Qipeng Yuan

A novel rapid method for simultaneous determination of eight active compounds in silymarin using a reversed-phase UPLC-UV detector.

A novel rapid chromatographic method based on utilization of UPLC column was developed for the analysis of eight active compounds in silymarin. The analysis was performed on a Waters Acquity UPLC system with an Acquity UPLC(BEH) C18 column (5mmx2.1mm I.D., 1.7mum) and a gradient elution of methanol and water containing 0.01% formic acid with a run time of 9min, in which the retention time of the last analyte was 5.8min. And all eight active compounds achieved complete separation. Comparison of system performance with conventional HPLC was made with respect to analysis time, efficiency and sensitivity. The results indicated that the type of column, the type of mobile phase and the modified addition were significant to the separation of isomeric compounds in herb extracts.

Microbial transformation of dehydroandrographolide by Cunninghamella elegans.

The biotransformation of dehydroandrographolide (1) by Cunninghamella elegans was performed and four transformed products were obtained. Based on their extensive spectral data, the structures of these metabolites were identified as 3-oxo-dehydroandrographolide (2), 3-oxo-2β-hydroxy-dehydroandrographolide (3), 3-oxo-8β,17α-epoxydehydroandrographolide (4), 3,19-dihydroxy-7,11,13-ent-labdatrien-15,16-olide (5), respectively. Among them, products 3–5 are new compounds.

Microbial transformation of Norkurarinone by Cunninghamella blakesleana AS 3.970

In this paper, microbial transformation of norkurarinone (1) by Cunninghamella blakesleana AS 3.970 was investigated and seven transformed products were isolated and characterized as kurarinone (2), 4″,5″-dihydroxykurarinone (3), 6″-hydroxyl-2′-methoxyl-norkurarinone 7-O-β-d-glucoside (4), 6″-hydroxyl-norkurarinone 4′-O-β-d-glucoside (5), 4″,5″-dihydroxynorkurarinone (6), 7-methoxyl-norkurarinone (7), and 7-methoxyl-4″,5″-dihydroxynorkurarinone (8), respectively. Among them, 3–5 are new compounds, and the glycosylation reaction in microbial transformation process was reported rarely. In addition, the cytotoxicities of transformed products (1–8) were also investigated.