Buckwheat (Fagopyrum sp.) is a plant that has been grown for its use in food and pharmacy for years. Lately, it has made it to the forefront with its beneficial effects on human health. Additionally to its high levels of proteins and minerals it is known for its high content of phenolic compounds, especially rutin, which is mostly found in its herb. Its diverse composition of bioactive substances has a positive effect on the development of common disease states like high blood pressure, hypercholesterolemia and diabetes. It is also attributed with neuroprotective, antitumor and antiinflammatory effects.
In this master's thesis we determined the flavonoid contents of rutin, quercetin and quercitrin along with fagopyrins found in the common buckwheat (Fagopyrum esculentum) extracts of the Darja variety, that were obtained by extraction with supercritical CO2 and ethanol. The content of the studied compounds was determined in the extracts of leaves, flowers, unripened and ripened fruits as well as in buckwheat pulp with UPC2 and HPLC analyses. We also performed a GC-MS analysis for a more detailed insight into the composition of the samples.
The flavonoids were not detected in all samples. The highest content (52,54 mg/g of the drug) was determined in dry leaves of common buckwheat. Out of all three flavonoids, we most frequently measured the content of quercitrin namely in the ethanolic flower extract of the CV1 fraction (2,63 mg/g of the drug). Out of the CO2 and ethanol extracts, the most rutin is in the ethanolic leaves extract of the CV1 fraction (0,23 mg/g of the drug), and the most of the quercetin is in the ethanolic leaves extract of the fraction CV3 (0,50 mg/g of the drug). We can summarize that in the common buckwheat (F. esculentum) of the Darja variety, leaves and flowers come in with the highest flavonoid levels while the pulp comes in last with the lowest amounts. In contrast to flavonoids, fagopyrins were detected in all samples. The highest content was found in the CO2 leaves extract of the CV1 fraction (25,54 mg/g of the drug). Most compounds (21) were identified in the ethanolic leaves extract of the CV3 fraction, and at the least here in the pulp. Most unidentified substances (18) were analyzed in the ethanolic flower extract of the CV1 fraction. The proportion of identified substances in almost all analyzed extracts, except for pulp, is about 80 %.
|