Laktosa - Wikiwand

Laktosa (latinez lactis "esnea" eta azukreen -osa atzizkia) edo esne-azukrea^[1] glukosa eta galaktosaz osatutako disakaridoa da, ugaztunen esnetan egoten dena. Ugaztunen esneetako gluzidorik garrantzitsuena da, % 4-5 artean agertzen da-eta.

Datu azkarrak Formula kimikoa, SMILES kanonikoa ...

Laktosa

Formula kimikoa	C₁₂H₂₂O₁₁
SMILES kanonikoa	2D eredua
SMILES isomerikoa	C([C@@H]1[C@@H]([C@@H]([C@H]([C@@H](O1)O[C@@H]2[C@H](O[C@H]([C@@H]([C@H]2O)O)O)CO)O)O)O)O
MolView	3D eredua
Konposizioa	oxigeno, karbono eta hidrogeno
Mota	α/β-lactose ^(en)
Estereoisomeroa	β-maltose ^(en) , α-lactose ^(en) , Gal(a1-4)a-Alt ^(en) , [[alpha-D-glucosyl-(1->4)-beta-D-mannose\|alpha-D-glucosyl-(1->4)-beta-D-mannose]] ^(en) , [[beta-D-glucosyl-(1->4)-alpha-D-mannose\|beta-D-glucosyl-(1->4)-alpha-D-mannose]] ^(en) , [[beta-D-mannopyranosyl-(1->4)-beta-D-glucopyranose\|beta-D-mannopyranosyl-(1->4)-beta-D-glucopyranose]] ^(en) , [[alpha-D-Galp-(1->4)-beta-D-Glcp\|alpha-D-Galp-(1->4)-beta-D-Glcp]] ^(en) , [[alpha-D-Manp-(1->4)-alpha-D-Manp\|alpha-D-Manp-(1->4)-alpha-D-Manp]] ^(en) , L-Gul(a1-4)b-Tal ^(en) , [[alpha-D-Galp-(1->4)-beta-D-Galp\|alpha-D-Galp-(1->4)-beta-D-Galp]] ^(en) , beta-cellobiose ^(en) , α-maltose ^(en) , [[alpha-D-Galp-(1->4)-alpha-D-Glcp\|alpha-D-Galp-(1->4)-alpha-D-Glcp]] ^(en) , [[beta-D-Manp-(1->4)-beta-Galp\|beta-D-Manp-(1->4)-beta-Galp]] ^(en) , alpha-mannobiose ^(en) , [[beta-D-glucosyl-(1->4)-beta-D-mannose\|beta-D-glucosyl-(1->4)-beta-D-mannose]] ^(en) , [[alpha-D-Manp-(1->4)-beta-D-Manp\|alpha-D-Manp-(1->4)-beta-D-Manp]] ^(en) , [[alpha-D-Glcp-(1->4)-alpha-D-Galp\|alpha-D-Glcp-(1->4)-alpha-D-Galp]] ^(en) , alpha-cellobiose ^(en) , beta-epilactose ^(en) , [[alpha-D-glucosyl-(1->4)-alpha-D-mannose\|alpha-D-glucosyl-(1->4)-alpha-D-mannose]] ^(en) , [[beta-D-Glcp-(1->4)-beta-D-Galp\|beta-D-Glcp-(1->4)-beta-D-Galp]] ^(en) , [[beta-D-galactopyranosyl-(1->4)-alpha-D-galactopyranose\|beta-D-galactopyranosyl-(1->4)-alpha-D-galactopyranose]] ^(en) , [[beta-D-Gal-(1->4)-alpha-D-Man\|beta-D-Gal-(1->4)-alpha-D-Man]] ^(en) , Galactobiose ^(en) , Gal(a1-4)a-Ido ^(en) , beta-Mannobiose ^(en) , [[alpha-D-Glcp-(1->4)-beta-D-Galp\|alpha-D-Glcp-(1->4)-beta-D-Galp]] ^(en) , [[alpha-D-Galp-(1->4)-alpha-D-Galp\|alpha-D-Galp-(1->4)-alpha-D-Galp]] ^(en) eta [[beta-D-Glcp-(1->4)-alpha-D-Galp\|beta-D-Glcp-(1->4)-alpha-D-Galp]] ^(en)
Masa molekularra	342,116 Da
Erabilera
Rola	Eszipiente
Arriskuak
NFPA 704	0 1 0
Identifikatzaileak
InChlKey	GUBGYTABKSRVRQ-DCSYEGIMSA-N
CAS zenbakia	63-42-3
ChemSpider	5904
PubChem	6134
Reaxys	90841
Gmelin	36218
ChEBI	342369
ChEMBL	CHEMBL417016
ZVG	100321
EC zenbakia	200-559-2
ECHA	100.000.509
Human Metabolome Database	HMDB0041627
UNII	13Q3A43E0S
KEGG	C01970
PDB Ligand	LAT

Itxi

Historia

Fabrizio Bartoletti (1576-1630) mediku italiarrak isolatu zuen eta baina bere lanak 1633 urtean argitaratu zen, jadanik hila zela. 1700 urtean Lodovico Testi botikari veneziarrak esnearen azukrearen (saccharum lactis) onurak azaltzen zituen liburua plazaratu zuen^[2], bereziki artritisaren eraginak lasaitzeko duen gaitasuna goraipatuz. 1715 urtean Testik laktosa isolatzeko erabili zuen teknika argitaratu zuen Antonio Vallisnerik.^[3] Laktosa Carl Wilhelm Scheelek identifikatu zuen 1780 urtean.^[4]

Heinrich Vogelek 1812an laktosa hidrolisatuz glukosa lortzen dela ikusi zuen, eta Louis Pasteurrek 1856an beste osagaia kristalizatzea lortu zuen, galaktosa.^[5] 1894an Hermann Emil Fischerrek laktosaren egitura molekularra finkatu zuen.^[6]

Egitura

Laktosaren formula enpirikoa ${\ce {C12H22O11}}$ da, eta bere pisu molekularra 342,30 g/mol. β-galaktosa eta glukosa (α edo β) monosakarido bana lotzen dira β-1→4 lotura O-glukosidikoaren bidez eta ur molekula bat askatzen da. Horrela beraz laktosaren izen sistematikoa honako hau da:

β-D-galaktopiranosil-(1→4)-D-glukopiranosa

Glukosaren karbono anomerikoan dagoen hidroxilo taldea aske dagoenez ahalmen erreduzitzailea duen azukrea da.

Metabolismoa

Laktosa ongi digeritzeko gizakiak laktasa (β-D-galaktosidasa) entzima behar du. Entzima horrek laktosa hidrolizatzen du, glukosa eta galaktosa sortuz; bi monosakarido horien xurgapena heste meharraren muki-mintzean gertatzen da. Laktosak kaltzioaren xurgapena ere errazten du, eta hezurralen mineralizazio egokian laguntzen du. Heste-florarentzat onuragarriak diren eragin probiotikoak ere baditu^[7].

Laktosarekin beste hainbat aldaketa ere egiten dituzte entzimek. Disoluzio alkalinoan isomerizatu egiten dute laktulosa bihurtuz (idorreriaren aurkako botika). Bestalde murriztu ere egin daiteke, laktitol izeneko polialkohola lortuz^[8].

Erabilerak

Elikagaien industrian erabiltzen da batez ere^[9].

Esnekien industria antzinatik ezagutzen diren hamaika produkturen ekoizpenean oinarritzen da, hala gazta, jogurta, gatzatua eta beste hainbat elikagai. Munduan garrantzia handia duen jarduera ekonomikoa da.
Legamia gehienek ez dute laktosaren hartzidurarik egiten eta garagardo beltzetan erabili izan da uki krematsua emateko^[8].
Kluyveromyces generoko legamiak laktosaren hartzidura egiteko gaitasuna du, eta etanola ekoizten du. Bioerregai gisa erabiltzeko frogak egiten ari dira.
Laktosaren lurrin leuna eta erabilterraztasuna dela eta, botiken usainak egonkortzeko erabiltzen da^[9].

Jasanezintasuna

Sakontzeko, irakurri: «Laktosarekiko jasanezintasun»

Laktasaren gabeziak laktosarekiko jasanezintasun izeneko gaitza sortzen du, zenbait tokitan (Asian, adibidez) oso zabaldua dena.

Erreferentziak

[1]
«lactosa» www.ehu.eus (Zehazki - UPV/EHU) (Noiz kontsultatua: 2023-02-22).
[2]
(Ingelesez) Testi, Lodovico. (1700). De novo Saccharo Lactis ... iudicia. (Noiz kontsultatua: 2018-11-09).
[3]
(Ingelesez) «Academiae Caesareo-Leopoldinae naturae curiosorum ephemerides, sive Observationum medico-physicarum ... Cent. 3-4.» HathiTrust (Noiz kontsultatua: 2018-11-09).
[4]
(Suedieraz) Kungl. Svenska vetenskapsakademiens handlingar. 1780 (Noiz kontsultatua: 2018-11-09).
[5]
(Frantsesez) Académie des sciences (France). (1856). Comptes rendus Academie des sciences 0042. http://gallica.bnf.fr/+(Noiz kontsultatua: 2018-11-09).
[6]
(Frantsesez) texte, Deutsche chemische Gesellschaft. Auteur du. (1891-01). «Berichte der Deutschen chemischen Gesellschaft zu Berlin» Gallica (Noiz kontsultatua: 2018-11-09).
[7]
(Ingelesez) Grenov, Benedikte; Briend, André; Sangild, Per T.; Thymann, Thomas; Rytter, Maren H.; Hother, Anne-Louise; Mølgaard, Christian; Michaelsen, Kim F.. (2016-02-18). «Undernourished Children and Milk Lactose» Food and Nutrition Bulletin 37 (1): 85–99. doi:10.1177/0379572116629024. ISSN 0379-5721. (Noiz kontsultatua: 2018-11-09).
[8]
Linko, P.. (1982). Lactose and Lactitol. London & New Jersey: Applied Science Publishers, 109–132 or. ISBN 0-85334-997-5..
[9]
(Ingelesez) Westhoff, Gerrit M.; Kuster, Ben F.M.; Heslinga, Michiel C.; Pluim, Hendrik; Verhage, Marinus. (2014-01-31). Lactose and Derivatives. Wiley-VCH Verlag GmbH & Co. KGaA, 1–9 or. doi:10.1002/14356007.a15_107.pub2. ISBN 9783527306732. (Noiz kontsultatua: 2018-11-09).

Ikus, gainera

Kanpo-estekak

Datuak: Q127900
Multimedia: Lactose / Q127900

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Laktosa

Formula kimikoa	C₁₂H₂₂O₁₁
SMILES kanonikoa	2D eredua
SMILES isomerikoa	C([C@@H]1[C@@H]([C@@H]([C@H]([C@@H](O1)O[C@@H]2[C@H](O[C@H]([C@@H]([C@H]2O)O)O)CO)O)O)O)O
MolView	3D eredua
Konposizioa	oxigeno, karbono eta hidrogeno
Mota	α/β-lactose ^(en)
Estereoisomeroa	β-maltose ^(en) , α-lactose ^(en) , Gal(a1-4)a-Alt ^(en) , [[alpha-D-glucosyl-(1->4)-beta-D-mannose\|alpha-D-glucosyl-(1->4)-beta-D-mannose]] ^(en) , [[beta-D-glucosyl-(1->4)-alpha-D-mannose\|beta-D-glucosyl-(1->4)-alpha-D-mannose]] ^(en) , [[beta-D-mannopyranosyl-(1->4)-beta-D-glucopyranose\|beta-D-mannopyranosyl-(1->4)-beta-D-glucopyranose]] ^(en) , [[alpha-D-Galp-(1->4)-beta-D-Glcp\|alpha-D-Galp-(1->4)-beta-D-Glcp]] ^(en) , [[alpha-D-Manp-(1->4)-alpha-D-Manp\|alpha-D-Manp-(1->4)-alpha-D-Manp]] ^(en) , L-Gul(a1-4)b-Tal ^(en) , [[alpha-D-Galp-(1->4)-beta-D-Galp\|alpha-D-Galp-(1->4)-beta-D-Galp]] ^(en) , beta-cellobiose ^(en) , α-maltose ^(en) , [[alpha-D-Galp-(1->4)-alpha-D-Glcp\|alpha-D-Galp-(1->4)-alpha-D-Glcp]] ^(en) , [[beta-D-Manp-(1->4)-beta-Galp\|beta-D-Manp-(1->4)-beta-Galp]] ^(en) , alpha-mannobiose ^(en) , [[beta-D-glucosyl-(1->4)-beta-D-mannose\|beta-D-glucosyl-(1->4)-beta-D-mannose]] ^(en) , [[alpha-D-Manp-(1->4)-beta-D-Manp\|alpha-D-Manp-(1->4)-beta-D-Manp]] ^(en) , [[alpha-D-Glcp-(1->4)-alpha-D-Galp\|alpha-D-Glcp-(1->4)-alpha-D-Galp]] ^(en) , alpha-cellobiose ^(en) , beta-epilactose ^(en) , [[alpha-D-glucosyl-(1->4)-alpha-D-mannose\|alpha-D-glucosyl-(1->4)-alpha-D-mannose]] ^(en) , [[beta-D-Glcp-(1->4)-beta-D-Galp\|beta-D-Glcp-(1->4)-beta-D-Galp]] ^(en) , [[beta-D-galactopyranosyl-(1->4)-alpha-D-galactopyranose\|beta-D-galactopyranosyl-(1->4)-alpha-D-galactopyranose]] ^(en) , [[beta-D-Gal-(1->4)-alpha-D-Man\|beta-D-Gal-(1->4)-alpha-D-Man]] ^(en) , Galactobiose ^(en) , Gal(a1-4)a-Ido ^(en) , beta-Mannobiose ^(en) , [[alpha-D-Glcp-(1->4)-beta-D-Galp\|alpha-D-Glcp-(1->4)-beta-D-Galp]] ^(en) , [[alpha-D-Galp-(1->4)-alpha-D-Galp\|alpha-D-Galp-(1->4)-alpha-D-Galp]] ^(en) eta [[beta-D-Glcp-(1->4)-alpha-D-Galp\|beta-D-Glcp-(1->4)-alpha-D-Galp]] ^(en)
Masa molekularra	342,116 Da
Erabilera
Rola	Eszipiente
Arriskuak
NFPA 704	0 1 0
Identifikatzaileak
InChlKey	GUBGYTABKSRVRQ-DCSYEGIMSA-N
CAS zenbakia	63-42-3
ChemSpider	5904
PubChem	6134
Reaxys	90841
Gmelin	36218
ChEBI	342369
ChEMBL	CHEMBL417016
ZVG	100321
EC zenbakia	200-559-2
ECHA	100.000.509
Human Metabolome Database	HMDB0041627
UNII	13Q3A43E0S
KEGG	C01970
PDB Ligand	LAT

Laktosa

Formula kimikoa

C₁₂H₂₂O₁₁

SMILES kanonikoa

2D eredua

SMILES isomerikoa

C([C@@H]1[C@@H]([C@@H]([C@H]([C@@H](O1)O[C@@H]2[C@H](O[C@H]([C@@H]([C@H]2O)O)O)CO)O)O)O)O

MolView

3D eredua

Konposizioa

oxigeno, karbono eta hidrogeno

Mota

α/β-lactose ^(en)

Estereoisomeroa

β-maltose ^(en) , α-lactose ^(en) , Gal(a1-4)a-Alt ^(en) , [[alpha-D-glucosyl-(1->4)-beta-D-mannose|alpha-D-glucosyl-(1->4)-beta-D-mannose]] ^(en) , [[beta-D-glucosyl-(1->4)-alpha-D-mannose|beta-D-glucosyl-(1->4)-alpha-D-mannose]] ^(en) , [[beta-D-mannopyranosyl-(1->4)-beta-D-glucopyranose|beta-D-mannopyranosyl-(1->4)-beta-D-glucopyranose]] ^(en) , [[alpha-D-Galp-(1->4)-beta-D-Glcp|alpha-D-Galp-(1->4)-beta-D-Glcp]] ^(en) , [[alpha-D-Manp-(1->4)-alpha-D-Manp|alpha-D-Manp-(1->4)-alpha-D-Manp]] ^(en) , L-Gul(a1-4)b-Tal ^(en) , [[alpha-D-Galp-(1->4)-beta-D-Galp|alpha-D-Galp-(1->4)-beta-D-Galp]] ^(en) , beta-cellobiose ^(en) , α-maltose ^(en) , [[alpha-D-Galp-(1->4)-alpha-D-Glcp|alpha-D-Galp-(1->4)-alpha-D-Glcp]] ^(en) , [[beta-D-Manp-(1->4)-beta-Galp|beta-D-Manp-(1->4)-beta-Galp]] ^(en) , alpha-mannobiose ^(en) , [[beta-D-glucosyl-(1->4)-beta-D-mannose|beta-D-glucosyl-(1->4)-beta-D-mannose]] ^(en) , [[alpha-D-Manp-(1->4)-beta-D-Manp|alpha-D-Manp-(1->4)-beta-D-Manp]] ^(en) , [[alpha-D-Glcp-(1->4)-alpha-D-Galp|alpha-D-Glcp-(1->4)-alpha-D-Galp]] ^(en) , alpha-cellobiose ^(en) , beta-epilactose ^(en) , [[alpha-D-glucosyl-(1->4)-alpha-D-mannose|alpha-D-glucosyl-(1->4)-alpha-D-mannose]] ^(en) , [[beta-D-Glcp-(1->4)-beta-D-Galp|beta-D-Glcp-(1->4)-beta-D-Galp]] ^(en) , [[beta-D-galactopyranosyl-(1->4)-alpha-D-galactopyranose|beta-D-galactopyranosyl-(1->4)-alpha-D-galactopyranose]] ^(en) , [[beta-D-Gal-(1->4)-alpha-D-Man|beta-D-Gal-(1->4)-alpha-D-Man]] ^(en) , Galactobiose ^(en) , Gal(a1-4)a-Ido ^(en) , beta-Mannobiose ^(en) , [[alpha-D-Glcp-(1->4)-beta-D-Galp|alpha-D-Glcp-(1->4)-beta-D-Galp]] ^(en) , [[alpha-D-Galp-(1->4)-alpha-D-Galp|alpha-D-Galp-(1->4)-alpha-D-Galp]] ^(en) eta [[beta-D-Glcp-(1->4)-alpha-D-Galp|beta-D-Glcp-(1->4)-alpha-D-Galp]] ^(en)

Masa molekularra

342,116 Da

Erabilera

Rola

Eszipiente

Arriskuak

NFPA 704

Identifikatzaileak

InChlKey

GUBGYTABKSRVRQ-DCSYEGIMSA-N

CAS zenbakia

63-42-3

ChemSpider

5904

PubChem

6134

Reaxys

90841

Gmelin

36218

ChEBI

342369

ChEMBL

CHEMBL417016

ZVG

100321

EC zenbakia

200-559-2

ECHA

100.000.509

Human Metabolome Database

UNII

KEGG

PDB Ligand