Optimization of Phenolic Compounds Extraction from Crataegi Fructus

Growing interest in the medicinal and nutraceutical uses of hawthorn highlights the need to improve the extraction of bioactive compounds in order to produce high-value products. This study aimed to refine extraction methods to improve the quality and quantity of phenolic compounds, flavonoids, and tannins in Crataegi fructus extracts while preserving their integrity and minimizing the impact of impurities. Phenolic compounds and flavonoids were extracted using ethanol, tannins and water via unconventional ultrasound-assisted extraction protocols. According to the results, significant variations in the total phenolic (TPC), total flavonoid (TFC), and total tannin (TTC) content were observed in correlation with the genotype and the extraction time. The optimal extraction time for TPC and TFC was 150 min of sonication of the samples, while the optimal extraction time for TTC was 30 min of sonication at 99 °C. Ten phenolic compounds, acids (chlorogenic, gallic and syringic acids) and flavonoids (epicatechin, catechin, procyanidin B2, hyperoside, quercetin, isoquercetin and vitexin), were identified in hawthorn fruits extracts by HPLC. Among them, the most abundant were epicatechin, chlorogenic acid, procyanidin B2, catechin and gallic acid. By comparing the maximum contents of phenolic compounds, flavonoids, and tannin extracted from the two species of Crataegi fructus, Crataegus monogyna presented a lower amount of phenolic compounds and tannins, but higher amount of flavonoids, compared to C. pentagyna (1222.15 mg GAE 100 g−1 TPC, 502.47 mg GAE 100 g−1 TTC, and 723.48 mg CE 100 g−1 TFC in C. monogyna vs. 1240.01 mg GAE 100 g−1 TPC, 709.61 mg GAE 100 g−1 TTC, and 549.67 mg CE 100 g−1 TFC in C. pentagyna). Since the climate can influence both the content of bioactive compounds in plants and their extractability, the importance of this study lies in the description for the first time in the literature of hawthorn genotypes selected in Olt County, Romania, in a continental temperate climate with subtropical influences. The results of the study help obtain valuable genotypes for high-quality drugs and food supplements.