[Fluorescence microscopy and HPLC assay for rapid detection of distribution and content of resveratrol in Polygonum cuspidatum].

Objective: To establish fluorescence microscopy combined with HPLC method for rapid detection the distribution and content of resveratrol tissues in different growth stages of Polygonum cuspidatum.

Methods: Used sequential experiment to design conditions of frozen and observe of the section by fluorescence microscopy; Resveratrol was extracted by ultrasonic-assisted extraction and its content was detected by HPLC.

Results: The results showed that frozen condition for concentration of gum Arabic was from 20% (dipping time was 5 - 6 h) to 40% (2 - 5 min), the freezer temperature was -5 degrees C, and the thickness was 15 microm.

[Extraction and separation of flavonoids from leave of Eucommia ulmoides in aqueous two-phase system].

Objective: To optimize the aqueous two-phase extraction and separation technology of flavonoids from the leaves of Eucommia ulmoides.

Methods: The system was prepared by dissolving suitable amounis of polyethylene glycol 4000 (PEG4000) and dextran 40000 ( D40) in aqueous solution. Phase map of the system, the mass fraction of PEG4000 and D40, the effects of amount of added sample, pH value and temperature on target compounds were investigated systematically.

[Spectral determination of the contents of mineral elements in polygonum cuspidatum].

The present paper reports the determination of mineral elements by FAAS, including K, Ca, Na, Mg, Fe, Zn, Mn and Cu. The best condition for the determination was investigated. The best ionization inhibitor and acidity media were confirmed.