HPLC conditions involved an isocratic system passing 0.25M NH4H2PO4 (HPLC

grade) in water (pH 3.4) at 1mL/min through a Zorbax SAX column (4.6mm i.d. x 250

mm, 5 C1M) with UV detection at 260 nm. The elution times of some physiologically

important chemicals, including UDPGA, are given in Table 6-2.


Table 6-2. Elution times of certain physiological substances (standards dissolved in
 mobile phase ) using the anion-exchange HPLC conditions described above.

 Compound Approximate elution time (min)



 UDP-glucuronic acid 23

 UJDP-glucose 7

 UDP 18

 UJDP-galacturonic acid 21

 PAPS1 45



 1 The PAPS (3 '-phosphoadenosine-5 '-phosphosulfate, co-substrate for sulfonate
conjugation) standard was dissolved in water in view of uncertainties regarding its heat
liability and/or acid stability.


 UDP-galacturonic acid, an epimer of UDPGA, could be resolved from UDPGA

using this method (Figure 6-6). The usefulness of anion-exchange chromatography in

separating these structurally related nucleotide sugars has been demonstrated elsewhere

(Liljebjelke et al., 1995; Schltipmann et al., 1994).