Identification of Chemical Constituents Occurring in Leaves of Alpinia officinarum
TAN Yin-feng;LI Hai-long;LI You-bin;LI Yong-hui;LAI Wei-yong;WANG Yong;CHEN Feng;KANG Sheng-li;School of Pharmacy Hainan Provincial Key Laboratory of Research and Development of Tropical Herbs,Hainan Medical University;
Objective: The current study aimed to identify the chemical constituents occurring in the leaves of Alpinia officinarum. Method: The collected leaves of A. officinarum were dried in an electric thermostatic drying oven at 40° C overnight. The freshly dried leaves were smashed using a universal high-speed smashing machine and then sieved manually by an 80 mesh. The resulting fine powders and residue were mixed evenly. An aliquot( 0. 6 g) was weighed precisely and macerated with 30 m L of methanol and then ultrasonicated three times for 30 min each. For each ultrasonication extraction,the resulting extract solutions were centrifuged at8 000 rpm for 10 min. One micro liter of supernatant was sampled and the remaining was discarded. The residue was extracted with methanol for 2 more times. The sampled methanol extracts( 3 m L) were combined and centrifuged at 13 000 rpm for 10 min to obtain the supernatant fractions that were frozen at-40 ℃ until analysis.The extract solution was appropriately diluted with methanol before analysis. Finally,a 10 μL aliquot was injected into the LC-MS / MS system,which was operated in the positive ion ESI mode with selected reaction monitoring for all the potential analytes. Result: Sixteen chemicals,including flavonoids and diarylheptanoids,were identified using LC-MS / MS with selected reaction monitoring mode( MRM). Twelve flavonoids were chrysin,pinocembrin,tectochrysin,apigenin,galangin,3-methylgalangin,acacetin,kaempferol,kaempferide,quercetin,isorhamnetin and rutin,respectively. Four diarylheptanoids included yakuchinone A,oxyphyllacinol,hexahydrocurcumin and hannokinol. Conclusion: Sixteen chemicals were identified using LC-MS / MS and some unknown diarylheptanoids need to be identified in the future.