Extraction Of Oleanolic Acid Research Articles

Extraction of oleanolic acid from wine pomace using betaine-based deep eutectic solvents

Extraction of oleanolic acid from wine pomace using betaine-based deep eutectic solvents

Extraction of Oleanolic Acid from Clematis mandshurica and Protective Effect of the Acid on Neural Function and Early Brain Injury after Subarachnoid Haemorrhage

This paper aims to design a simple and rapid way to extract and determination of oleanolic acid from Clematis mandshurica Rupr. (C. mandshurica), and to disclose the protective effect of the acid on neural function and early brain injury after subarachnoid haemorrhage. To this end, an orthogonal test was performed to examine the effects of ultrasonic-assisted extraction (UAE) variables (i.e. liquid-material ration, time, temperature and frequency) on the extraction of oleanolic acid from C. mandshurica. Then, the oleanolic acid from C. mandshurica was quantified and analysed by liquid chromatography with photodiode array detection (LC-DAD), and the fraction of oleanolic acid was collected by automatic fraction collector. Finally, the author investigated how oleanolic acid influences the neural function and early brain injury after subarachnoid haemorrhage. Through the analysis, the highest oleanolic acid yield of 0.7192% was obtained with the extraction temperature of 70°C, extraction frequency of 90kHz, extraction time of 10min and liquid-material ratio of 30:1. Meanwhile, significant improvement of neural function was observed in the oleanolic acid group of 20mg/kg, and the model group suffered from much more serious neural function injuries than the sham-operated group. This means the oleanolic acid group of 20mg/kg can effectively reduce the cerebral vascular permeability caused by subarachnoid haemorrhage. This research reveals the protective mechanism of oleanolic acid on protection against early brain injury after subarachnoid haemorrhage in rats.

Valorization of olive tree leaves: Extraction of oleanolic acid using aqueous solutions of surface-active ionic liquids.

The global olive oil industry annually generates approximately 750,000-1,500,000 tons of Olea europaea leaves as waste that are typically burned for energy production. Yet, this agricultural by-product is a rich source of oleanolic acid, a high value triterpenic acid with outstanding pharmaceutical and nutraceutical activities. The present study focuses on the extraction of oleanolic acid from dried O. europaea leaves using aqueous solutions of surface-active ionic liquids as alternative solvents. A number of imidazolium-based ionic liquids with variable chain length, different anions and optional side-chain functionalization was synthesized and employed in the extraction of oleanolic acid. Ionic liquids with long alkyl chains remarkably enhance the solubility of oleanolic acid in water, thus being able to compete with the solubilities afforded by molecular organic solvents, such as chloroform. Consequently, they are suitable alternatives for the solid-liquid extraction of triterpenic acids from natural matrices and provide improved extraction yields of up to 2.5 wt% oleanolic acid extracted from olive tree leaves.

Ionic Liquid Based Ultrasonic-Assisted Extraction of Oleanolic Acid from Grape Seeds

Ionic liquid based ultrasonic-assisted extraction (ILUAE) was successfully applied to extract Oleanolic acid (OA) from grape seeds. Different kinds of 1-alkyl-3-methylimidazolium ionic liquids with different kinds of cations and anions were studied and 1-butyl-3-methylimidazolium chloride ([C4mim]Cl) solution was selected as extractants. The optimal conditions of ILUAE were determined by single factor experiments and Box-Behnken design as follows: [C4mim]Cl concentration of 0.7 mol/L, extraction time of 4 h, liquid-solid ratio of 15:1 mL/g, ultrasonic power of 195 W, the ultrasonication time of 13 min, and extraction temperature of 48℃·min. The extraction yield of OA was 13.4 mg/g, which is well in close agreement with the value predicted by the model. Compared with the regular ultrasonic-assisted extraction (UAE), the proposed approach exhibited 1.64 times higher efficiency, which indicated that ILUAE has a broad prospect for sample preparation of the bioactive compounds.

Supercritical CO2 extraction of oleanolic acid from grape pomace

SummaryIn this work, we investigated the possibility to extract oleanolic acid through supercritical fluid extraction from waste materials such as grape pomace, which can represent a yet unexploited source of highly added‐value products. Preliminary supercritical fluid extractions were performed on dried grape skin samples and compared with solid–liquid extraction. After optimising extraction parameters such as temperature, pressure and extraction time, the ratio between supercritical and solid–liquid extraction yields was approximately 1/5. Supercritical CO2 extractions were also carried out on dried grape pomace samples. In this case, the ratio between supercritical and solid–liquid extraction yields was increased up to 1/3, thanks to a combination of static and dynamic extraction and the use of ethanol as modifier. This extraction technique proved successful in extracting oleanolic acid from grape pomace samples with extraction yields that were comparable with those obtained with well‐established extraction techniques such as solid–liquid extraction.