Submitted to: Journal of Agricultural and Food Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/15/2005
Publication Date: 12/6/2005
Citation: Corbit, R., Ferreira, J.F., Ebbs, S., Murphy, L.L. 2005. Simplified cxtraction of ginsenosides from American ginseng (panax quinquefolius L.) for high-performance liquid chromatography-ultraviolet analysis. Journal of Agricultural and Food Chemistry. 53:9867-9873.
Interpretive Summary: Several methods have been used to extract ginsenosides from Panax ginseng roots. These methods involve extensive sample purification, which makes them laborious and expensive. Different methods for the extraction of ginsenosides from ginseng roots were compared for efficiency and simplicity. A simple method, using hot methanol, was chosen for its efficiency and good ginsenoside recovery. The sample purification step was simplified to one single filtration step to remove impurities. This method is important because it allows fast, simple, and reliable extraction of ginsenosides from ginseng roots without the need for highly specialized labor. The method can also be adapted to the analysis of commercial ginseng botanicals for their quality control.
Technical Abstract: Several methods have been used to extract ginsenosides from American ginseng (Panax quinquefolius, L.) roots or ginseng botanicals commercialized in the US. Most extraction methods are labor intense and require trained personnel to be efficient. A simplified method would allow a higher sample output and increased recovery of ginsenosides from each sample. The methods tested to extract six root ginsenosides included refluxing samples in hot water or methanol, sonication alone, and sonication with heat. A second aqueous or methanolic extraction was performed to determine the effectiveness of a subsequent extraction on ginsenoside recovery. In addition, water extracts were analyzed before and after lyophilization to determine the effect of lyophilization on ginsenoside recovery. Heat application during sonication significantly increased recovery of all six ginsenosides when compared to sonication alone. All methods omitted solid phase extraction, in favor of a simple filtration step, without harming peak resolution and identification. Ginsenoside yields and recoveries were quantified by HPLC-DAD to establish the best solvent-physical treatment combinations. Ginsenoside F2 was used as internal standard to quantify recovery of both individual and total ginsenosides. Refluxing with methanol resulted in the highest recoveries for ginsenosides Re, Rb1, Rc, Rb2, and Rd, but no significance was found for Rg1. In all 6 ginsenosides tested, the combination of methanol and sonication resulted in the lowest concentration of all of the solvent-physical method combinations studied. The same trend was observed when comparing the effectiveness of a second extraction with water or methanol with respect to individual ginsenoside contents. Recoveries calculated for extractions using refluxing in water (>80 deg C) were apparently low (31.3%), but that was due to the degradation of the internal standard (F2) and not due to degradation of root ginsenosides. Degradation of F2 was not observed when extraction was performed in methanol at 60 deg C. There was no significant reduction in ginsenoside yield when pre- and post-lyophilized aqueous extracts were compared, suggesting that lyophilization before storage does not affect ginsenosides content. This method, with a single filtration step, is easy to use, increases sample output, decreases the chances for loss in ginsenosides, and can be adapted for quality control of commercial samples.