Quantitative anhydrous mercaptolysis of algal galactans followed by HPLC of component sugars.
This paper describes a new HPLC method for the sugar analysis of algal galactans containing 3,6-anhydrogalactose, which is readily destroyed during usual acid hydrolysis and methanolysis. By anhydrous mercaptolysis of galactans at 60 degreesC for 6 h with the newly developed solvent system, 0.5 N HCl/[ethanethiol:methanol (2:1, v/v)], component sugars, including 3,6-anhydrogalactose, were liberated quantitatively as their diethyl dithioacetals. The resultant sugar diethyl dithioacetals were found to have strong UV-absorption (absorption maximum of 3,6-anhydrogalactose diethyl dithioacetal in water, 191-192 nm; molar extinction coefficient, 4,400). The sugar diethyl dithioacetals were then resolved simultaneously within 15 min by reversed phase HPLC with 30% acetonitrile as the eluent and detected by UV-absorption at 215 nm. Amounts of sugar diethyl dithioacetals less than 50 pmol can be determined without further derivatization.
Hama
Y
Y
Department of Applied Biological Sciences, Faculty of Agriculture, Saga University, Saga, 840-8502, Japan.
Nakagawa
H
H
Mochizuki
K
K
Sumi
T
T
Hatate
H
H
D000042:Absorption; D001671:Biochemistry / Q000379:methods*; D002241:Carbohydrates / Q000032:analysis*; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D056890:Eukaryota / Q000737:chemistry*; D005685:Galactans / Q000032:analysis* / Q000737:chemistry; D005690:Galactose / Q000031:analogs & derivatives / Q000032:analysis / Q000737:chemistry; D013056:Spectrophotometry, Ultraviolet; D013438:Sulfhydryl Compounds / Q000737:chemistry
D002241:Carbohydrates; D005685:Galactans; D013438:Sulfhydryl Compounds; C117625:3,6-anhydrogalactose; C007638:ethanethiol; D005690:Galactose