction and does not involve chemical modifications |journal=Carbohydrate Polymers |language=en |volume=171 |pages=143–151 |doi=10.1016/j.carbpol.2017.05.013|pmid=28578948 }}</ref> It was observed there was less of the gelling characteristic (as well as the polymeric chains being more likely to degrade) when fewer galactans were present in the polymeric side chains. <ref name=":0" /><ref>{{Cite journal |last1=Robal |first1=Marju |last2=Truus |first2=Kalle |last3=Volobujeva |first3=Olga |last4=Mellikov |first4=Enn |last5=Tuvikene |first5=Rando |date=November 2017 |title=Thermal stability of red algal galactans: Effect of molecular structure and counterions |journal=International Journal of Biological Macromolecules |volume=104 |issue=Pt A |pages=213–223 |doi=10.1016/j.ijbiomac.2017.05.175 |pmid=28587967 |issn=0141-8130}}</ref>
==See also== * Agar * Galactooligosaccharide
==References== {{reflist}}
{{Carbohydrates}} Category:Carbohydrates