Effect of Solvent Polarity on Extraction Yield of Total Flavonoids with Special Emphasis to Glabridin from Glycyrrhiza glabra Roots

Abstract

Different organic solvents (ethanol, dichloromethane, ethyl acetate and acetone) were studied for their effects on the extraction efficiency of glabridin and total flavonoids (TF) from Glycyrrhiza glabra roots. The extract yield of Glycyrrhiza glabra roots was in the range of 3% to 6% following the extraction efficiency in the order ethanol>acetone>ethyl acetate>dichloromethane. A higher extraction yield of TF and glabridin was obtained with dichloromethane, followed by ethyl acetate, acetone and ethanol, indicating that the non-polar solvents help in optimal extraction of TF and glabridin. We also demonstrate for the first time, that the extraction efficiency of the flavonoids is not significantly affected by the use of the recovered solvents except in case of ethanol which reflects that the moistureabsorbing capacity of the solvent dictates the extraction efficiency of such compounds. The glycyrrhizin content in all the extract types was rather low (0.1 % to 1%) except for extract prepared with water, where the glycyrrhizin content was ~10% as expected since glycyrrhizin is a polar compound. Interestingly, we observed that ethyl acetate selectively isolated only glabridin with no traces of glycyrrhizin, which is a finding reported for the first time.

Surfactant-mediated extraction of capsaicin from Capsicum annuum L. fruit in various solvents

“…Since one of the most important factors affecting extraction of chemical constituents of a plant material is choice of solvents, the findings of the present work are important for future studies. Ethyl acetate has been found not only a very efficient extracting medium for capsaicin, but it is also considered an environmentally friendly or green solvent [ 31 , 32 , 33 ]. The efficacy of ethyl acetate in extracting phenolics has been attributed to its moderately polar nature [ 34 ].…”

Use of Diaion HP20 Resin to Achieve High Rutin Containing Moringa oleifera Extract: Its Solubility and Anti-Bacterial Properties and Possible Applications in Nebulizer Formulation for COVID Patients

“…The rutin content achieved from Moringa oleifera leaves is highly variable based on the solvent, time and extraction temperature employed for its isolation (Table 2). The values ranged from 0.006% (Mohamed et al, 2021a) Use of non-polar solvents such as ethyl acetate that are known to improve extraction of non-polar compounds (Yewale et al, 2021), however, the rutin yield was merely 0.31% with ethyl acetate while with butanol also the yield was merely 1% (Mohamed, Ibrahim, Abdel-Azima, & El-Missiry, 2021b) while acidic water yielded 6% rutin (Oyeleye et al, 2019).…”

Construction of a monoclonal antibody against glabridin (2G4) and development of an enzyme‐linked immunosorbent assay

“…However, there is a gap in the identification of other active compounds, including glabridin, which are important pharmacological components of this plant. Previous reports on the development of glabridin analysis involved the use of HPLC with a UV detector 9,10 . However, as glabridin has limited UV absorption, the detection sensitivity of this method is inadequate.…”

“…Previous reports on the development of glabridin analysis involved the use of HPLC with a UV detector. 9,10 However, as glabridin has limited UV absorption, the detection sensitivity of this method is inadequate. A literature review indicated that an immunological method using antibodies to develop an enzyme-linked immunosorbent assay (ELISA) method for licorice active compounds can enhance the sensitivity of the analysis compared to the conventional HPLC method.…”