on-exchange high performance liquid chromatography (HPLC) with an Aminex column and photodiode-array detection was used to purify, from soybean root nodules, highly polar phenolic acid conjugates that are recalcitrant to isolation by conventional techniques based on reversed-phase chemistry. HPLC, acid and enzymatic hydrolysis, ultraviolet spectroscopy, high resolution fast atom bombardment mass spectrometry (MS) and single and tandem electrospray MS were used to identify the 4-O-β-glucosides of p-hydroxybenzoic, protocatechuic and vanillic acids (which are reported in legumes for the first time) and the 5-O-β-glucoside of gentisic acid. The four phenolic acids, as well as gallic acid and its methyl ester, were also found in soybean nodules.

This work was financed by Acciones Hispano-Britá́nicas HB91-218 and HB92-185, and grant PB95-0091 from the Dirección General de Enseñanza Superior (Ministry of Education and Culture, Spain).

6 Pags.- 3 Tabls.- 1 Fig.

Peer reviewed