Application of Ultra-High-Performance Liquid Chromatography Coupled with LTQ-Orbitrap Mass Spectrometry for the Qualitative and Quantitative Analysis of Polygonum multiflorum Thumb. and Its Processed Products.

In order to quickly and simultaneously obtain the chemical profiles and control the quality of the root of Polygonum multiflorum Thumb. and its processed form, a rapid qualitative and quantitative method, using ultra-high-performance liquid chromatography coupled with electrospray ionization-linear ion trap-Orbitrap hybrid mass spectrometry (UHPLC-LTQ-Orbitrap MS(n)) has been developed. The analysis was performed within 10 min on an AcQuity UPLC™ BEH C18 column with a gradient elution of 0.1% formic acid-acetonitrile at flow rate of 400 µL/min. According to the fragmentation mechanism and high resolution MS(n) data, a diagnostic ion searching strategy was used for rapid and tentative identification of main phenolic components and 23 compounds were simultaneously identified or tentatively characterized. The difference in chemical profiles between P. multiflorum and its processed preparation were observed by comparing the ions abundances of main constituents in the MS spectra and significant changes of eight metabolite biomarkers were detected in the P. multiflorum samples and their preparations. In addition, four of the representative phenols, namely gallic acid, trans-2,3,5,4'-tetra-hydroxystilbene-2-O-ß-d-glucopyranoside, emodin and emodin-8-O-ß-d-glucopyranoside were quantified by the validated UHPLC-MS/MS method. These phenols are considered to be major bioactive constituents in P. multiflorum, and are generally regarded as the index for quality assessment of this herb. The method was successfully used to quantify 10 batches of P. multiflorum and 10 batches of processed P. multiflorum. The results demonstrated that the method is simple, rapid, and suitable for the discrimination and quality control of this traditional Chinese herb.

Cytotoxic ent-kaurane diterpenoids from Isodon nervosus.

Four new ent-kaurane diterpenoids, rabdonervosins G-J (1-4, resp.), were isolated from the leaves and stems of Isodon nervosus. Their structures were elucidated by extensive spectroscopic analyses, including 1D-, 2D-NMR and HR mass spectra. Compound 2 showed potent cytotoxicity against the HepG2 and PC-9/ZD cell lines with IC50 values of 2.36 and 6.07 µM, respectively, and compound 3 exhibited cytotoxicity against the HepG2 and CNE2 cell lines with IC50 values of 8.64 and 9.77 µM, respectively.