Study on enhanced extraction and seasonal variation of secondary metabolites in Eucommia ulmoides leaves using deep eutectic solvents

Current developments and trends in hybrid extraction techniques for green analytical applications in natural products

Natural product extraction has advanced significantly due to the growing need for environmentally friendly and sustainable analytical techniques. The medicinal benefits of natural products are gaining worldwide recognition. This shift emphasizes the need for sustainable extraction methods, as traditional organic solvents can negatively impact biodiversity. This review looks at new green extraction methods such as pressurized liquid extraction, ultrasound-assisted extraction, microwave-assisted extraction, and supercritical fluid extraction. The overview describes the main goals, workings, and extraction principles of these techniques, which are used to extract phytochemicals from various plant sources. Additionally covered is how green solvents, more especially bio-based and deep eutectic solvents, can enhance the sustainability of these techniques. This review examines the developments in synergistic extraction, emphasizing how these hybrid techniques can be used to isolate a variety of natural products, including polyphenols, alkaloids, essential oils, and more. It also emphasizes how crucial these techniques are to the development of high-performance, environmentally friendly analytical platforms for the use of natural products. The recent uses of these extraction techniques are covered in this review. Despite the positive results, standardization, selectivity, scalability, and economic viability issues must be recognized and addressed.

Ultrasonic and Deep Eutectic Solvent for Efficient Extraction of Phenolics from Eucommia ulmoides Leaves

The purpose of this research was to establish an effective method for extracting phenolic compounds from Eucommia ulmoides leaves. Seven different deep eutectic solvents (DESs) were prepared, and ultrasonic-assisted technology was employed to optimize the extraction parameters. Factors such as the DES molar ratio, water content, liquid-to-solid ratio, ultrasonic duration, temperature, and power were systematically investigated. The optimal extraction conditions were determined to include a choline-chloride-to-ethylene-glycol molar ratio of 1:4, 30% water content, a liquid-to-solid ratio of 40:1 mL/g, an ultrasonication time of 48 min, a temperature of 53 °C, and ultrasonication power of 60%. Under these optimized conditions, the yields of phenolic compounds and flavonoids reached 17.16 mg/g and 48.23 mg/g, respectively, which were significantly higher (p < 0.05) than those obtained by traditional extraction methods. These findings indicate that the use of ultrasonic-assisted DES extraction notably improved the content of active compounds and the antioxidant properties of the extracts. Fourier transform infrared spectroscopy and scanning electron microscopy analyses revealed that this method promotes the release of active compounds by disrupting the integrity of the cell walls. This research offers a theoretical foundation and practical guidance for the efficient utilization and advanced processing of E. ulmoides leaves.

Development of machine learning models using multi-source data for geographical traceability and content prediction of Eucommia ulmoides leaves

Rapid and scientific quality evaluation is a hot topic in the research of food and medicinal plants. With the increasing popularity of derivative products from Eucommia ulmoides leaves, quality and safety have attracted public attention. The present study utilized multi-source data and traditional machine learning to conduct geographical traceability and content prediction research on Eucommia ulmoides leaves. Explored the impact of different preprocessing methods and low-level data fusion strategy on the performance of classification and regression models. The classification analysis results indicated that the partial least squares discriminant analysis (PLS-DA) established by low-level fusion of two infrared spectroscopy techniques based on first derivative (FD) preprocessing was most suitable for geographical traceability of Eucommia ulmoides leaves, with an accuracy rate of up to 100 %. Through regression analysis, it was found that the preprocessing methods and data blocks applicable to the four chemical components were inconsistent. The optimal partial least squares regression (PLSR) model based on aucubin (AU), geniposidic acid (GPA), and chlorogenic acid (CA) had a residual predictive deviation (RPD) value higher than 2.0, achieving satisfactory predictive performance. However, the PLSR model based on quercetin (QU) had poor performance (RPD = 1.541) and needed further improvement. Overall, the present study proposed a strategy that can effectively evaluate the quality of Eucommia ulmoides leaves, while also providing new ideas for the quality evaluation of food and medicinal plants.

Microwave-assisted extraction with natural deep eutectic solvents for polyphenol recovery from agrifood waste: Mature for scaling-up?

Agrifood industries generate large amounts of waste that may result in remarkable environmental problems, such as soil and water contamination. Therefore, proper waste management and treatment have become an environmental, economic, and social challenge. Most of these wastes are exceptionally rich in bioactive compounds (e.g., polyphenols) with potential applications in the food, cosmetic, and pharmaceutical industries. Indeed, the recovery of polyphenols from agrifood waste is an example of circular bioeconomy, which contributes to the valorization of waste while providing solutions to environmental problems. In this context, unconventional extraction techniques at the industrial scale, such as microwave-assisted extraction (MAE), which has demonstrated its efficacy at the laboratory level for analytical purposes, have been suggested to search for more efficient recovery procedures. On the other hand, natural deep eutectic solvents (NADES) have been proposed as an efficient and green alternative to typical extraction solvents. This review aims to provide comprehensive insights regarding the extraction of phenolic compounds from agrifood waste. Specifically, it focuses on the utilization of MAE in conjunction with NADES. Moreover, this review delves into the possibilities of recycling and reusing NADES for a more sustainable and cost-efficient industrial application. The results obtained with the MAE-NADES approach show its high extraction efficiency while contributing to green practices in the field of natural product extraction. However, further research is necessary to improve our understanding of these extraction strategies, optimize product yields, and reduce overall costs, to facilitate the scaling-up.

Research Progress of Eucommia ulmoides Oliv and Predictive Analysis of Quality Markers Based on Network Pharmacology

Du Zhong is a valuable Chinese medicinal herb unique to China. It is a national second- class precious protected tree, known as "plant gold", which has been used to treat various diseases since ancient times. The main active ingredients are lignans, phenylprophetons, flavonoids, iridoids and steroids and terpenoids, which have pharmacological effects such as lowering blood pressure, enhancing immunity, regulating bone metabolism, protecting nerve cells, protecting liver and gallbladder and regulating blood lipids. In this paper, a comprehensive review of Eucommia ulmoides Oliv. was summarized from the processing and its compositional changes, applications, chemical components, pharmacological effects, and pharmacokinetics, and the Q-marker of Eucommia ulmoides Oliv. is preliminarily predicted from the aspects of traditional efficacy, medicinal properties and measurability of chemical composition, and the pharmacodynamic substance basis and potential Q-marker of Eucommia ulmoides Oliv. are further analyzed through network pharmacology. It is speculated that quercetin, kaempferol, β-sitosterol, chlorogenic acid and pinoresinol diglucoside components are selected as quality markers of Eucommia ulmoides Oliv., which provide a basis for the quality control evaluation and follow-up research and development of Eucommia ulmoides Oliv.

ccTCM: A quantitative component and compound platform for promoting the research of traditional Chinese medicine

Traditional Chinese medicine (TCM) databases play a vital role in bridging the gap between TCM and modern medicine, as well as in promoting the popularity of TCM. Elucidating the bioactive ingredients of Chinese medicinal materials is key to TCM modernization and new drug discovery. However, one drawback of current TCM databases is the lack of quantitative data on the constituents of Chinese medicinal materials. Herein, we present ccTCM, a web-based platform designed to provide a component and compound-content-based resource on TCM and analysis services for medical experts. In terms of design features, ccTCM combines resource distribution, similarity analysis, and molecular-mechanism analysis to accelerate the discovery of bioactive ingredients in TCM. ccTCM contains 273 Chinese medicinal materials commonly used in clinical settings, covering 29 functional classifications. By searching and comparing, we finally adopted 2043 studies, from which we collected the compounds contained in each TCM with content greater than 0.001 %, and a total of 1449 were extracted. Subsequently, we collected 40,767 compound-target pairs by integrating multiple databases. Taken together, ccTCM is a versatile platform that can be used by TCM scientists to perform scientific and clinical TCM studies based on quantified ingredients of Chinese medicinal materials. ccTCM is freely accessible at http://www.cctcm.org.cn.

Progress and prediction of multicomponent quantification in complex systems with practical LC-UV methods

Complex systems exist widely, including medicines from natural products, functional foods, and biological samples. The biological activity of complex systems is often the result of the synergistic effect of multiple components. In the quality evaluation of complex samples, multicomponent quantitative analysis (MCQA) is usually needed. To overcome the difficulty in obtaining standard products, scholars have proposed achieving MCQA through the "single standard to determine multiple components (SSDMC)" approach. This method has been used in the determination of multicomponent content in natural source drugs and the analysis of impurities in chemical drugs and has been included in the Chinese Pharmacopoeia. Depending on a convenient (ultra) high-performance liquid chromatography method, how can the repeatability and robustness of the MCQA method be improved? How can the chromatography conditions be optimized to improve the number of quantitative components? How can computer software technology be introduced to improve the efficiency of multicomponent analysis (MCA)? These are the key problems that remain to be solved in practical MCQA. First, this review article summarizes the calculation methods of relative correction factors in the SSDMC approach in the past five years, as well as the method robustness and accuracy evaluation. Second, it also summarizes methods to improve peak capacity and quantitative accuracy in MCA, including column selection and two-dimensional chromatographic analysis technology. Finally, computer software technologies for predicting chromatographic conditions and analytical parameters are introduced, which provides an idea for intelligent method development in MCA. This paper aims to provide methodological ideas for the improvement of complex system analysis, especially MCQA.

Simultaneous quantification of fourteen characteristic active compounds in Eucommia ulmoides Oliver and its tea product by ultra-high performance liquid chromatography coupled with triple quadrupole mass spectrometry (UPLC-QqQ-MS/MS)

Various kinds of bioactive compounds contribute to versatile health-promoting properties of Eucommia ulmoides Oliver (E. ulmoides). In present study, we developed a UPLC-QqQ-MS/MS method for simultaneous quantification of fourteen characteristic active compounds, including 3 lignans, 4 iridoids, 3 flavonoids and 4 phenolics in E. ulmoides and its tea product for the first time. The running time of the method is 6.5 min. It has good linearity, sensitivity, precision, accuracy, and stability. Using this high-throughput method, the distributions of fourteen characteristic active compounds in E. ulmoides and its tea product were clarified. Also, it was found that E. ulmoides tea exhibited superiority in contents of chlorogenic acid as compared with natural resources. Overall, the study provided a rapid, reliable, and efficient analysis method, which could be applied for the quality evaluation of E. ulmoides natural resources and their relative products in the field of food and medicine.