Xingnuo Li

Profiling the Ginsenosides of Three Ginseng Products by Lc‐Q‐Tof/Ms

Ginseng is a well-known herbal medicine that has been gaining increasingly popularity as a potential chemopreventive agent. In traditional Chinese medicine practice, white ginseng (WG), red ginseng (RG), and dali ginseng (DG) are 3 different ginseng-processed products used for different purposes. Although the morphological appearance and some constituents contained in these ginseng products are similar, their pharmacological activities are significantly different due to the varied types and quantity of ginsenosides in each product. In the present study, a practical method based on rapid liquid chromatography coupled with quadrupole time of flight mass spectrometry (LC-Q-TOF/MS) was developed to identify the chemical profiles of ginsenosides in these 3 ginseng products. The results demonstrated that a total of 55, 53, and 43 compounds were unambiguously assigned or tentatively identified in DG, WG, and RG samples, respectively. The featured compounds are mainly malonyl ginsenosides in WG, and decarboxyl products of mal-ginsenosides and the dehydrated compounds from polar ginsenosides were characteristic in RG, while DG contain some characteristic components present both in WG and RG. We presume that heating processing is the major factor affecting the chemical profile of ginseng products. The difference of chemical information revealed by LC-Q-TOF/MS could be used to discriminate the WG, RG, and DG samples.

Anti-proliferative and apoptosis-inducing effects of camptothecin-20(s)-O-(2-pyrazolyl-1)acetic ester in human breast tumor MCF-7 cells.

Camptothecin-20(s)-O-(2-pyrazolyl-1)acetic ester (CPT6) is a novel semi-synthetic analog of camptothecin. In a previous report, CPT6 possessed higher cytotoxic activity in vitro towards human breast tumor MCF-7 cells than topotecan. In this study, the antitumor activity of CPT6 on the human breast tumor MCF-7 cell line was analyzed using the MTT method. The underlying mechanism of CPT6 action was investigated by analyzing the cell cycle distribution, apoptotic proportion, changes in mitochondrial membrane potential, and intracellular Ca2+ concentration using flow cytometry. Nuclear and mitochondrial morphologies were also observed by laser scanning confocal and transmission electron microscopy. DNA damage was observed in MCF-7 cells treated with CPT6. Low-dose CPT6 had a significant cytotoxic effect and could inhibit proliferation and induce apoptosis in MCF-7 cells, possibly through cell nucleus fragmentation and DNA damage. CPT6 thus appears to display potent antitumor activity against human breast tumor MCF-7 cells via the induction of apoptosis, and may be a useful alternative drug for breast cancer therapy.

Preparative enantioseparation of propafenone by counter-current chromatography using di-n-butyl L-tartrate combined with boric acid as the chiral selector.

This paper extends the research of the utilization of borate coordination complexes in chiral separation by counter-current chromatography (CCC). Racemic propafenone was successfully enantioseparated by CCC with di-n-butyl l-tartrate combined with boric acid as the chiral selector. The two-phase solvent system was composed of chloroform/ 0.05 mol/L acetate buffer pH 3.4 containing 0.10 mol/L boric acid (1:1, v/v), in which 0.10 mol/L di-n-butyl l-tartrate was added in the organic phase. The influence of factors in the enantioseparation of propafenone were investigated and optimized. A total of 92 mg of racemic propafenone was completely enantioseparated using high-speed CCC in a single run, yielding 40-42 mg of (R)- and (S)-propafenone enantiomers with an HPLC purity over 90-95%. The recovery for propafenone enantiomers from fractions of CCC was in the range of 85-90%.

A new furolactone-type lignan from Lycium chinense

The phytochemical investigation of extracts from the root barks of Lycium chinense yielded a new furolactone-type lignan, lyciumin (1). Its structure and absolute configurations were established on the basis of spectral data, particularly by the use of 1D NMR, 2D shift-correlated NMR pulse sequences (1H–1H COSY, HSQC, HMBC and ROESY) and CD spectra.

Two phthalide dimers from the radix of Angelica sinensis

The phytochemical investigation of extracts from the radix of Angelica sinensis yielded a new phthalide dimer, 3,3′Z-6.7′,7.6′-diligustilide (1), along with a known dimer, levistolide A (2). Their structures were established on the basis of spectral data, particularly using 1D-NMR and several 2D shift-correlated NMR pulse sequences (1H–1H COSY, HSQC, HMBC and NOESY).

Elution-extrusion counter-current chromatography for the separation of two pairs of isomeric monoterpenes from Paeoniae Alba Radix.

In this work, a simple and efficient protocol for the rapid separation of two pairs of isomeric monoterpenes from Paeoniae Alba Radix was developed by combining macroporous resin and elution-extrusion counter-current chromatography. The crude extract was firstly subjected to a D101 macroporous resin column eluted with water and a series of different concentrations of ethanol. Then, effluents of 30 and 95% ethanol were collected as sample 1 and sample 2 for further counter-current chromatography purification. Finally, a pair of isomers, 96 mg of compound 1 and 48 mg of compound 2 with purities of 91.1 and 96.2%, respectively, was isolated from 200 mg of sample 1. The other pair of isomers, 14 mg of compound 3 and 8 mg of compound 4 with purities of 93.6 and 88.9%, respectively, was isolated from 48 mg of sample 2. Their purities were analyzed by high-performance liquid chromatography, and their chemical structures were identified by mass spectrometry and (1) H NMR spectroscopy. Compared to a normal counter-current chromatography separation, the separation time and solvent consumption of elution-extrusion counter-current chromatography were reduced while the resolutions were still good. The established protocol is promising for the separation of natural products with great disparity of content in herbal medicines.

Synthesis and Biological Activity of Some Bile Acid-Based Camptothecin Analogues

In an effort to decrease the toxicity of camptothecin (CPT) and improve selectivity for hepatoma and colon cancer cells, bile acid groups were introduced into the CPT 20 or 10 positions, resulting in the preparation of sixteen novel CPT-bile acid analogues. The compounds in which a bile acid group was introduced at the 20-hydroxyl group of CPT showed better cytotoxic selectivity for human hepatoma and colon cancer cells than for human breast cancer cells. Fluorescence microscopy analysis demonstrated that one compound (E2) entered human hepatoma cells more effectively than it did human breast cancer cells. Compound G4 exhibited the best anti-tumour activity in vivo. These results suggested that introduction of a bile acid group at the 20-position of CPT could decrease toxicity in vivo and improve selectivity for hepatoma cells.

Coumarins from Edgeworthia chrysantha.

A new coumarin, edgeworic acid (1), was isolated from the flower buds of Edgeworthia chrysantha, together with the five known coumarins umbelliferone (2), 5,7-dimethoxycoumarin (3), daphnoretin (4), edgeworoside C (5), and edgeworoside A (6). Their structures were established on the basis of spectral data, particularly by the use of 1D NMR and several 2D shift-correlated NMR pulse sequences (1H-1H COSY, HSQC and HMBC), in combination with acetylation reactions.

Two Alkaloids from Asparagus cochinchinensis

The phytochemical investigation of extracts from the roots of Asparagus cochinchinensis yielded a new indole alkaloid dimer, N-methyl-2,2′-ditryptamine (1), and a known β-carboline alkaloid, (–)-(1S,3S)-1-methyl-1,2,3,4-tetrahydro-β-carboline-3-carboxylic acid (2). Their structures were established on the basis of spectral data, particularly by the use of 1D NMR and several 2D shift-correlated NMR pulse sequences (1H–1H COSY, HSQC and HMBC).

PREPARATIVE SEPARATION OF TERTIARY ALKALOIDS FROM CORYDALIS YANHUSUO W. T. WANG BY pH-ZONE-REFINING COUNTER-CURRENT CHROMATOGRAPHY

Preparative separation of alkaloids from the crude extract of Corydalis yanhusuo by pH-zone-refining counter-current chromatography was successfully performed, The method used a biphasic solvent system composed of methyl-tert-butyl ether-acetonitrile-water (2:2:3, v/v), in which the organic phase containing 10 mM of triethylamine was used as a retainer in the stationary phase, while the aqueous phase containing 5 mM of hydrochloric acid as an eluter was used as the mobile phase. In the present study, 80 mg of glaucine, 41 mg of tetrahydropalmatine, and 67 mg of corydaline were separated from 1.16 g of the crude sample of C. yanhusuo with purity of 91.4%, 84.3%, and 98.2%, respectively. The structures of alkaloids were identified by 1H NMR and 13C NMR.