Search Results

1 - 2 of 2 items

  • Author: Jozef Sokol x
Clear All Modify Search
Determination of selected phenolic acid and majoritarian avenanthramides in different varieties of naked oats (Avena sativa L.) grown in Slovakia

Abstract

Oats are important cereals. Oats are a good source of protein and lipids, polyphenolics, phenolic acids, flavonoids and avenanthramides. Avenanthramides is phenolic group, which is unique in oats and have antioxidant activity, anti-inflammatory, anti-atherogenic and anti-proliferative effect. The aim of study is determination of the majoritarian avenanthramides (2c, 2p and 2f) and phenolic acids (p-coumaric and ferulic) in selected varieties of oat (Avena sativa L.) grown in two consecutive years using the HPLC method. The oats were exposed to ultrasound supported extraction (two 15 min cycles).The simultaneous separation was performed using C18 type of stationary phase. The method showed a good linearity in the concentration range 0.04 - 5.24 μg/mL for p-coumaric acid, 0.04 - 5.13 μg/mL for ferulic acid, 0.19 - 24.5 μg/mL for avenanthramide 2c, 0.53 - 17.1 μg/mL for avenanthramide 2p, 0.8 - 25.6 μg/mL for avenanthramide 2f. Correlation coefficients were higher than 0.9997. Detector operated at a wavelength 320 nm. The repeatability of the method was evaluated in three concentration levels with satisfactory results for each analyte. The content of both phenolic acids is significantly lower (50- - 100-times) compared to the total content of avenanthramides in both years’ harvests for all analyzed varieties. Content of total avenanthramides was the highest in varieties Racoon (723.28 mg/kg) followed by Oliver (578.59 mg/kg) and Kamil (384.17 mg/kg).

Open access
Biologically valuable components, antioxidant activity and proteinase inhibition activity of leaf and callus extracts of Salvia sp.

Abstract

Sage is medicinal plant, known for its antioxidant and anti-inflammatory effects. Eight extract samples were tested in this study: extract from Salvia officinalis L. varieties from two different geographical localities (Jaslovské Bohunice and Pobedim, Slovakia), Salvia officinalis L., variety “bicolor”, Salvia officinalis L., variety “purpurescens”, Salvia apiana, Salvia divinorum, and two callus cultures of Salvia sclarea L. and Salvia aethiopis L. The highest values for composite parameters were observed for extract from Salvia apiana. It can be concluded that prepared sage extract samples are rich on polyphenolic acids (2 950±265 μg.mL−1 GAeq.) and amines (197±5.50 μg.mL−1 TRPeq.). HPLC analysis confirmed the dominant content of rosmarinic acid in the extracts; the highest content was detected in the Salvia apiana extract (1 120±15 μg.mL−1). Extract from Salvia apiana expressed too the highest antioxidant activity (1 710 – 4 669 μg.mL−1TEAC). Similarly, the highest inhibition activity was observed for this extract on thrombin (57±3.3 %) and on other proteinases (over 80 %). Spearman correlation analysis and PCA analyses revealed a coherence between antioxidant activity of samples and their content of rosmarinic acid as well as inhibitory activity towards particular proteases, and revealed the significance of thiol based secondary metabolites. Cluster analysis demonstrates the differences of Salvia apiana extract from extracts of S. officinalis L., the group of S. divinorum extract and from callus cultures.

Open access