Search Results

You are looking at 1 - 4 of 4 items for :

  • Author or Editor: Tao Zheng x
  • Chemistry and Chemical Engineering x
Clear All Modify Search

A simple and accurate high-performance thin-layer chromatography (HPTLC)-bioautographic method was developed for the quantitative analysis of magnolol and honokiol in the herbal medicine Magnoliae officinalis Cortex. The samples were separated on a silica gel HPTLC plate with a mixture solution of toluene-methanol (10:1, v/v) as the mobile phase. Spots were visualized by dipping in 2,2-diphenyl-1-picrylhydrazyl radical (DPPH*) reagent and measured at a wavelength of 550 nm in a reflection mode, scanning after derivatization for 40 min. The method had excellent linearity (r2 = 0.9939 for magnolol and r2 = 0.9989 for honokiol, respectively) in the concentration range of 0.16–0.97 mg spot−1 for both analytes. The recoveries were 94.5–105.9% for magnolol and 86.6–103.4% for honokiol, respectively. The established HPTLC-bioautographic method was evaluated comprehensively in quantitative and antioxidant activity analysis of magnolol and honokiol in Magnoliae officinalis Cortex and various plants.

Restricted access

Abstract  

The effect of different solid soil components of calcareous soils on the retention of SeO3 has been investigated by a batch technique and selective extraction method. The sorption and desorption isotherms of SeO3 on the untreated calcareous soil and the three treated soils were determined at 20°C, pH 7.8±0.2 and in the presence of 0.001M CaCl2. It was found that all isotherms are linear, the sorption-desorption hysteresis for untreated soil and treated soils is obvious and the retention of SeO3 in calcareous soil is mainly attributed to the oxides.

Restricted access

Abstract  

The kinetics of particle-diffusion controlled ion exchange in the ternary system of cations UO 2 2+ –Na+–H+–001×7 strong acidic resin has been studied. In the [R–H+]/(Na++UO 2 2+ ) system, the change of the amount of Na+ in the resin phase with time showed a high peak. In the [R–Na+]/(H++UO 2 2+ ) system, the change of the amount of H+ in the resin phase with time also showed a high peak. In the [R2–UO 2 2+ ]/(H++Na+) system, the change of amount of H+ in the resin phase with time showed merely a small peak. This kinetic character of the ternary ion exchange system in the finite solution volume has been analyzed according to the Nerst-Planck equation, and on the whole, the trend of the experimental results is consistent with the resulting numerical solution of the set of Nerst-Planck equations.

Restricted access

In traditional Chinese medicine, plants of the genus Peganum have been used to treat cough, hypertension, diabetes, asthma, jaundice, lumbago, and many other ailments. In this study, seeds of the plants of genus Peganum, including P. harmala Linn., P. multisectum (Maxim) Bobr, P. nigellastrum Bunge, and Peganum variety were collected from different provinces in China. A simple, rapid, and effective thin-layer chromatographic (TLC) fingerprint combined with bioautographic technique has been established for the identification of acetylcholinesterase (AChE) inhibitors from these seeds. The methanol extracts of seeds were separated on silica gel plates with ethyl acetate-methanol-ammonia 10:1.5:0.5 (ν/ν) as mobile phase, and then the plates were inspected under UV 366 nm and visualized by spraying with both Dragendorff’s and vanillin-sulfuric acid reagents as well as by bioautographic assay. Moreover, the limits on AChE inhibitive activity of harmine and harmaline were found to be 0.01 μg, in comparison to that of galanthamine of also 0.01 μg. The TLC fingerprints combined with the bioautographic method could distinguish the seeds of the different species of genus Peganum investigated. Moreover, harmine and harmaline displayed similar AChE inhibition compared to galanthamine.

Restricted access