HPLC–DAD Analysis, SFE-CO2 Extraction, and Antibacterial Activity on Bioactive Compounds from Mosla chinensis Maxim

Mosla chinensisMaxim is an annual herb with many potential purposes in agricultural, industrial, and pharmaceutical fields. At present, the extract of the whole plant fromM. chinensishas been proven to demonstrate antifungal, antioxidant, and anti-inflammatory activities. Previous studies focused on the enzyme pretreatment in hydrodistillation fromM. chinensis. However, organic solvent or supercritical fluid carbon dioxide extraction (SFE-CO2) methods, which are commonly utilized in industry, have seldom been studied and cannot provide multiple evaluations of yield. In this work, we analysed compounds fromM. chinensisby HPLC–DAD, discussedn-hexane extraction, and conducted further investigations on SFE-CO2through the design of response surface methodology (RSM). The sample obtained from pilot-scale SFE-CO2was also tested against nine kinds of microorganisms. Single-factor results revealed that the extraction rates fromM. chinensisby steam distillation,n-hexane extraction, and SFE-CO2were 1%, 2.09%, and 3.26%, respectively. RSM results showed a significant improvement in extraction rate through optimising pressure and time, and the interaction of both factors was more important than that of temperature–pressure and temperature–time. A pilot-scale test with an extraction rate of 3.34% indicated that the predicted RSM condition was operable. In addition, samples from the pilot-scale SFE-CO2showed antibacterial effects against three previously unreported bacteria (Gardnerella vaginalis, methicillin-resistantStaphylococcus aureus, andPropionibacterium acnes). These results fill the gap in previous research and provide more information for the application and development ofM. chinensisin the future.Keywords:Mosla chinensisMaxim;HPLC–DAD analysis;SFE-CO2;response surface methodology;antibacterial activity