Propolis has gained popularity in recent years as a potential preventive and therapeutic agent due to its numerous health benefits, which include immune system boosting, blood pressure lowering, allergy treatment, and skin disease treatment. The pharmacological activity of propolis is primarily attributed to phenolics and their interactions with other compounds. Given that phenols account for most of propolis\'s biological activity, various extraction methods are being developed. The resin-wax composition of the propolis matrix necessitates the development of an extraction procedure capable of breaking matrix-phenol bonds while maintaining phenol stability. Therefore, the aim of this study was to assess the stability of two major groups of phenolic compounds, flavonoids and phenolic acids, in propolis methanol/water 50/50 (v/v) extracts obtained after ultrasound-assisted extraction (USE) under different extraction parameters (extraction time and pH) and heat reflux extraction (HRE). The methodology involved varying the USE parameters, including extraction time (5, 10, and 15 min) and pH (2 and 7), followed by analysis using liquid chromatography-tandem mass spectrometry (LC-MS/MS) to quantify phenolic recoveries. Results revealed that benzoic acid and chlorogenic acid derivatives demonstrated excellent stability across all ultrasound extraction procedures. The recoveries of flavonoids were highly diverse, with luteolin, quercitrin, and hesperetin being the most stable. Overall, neutral pH improved flavonoid recovery, whereas phenolic acids remained more stable at pH = 2. The most important optimization parameter was USE time, and it was discovered that 15 min of ultrasound resulted in the best recoveries for most of the phenols tested, implying that phenols bind strongly to the propolis matrix and require ultrasound to break the bond. However, the high variability in phenol extraction and recovery after spiking the propolis sample shows that no single extraction method can produce the highest yield of all phenols tested. As a result, when working with a complex matrix like propolis, the extraction techniques and procedures for each phenol need to be optimized.

Innovative solvents such as deep eutectic solvents (DESs) and process intensification technologies assisted by ultrasound have been demonstrated to be promising pathways for enhancing solid-liquid extraction. Nevertheless, quantitative and systematic knowledge of their environmental impact is still limited. In this work, a case study of flavonoids extraction from Ginkgo biloba leaves was evaluated by using life cycle assessment (LCA) for comparison of three extraction scenarios. The first used DES as extractant (DESE), and the other two adopted ethanol, including heat reflux extraction (HRE), and ultrasound-assisted extraction (UAE). Among eight key midpoints investigated, all these from UAE were 10.0 %-80.0 % lower than from DESE and HRE except water consumption. The UAE was the eco-friendliest option due to its higher extraction yield, shorter duration and lower solvent consumption. The DESE exhibited the lowest water consumption, the highest freshwater ecotoxicity and human carcinogenic toxicity, while HRE had the highest impacts for the other 6 midpoints. Moreover, solvent production was the key contributor for all the categories. The standardized sensitivity analysis showed that the overall environmental footprint can be further decreased by 15.4 % for DESE pathways via substituting choline chloride/glycerine with choline chloride/ethylene glycol. Furthermore, all pathways using DESs had higher standardized impacts than those employing ethanol from sugarcane or wood. Replacing ethanol from maize with other feedstocks can significantly lessen the overall impacts, among which the UAE using ethanol from sugarcane demonstrated the least environmental impacts. The promotion of DESs as \"green and sustainable\" alternative to traditional solvents requires careful consideration.

Microwave-assisted extraction and efficient ultra-high performance liquid chromatography with triple quadrupole mass spectrometry were previously used to quickly extract and simultaneously quantify ginsenoside Rf, Ro, and Rd, 20(S)-ginsenoside-Rg2 , 20(R)-ginsenoside-Rg2 , tanshinone IIA, cryptotanshinone, dihydrotanshinone I, lithospermic acid, and osthole from Zibu Piyin Recipe. We here showed that heat reflux extraction provides higher extraction efficiency of these target compounds but is more time consuming. Chromatographic separation was achieved on an Agilent ZORBAX RRHD Eclipse Plus C18 column with a gradient mobile phase consisting of water/0.5% formic acid and acetonitrile at a flow rate of 0.2 mL/min, and detection was performed by positive and negative ion multiple-reaction monitoring mode. All analytes showed good linearity (r, 0.9989-0.9999) within the test range, with a limit of detection of 0.002-0.180 μg/mL. The overall intra- and interday variations of the ten compounds were ≤2.9%, and the accuracy was evaluated using a recovery test at three concentrations and was in the range 97.61-103.18% (RSD ≤ 4.25%). The analytical results showed remarkable differences in the concentrations of the ten compounds extracted from Zibu Piyin Recipe by microwave-assisted extraction and heat reflux extraction. These findings provide important information for determining the quality of Zibu Piyin Recipe.

This study evaluated ultrasound-assisted supercritical carbon dioxide (USC-CO2) extraction for determining the extraction yields of oils and the contents of eugenol, β-caryophyllene, eugenyl acetate and α-humulene from clove buds. Compared to traditional SC-CO2 extraction, USC-CO2 extraction might provide a 13.5% increase in the extraction yield for the oil while utilizing less severe operating parameters, such as temperature, pressure, CO2 flow rate and the time consumed by the process. Our results were comparable to those obtained using the heat reflux extraction method, though the yield was improved by 20.8% using USC-CO2. In kinetic studies, the USC-CO2 extraction of clove oil followed second-order kinetics. The activation energy for the oil extraction was 76.56kJ/mol. The USC-CO2 procedure facilitated the use of mild extraction conditions, improved extraction efficiency and the quality of products and is a potential method for industry.