ABSTRACT
Objective To investigate the total flavonoids extraction process, solvent extraction rate, solvent recovery, and utilization using a new green solvent that nature deep eutectic solvents (NADESs) extraction of total flavonoids from Polygonati Odorati Rhizoma. Methods The extraction technology of total flavonoids was optimized by response surface methodology. The extraction efficiency of NADESs was evaluated by literature comparison and NADESs was recovered by macroporous resin adsorption. Results The NADESs (mole ratio 1:5) synthesized by sodium acetate and lactic acid was the best medium for extraction. After optimization by response surface methodology, the extraction rate of total flavonoids reached 20.13 mg/g at the best extraction condition of water 22%, extraction time 51 ℃, extraction time 21 min and liquid solid ratio 21 mL/g. The extraction rate of NADESs was significantly higher than the existing methods reported in the literature. The recovery experiments showed that the adsorption efficiency of NAK-9 on total flavonoids (88.67%) was significantly higher than that of D-101 (77.33%), and AB-8 (79.15%). Using methanol as solvent, the total flavonoids in Polygonati Odorati Rhizoma desorption rate was 80.46%. The recovered NADESs can be used for the extraction of total flavonoids in the next round, the extraction rate was 18.79 mg/g, and the recovery and utilization rate of solvent is 94.56%. Conclusion NADESs has the advantages of high efficiency, green environmental protection and can be reused as extraction medium, can be used for the extraction of total flavonoids from Polygonati Odorati Rhizoma. Meanwhile, the result provides a new idea that NADESs as an extraction medium for the extraction of other effective components of traditional Chinese medicine.
ABSTRACT
Flavonoids have attracted much attention due to their good anti-inflammatory, anti-oxidation and anti-tumor effects. At present, the extraction of flavonoids is mainly based on organic solvent, while the researches on the use of green and safe solvents are quite limited. Therefore, in the present study, different types of deep eutectic solvents (DESs) were applied to investigate their effect on extraction of flavonoids and optimize the process, also investigate the recovery efficiency of DESs and evaluate the recovery method for total flavonoids. The extraction yield of the total flavonoids acted as the comprehensive evaluation indexes, and a central composite design (CCD) of response surface methodology (RSM) was employed to further optimize the alcohol-based DES extraction conditions. The results showed that the optimized extraction conditions were as follows: water-DES ratio of 27%, solid-liquid ratio of 15 mL·g⁻¹, extraction temperature of 83 °C and extraction time of 42 min in ChCl-glycerol at 1:4 ratio. Under these conditions, the mean experimental value of the extraction yield (75.05 mg·g⁻¹) corresponded well with the predicted value (77.86 mg·g⁻¹). Moreover, these experimental results showed more advantages such as in higher efficiency, economy and environmental protection as compared with previously reported conventional extraction methods. In addition，the recovery yield of the total flavonoids from the DESs extraction solution achieved 97.88% by using AB-8 macroporous resin, and 88.12% desorption ratio can be achieved by 100% ethanol with 5 times resin content. After the above treated DESs were collected, the extraction yield with the same method reached 95.23%, indicating that the method of macroporous resin can be used for efficient and simple recovery and reuse. This study suggests that DESs can be used as a kind of sustainable and efficient natural extraction solvents for extraction of flavonoids from Prunella vulgaris.
ABSTRACT
Prunellae Spica is a perennial edible and medicinal plant, rich in antioxidant substances. Total flavonoids (TFC), Phenolics (TPC), triterpenoids (TSC), polysaccharides (PC) and their antioxidant capacities (by the FRAP, DPPH and ABTS⁺ methods) of ethyl acetate fraction, n-butanol fraction and other fractions of aqueous extract from Prunellae Spica were investigated in this study. Then the multivariate statistical method was adopted to analyze the relationship between the multiple pharmaceutical ingredients and antioxidant capacities of Prunellae Spica. The results showed that ethyl acetate fraction had relatively high concentration of TFC (0.61±0.10) g·g⁻¹DW, TPC (0.52±0.09) g·g⁻¹DW, and TSC (0.21±0.03) g·g⁻¹DW, with high scavenging capacity of DPPH (3.1±0.38) mmol·L⁻¹·g⁻¹DW and FRAP (2.56±0.35) mmol·L⁻¹·g⁻¹DW. Hierarchical clustering analysis (HCA) and principal component analysis (PCA) results indicated the information from chemical compositions and antioxidant capacity can represent the "differences" of different fractions. Canonical correlation analysis (CCorA) revealed a high positive correlation between the amounts of multiple chemical compositions and the antioxidant capacities (r=0.970 0), and the first canonical variate had been reached. Moreover, ABTS⁺ method showed a low response to the compositions of different fractions, so this method may not be suitable for evaluation of Prunellae Spica antioxidant capacities, while DPPH evaluation method was more suitable for TSC and TPC. The results of this study have important reference significance for the evaluation method on antioxidant activity of Prunellae Spica in the field of food or medicine as well as for the development of related extracts.
Subject(s)
Antioxidants , Flavonoids , Phenols , Plant ExtractsABSTRACT
To establish a random forest algorithm for identifying and classifying different brands of Xiasangju granules, and provide effective reference for identifying multi-index complex fingerprint. HPLC method was used to collect the fingerprint of 83 batches of Xiasangju granules from different manufacturers. The classification of Xiasangju granules samples based on chromatographic fingerprints was identified by chemometric methods including principal component analysis (PCA), partial least squares discriminate analysis (PLS-DA) and random forest analysis (RF). The superiority of the above three chemometric methods was compared. The results showed that the fingerprints of 83 batches of Xiasangju granules were established in this study. PCA could only explicate 56.52% variance contribution rate and could not completely classify the samples; PLS-DA analysis was superior to PCA, explicating 63.43% variance contribution rate and could obtain certain separation; RF could well classify the samples into 3 types, and the predication accuracy of the proposed method was 96.5%. Therefore, The results indicate that RF combined with HPLC fingerprint could effectively construct traditional Chinese medicine quality control and analysis system.