METHODS The determintion was performed by HPLC with the Zorbax-ODS C18column(250 mm×4.6 mm,5 μm) under 35℃,the mobile phase was consisted of 0.01mol/L phosphate buffer(adjusted pH to 5.2 with orthophosphoric acid) methanol(85∶15) with the flow rate at 1.0 mL/min,the UV detected wavelength was at 273 nm.
Methods: The analytical column was ODS C18 (250 mm×4. 6 mm,5 μm), the mobile phase was composed of 0. 05 mol/L NaH2PO4, acetonitrile and methanol (65 : 25 : 10, V/V/V) with the flow rate of 0. 8 mL/min, the detection wavelength was 290 nm and column temperature was 30℃.
Methods:The Shim-pack CLC-ODS (150mm×4.6mm,5μm) column was used,0.05 mol·L~(-1) phosphate buffer(pH 6.0)-methanol(38:62) as mobile phase,flow rate was 1.2 mL·min~(-1),wavelength of detector was 280 nm.
A Hypersil ODS C18 column was used with the mobile phase of 0.1mol/L KH2PO4 solution(pH6.8)-methanol(65∶35), atthe detection wavelength of 254nm and flow rate of 0.9ml/min.
The results showed five species of unsaturated fatty acids, including C16∶1,C18∶1,C18∶3,(9,12,15),EPA, and DHA, were extracted by chloroform-methanol (2∶1,v/v) from Phaeodactylum tricornutum, and their content based on the total fatty acid are 9.70%,2.78%,4.53%,18.86% and 3.14%, respectively.
Methanol extracts demonstrated better inhibitory effects on cultured L929 cells followed by purified berberine from cell suspension cultures and water extracts.
In this article it is pointed out that the semi-empirical van der Waals' equation of state for gases is particularly unsatisfactory in the neighborhood of the critical point, as indicated by the fact that the experimental values of the critical ratio (?) seldom agree with the theoretical constant value 8/3. It is also noted that this τ value may serve as a satisfactory measure (at least to a first approximation) of the deviation of the law of corresponding states when applied to gases at high densities. We ...
本文指出任何僅含兩個常數的氣態方程,在臨界點附近的缺點是特別顯著的。同時也指出,對應態定律應用到高密度氣體的偏差,可以相當滿意地用臨界係數(?)來衡量。因此我們建議將van der Waals方程,修改爲三常數的經驗方程,它的優點是這三個常數可以直接從氣體的臨界點數據計算出來;而且實例計算(包括極性很強和τ值很大的甲醇)說明它在相當大的温度和密度範圍內可以適用。將這個經驗式,寫成對比方程顯然含有臨界係數τ,就離開臨界點不太遠的氣體來說,這個函數關係可以相當满意地用本文方程總結出來。
Aureomycin (Ⅰ) on reduction with zinc-acetic acid gives desdimethylaminoaureomycin (Ⅱ) under mild conditions and desdimethylaminodesoxyaureomycin (Ⅲ) under more drastic conditions. Ⅱ can be converted into Ⅲ by further reduction. Treatment of Ⅰ, Ⅱ or Ⅲ with concentrated hydrochloric acid or methanolic HCl produces anhydroaureomycin (Ⅳ), desdimethylaminoanhydroaureomycin (Ⅴ) or desdimethylaminodes- oxyanhydroaureomycin (Ⅵ) respectively. Compound (Ⅴ) can be obtained from Ⅳ by hydrogenolysis, and, similarly, ...
Desdimethylaminoaureomycin (Ⅳ) and desdimethylaminodesoxyaureomycin (Ⅴ), when subjected to catalytic hydrogenation, yield deschlorodesdimethylaminoaureomycin (Ⅶ) and deschlorodesdimethylaminodesoxyaureomycin (Ⅷ) respectively. On warming with methanolic hydrogen chloride, Ⅶ and Ⅷ give their corresponding anhydro-compounds: deschlorodesdimethylaminoanhydroaureomycin (Ⅹ) and deschlorodesdimethylaminodesoxy- anhydroaureomycin (Ⅺ). On catalytic hydrogenation, anhydroaureomycin (Ⅵ) is converted into deschloroanh...