SECONDARY METABOLITES OF Phaseoli pericarpium

Abstract

The pericarp of common bean Phaseoli Pericarpium syn. Fructus Phaseoli sine semine, is a medicinal raw material that has been long used in traditional folk medicine as an antidiabetic drug and now it is a pharmacopoeial material that belongs to one of the most frequently used plant raw materials that support treatment of diabetes. The aim of this study was to characterize the morphological characteristics of Phaseoli Pericarpium of over a dozen bean cultivars and to determine the content of phenolic compounds and the antioxidant properties of pericarp extracts. Bean pericarp used for phytochemical analysis came from field experiments conducted over the period 2010–2011. The experimental material consisted of white-flowered varieties of common bean – 5 cultivars and of runner bean – 6 cultivars. The bean pericarp, Phaseoli Pericarpium, was characterized by a high content of secondary metabolites: phenolic acids, flavonoids and tannins, whereas the pericarp extracts also exhibited antioxidant activity in scavenging DPPH. The pericarp of common bean was found to show high variation (V – 40.8%) in phenolic acid content, whereas the runner bean pericarp was characterized by high variation V (45.1%) in flavonoid content. Among the common bean cultivars studied, the pericarp of cv. ‘Laponia’ showed the greatest accumulation of biologically active substances – phenolic acids (CAE) – 0.18 mg·g–1 DM, flavonoids (QE) – 13.2 mg·100 g–1 DM, and tannins 3.43% DM. Likewise, the pericarp of the ‘Felicja’ runner bean cultivar stood out in terms of the accumulation of these compounds, as it contained the following amounts: phenolic acids – 0.33 mg·g–1 DM, flavonoids (QE) – 10.8 mg·100 g–1 DM, and tannins – 2.72% DM.

Keywords

• phenolic acids
• flavonoids
• tannins
• common bean
• runner bean
• cultivars