Affinity chromatography with immobilized DNA stationary phase for biological fingerprinting analysis of traditional Chinese medicines

Two-dimensional chromatography in screening of bioactive components from natural products

INTRODUCTION

Screening and analysis of bioactive components from natural products is a fundamental part of new drug development and innovation. Two-dimensional (2D) chromatography has been demonstrated to be an effective method for screening and preparation of specific bioactive components from complex natural products.

OBJECTIVE

To collect details of application of 2D chromatography in screening of natural product bioactive components and to outline the research progress of different separation mechanisms and strategies.

METHODOLOGY

Three screening strategies based on 2D chromatography are reviewed, including traditional separation-based screening, bioactivity-guided screening and affinity chromatography-based screening. Meanwhile, in order to cover these aspects, selections of different separation mechanisms and modes are also presented.

RESULTS

Compared with traditional one-dimensional (1D) chromatography, 2D chromatography has unique advantages in terms of peak capacity and resolution, and it is more effective for screening and identifying bioactive components of complex natural products.

CONCLUSION

Screening of natural bioactive components using 2D chromatography helps separation and analysis of complex samples with greater targeting and relevance, which is very important for development of innovative drug leads.

Aptamer-based microcantilever-array biosensor for profenofos detection

Profenofos, a highly poisonous organophosphorus pesticide, has been widely used in agricultural production. These pesticide residues have seriously influenced food security and threatened human health, and new methods with high sensitivity are greatly needed to detect profenofos. Here, we developed an aptamer-based microcantilever-array sensor operated in stress mode to detect profenofos, with advantages of being a label-free, highly sensitive, one-step immobilization method capable of quantitative and real-time detection. The microcantilevers were functionalized with a profenofos-specific aptamer (SS2-55), and then the specific binding of profenofos to aptamer induced a deflection of the microcantilever, which was monitored using an optical method in a real-time manner. The microcantilever deflection showed a positive relationship with profenofos concentration, and the detection limit was low to 1.3 ng mL^-1 (3.5 nM) for profenofos, which was much lower than other aptamer-based detection methods. The selectivity of the sensor was verified with another organophosphorus pesticide. Additionally, we successfully detected profenofos dissolved in vegetable-soak solution. Our results showed that this aptamer-based microcantilever-array sensor is a convenient and label-free method for detecting profenofos in small amounts and has great potential for food-security applications.

Screening for the bioactive constituents of traditional Chinese medicines—progress and challenges

The search for lead compounds from traditional Chinese medicines (TCMs) may be promising for new drug development.

Crude extract of Rheum palmatum L inhibits migration and invasion of LS1034 human colon cancer cells acts through the inhibition of matrix metalloproteinase-2/-9 by MAPK signaling

Crude extract of Rheum palmatum L. (CERP) has been used to treat different diseases in the Chinese population for decades. In this study, we investigated the anti-metastasis effects of CERP on LS1034 human colorectal cancer cells in vitro and examined potential mechanisms of its effects. CERP significantly inhibited cell migration and invasion of LS1034 cells. We also found that CERP inhibited protein levels of matrix metalloproteinases-2 (MMP-2) and matrix metalloproteinases-9 (MMP-9), and cytosolic NF-kB p65, RHO A, ROCK 1. Furthermore, we found CERP inhibited protein levels of GRB2, SOS1, MKK7, FAK, Rho A, ROCK 1, VEGF, PKC, AKT, phosphor-AKT (Thr308), Cyclin D, iNOS, COX2, NF-kB p65, p-ERK1/2, p-JNK1/2, p-p38, p-c-jun, MMP-2, MMP-9, MMP-1, MMP-7, MMP-10, UPA and increased the protein level of Ras in LS1034 cells. In conclusion, our results suggest that CERP may be used as a novel anti-metastasis agent for the treatment of human colon cancer cells.

Effects of substitution groups of glutamide-derived molecular gels on molecular shape recognition

We have reported that self-assembling glutamide lipid-grafted porous silica particles show high selectivity towards polycyclic aromatic hydrocarbons (PAHs) and bio-molecules. This enhancement of molecular recognition is brought about by the formation of a highly ordered structure in the glutamide lipid through intermolecular hydrogen bonding. To utilise, for selective separations, the highly oriented structure of glutamide lipids on the silica surface, in this study, we synthesised four glutamide lipids with different substitution groups and studied the separation behaviours of the glutamide lipid-grafted porous silica particles as reversed phase high-performance liquid chromatography (RP-HPLC) stationary phases. According to the HPLC studies, the functional group substitutions and the spacer group connecting the glutamide moiety and silica surface had a noticeable effect on the retention behaviours. Particularly, glutamide lipids with a long spacer group (C10) showed a higher selectivity towards positional (o-/m-/p-terphenyl) and geometrical (cis-/trans-stilbene) isomers. Differential scanning calorimetric and Fourier transform infrared spectroscopic studies suggested that the long spacer group induced the assembled structure of the glutamide lipid on the silica surface. Interestingly, the glutamide lipids with dodecyl groups and benzyl groups showed reverse elution orders towards the length to breadth ratio of PAHs.

Prospects for multitarget lipid-raft-coated silica beads: a remarkable online biomaterial for discovering multitarget antitumor lead compounds

Application of lipid raft biomaterial with multiple cancer-related receptors for screening novel multitarget antitumour lead compounds.

Biological Fingerprinting of Herbal Samples by Means of Liquid Chromatography

Biological chromatographic fingerprinting is a relatively new concept in the quality control of herbal samples. Originally it has been developed with the application of HPLC, and recently herbal samples' biological profiles have been obtained by means of thin-layer chromatography (TLC). This paper summarizes the application of liquid chromatographic techniques for the purpose of biological fingerprint analysis (BFA) of complex herbal samples. In case of biological TLC fingerprint, which is a relatively novel solution, perspectives of its further development are outlined in more detail. Apart from already published data, some novel results are also shown and briefly discussed. The paper aims at drawing scientists' attention to the unique solutions offered by biological fingerprint construction.

Bioactivity-based liquid chromatography-coupled electrospray ionization tandem ion trap/time of flight mass spectrometry for β₂AR agonist identification in alkaloidal extract of Alstonia scholaris

Although chromatographic fingerprinting combined with chemometrics, is a rational method for the quality control of traditional Chinese medicine (TCM), chemometrics cannot fully explore the relationship between chemical information and the efficacy of the potential activity. In the present work, a cell-based β₂ adrenergic receptor (β₂AR) agonist functional evaluation model coupled with high-performance liquid chromatography was developed to screen the potential β₂AR agonist components in the alkaloidal extract of Alstonia scholaris leaves. Using a liquid chromatography with ion trap time-of-flight mass spectrometry (LCMS-IT-TOF) system, the potential bioactive compounds in the prescription were identified and deduced based on the mass spectrometric fragmentation patterns, tandem mass spectrometry (MS/MS) data, and relevant literature. Several new β₂AR agonists of indole alkaloids were successfully found, and their activities were confirmed through an in vivo relaxant test on guinea pig tracheal muscles. The developed method is rapid and reliable compared with conventional fingerprinting and showed high sensitivity and resolution for the identification of β₂AR agonists in TCM prescriptions. This strategy clearly demonstrates that bioactivity-integrated fingerprinting is a powerful tool not only in screening and identifying potential lead compounds and in determining the therapeutic material basis of Chinese herbal prescriptions, but also in supplying suitable chemical markers for their quality control.

Identification of Enzyme Inhibitors Using Therapeutic Target Protein - Magnetic Nanoparticle Conjugates

Target protein - magnetic nanoparticle (MNP) conjugates, i.e. α-glucosidase-MNP and protein tyrosine phosphatase 1B (PTP1B)-MNP, were prepared and evaluated for the first time for affinity extraction of the enzyme inhibitors from herbal extracts. Four ligands extracted from granati pericarpium were identified by ESI-MS analysis. In vitro tests indicated that they inhibited both α-glucosidase and PTP1B, two important target proteins for diabetic treatment.

Screening the bioactive compounds in aqueous extract of Coptidis rhizoma which specifically bind to rabbit lung tissues beta2-adrenoceptor using an affinity chromatographic selection method

A receptor affinity chromatographic selection method was developed for screening the bioactive compounds binding to beta(2)-adrenoceptor (beta(2)-AR) in Coptidis rhizome. The bioactive compounds were analyzed by molecular recognition with a beta(2)-AR affinity column. The retention compounds eluted from the beta(2)-AR column were separated online with reverse-phase high-performance liquid chromatography by column switching technology, and identified by a coupled ion-trap mass spectrometer. Four compounds were screened as the bioactive compounds of Coptidis rhizome and identified as 2,9,10-trimethoxy-3-hydroxyl-protoberberine (jateorhizine), 2,3-methylenedioxy-9-methoxy-protoberberine, 2,3,9,10-tetramethoxy-protoberberine (palmatine) and 2,3-methylenedioxy-9,10-dimethoxy-protoberberine (berberine). The association constants of jatrorrhizine, palmatine and berberine to the beta(2)-AR were determined by the zonal elution method with standards. Berberine and palmatine had only one type of binding site on the immobilized beta(2)-AR. Their association constants were (2.28+/-0.11)x10(4)/M and (3.00+/-0.10)x10(4)/M, respectively. Jatrorrhizine had at least two type of binding sites on the immobilized beta(2)-AR, and the corresponding association constants were (2.20+/-0.09)x10(-4)/M and (6.78+/-0.001)x10(5)/M.

Screening of antinociceptive components in Corydalis yanhusuo W.T. Wang by comprehensive two-dimensional liquid chromatography/tandem mass spectrometry

Formalin-induced pain models were used in rats to evaluate the antinociceptive effect of the total alkaloids of Corydalis yanhusuo (TAC). The results indicated that formalin-evoked spontaneous nociceptive responses (licking behavior) could be inhibited significantly by giving (intragingival) TAC at a single dose of 150 mg/kg. Subsequently, an online comprehensive two-dimensional biochromatography method with a silica-bonded human serum albumin (HSA) column in the first dimension and a monolithic ODS column in the second was developed. The absorbed bioactive components were screened by comparing and contrasting the components detected in the plasma and striatum with those in TAC. More than 100 compounds were separated and detected in the TAC, among which 13 compounds were identified. About 40 compounds (seven compounds identified) were absorbed into the plasma with appropriate concentrations and about 20 compounds (four compounds identified) passed through the blood-brain barrier into the striatum. Of interest, four compounds (protopine, glaucine, tetrahydropalmatine, and corydaline) which were reported to possess profound antinociceptive effects exhibited high concentrations in the striatum. This may result from their synergistic effects in regulating the formalin-induced nociception. The results indicated that the comprehensive two-dimensional biochromatography method developed is capable of screening the bioactive components in Corydalis yanhusuo and providing valuable information for understanding the mechanisms by which Corydalis yanhusuo alleviates nociception.

Recent analytical approaches in quality control of traditional Chinese medicines--a review

Traditional Chinese medicines (TCMs) are gaining more and more attention all over the world, due to their specific theory and long historical clinical practice. But the uncontrollable quality is a bottleneck for its modernization and globalization. This paper reviewed the recent analytical methods in the quality control of TCMs, including screening strategies of bioactive markers from TCMs through biochromatographic methods, the traditional chromatographic methods, DNA methods, as well as the spectroscopic methods, including FT-IR, NIR and NMR. The comprehensive methods, such as fingerprint and multi-component quantification are emphasized; hyphenated techniques, like HPLC-MS, GC-MS, CE-MS, LC-NMR, chemometric methods, and combination of chemical and biological methods, such as biofingerprint, metabolic fingerprint are now more and more widely used in TCMs. In a few word, the analysis and quality control of TCMs are moving towards an integrative and comprehensive direction, in order to better address the inherent holistic nature of TCMs.

Traditional Chinese medicine and separation science

Traditional Chinese medicines (TCMs) are getting more and more popular nowadays in the whole world for improving health condition of human beings as well as preventing and healing diseases. TCM is a multi-component system with components mostly unknown, and only a few compounds are responsible for the pharmaceutical and/or toxic effects. The large numbers of other components in the TCM make the screening and analysis of the bioactive components extremely difficult. So, separation and analysis of the desired chemical components in TCM are very important subjects for modernization research of TCM. Thus, many novel separation techniques with significant advantages over conventional methods were introduced and applied to separation and analysis of the chemical constituents in TCM. This review presents just a brief outline of the applications of different separation methods for the isolation and analysis of TCM constituents.