Relationship in annual species of Medicago. V. Analysis of Phenolics by means of one-dimensional chromatographic techniques

Abstract

The incidence of phenolic substances was investigated in leaf hydrolysates of 26 annual and 11 perennial species of Medicago.

One-dimensional chromatograms showed a very common phenolic pattern for most of the species belonging to the same subsection or section. Quercetin, ferulic acid, and coumestrol were detected, with few exceptions, in all the species examined, and cyanidin, in most cases as the aglycone of leucocyanidin, was consistently observed in the annual but not in the perennial species (section Falcago).

Sinapic acid occurred sporadically in the species, but was absent in M. radiata (section Medicago) and M. orbicularis (section Orbiculares). Kaempferol was not observed in species from subsection Pachyspirae (section Spirocarpos) or in the perennial species. Three of the seven unidentified compounds, U₅, U₆, and U₇ believed to be the isoflavone formononetin, were of wide occurrence. U₃ was observed in the chromatograms of the perennial species (section Falcago) and was consistently present in species of subsection Pachyspirae and in some species of subsection Leptospirae (section Spirocarpos), while both U₂ and U₄ were restricted to species of subsection Rotatae, the former being observed only in M. scutellata. U₁ was present only in some accessions of the three species M. rigidula, M. truncatula (subsection Pachyspirae), and M. laciniata (subsection Leptospirae) of section Spirocarpos.