CONTRIBUTIONS TO THE STUDY OF THE BIOCHEMICAL VARIABILITY OF THE POLYPHENOLS EXISTING IN 8 THYMUS PULEGIOIDES POPULATIONS FROM

In the frame of some investigations performed to establish the chemical variability in the polyphenolic fraction of some plants belonging to the Lamiaceae family, we studied 8 Thymus pulegioides populations harvested in the spontaneous flora of Northern Moldavia in 2010. The polyphenolic fraction was investigated by thin layer chromatography, spectrophotometric determinations of the polyphenolic components and of the derivates of polyphenolcarboxylic acids, as well as by high performance liquid chromatography. The determinations were performed on methanolic extracts (DER 1:200 g/ml) and their concentrates (DER 0.125:1 g/ml). We could notice the constant presence of some quantitative variations between the analyzed samples, but qualitative differences could not be highlighted. If the flavonoid content varied between 0.1425 and 0.2845 g% equivalent rutoside, in case of the polyphenolcarboxylic acids the determined values were between 1.7201 and 4.0715 g% equivalent caffeic acid. To be noticed that both the maximum concentrations and the minimum regarding the content of flavonoids and that of polyphenolic acids is to be found in the same populations (Brosteni and Farcasa-1). In case of the vegetal material originated from three different populations from close areas (Farcasa 1,2,3) the quantitative differences are also significant.