title: Online screening of nitric oxide scavengers in natural products using high performance liquid chromatography coupled with tandem diode array and fluorescence detection.
abstract: Nitric oxide (NO) is an important cellular signaling molecule with extensive physiological and pathophysiological effects. NO scavengers have the potential to treat inflammation, septic shock and other related diseases, and numerous examples have been chemically synthesized or isolated from natural products. The chemical diversity of natural products, however, means that a huge effort is necessary to efficiently screen and identify bioactive compounds, especially NO scavengers. In this article, we propose an effective analytical method to screen for NO scavengers in three natural products using an online system that couples high performance liquid chromatography with tandem diode array and fluorescence detection (HPLC-DAD-FLD). Eighteen compounds from radix of Scutellaria baicalensis Georgi and green tea displayed significant NO scavenging activity whereas components of Pueraria lobata (Willd.) Ohwi had no discernable activity. The structures of the active compounds were elucidated using Agilent Accurate-Mass Q-TOF LC/MS system. Preliminary analysis of structure-activity relationships indicated that, in flavonoids, a 2,3-double bond and a 3-H atom or a 3-OH group are essential for activity. In tannins, poly-hydroxyl groups are important for NO scavenging activity. Method validation indicated that the newly developed method is both reliable and repeatable. The online method that we present provides a simple, rapid and effective way to identify and characterize NO scavengers present in natural products.
authors.affiliation: Jiangsu Key Laboratory of TCM Evaluation and Translational Research, China Pharmaceutical University, Nanjing 210009, China.
authors.forename: Dapeng
authors.initials: D
authors.lastname: Li
authors.affiliation: Jiangsu Key Laboratory of TCM Evaluation and Translational Research, China Pharmaceutical University, Nanjing 210009, China.
authors.forename: Ting
authors.initials: T
authors.lastname: Wang
authors.affiliation: Jiangsu Key Laboratory of TCM Evaluation and Translational Research, China Pharmaceutical University, Nanjing 210009, China.
authors.forename: Yujie
authors.initials: Y
authors.lastname: Guo
authors.affiliation: State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macao 999078, China.
authors.forename: Yuanjia
authors.initials: Y
authors.lastname: Hu
authors.affiliation: State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing 210009, China; Jiangsu Key Laboratory of TCM Evaluation and Translational Research, China Pharmaceutical University, Nanjing 210009, China. Electronic address: boyangyu59@163.com.
authors.forename: Boyang
authors.initials: B
authors.lastname: Yu
authors.affiliation: State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing 210009, China; Jiangsu Key Laboratory of TCM Evaluation and Translational Research, China Pharmaceutical University, Nanjing 210009, China. Electronic address: qijin2006@163.com.
authors.forename: Jin
authors.initials: J
authors.lastname: Qi
mesh_terms: D001688:Biological Products / Q000737:chemistry*; D002623:Chemistry Techniques, Analytical / Q000379:methods*; D002851:Chromatography, High Pressure Liquid; D005419:Flavonoids / Q000032:analysis; D005453:Fluorescence; D016166:Free Radical Scavengers / Q000032:analysis*; D013058:Mass Spectrometry; D009569:Nitric Oxide / Q000378:metabolism; D010936:Plant Extracts / Q000737:chemistry; D029908:Pueraria / Q000737:chemistry; D015203:Reproducibility of Results; D031364:Scutellaria baicalensis / Q000737:chemistry
chemical_list: D001688:Biological Products; D005419:Flavonoids; D016166:Free Radical Scavengers; D010936:Plant Extracts; C499814:Scutellaria baicalensis extract; D009569:Nitric Oxide
keywords: Natural products; Nitric oxide; Online HPLC-DAD-FLD system; Scavenger; Screening