Determination of carotenoids in Taraxacum formosanum by HPLC–DAD–APCI-MS and preparation by column chromatography

• Published in: Journal of pharmaceutical and biomedical analysis 2012-07, Vol.66, p.144-153
• Main Authors: Kao, T.H., Loh, C.H., Inbaraj, B. Stephen, Chen, B.H.
• Format: Article
• Language: English
• Subjects: adsorbents; Analysis; Analytical, structural and metabolic biochemistry; antheraxanthin; Biological and medical sciences; Carotenoids; Carotenoids - analysis; Carotenoids - chemistry; Carotenoids - isolation & purification; chromatography; Chromatography, High Pressure Liquid - methods; cis-trans isomers; Drugs, Chinese Herbal - analysis; Drugs, Chinese Herbal - chemistry; epoxides; ethyl acetate; Fundamental and applied biological sciences. Psychology; General pharmacology; glass; health foods; HPLC–DAD–APCI-MS; Isomerism; Limit of Detection; magnesium; Mass Spectrometry - methods; Medical sciences; methylene chloride; Pharmacology. Drug treatments; Preparative column chromatography; raw materials; Taraxacum; Taraxacum - chemistry; Taraxacum formosanum
• ISSN: 0731-7085; 1873-264X
• DOI: 10.1016/j.jpba.2012.03.035

The objectives of this study were to determine the variety and content of carotenoids in Taraxacum formosanum, a traditional Chinese herb possessing vital biological activities, by developing an HPLC–DAD–APCI-MS method and a preparative column chromatographic method for carotenoid isolation. A total of 25 carotenoids were resolved within 66min by employing a YMC C30 column and a gradient mobile phase of methanol–acetonitrile–water (79:14:7, v/v/v) and methylene chloride (100%) with flow rate at 1.0mL/min and detection at 450nm. All-trans-canthaxanthin was shown to be an appropriate internal standard for quantitation, with all-trans-β-carotene and its cis isomers present in largest amount (413.6μg/g), followed by all-trans-violoxanthin and its cis isomers (209.5μg/g), all-trans-lutein and its cis isomers (212.4μg/g), all-trans-neoxanthin and its cis isomers (134.6μg/g), antheraxanthin (16.5μg/g), all-trans-β-cryptoxanthin and its cis isomers (5.8μg/g), all-trans-zeaxanthin (3.6μg/g) and neochrome (0.1μg/g). For preparative chromatography, with a glass column containing 52g of magnesium oxide-diatomaceous earth (1:3, w/w) as adsorbent, the carotenoid fraction was eluted with 300mL of ethyl acetate with flow rate at 10mL/min. Some more epoxides and cis isomers of carotenoids were generated during preparative column chromatography. Nevertheless, the carotenoids isolated from T. formosanum may be used as raw material for possible production of health food in the future.