Bioactive compounds of Shuang-Huang-Lian prescription and an insight into its binding mechanism by β2 -adrenoceptor chromatography coupled with site-directed molecular docking

Advances in receptor chromatography for drug discovery and drug-receptor interaction studies

Receptor chromatography involves high-throughput separation and accurate drug screening based on specific drug-receptor recognition and affinity, which has been widely used to screen active compounds in complex samples. This review summarizes the immobilization methods for receptors from three aspects: random covalent immobilization methods, site-specific covalent immobilization methods and dual-target receptor chromatography. Meanwhile, it focuses on its applications from three angles: screening active compounds in natural products, in natural-product-derived DNA-encoded compound libraries and drug-receptor interactions. This review provides new insights for the design and application of receptor chromatography, high-throughput and accurate drug screening, drug-receptor interactions and more. Teaser: This review summarizes the immobilization methods of receptors and the application of receptor chromatography, which will provide new insights for the design and application of receptor chromatography, rapid drug screening, drug-receptor interactions and more.

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.

Screening the bioactive compound from Coptis chinensis inflorescence by immobilized Peroxisome proliferator activated receptor gamma

Coptis chinensis inflorescence is a by-product of Coptis chinensis Franch and riches in alkaloids. We screened the bioactive compounds in the by-product through an immobilized peroxisome proliferator-activated receptor gamma. The receptor was covalently immobilized on the macroporous silica gel through amino groups to generate the affinity stationary phase and was applied for screening. Berberine, palmatine, and jatrorrhizine were identified as the retained components of the herb on the affinity column. We evaluated the binding of the three bioactive compounds with the receptor by nonlinear chromatography and molecular docking. The affinities of the compounds to the receptor were (1.42±0.10) ×10⁸ M^-1 , (4.88±0.38) ×10⁷ M^-1 , and (1.65±0.13) ×10⁷ M^-1 for berberine, palmatine, and jatrorrhizine, with dissociation rate constants of (17.70±0.03) ×10^-3 S^-1 , (5.18±0.25) ×10^-2 S^-1 , and (15.7±0.05) ×10^-2 S^-1 , respectively. Cys285, Arg288, Ile326, Leu330, and His449 in the agonist binding pocket of the receptor participated in the formation of bioactive compound-receptor conjugates. These data indicated that the immobilized receptor is a reliable alternative for screening the bioactive compounds. In addition, Coptis chinensis inflorescence has the potential to be a source for drug discovery. This article is protected by copyright. All rights reserved.

Development and characterization of a selective chromatographic approach to the rapid discovery of ligands binding to muscarinic-3 acetylcholine receptor

The pursuit of new ligands binding to muscarinic-3 acetylcholine receptor (M₃R) is viewed as challenging due to the lack of screening methods with high efficiency. To address such challenges, this work developed and characterized an approach to the rapid discovery of M₃R ligands using the immobilized receptor as the chromatographic stationary phase. We fused haloalkane dehalogenase (Halo) as a tag at the C-terminus of M₃R. The fusion M₃R was immobilized on 6-chlorocaproic acid-activated ammino-microspheres by the specific covalent reaction between the Halo-tag and the linker. Comprehensive characterizations of the immobilized M₃R were performed by scanning electron microscope, X-ray photoelectron spectroscopy, and the investigation on the binding of three specific ligands to the receptor. The feasibility of the immobilized M₃R in complex matrices was tested by screening the bioactive compounds in Zhisou oral liquid, assessing the interaction between the screened compounds and the receptor using zonal elution, and evaluating the in vivo activity of the targeted compounds. The results evidenced that the immobilized M₃R has high specificity, good stability, and the capacity to separate M₃R ligands from complex matrices. These allowed us to identify naringin, hesperidin, liquiritigenin, platycodin D, and glycyrrhizic acid as the potential ligands of M₃R. The association constants of the five compounds to M₃R were 4.44 × 10⁴, 1.11 × 10⁴, 7.20 × 10⁴, 4.15 × 10⁴, and 3.36 × 10⁴ M^-1. The synergistic application of the five compounds exhibited an equivalent expectorant activity to the original formula. We reasoned that the current method is possible to provide a highly efficient strategy for the discovery of receptor ligands.

Rapidly identifying bioactive compounds from Zhisou oral liquid by immobilized receptor-based high-performance affinity chromatography

The identification of bioactive compounds in complex matrices remains a major challenge due to the lack of highly efficient and specific methods. This work developed an approach based on high-performance affinity chromatography to identify the potential antitussive compounds from Zhisou oral liquid . The main methods include the synthesis of immobilized beta2-adrenoceptor by a one-step method, the screening and identification of the potential bioactive compounds by the receptor column coupled with mass spectrometry, and the binding mechanism analysis of the compounds to the receptor by the in vivo experiment, injection amount dependent method and molecular simulation. We identified the potential bioactive compounds of Zhisou oral liquid as glycyrrhizic acid, platycodin D, tuberostemonine, and hesperidin. In vivo experiment showed that the combinational utilization of the four compounds was possible to present an equivalent antitussive effect to the formula. The docking results demonstrated that hydrogen bonds and Van der Waals forces were the main forces to drive the binding of the four compounds to beta2-adrenoceptor. We concluded that the four compounds are the effective components in Zhisou oral liquid. The proposed strategy is possible to provide an alternative for the development of highly efficient methods to pursue the bioactive compounds of complex matrices.

Screening Bioactive Compounds of Siraitia grosvenorii by Immobilized β2-Adrenergic Receptor Chromatography and Druggability Evaluation

As the first and key step of traditional Chinese medicine (TCM)-guided drug development, lead discovery necessitates continuous exploration of new methodology for screening bioactive compounds from TCM. This work intends to establish a strategy for rapidly recognizing β2-adrenergic receptor (β2-AR) target compounds from the fruit of Siraitia grosvenorii (LHG). The method involved immobilization of β2-AR onto amino-microsphere to synthesize the receptor column, the combination of the column to high-performance liquid chromatography (HPLC) to screen bioactive compounds of LHG, the identification of the compounds by HPLC coupled with mass spectrometry (MS), and the evaluation of druggability through pharmacokinetic examination by HPLC-MS/MS. Mogroside V was screened and identified as the β2-AR-targeted bioactive compounds in LHG. This compound exhibited desired pharmacokinetic behavior including the time to reach peak plasma concentrations of 45 min, the relatively low elimination of 138.5 min, and the high bioavailability. These parameters indicated that mogroside V has a good druggability for the development of new drugs fighting β2-AR-mediated respiratory ailments like asthma. The combination of the methods in this work is probably becoming a powerful strategy for screening and early evaluating the bioactive compounds specifically binding to G-protein-coupled receptor target from complex matrices including TCM.

Recent applications of immobilized biomaterials in herbal analysis

Immobilization of biomaterials developed rapidly due to the great promise in improving their stability, activity and even selectivity. In this review, the immobilization strategies of biomaterials, including physical adsorption, encapsulation, covalent attachment, cross-linking and affinity linkage, were briefly introduced. Then, the major emphasis was focused on the reported various types of immobilized biomaterials, including proteins, enzymes, cell membrane and artificial membrane, living cells, carbohydrates and bacteria, used in the herbal analysis for bioactive compound screening, drug-target interaction evaluation and chiral separation. In addition, a series of carrier materials applied in biomaterials immobilization, such as magnetic nanoparticles, metal-organic frameworks, silica capillary column, cellulose filter paper, cell membrane chromatography, immobilized artificial membrane chromatography and hollow fiber, were also discussed. Perspectives on further applications of immobilized biomaterials in herbal analysis were finally presented.

Chinese herbal medicine for acute upper respiratory tract infections and reproductive safety: A systematic review

Acute upper respiratory tract infections (AURTIs) are common and self-limited in people with normal immunity but sometimes lead to poor clinical outcomes under specific conditions such as pregnancy if not treated appropriately. Chinese herbal medicines (CHM), which are widely used to treat AURTIs, have proven to be effective in preclinical and clinical studies. This review focuses on the bioactivities of typical CHM and the adverse reactions they cause, and especially issues with reproductive safety when treating AURTIs. The main mechanisms for clinical efficacy may include anti-viral, anti-bacterial, anti-inflammatory, antipyretic, and immunomodulatory action as indicated by preclinical evidence. Most clinical trials indicate that CHM shortens the natural course of AURTIs and that it relieves related symptoms such as a fever, headaches, coughing, myalgia, a cold, sore throat, and a nasal obstruction. However, some CHM have a range of adverse effects and potentially affect reproduction from endocrinal secretion to embryo development while others do not. Therefore, clinical adverse reactions and preclinical studies on the toxicity of CHM are discussed. More reliable evidence is required to conclude that CHM are efficacious and safe for pregnant women with AURTIs. This review should help to promote advances in the research on and development of CHM as alternative treatments for AURTIs and offer insight into strategies to manage the safety of CHM during clinical use.

Rapid screening and identification of bioactive compounds specifically binding to beta 2-adrenoceptor from San-ao decoction using affinity magnetic fine particles coupled with high-performance liquid chromatography-mass spectrometry

Background

San-ao decoction (SAD) has been widely used in Chinese medicine against respiratory diseases, such as asthma and rhinallergosis. The bioactive compounds for such pharmacological action remain unknown.

Methods

We developed a methodology to isolate the bioactive compounds of SAD. The assay involved the immobilization of beta 2-adrenoceptor (β ₂-AR) onto magnetic fine particles, the capture of target compounds by the immobilized receptor, the identification of the receptor bound compounds by reversed-phase high-performance liquid chromatography coupled with tandem mass spectrometry.

Results

Vicenin, shaftoside, isoshaftoside, liquiritin apioside and isoliquiritin apioside were identified as β ₂-AR ligands in SAD extract. The binding of these compounds to β ₂-AR occurred on serine¹⁶⁹, serine¹⁷⁰ and phenylalanine²⁵⁶ of the receptor.

Conclusions

The developed methodology has high stability and specificity for recognizing and isolating target compounds. It is an alternative method for rapidly screening bioactive compounds of immobilized receptor from Chinese prescriptions.