Chinensis Lour Research Articles

Two‐dimensional liquid chromatography coupled with mass spectrometry for the analysis of Lobelia chinensis Lour. using an ESI/APCI multimode ion source

A comprehensive approach for the separation and identification of components in a traditional Chinese medicine Lobelia chinensis Lour. was developed using 2D-HPLC coupled with an online photodiode array (PDA) detector and a mass spectrometer. The extract of L. chinensis Lour. was separated on a CN column in the first-dimensional HPLC, and then each of the collected fractions was further separated on an ODS column followed by an online PDA detector. After separation in the two different chromatographic modes, the eluents were delivered to a quadrupole mass spectrometer equipped with a multimode ion source of an ESI and an atmospheric pressure chemical ionization (ESI/APCI). At least 536 components in L. chinensis Lour. extract were detected and 6 of them were identified as apigenin 7-O-rutinoside, luteolin, lobetyolinin, lobetyolin, diosmin, and linarin, respectively, according to their UV spectrum and mass spectrum. The results demonstrated the powerful resolution, high peak capacity, as well as the identification capability of the 2D-HPLC combined with PDA and ESI/APCI-MS for the analyses of complex samples.

Is tamarisk allelopathic?

Tamarisk (Tamarix ramosissima Ledeb., T. chinensis Lour.), a pernicious invader of riparian areas in the western U.S., is often considered to be allelopathic by virtue of an ability to exude salt from its leaves. However, there is no evidence demonstrating allelopathy or even salinization of soils under tamarisk. We collected soil samples from beneath and just outside of tamarisk canopies at 12 sites along a 110-km reach of Fort Peck Reservoir in northeastern Montana. Samples were analyzed for electrical conductivity (EC), pH and concentration of several nutrients. Plants of western wheatgrass (Agropyron smithii Rydb.), the dominant herbaceous native plant in habitats invaded by tamarisk, were grown in the soil samples as a bioassay. We used principal components analysis (PCA) to explore how intercorrelated soil variables were affected by a tamarisk canopy. EC averaged more than twice as high under a tamarisk canopy than in the open. However, western wheatgrass plants growing in tamarisk-affected soil were 73% larger than those in unaffected soil. PCA analysis indicated that soil beneath a tamarisk canopy had higher values along a gradient of increasing EC and total inorganic N and decreasing pH and NH 4 + /NO 3 − ratio. This same gradient was also associated with increasing growth of the bioassay. We hypothesize that this fertilization was due to leaf secretions and/or leaf fall, possibly by increased input of nitrogenous organic compounds or increased P solubility. Our study provided no support for an allelopathic effect of tamarisk.