Spectrophotometric quantification of flavonoids in herbal material, crude extract, and fractions from leaves of Eugenia uniflora Linn

Abstract

Background:The traditional use of Eugenia uniflora L. (“Pitanga”) is reported due to several properties, which have often been related to its flavonoid content.Objective:The aim was to evaluate analytical procedures for quantification of total flavonoids content (TFCs) by ultraviolet-visible (UV-Vis) spectrophotometry in the herbal material (HM), crude extract (CE), and fractions from leaves of E. uniflora.Materials and Methods:The method for quantification of flavonoids after complexation with aluminum chloride (AlCl3) was evaluated: amount of sample (0.25–1.5 g); solvent (40%–80% ethanol); reaction time and AlCl3 concentration (2.5%–7.5%). The procedures by direct dilution (DD) and after acid hydrolysis (AH) were used and validated for HM and CE and applied to the aqueous fraction (AqF), hexane fraction, and ethyl acetate fractions (EAF).Results:The ideal conditions of analysis were ethanol 80% as solvent; 0.5 g of sample; λmax of 408 (DD) and 425 nm (AH); 25 min after addition of AlCl3 5%. The procedures validated for standards and samples showed linearity (R2 > 0.99) with limit of detection and limit of quantification between 0.01 and 0.17 mg/mL (rutin and quercetin); and 0.03 and 0.09 mg/mL (quercetin), for DD and AH, respectively. The procedures were accurate (detect, practice, and repair < 5% and recovery >90%), and stable under robustness conditions (luminosity, storage, reagents, and equipment). The TFCs in AqF and EAF were 0.65 g% and 17.72 g%, calculated as rutin.Conclusions:UV-Vis methods for quantification of TFC in HM, CE, and fractions from leaves of E. uniflora were suitably validated. Regarding the analysis of fractions, the EAF achieved enrichment of about nine times in the content of flavonoids.SUMMARY The total flavonoids content (TFCs) of herbal material, crude extract, and fractions from Eugenia uniflora can be quantified by ultraviolet-visibleThe spectrophotometric methods (direct dilution and acid hydrolysis) were reproducible and able to quantify TFC in raw material and derivatives from leaves of E. unifloraHigher flavonoids content was observed in ethyl acetate fractions after enrichment. Abbreviations Used: HM: Herbal material, CE: Crude extract, AqF: Aqueous fraction, HF: Hexanic fraction, EAF: Ethyl acetate fraction, TFC: Total flavonoids content, HCl: Hydrochloric acid, DD: Direct dilution, AH: After hydrolysis, RSD: Relative standard, A.U.: Absorption units.

Effect of the Ethyl Acetate Fraction of Eugenia uniflora on Proteins Global Expression during Morphogenesis in Candida albicans

“…This ethyl acetate fraction (EAF) was concentrated, frozen and lyophilized. The EAF was standardized as 17.82% m/m (expressed in rutin) of total flavonoids by UV/VIS and 6.56 % m/m (expressed as myricitrin) by HPLC (Ramos et al, 2017 ).…”

“…Therefore, we used the ethyl acetate (EAF) fraction of this natural product by obtaining a fraction enriched in polyphenols. According to Ramos et al ( 2017 ), the fraction has a flavonoid content about 9 times higher than the crude extract and this enrichment showed better anti- Candida activity. We decided to investigate whether this fraction, in addition to inhibiting fungal growth, could interact directly with the expression of virulence factors, specifically morphogenesis in C. albicans .…”

Phytochemical analysis and anti-inflammatory activity of Cladophora aegagropila extract

“…Then, the flavonoid content of the extracts was determined. Total flavonoid content as rutin equivalent in an ethanol-aqueous extract was performed using spectrometric method (6,7). The method was based on the flavonoids ability to form complexes with aluminium chloride solution in ethanolaqueous medium.…”

Biopharmacotechnical and physical properties of solid pharmaceutical forms containing rutin commercially acquired in Juiz de Fora city, Brazil

“…The quantification of the rutin contents was performed spectrophotometrically ( Ramos, Bezerra, Ferreira, & Soares, 2017). Rutin ® (≥95%, Sigma-Aldrich, 2-30 µg mL -1 ) was used as a standard to obtain the calibration line.…”