Jing Li

Publications (2)5.58 Total impact

• Article: Identification of phenolic compounds from Scutellaria lateriflora by liquid chromatography with ultraviolet photodiode array and electrospray ionization tandem mass spectrometry.

  Jing Li, Yan-Hong Wang, Troy J Smillie, Ikhlas A Khan
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  ABSTRACT: Scutellaria lateriflora has been used more than 200 years as a mild relaxant and as a therapy for anxiety, nervous tension, and convulsions. Currently, it is one of the most popular botanicals with many products on the USA market. Flavonoids with anxiolytic property have been reported from the aerial parts of this plant. From the HPLC chromatogram of the methanolic extract of this plant, it can be concluded that some flavonoids have not been identified yet. In the present study a simple high-performance liquid chromatography with UV and electrospray ionization mass spectrometric detection (HPLC-DAD/ESI-MS(n)) method has been developed for the identification of major phenolic compounds from it. The ESI-MS(n) fragmentation pathways of four types of flavonoid references have been interpreted which provide very useful guidance for the characterization of different types of flavonoids from this plant. Further analysis of the methanolic extract of S. latellaria based on the combination of their fragmentation patterns with the UV spectra led to characterize thirteen flavonoids and one stilbene derivative, seven of which are described for the first time from this species.
  Journal of pharmaceutical and biomedical analysis 01/2012; 63:120-7. · 2.45 Impact Factor
• Article: Scuteflorins A and B, dihydropyranocoumarins from Scutellaria lateriflora.

  Jing Li, Yuanqing Ding, Xing-Cong Li, Daneel Ferreira, Shabana Khan, Troy Smillie, Ikhlas A Khan
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  ABSTRACT: Two new dihydropyranocoumarins, scuteflorins A (1) and B (2), together with the known compounds decursin (3), chrysin (4), oroxylin A (5), wogonin (6), 5,7-dihydroxy-8,2'-dimethoxyflavone, dihydrochrysin, dihydrooroxylin A, lupenol, scutellaric acid, pomolic acid, ursolic acid, beta-sitosterol, daucosterol, and palmitic acid, were isolated from the aerial parts of Scutellaria lateriflora, commonly used as a dietary supplement. The structures of 1 and 2 were established by means of 1D and 2D NMR spectra as well as HRMS data. The absolute configuration of coumarins 1 and 2 was determined by comparison of experimental and theoretical calculated CD spectra. The cytotoxicity and antioxidant effects of the methanol extract of this plant and some of the constituent flavonoids were evaluated in vitro.
  Journal of Natural Products 07/2009; 72(6):983-7. · 3.13 Impact Factor