Simultaneous quantification of seventeen bioactive components in rhizome and aerial parts of Alpinia officinarum Hance using LC-MS/MS
The rhizomes of Alpinia officinarum Hance (Zingiberaceae family) have been used as antiemetics, stomachics and analgesics in Asia for centuries. Unfortunately, the aerial parts were thrown away as waste whilst harvesting the rhizomes of A. officinarum. Recently, scientists reported that the ethanol extract of the aerial parts displayed anti-proliferation activity through mitochondrial pathway-induced cell apoptosis. However, the chemical composition of this extract remained largely unknown. We have identified sixteen chemicals including twelve flavonoids and four diarylheptanoids from the methanol extract of A. officinarum leaves using liquid chromatography/tandem mass spectrometry (LC-MS/MS). In order to better explore the potential value of the aerial parts, we need to know what the main constituents occurring in the aerial parts are and how the content of these chemicals is influenced by growing period. In the present study, a LC-MS/MS method was developed and validated for determination of seventeen compounds occurring both in the aerial parts and rhizomes sampled at different growing periods. The validation indices evaluated were satisfactory and the method was successfully employed to analyze the above-mentioned plant samples. Notably, we found that the content of these compounds, except for quercetin, was higher in rhizomes than in aerial parts. The six major constituents both in the aerial parts and rhizomes were galangin, kaempferide, hexahydrocurcumin, pinocembrin, chrysin and isorhamnetin. Moreover, the trends of change in content along with the sample period for most of the monitored phytochemicals were almost similar between the aerial parts and rhizomes. Our study should be of value in arousing everyone's interest to make the best use of the aerial parts of A. officinarum in the future.