Simultaneous determination and assignment of 13 major flavonoids and glycyrrhizic acid in licorices by HPLC-DAD and Orbirap mass spectrometry analyses

Histone deacetylases repress the accumulation of licochalcone A by inhibiting the expression of flavonoid biosynthetic pathway-related genes in licorice (Glycyrrhiza inflata)

Histone deacetylases (HDACs) play a crucial role in regulating plant growth, stress responses, and specialized metabolism. Licorice, utilized as both food and herbal medicine for millennia, includes Glycyrrhiza inflata as one of its primary medicinal species used globally. This study investigated the regulatory function of HDAC-mediated histone deacetylation in flavonoid biosynthesis in licorice. The research identified nineteen HDACs in the G. inflata genome. Abiotic stresses and plant hormones were found to influence flavonoid compound accumulation, correlating with altered expression patterns of HDAC genes and global histone H3 acetylation (H3ac) levels. Notably, several HDAC inhibitors enhanced flavonoid accumulation in G. inflata. Subsequent RNA-seq analysis revealed that the HDAC inhibitor suberoylanilide hydroxamic acid (SAHA) activated the expression of multiple genes related to flavonoid biosynthesis. ChIP-qPCR demonstrated that SAHA treatment increased the H3ac levels of flavonoid synthesis-related genes. Furthermore, overexpression of GiHDA2b, an HDAC member, decreased, while RNAi of GiHDA2b increased, the levels of expression and H3K18 acetylation of licochalcone A (LCA) biosynthetic genes indicating its negative role in flavonoid biosynthesis. This research provides valuable insights into the regulatory roles of GiHDACs and histone deacetylation in flavonoid biosynthesis in licorice, potentially contributing to improved bioactive compound production in medicinal plants.

Simultaneous separation of glycyrrhizic acid, baicalein and wogonin from Radix Glycyrrhizae and Radix Scutellariae using foam fractionation and in vitro activity evaluation

BACKGROUND

In this study, the optimal conditions for the extraction and purification of glycyrrhizic acid from Radix Glycyrrhizae (RG) and baicalein and wogonin from Radix Scutellariae (RS) by foam fractionation were studied on the basis of central composite design (CCD) and response surface methodology.

RESULTS

The results showed that herbal proportion (RG:RS), gas flow and ethanol concentration were the main factors guiding the foam fractionation of RG and RS. The optimum technological parameters were obtained as follows: herbal proportion (RG:RS), 1.86:1.14; gas flow, 109 mL min^-1 ; and ethanol concentration, 53%. Under the optimal operating conditions, the maximal extraction yields of baicalein, glycyrrhizic acid and wogonin were 56.67, 13.25 and 9.51 mg g^-1 , respectively, which were 2.32-, 1.22- and 1.84-fold higher than those of ultrasonic extraction and 17.28-, 1.15- and 9.91-fold higher than those of ultrasonic extraction without hydrolysis, respectively. Investigations on the antioxidant activity showed that the foam-fractionated extract exhibited better free radical scavenging activity (IC₅₀ 13.80 μg mL^-1 ) than that of the ultrasonic extract (IC₅₀ 223.00 μg mL^-1 ). Antibacterial activity showed that the minimum inhibitory concentrations of the foam fractionated extract against Staphylococcus aureus, Candida albicans, Group A Streptococcus and Pseudomonas aeruginosa were 1.38, 1.38, 0.69 and 5.50 mg mL^-1 , respectively.

CONCLUSION

The results indicate that the foam fractionated extract exhibited better extraction yields and free radical scavenging activity than did the ultrasonic extract. Therefore, this fast and eco-friendly method was established and could be a basis for the extraction and separation of other active constituents from herbal medicines. © 2022 Society of Chemical Industry.

Quality assessment of fried licorice based on fingerprints and chemometrics

Fried licorice is obtained by frying licorice without using any auxiliary materials, and it is widely used both as food and medicine in China. To explore the influence of licorice origin on the quality of fried licorice, a method based on fingerprinting and chemometrics was developed. Twenty batches of licorice were selected from four locations. The reference chromatograms of each location were established via similarity analysis. Chemometric methods, such as cluster, principal component, and orthogonal partial least squares discriminant analyses were used to evaluate the changes in the composition of fried licorice, predict its origin, and reflect its quality. Mass spectrometry was used to identify the chemical components. Finally, an origin prediction function was established via discriminant analysis to trace the origin of licorice. The model was demonstrated to be stable, reliable, and accurate in predicting licorice origin and to provide a reference for origin traceability.

Preparation and Characterization of Licorice-Chitosan Coatings for Postharvest Treatment of Fresh Strawberries

Several plant extracts are being investigated to produce edible coatings, mainly due to their antioxidant and antimicrobial activities. In this study, licorice root extracts were produced by ultrasound-assisted extraction and were combined with chitosan to elaborate edible coatings. Different solvents and temperatures were used in the extraction process, and the antioxidant and antimicrobial activity of the extracts were assessed. The most bioactive extracts were selected for the development of the edible coatings. The rheological properties of the coatings were studied, and they were applied on strawberry to evaluate their physicochemical and microbiological properties. The addition of licorice extract to chitosan resulted in positive effects on the rheological properties of the coatings: the incorporation of phytochemicals to chitosan decreased the shear stress and improved the restructuring ability of the coating solutions. The films presented a reduction of the Burger model parameter, indicating a reduction of rigidity. Furthermore, the strawberry coated with chitosan and licorice extract maintained good quality parameters during storage and showed the best microbiological preservation in comparison with controls. Hence, the use of chitosan with licorice extract is a potential strategy to produce edible coating for improving the postharvest quality of fruits.

Quality Evaluation of Wild and Cultivated Schisandrae Chinensis Fructus Based on Simultaneous Determination of Multiple Bioactive Constituents Combined with Multivariate Statistical Analysis

Schisandrae Chinensis Fructus, also called wuweizi in China, was a widely used folk medicine in China, Korea, and Russia. Due to the limited natural resources and huge demand of wuweizi, people tend to cultivate wuweizi to protect this species. However, the quality of wild and cultivated herbs of the same species may change. Little attention has been paid to comparing wild and cultivated wuweizi based on simultaneous determination of its active components, such as lignans and organic acids. An analytical method based on UFLC-QTRAP-MS/MS was used for the simultaneous determination of 15 components, including 11 lignans (schisandrin, gomisin D, gomisin J, schisandrol B, angeloylgomisin H, schizantherin B, schisanhenol, deoxyschizandrin, γ-schisandrin, schizandrin C, and schisantherin) and 4 organic acids (quinic acid, d(−)-tartaric acid, l-(−)-malic acid, and protocatechuic acid) in wuweizi under different ecological environments. Principal components analysis (PCA), partial least squares discrimination analysis (PLS-DA), independent sample t-test, and gray relational analysis (GRA) have been applied to classify and evaluate samples from different ecological environments according to the content of 15 components. The results showed that the differential compounds (i.e., quinic acid, l-(−)-malic acid, protocatechuic acid, schisandrol B) were significantly related to the classification of wild and cultivated wuweizi. GRA results demonstrated that the quality of cultivated wuweizi was not as good as wild wuweizi. The protocol not just provided a new method for the comprehensive evaluation and quality control of wild and cultivated wuweizi, but paved the way to differentiate them at the chemistry level.

Identification of Six Phytochemical Compounds from Asparagus officinalis L. Root Cultivars from New Zealand and China Using UAE-SPE-UPLC-MS/MS: Effects of Extracts on H₂O₂-Induced Oxidative Stress

A simple, rapid, specific, and sensitive method was developed for the simultaneous identification and quantification of six major bioactive compounds, namely, caffeic acid, quercetin, apigenin, ferulic acid, baicalein, and kaempferol, from Asparagus officinalis roots (ARs) native to New Zealand (green and purple cultivars) and China (yellow, green, purple, and white cultivars) using ultrasound-assisted, solid-phase extraction (UASE-SPE) coupled with ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). The method was validated in terms of linearity, limit of detection (LOD), limit of quantification (LOQ), accuracy (expressed as recovery %), and precision (expressed as relative standard deviation (%RSD)). The retention times, ultraviolet visible (UV-vis) data, and mass spectral patterns of the detected peaks matched those of commercial standards, allowing characterization of the target compounds. The LODs and LOQs were 23 ng/mL and 70 ng/mL, 50 ng/mL and 150 ng/mL, 10 ng/mL and 30 ng/mL, 18 ng/mL and 54 ng/mL, 14.4 ng/mL and 43.6 ng/mL, and 7.5 ng/mL and 22.5 ng/mL for caffeic acid, quercetin, apigenin, ferulic acid, baicalein, and kaempferol, respectively, and the mean recovery rates were 85.8%, 73.0%, 90.2%, 80.6%, 76.7%, and 74.5% for the six compounds, respectively. The levels of the target compounds were significantly different (p < 0.05) among the six cultivars. The Chinese yellow AR had the highest levels of bioactive compounds: 6.0, 3.9, 0.4, 1.0, 0.86, and 0.8 mg/g for caffeic acid, quercetin, apigenin, ferulic acid, baicalein, and kaempferol, respectively. The AR extracts showed protective effects against oxidative stress in the HepG2 and L929 cell lines. The results indicate that AR extracts contain high flavonoid levels that provide protective functions against oxidative stress and support the potential commercial application of AR extracts.

Identification and Chemical Standardization of Licorice Raw Materials and Dietary Supplements Using UHPLC-MS/MS

Defined as the roots and underground stems of principally three Glycyrrhiza species, Glycyrrhiza glabra L., Glycyrrhiza uralensis Fish. ex DC., and Glycyrrhiza inflata Batalin, licorice has been used as a medicinal herb for millennia and is marketed as root sticks, powders, and extracts. Identity tests described in most pharmacopeial monographs enabled the distinction of Glycyrrhiza species. Accordingly, an ultrahigh-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) assay using the method of standard addition was developed to quantify 14 licorice components (liquiritin, isoliquiritin, liquiritin apioside, isoliquiritin apioside, licuraside, liquiritigenin, isoliquiritigenin, glycyrrhizin, glycyrrhetinic acid, glabridin, glycycoumarin, licoricidin, licochalcone A, and p-hydroxybenzylmalonic acid), representing several natural product classes including chalcones, flavanones, saponins, and isoflavonoids. Using this approach, G. glabra, G. uralensis, and G. inflata in a variety of forms including root powders and extracts as well as complex dietary supplements could be differentiated and chemically standardized without concerns due to matrix effects.