Determination of Phenolic acids and Flavonoids in Rhinacanthus nasutus (L.) Kurz by High Performance Liquid Chromatography Coupled with Photodiode Array Detector and Tandem Mass Spectrometry

• Main Authors: Huang Jen Ting, 黃仁廷
• Other Authors: Chen Bing Huei
• Format: Others
• Language: zh-TW
• Published: 2014
• Online Access: http://ndltd.ncl.edu.tw/handle/18748540248652266543

碩士 === 輔仁大學 === 食品科學系碩士班 === 102 === Rhinacanthus nasutus (L.) Kurz, a traditional Chinese herb, has been used as a remedy for reducing cough and protecting liver as well as for treating skin diseases like tinea and eczema. Most recent studies have mainly focused on naphthoquinone, however, the other functional components like phenolic acids and flavonoids may also play a vital role in physiological activity and need to be investigated. The objective of this study was to determine the variety and content of phenolic acids and flavonoids in R. nasutus by using HPLC coupled with photodiode array detector (DAD) and tandem mass spectrometry (MSn). Results showed that both phenolic acids and flavonoids could be extracted simultaneously with 30% ethanol in a 60°C water bath for 3 h. By employing a Phenomenex Gemini C18 column and a binary solvent system of 0.1% formic acid (A) and acetonitrile (B) with the following gradient condition: 96 % A and 4 % B in the beginning for 4 min, raised to 6 % B in 10 min, 7 % B in 12 min, 8 % B in 15 min, 13 % B in 18 min, 15 % B in 25 min, 20 % B in 28 min, 28 % B in 32 min, maintained till 50 min. A total of 20 phenolic acids and 3 flavonoids could be separated within 50 min with flow rate at 0.8 mL/min, column temperature at 35oC and detection wavelength at 280 nm. Based on retention times, absorption and mass spectra, the phenolic acids identified in R. nasutus included hydroxycinnamic acid derivative (1) (403.6 μg/g), hydroxycinnamic acid derivative (2) (38.1 μg/g), hydroxy ferulic acid hexoside (1) (1032.4 μg/g), protocatechuic acid hexoside (388.6 μg/g), 5-OH-dihydroferulic acid derivative (154.8 μg/g), caffeic acid hexoside (1) (693.2 μg/g), dihydrocaffeic acid hexoside (287.4 μg/g), sinapic acid hexoside (1) (429.2 μg/g), hydroxy ferulic acid hexoside (2) (1686.4 μg/g), caffeic acid hexoside pentoside (1) (114.7 μg/g), p-coumaric acid hexoside (1) (123.4 μg/g), caffeic acid hexoside (2) (275.5 μg/g), hydroxy ferulic acid deoxyhexoside (323.2 μg/g), p-coumaric acid hexoside (2) (133.4 μg/g), sinapic acid hexoside (2) (680.4 μg/g), caffeic acid hexoside pentoside (2) (95.8 μg/g), dihydro- p-coumaric acid hexoside (64.6 μg/g), p-coumaric acid hexoside (3) (1069.2 μg/g), p-coumaric acid glucuronide (243.9 μg/g) and dihydrocaffeic acid hexoside pentoside (4933.2 μg/g); while the flavonoids included quercetin-3-O-rutinoside (1611.7 μg/g)、kaempferol-3-O-rutinoside (1017.3 μg/g) and quercetin pentoside (2813.0 μg/g)。