Galactopyranuronic acid

Fig. 27.—Circular Dichroism Spectra of Galactopyranuronic Acid for d.p. = 2 (First and Third Panels) and d.p. = 340 (Second and Fourth Panels) as a Function of Percent of Neutralization with NaOH (First and Second Panels) and Ca(OH)2 (Third and Fourth Panels) 0%...

Fig. 28.—Circular Dichroism of a Film of Poly(D-galactopyranuronic Acid). (Redrawn from Ref. 62.)...

Figure 1. A schematic model of a short sequence of the pectin backbone including a-D-Galactopyranuronic Acid, Methyl a-D-Galactop3mianosiduronate and a-D-Galacto-pyranosiduronamide.

In contrast with previous result [4] all exopolygalacturonase forms were inhibited by their product, D-galactopyranuronic acid [19] however the extent (Tab. 1) and the type of inhibition was various (competitive for enzyme with pH optimum 3.8 and mixed for the others). 

Candida boidinii was cultured at pH 3.51, 5.49 and 7.01, respectively. Czapek s Dox medium with citrus pectin (GENU Pectin, Denmark), sodium pectate or citrus pectin with 20% of D-galactopyranuronic acid (Fluka, Switzerland) as a carbon source were used. The growth curves were performed by measuring the optical density (OD) at 660 nm. 

Fig. 3. Isoelectric focusing in ultrathin polyacrylamide layers (pH gradient 3 -10) of multiple forms of polygalacturonase produced by Candida boidinii under different cultivation conditions a - pectin, pH 3.51 b - pectin, pH 5.49 c -pectin, pH 7.01 d - 20% of D-galactopyranuronic acid in pectin e - pectate. A - Activity detection with print technique on colouress D-galacturonan DP 10 dyed additionally with ruthenium red ( both exo- and polygalacturonases) and B - activity detection with Ostazin Brilliant Red/D-galacturonan DP 10 agar print (polygalacturonases).

Pectins are present in plant juices. These are now considered to be polymers containing a basic chain, designated pectic acid, of 4-linked D-galactopyranuronic acids, the-carboxyl groups of which exist in part as methyl esters and in part as salts. Variable amounts of an araban and a galactan are associated with this polysaccharide.12 A method of approximate assay for pectic substances13 depends upon saponification... 

K. Tajima, Degradation reaction of a-D-galactopyranuronic acid in an acetic anhydride-base system, Chem. Lett., (1985) 49-52. 

Tetra-A c 1,2,3,4- Tetra-O-acetyl-a-D-galactopyranuronic acid CmHisO, 362.29... 

Dodecasaccharides.— The phytoalexin elicitor of soyabean comprising twelve galactopyranuronic acid units linked a-(l->4) has been synthesised. ... 

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