Validation of HPLC method for quantitative determination of zerumbone in the rhizome of Zingiber ottensii Valeton

Abstract

The rhizome of Zingiber ottensii Valeton (ZOT), commonly known as Phlai Dum, has been long used in Thai traditional medicine for treatment of wounds, flatulence, peptic ulcers and muscle pain. Moreover, this plant, known to contain zerumbone as a major bioactive component, has recently gained considerable attention due to its diverse pharmacological properties, such as anti-inflammatory, anticancer, antimicrobial, and antioxidant activities. Thus, accurate and reliable zerumbone quantification is crucial for ensuring the quality, consistency, and efficacy of the plant materials and preparations. To our knowledge, a specific method for routine analysis of zerumbone in the ZOT rhizomes and extracts is not yet well-established. In addition, despite exiting methods (e.g. HPLC and UHPLC) for the quantification of zerumbone in various plant and product, the application of these methods may not be suitable for quantifying the content of zerumbone in the ZOT rhizomes and extracts due to the difference in phytochemical constituents and complexity of samples. Therefore, in this study, we aimed to develop and validate an HPLC analytical method that could accurately determine zerumbone content in the ethanolic extract of ZOT rhizome. The results indicated that the developed HPLC method complied with the ICH acceptance criteria. The method expressed a specificity to zerumbone with a high linearity in the range of 10 to 1000 µg/mL (R² > 0.999). The LOD and LOQ values were 2.89 and 8.75 µg/mL, respectively. The method demonstrated excellent precision, with a relative standard deviation (%RSD) lower than 2, as well as exhibited a high degree of accuracy within an acceptable recovery range of 95–105 %. Additionally, the HPLC method can also be applied to analyze a variation of zerumbone in ZOT raw materials obtained from six different locations in Thailand, which was found to be within the range of 4.30 to 10.46 mg/g of crude powder. This method, therefore, will be very useful for selecting good raw materials of ZOT and standardizing its extracts for future applications.