Quantitative determination of saturated oligogalacturonic acids in enzymatic digests of polygalacturonic acid, pectin and carrot pomace by on-line LC-ESI-MS

Abstract

A method for the quantitative determination of oligogalacturonic acids (OGAs) by on-line high-performance liquid chromatographic (HPLC) separation and mass spectrometric detection via an electrospray interface (ESI-MS) without additional desalting steps was developed. Saturated OGAs up to a degree of polymerization (dp) of 3 were quantified by comparison with reference compounds. The calibration plots showed high linearity (R(2)>0.99), and the detection limits for dp 1, 2, and 3 were 11, 28, and 6 ng per injection, respectively. Non- and partially methyl-esterified OGAs with a dp of 3 and 4 were calculated semi-quantitatively as dp 3. The analytical system was used for the quantification of OGAs of digests obtained by incubation of polygalacturonic acid, pectin, and carrot pomace with commercial enzyme preparations. Furthermore, methyl-esterified OGAs up to a dp of 12 containing up to 4 methyl esters were detected in a pectin digest.

Micellar electrokinetic capillary chromatography determination of alginic acid in pharmaceutical formulations after treatment with alginate lyase and UV detection

“…In particular, this approach is very sensitive as the LOD is 15 ng (0.25 mg/mL), about 1.6-fold lower than CE evaluation of intact AA [21] due to the strong UV asorption of unsaturated uronic acid residues. Moreover, the use of alginate lyase assures a great specificity as other similar polysaccharides having quite the same properties, such as pectins formed of oligogalacturonic acids [29,30] potentially present in preparations as polluting material, are not recognized by the enzyme and not determined by MEKC. As a consequence, this analytical approach is both qualitative and quantitative.…”

Side Streams of Plant Food Processing As a Source of Valuable Compounds: Selected Examples

“…The pomace may also be used for the production of a powder that contains antioxidant dietary fiber; however, the antioxidant activity is adversely affected by drying and blanching (Chantaro et al 2008). Treatment of carrot pomace with pectinolytic enzymes leads to the formation of anti-adhesive oligogalacturonic acids (Stoll et al 2003a).…”

Determination of pathogen-related enzyme action by mass spectrometry analysis of pectin breakdown products of plant cell walls

“…Mass spectrometry has been shown to be highly eVective in the analyses of GalUA oligomers [19][20][21][22][23][24][25][26]. Electrospray ionization with an ion trap mass analyzer was employed by Korner et al [27].…”