Optimization of Extraction of Polyphenolic Compounds from Medicinal Lungwort (Pulmonaria officinalis L.)

Abstract

Medicinal plants are potential natural sources of biologically active substances that have geroprotective properties, slowing down the aging process. Vegetable raw materials are used as antioxidants in the food industry. Pulmonaria officinalis L. has a high content of biologically active substances. The purpose of this work is to determine the operating parameters for extracting the maximum amount of biologically active substances from Pulmonaria officinalis L. by extracting ethanol and finding sources of natural antioxidants.The antioxidant activity of several ethanol extracts of Pulmonaria officinalis L. – 30-70% with a step of 10 ethanol obtained from the dried root culture of the medicinal plant of biologically active substances was determined. The total content of polyphenols, flavonoids and proanthocyanidins was estimated. According to the data obtained, the relationship between the values determined for the biologically active substances presented and the values of antioxidant activity was revealed. Extracts of Pulmonaria officinalis L. showed a high yield of polyphenolic compounds-889.39±4.29 mcg of Gallic acid/ml, flavonoids-728.90±6.98 mcg of rutin/ml, proanthocyanidins-211.65±5.31 mcg of catechin/ml at an ethyl alcohol concentration of 60% and an extraction temperature of 50°C in 4 hours. The antioxidant activity using 2 methods: A spectrophotometric method DPPH (2,2-diphenyl-1-picrylhydrazyl) and the FRAP method (iron reducing/antioxidant power) was investigated. During DPPH spectrophotometric analysis, the antioxidant activity is equal to 86.96% for polyphenols, 75.47% for flavonoids, and 51.25% for proanthocyanidins. FRAP analysis showed that extracts with operating parameters had a pronounced antioxidant activity (tэ= 4 ч; Tэ= 50°C; Сэ= 60%)и (tэ= 5 ч; Tэ= 60°C; Сэ, = 70%).