Li-xin Yang

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Acrylamide (AA) concentrations in instant noodles (90 samples, covering 10 different brands) from Hebei Province of China were determined by liquid chromatography-tandem mass spectrometry (LC-MS/MS). The instant noodles were sampled from the southern and northern areas of Hebei Province (Shijiazhuang and Tangshan, respectively). The average content of AA(More)
Nine new polyprenylated acylphloroglucinol derivatives, hypercohins B-J (1-9), and nine known analogues were isolated from the aerial parts of Hypericum cohaerens. The structures of 1-9 were elucidated based on spectroscopic analysis, and the absolute configuration of 1 was confirmed by X-ray crystallographic analysis. The inhibitory activities of these(More)
Two new phenolic compounds, 5-hydroxy-2-[2-(4-hydroxyphenyl) acetyl]-3-methoxylbenzoic acid (1) and (2S,3S)-3,7,8,3',4'-pentahydroxyflavane (2), were obtained from the aqueous extract of Acacia catechu, along with four known compounds identified as rhamnetin (3), 4-hydroxyphenyl ethanol (4), 3,3',5,5',7-pentahydroxyflavane (5), and fisetinidol (6). Their(More)
Hyperuralone A (1), a polycyclic polyprenylated acylphloroglucinol possessing an unprecedented tetracyclo-[5.3.1.1(4,9).0(4,11)]-dodecane core, was characterized from Hypericum uralum together with hyperuralone B (2), a congener with another complex caged skeleton. Their structures were determined by extensive spectroscopic analysis and ECD calculations. A(More)
Medicinal plants have a long history of use in China to treat diabetic symptoms. Ancient Chinese medical manuscripts and ethnobotanical surveys document plant remedies that continue to be actively used in China for the treatment of diabetic symptoms. Based on a systematic ancient Chinese medical manuscripts review in combination with ethnobotanical survey,(More)
Hyphenrones A-F (1-6), six polycyclic polyprenylated acylphloroglucinol derivatives with four architectures including three unprecedented cores as exemplified by 1, 3, and 4, were isolated from Hypericum henryi. Compounds 3 and 4 possess two unique 5/8/5 and 6/6/5/8/5 fused ring systems, respectively. Their absolute configurations were defined by(More)
To establish an HPLC-UV-ELSD method for the determination of the content of artemisinin, arteannuin B and artemisinic acid in Herba Artemisiae Annuae. The analytical column was Nucleodur RP-C18 (250 mm x 4.6 mm, 5 microm ID). The mobile phase was acetonirile-0.1% acetic acid (50: 50) and the flow rate was 1.0 mL x min(-1) with a UV detector for artemisinin,(More)
  • Li-Xin Yang
  • 2010
Based on RBF neural network, making chaotic time series that was generated by Lorenz dynamical system as an object of study. The network prediction model was established. Input variables of network model have been optimized to improve. And compared to the BP, RBF neural network models, based on improved RBF neural network for chaotic time series forecasting(More)
Analysis of aflatoxin B1 (AFB1), B2 (AFB2), G1 (AFG1) and G2 (AFG2) in 76 edible oil samples (peanut oil, soybean oil, corn embryo oil and blended oil) was performed by liquid chromatography-tandem mass spectrometry (LC-MS/MS). The oils were sampled from three areas (Shijiazhuang, Baoding and Tangshan) of Hebei Province of China. AFB1 was detected in 22(More)
OBJECTIVE To study the chemical constituents of the root of Salvia przewalakii. METHODS The chemical constituents were isolated and purified by means of chromatographic techniques and their structures were elucidated by spectroscopic methods. RESULTS 17 compounds were isolated and identified as danshenxinkun B (1), danshenol C (2), isotanshinone (3),(More)