Two new labdane diterpenoids from aerial parts of Leonurus japonicus and their anti-inflammatory activity.

Two new labdane diterpenoids, Leojaponin E (1) and F (2), together with three known compounds were isolated from the dried herb of Leonurus japonicus Houtt., Lamiaceae. Their structures were determined based on extensive spectroscopic analyses. The absolute configurations of 1 and 2 were elucidated on the basis of experimental and calculated electronic circular dichroism spectra. In addition, compounds 1 and 2 exerted inhibition of LPS-induced PGE2 production in a dose-dependent manner at concentrations ranging from 5 to 20 µM.

[Simultaneous determination of thirteen components in Tong'an injection by LC-MS/MS].

The aim of this study was to develop a simple, sensitive ultra performance liquid chromatography mass spectrometry (UPLC-MS/MS) method for the determination of syringaresinol, N-trans-feruloyltyramine, chelerythrine chloride, sinomenine, coptisine chloride, sanguinarine, chelidonine, magnolflorine, allocryptopine, protopine, farrerol, stylopine and dihydrosanguin-arine in Tong'an injection (TAI), which could be used for the quality control of TAI. The UPLC analysis was performed on Agilent Zorbax SB-Aq column (2.1 mm×150 mm,3.5 µm), with 0.1% formic acid solution (A) -acetonitrile (B) as the mobile phase for gradient elution (0.01-2 min, 5%B; 2-8 min, 5%-30%B; 8-11 min, 30%-95%B; 11-13 min, 95%B; 13-13.1 min, 95%-5%B; 13.1-14 min, 5%B). The flow rate was 0.5 mL•min⁻¹, and the column temperature was 25 ℃; multiple reaction monitoring (MRM) was performed in electrospray ion source positive ion mode for quantitative determination. The calibration curves for the above thirteen compounds showed good linear relationship in corresponding mass concentration range (r>0.999 0). The average recovery rate of the compounds ranged from 95.70% to 104.8%, with RSD of less than 1.9%. The contents of thirteen active components in 10 batches of TAI were 0.021 2-0.029 0, 0.001 7-0.002 3, 0.000 9-0.001 3, 5.952-6.205 2, 0.195 4-0.240 5, 0.002 0-0.002 9, 0.693-0.798 2, 0.069 3-0.078 2, 0.089 29-0.102 9, 0.386 5-0.420 1, 0.014 3-0.015 9, 0.755 3-0.842 1, and 0.008 2-0.011 2 g•L⁻¹ respectively. Methodology validation proved that this method was simple, rapid, sensitive and accurate, which can be used to provide reference for the comprehensive evaluation of TAI quality. The determination results of 10 batches of TAI showed the content of each batch had no significant difference. The results may provide a basis for the quality control of TAI.

[Simultaneous determination of eleven components in Ginkgo biloba leaves by high performance liquid chromatography method].

To study Ginkgo biloba leaves in different producing area, we establish an HPLC method for the simultaneously determination of seven flavonoids glycosides and four biflavonoids in G. biloba leaves. The analysis was performed on an Agilent ZORBAX SB-C18 column(4.6 mm×250 mm, 5 µm) wich acetonitrile, and 0.4% phosphoric acid as mobile phase at flow rate of 1 mL•min⁻¹ in a gradient edution, and the detection was carried out at 254 nm.The calibration curves of the seven flavonoids glycosides and four biflavonoids had a good linearitiy with good recoveries. The established HPLC method is simple, rapid, accurate, reliable, and sensitive, and can be applied to the identification and quality control of G. biloba leaves.

[Effect of rat intestinal flora on in vitro metabolic transformation of pumiloside].

To study the metabolic transformation of pumiloside by rat intestinal flora in vitro and identify its metabolites. Pumiloside was incubated in the rat intestinal flora in vitro. HPLC was used to monitor the metabolic process, and HPLC-Q-TOF-MS was used to identify the structures of biotransformation products. In vitro, pumiloside was easily metabolized by rat intestinal flora, and with the prolongation of metabolic time, pumiloside was transformed into several metabolites. Three metabolites were initially identified in this experiment. The study indicated that pumiloside could be extensively metabolized in the rat intestinal flora in vitro.

[Traditional Chinese medicine pairs (III)--effect of extract of Ginseng Radix et Rhizoma and Puerariae Lobatae Radix on intestinal absorption in rats].

This study focused on the intestinal absorption of traditional Chinese medicines (TCM) to reveal the scientific connotation of the compatibility of TCM pairs. The single pass intestinal perfusion (SPIP) was used in rats to compare the absorption of single extracts from Puerariae Lobatae Radix, single extracts from Ginseng Radix et Rhizoma, combined extracts from Puerariae Lobatae Radix and Ginseng Radix et Rhizoma and Puerariae Lobatae Radix and Ginseng Radix et Rhizoma mixture in rats. The content of puerarin, ginsenoside Rg1, ginsenoside Re and ginsenoside Rb1 in liquid were tested by HPLC. The speed constant (Ka) and apparent permeability coefficients (Papp) were calculated and compared. Specifically, the order of puerarin Ka and Papp values from high to low was Ginseng Radix et Rhizoma and Puerariae Lobatae Radix mixture > single extracts from Puerariae Lobatae Radix > combined extracts from Ginseng Radix et Rhizoma and Puerariae Lobatae Radix; the order of ginsenosides Ka and Papp values from high to low was Ginseng Radix et Rhizoma and Puerariae Lobatae Radix mixture > single extracts from Ginseng Radix et Rhizoma > combined extracts from Ginseng Radix et Rhizoma and Puerariae Lobatae Radix. The combined administration of Ginseng Radix et Rhizoma and Puerariae Lobatae Radix may improve the absorption in the intestinal tract.

Transformation of strictosamide to vincoside lactam by acid catalysis.

AIM: To identify the structure of the acid-catalyzed product of strictosamide and explore the reaction mechanism. METHODS: The acid-catalyzed reaction process of strictosamide was monitored by HPLC, and a macroporous resin was used to purify the reaction solution. The structure of the product was confirmed by MS, NMR, and ROESY spectra. RESULTS: The acid-catalyzed transformation yield from strictosamide to vincoside lactam was 52%. CONCLUSION: The reaction mechanism of the transformation from strictosamide to vincoside lactam may be related to the stability of the three-dimensional configuration of the compound. These results offer a new way to obtain vincoside lactam from the widely distributed indole alkaloid strictosamide by acid-catalysis.