ABSTRACT
The enantiomeric resolution of lactic acid was studied by reversed high performance liquid chromatography. β-cyclodextrin (β-CD), dimethyl (DM) and TM-β-CD were used as chiral mobile phase additives. The effects of different mobile phase, pH and concentration of chiral mobile phase additives on resolution of D,L-lactic acid were investigated. The results showed: the enantioselectivity of TM-β-CD was better than those of β-CD and DM-β-CD. D,L-lactic acid could be partly separated by DM-β-CD and could not be separated by β-CD, while it could be fully separated by TM-β-CD. As the concentration of TM-β-CD changed from 0.20 mmol/L to 1.00 mmol/L, The resolution varied slightly. The experiment of the effect of pH of mobile phase on Rs showed: as pH changed from 2.4 to 3.0, the Rs remain stable, and when pH＞3.1, the Rs decreased with the increase of pH. The RSD of retention time of L-lactic acid and D-lactic acid were 0.2% and 0.2%, respectively. The chromatographic systems with a dynamically-generated stationary phase with 2,3,6-tri-O-methyl-β-cyclodextrin proved to be an effective method for lactic acid enantiomer separation
ABSTRACT
Objective To compare the antitumor effects and chemical components of the extracts in cultivated Cordyceps sinensis (Cs) fungus HK-1 and natural Cs. Methods The cultivated Cs fungus HK-1 and natural Cs were extracted with petroleum ether (PE), ethyl acetate (EtOAc), ethanol (EtOH), and water. The cytotoxicity of all the extracts was observed with MTT assay on breast cancer cell line MCF-7, mouse melanoma cell line B16, human premyelocytic leukemia cell line HL-60, and human hepatocellular carcinoma cell line Hep G2. The antitumor activity in vivo of the extract was further studied with animal model. The chemical constituents in the extracts were analyzed by HPLC. Results All of the extracts from the cultivated Cs fungus HK-1 had much stronger cytotoxicity on B16 than those from natural Cs, and the EtOAc extract had the most potent activity. The activity of EtOAc extract from the cultivated Cs fungus HK-1 was more potent than that from natural Cs on all the four cancer cell lines. EtOAc extract from the cultivated Cs fungus HK-1 also can inhibit the growth of tumor in vivo. Chemical components of all extracts were analyzed and ergosterol and adenosine were found to be potential compounds. Conclusion The cultivated Cs fungus HK-1 has stronger antitumor activity than natural Cs and is a potential source of antitumor compounds.
ABSTRACT
Membrane immobilization of Catharathus roseus (L. )G. Don cell culture was stuudied. Results showed that the production capacity can attain a higher level when the cell layer was 7~8mm thick. Stainless-steel screen(80?m)was suitable for immobllization of C. roses cell. Pressure pulse can enhance the release of intracelluler metabolites. A method to determine allowable cell layer thickness was developed. The calculated value agreed well with experimental results.