Abstract  Supercritical-fluid extraction (SFE) with pure carbon dioxide and with carbon dioxide modified by addition of methanol, ethanol, or water have been used to extract bilobalide and ginkgolides A, B, and C from Ginkgo biloba leaves. Each extract was analyzed by HPLC-ESIMS. Although addition of methanol or ethanol led to enhonced SFE yields of the compounds compared with use of pure carbon dioxide, the amounts extracted were only 10% those obtained by extraction with an organic solvent such as methanol or acetone-water 1:1. Addition of small amounts (4%, v/v) of water as modifier of the carbon dioxide, however, led to a dramatic improvement in the extraction yield of the compounds - to amounts which were 80-150% of the yields obtained by extraction with organic solvent. In addition, levels of ginkgolic acids, the toxic constituents of Ginkgo biloba leaves, extracted by SFE with carbon dioxide-methanol-water, 80:16:4, were substantially lower after continuous pre-extraction with n-hexane and with pure carbon dioxide.

Abstract  A simple, rapid and valid analysis method for simultaneously determination of ten characteristic components, including six phthalides [(Z)-ligustilide, (Z)-butylidene phthalide, riligustilide, levistolide A, (3Z)-(3aR,6S,3′R,8′S)-3a.8′,6.3′-diligustilide and 3,9-dihydroxyl-ligustilide], three aromatic acids (o-phthalic acid, vanillic acid and ferulic acid) and one macrolide (brefeldin A), in the radix of Angelica sinensis, a valued traditional Chinese medicinal herb was developed by liquid chromatography coupled with photodiode array detection. Riligustilide, levistolide A, (3Z)-(3aR,6S,3′R,8′S)-3a.8′,6.3′-diligustilide, 3,9-dihydroxyl-ligustilide and brefeldin A were first quantitatively determined in Angelica sinensis. Separation was performed on an Alltima C-18 analytical column by gradient elution with (A) 0.2% aqueous formic acid and (B) methanol as mobile phase. The column temperature was set at 25 °C. The method was validated for system suitability, precision accuracy and linearity. The average recovery of the method was 93.8–102.2% and linearity was (R 2 > 0.998). Furthermore, the method was successfully applied to the simultaneous determination of ten analytes in 46 samples of A. sinensis from various sources including different collecting locations, harvesting time, storage time, drying methods, and medicinal portions of the herb. The results obtained suggest that the method can efficiently evaluate the quality of A. sinensis from different sources, which benefit its quality control.

Abstract  Derivation of trifluoromethyl radical to 2-aminobenzonitrile(2-ABN) was carried out by using Pt anode and stainless steel(sus) cathode at 0°C. 4 mmol trifluoroacetic acid(TFA) and 1 mmol 2-ABN dissolved in aqueous acetonitrile solution(18 ml) of 1 mmol K2CO3 was electrolyzed for 2 hours at the constant current of 50 mA. The products obtained from the electrolytic reaction were extracted into CH2Cl2 from neutral solution of the mixture(pH 7). The column chromatography packed with silica gel was applied to separate the mixture by gradient elution using the eluant of n-hexane, ethylacetate, and methanol. The major product, amino-2,4-ditrifluoromethyl benzonitrile was identified by GC-Mass spectrometer, 1H-NMR spectometer, and 13C-NMR spectometer. ©2001 IEEE.