Identification of the flavonoids in five chemical races of cultivated barley

Abstract

Twenty‐seven flavonoids have been identified variously in leaf extracts of the five known chemical races of barley. Five are flavone O‐glycosides, the remainder being C‐glycosylflavones based on apigenin, luteolin or chrysoeriol. Most of the variation is due to the attachment of various sugars, including galactose, to the C‐glucosyl moieties in the 6‐positions, but there are also a range of 7‐O‐glycosides, including two with acyl attachments. Analyses of the results indicate that race A is closest to race C, races B1 and B2 are very similar and race S is about equidistant from A, B1 and C. Genetic evidence shows that the S pattern is the original one and that the others have evolved from it; the chemical results are completely consistent with such an interpretation.

Combined mass spectrometric and chromatographic methods for in-depth analysis of phenolic secondary metabolites in barley leaves

“…Conclusions regarding a large diversity of metabolites between barley strains from different geographic regions were drawn from chemotaxonomic studies undertaken previously. In varieties from Europe, South Africa and Mexico were grouped on the basis of having the same patterns of flavonoids, distinct from the varieties of Ethiopia and the Near East.…”

“…Structural studies on the flavonoids in barley resulted in characteristics of flavanols, flavones and flavonols with diversified substituents. Paper and thin layer chromatography allowed to identify 27 flavonoids in barley leaves and dividing of barley varieties into five chemical races . It is also known that interglycosidic bounds are formed as glycosyl(1 → 6)glycosides or glycosyl(1 → 2)glycosides .…”

A differential rate of regional distribution of barley flavonoid patterns in Ethiopia, and a view on the center of origin of barley

“…24. But it is well proved from various evidence (FROST et al 1977) that it is a genuine pattern. The present numerical treatment, thus, is also a good illustration of the fact that the result of numerical treatment alone is not a truth, but a picture of the truth; in my case here, it is a distorted picture of the truth.…”

“…The high frequency of certain flavonoid patterns observed in Ethiopian barley and the possibility of placing flavonoid patterns in an ascending order of evolution, S-+C-B,-B,-,A by FROST et al (1977); the high outcrossing rate of Hordeum spontaneum observed in some regions of Israel (BROWN et al 1978), and of Hordeirm vulgare in Ethiopia (BEKELE, in preparation); the discovery of barley grains in southern Egypt dating back 18,000 years (WENDOKF et al 1979); the possibility of independent invention of agriculture (DE CANDOLLE 1886; SAUER 1952) brings into focus the question of the evolution and center of origin of barley. The central position of Ethiopia in this issue has been a matter of debateful discussion.…”

“…discontinuous distributions of flavonoids which might reflect the microenvironmental differences. The geographical distribution of the differences in flavonoid patterns was exemplified by the almost exclusive occurrence of the C pattern in Ethiopian barley (FROST et al 1977).…”