Characterization of Polymethoxylated Flavonoids (PMFs) in the Peels of ‘Shatangju’ Mandarin (Citrus reticulata Blanco) by Online High-Performance Liquid Chromatography Coupled to Photodiode Array Detection and Electrospray Tandem Mass Spectrometry

Abstract

A sensitive HPLC-DAD-ESI-MS/MS method was established to screen and identify the polymethoxylated flavonoids (PMFs) in the peels of 'Shatangju' mandarin ( Citrus reticulata Blanco). Eight PMF standards, including four polymethoxylated flavones, two polymethoxylated flavanones, and two polymethoxylated chalcones, were first to be analyzed in positive mode by CID-MS/MS. On the basis of the ESI-MS(n) characteristics of PMFs and the results of EIC-MS/MS experiment, 32 PMFs including 24 flavones and 8 flavanones or chalcones were screened from the complex extract of the peels of 'Shatangju' mandarin. Among them, 10 PMFs were hydroxylated polymethoxyflavonoids (OH-PMFs), and the rest were all permethoxylated PMFs. This was the first systematic report of the presence of PMFs in the peels of 'Shatangju' mandarin, especially for polymethoxylated flavanones and chalcones. Meanwhile, the contents of the three main PMFs and total flavonoids in the peels of 'Shatangju' were determined by HPLC and UV spectrophotometry, respectively. The results indicated that the developed analytical method could be employed as an effective technique for the characterization of PMFs.

Profiling and identification of the metabolites of baicalin and study on their tissue distribution in rats by ultra-high-performance liquid chromatography with linear ion trap-Orbitrap mass spectrometer

“…Therefore, highresolution EICs of baicalin metabolites were detected by processing the full-scan MS data sets using predictive metabolite weights within 5 ppm mass tolerance. Meanwhile, based on the similarity of mass defects of metabolites and their core substructures, the MMDF method can be adopted to search for the relevant compounds, especially the uncommon compounds that could not be detected by the EIC method [16]. Therefore, the combination of full-scan MS-based EIC and MMDF methods can be adopted to target both common and uncommon metabolites.…”

Identification and characterization of Phytopythium helicoides causing stem rot of Shatangju mandarin seedlings in China

“…It is highly valued as an excellent mandarin cultivar, and is popular for domestic consumption in East and Southeast Asia because of its very tasty, loose peel and nutrientrich characters. In addition, the peel has been long used as Pericarpium Citri Reticulatae ('Chen-Pi' in Chinese) in traditional Chinese medicine (Zhang et al 2012). This cultivar currently accounts for two-thirds of the total citrus acreage in Guangdong Province with about 250,000 ha (Deng et al 2012;Ye et al 2013).…”

Chemical compositions, chromatographic fingerprints and antioxidant activities of Citri Exocarpium Rubrum (Juhong)

“…MS 2 fragmentation analysis of the protonated molecular ion peak with an m/z value of 403 revealed several daughter peaks with m/z values of 373 [M–CH 2 O+H] + , 388 [M–CH 3 +H] + , 343 [M–2CH 2 O+H] + , 313 [M–3CH 2 O+H] + , 283 [M–4CH 2 O+H] + , 239 [M–C 10 H 12 O 2 +H] + and 211 [M–C 10 H 12 O 2 –CO+H] + . A comparison of these data with those obtained from a reference compound and the literature [7, 20, 22] revealed that this peak was nobiletin.…”