TY - JOUR
T1 - Behaviour of xyloisosaccharinic acid and xyloisosaccharino-1,4-lactone in aqueous solutions at varying pHs
AU - Almond, Michael
AU - Shaw, Paul B.
AU - Humphreys, Paul N.
AU - Chadha, Marcus J.
AU - Niemelä, Klaus
AU - Laws, Andrew P.
PY - 2012/12/1
Y1 - 2012/12/1
N2 - Xyloisosaccharinic acid is one of the major degradation products formed during the alkali catalysed hydrolysis of hemicelluloses. In acidic solution xyloisosaccharinic acid undergoes an acid catalysed lactonisation to generate xyloisosaccharino-1,4-lactone. We report here the solution phase properties of xyloisosaccharinic including measurement of its aqueous pKa (3.00 ± 0.05) using 13C NMR methods. We also report rate constants for the acid catalysed lactonisation, klact(D20), of xyloisosaccharinic acid and the results of our investigations of the kinetics of hydrolysis of xyloisosaccharino-1,4-lactone at acidic and basic pHs. The second-order rate constants for the hydrolysis reactions kHO- (25 M-1 s-1) and kD+ (4.13 E-4 M-1 s-1).
AB - Xyloisosaccharinic acid is one of the major degradation products formed during the alkali catalysed hydrolysis of hemicelluloses. In acidic solution xyloisosaccharinic acid undergoes an acid catalysed lactonisation to generate xyloisosaccharino-1,4-lactone. We report here the solution phase properties of xyloisosaccharinic including measurement of its aqueous pKa (3.00 ± 0.05) using 13C NMR methods. We also report rate constants for the acid catalysed lactonisation, klact(D20), of xyloisosaccharinic acid and the results of our investigations of the kinetics of hydrolysis of xyloisosaccharino-1,4-lactone at acidic and basic pHs. The second-order rate constants for the hydrolysis reactions kHO- (25 M-1 s-1) and kD+ (4.13 E-4 M-1 s-1).
KW - 2,4-Dihydroxy-2-hydroxymethylbutanoic acid
KW - 3-Deoxy-2-C-hydroxymethyl-d,l-tetronic acid
KW - pK measurement
KW - Xyloisosaccharinic acid
KW - Xyloisosaccharino-1,4-lactone
UR - http://www.scopus.com/inward/record.url?scp=84868260758&partnerID=8YFLogxK
U2 - 10.1016/j.carres.2012.09.019
DO - 10.1016/j.carres.2012.09.019
M3 - Article
C2 - 23123572
AN - SCOPUS:84868260758
VL - 363
SP - 51
EP - 57
JO - Carbohydrate Research
JF - Carbohydrate Research
SN - 0008-6215
ER -