Molecular interactions between the main components of Shuanghuanglian injection and ciprofloxacin injection based on self-assembly / 药学学报

The combination of Shuanghuanglian injection (SHLI) and ciprofloxacin injection (CIPI) is frequently prescribed in clinical practice, but the basis for the combination is weak. In this study, isothermal titration calorimetry and ultraviolet-visible absorption spectrometry were applied to identify the molecular interactions of SHLI and its main components, chlorogenic acid and neochlorogenic acid with CIPI. Scanning electron microscopy, Fourier-transform infrared spectroscopy, and cold-spray ionization mass spectrometry were performed to confirm that this molecular interaction was related to the formation of self-assembled supramolecular systems induced by chlorogenic acid and neochlorogenic acid with CIPI through weak intermolecular bonds. The antibacterial activity toward Pseudomonas aeruginosa (P. aeruginosa) was evaluated via molecular interactions, and the inhibitory ability of SHLI, chlorogenic acid and neochlorogenic acid against P. aeruginosa was significantly reduced after interaction with CIPI. A molecular docking study demonstrated that the reduced antibacterial ability was closely related to the competitive binding of drug molecules to the same binding site of the DNA gyrase B (GyrB) subunit of P. aeruginosa. The present study uncovered the intermolecular interactions of SHLI and its main components chlorogenic acid and neochlorogenic acid with CIPI from the perspective of molecular self-assembly and contribute to the reduction of its antibacterial ability, providing a basis for the clinical combination of SHLI and CIPI.

Evaluation of interaction of chlorogenic acid and cefotaxime sodium based on sequential analysis / 药学学报

The joint application of traditional Chinese medicine injection containing chlorogenic acid (CA) and cefotaxime sodium (CS) is sometimes appeared in clinical practice, but the scientific basis of drug molecular compatibility is still weak. This study proposes a sequential analysis strategy based on isothermal titration calorimetry (ITC), cold-spray ionization mass spectrometry (CSI-MS) and antibacterial activity test to evaluate the molecular interactions between CA and CS. The results of ITC experiments showed that the Gibbs free energy ΔG < 0 and it was driven by enthalpy change when CA titrated CS, suggesting CA could spontaneously chemically react with CS. Subsequently, the parent ions (m/z 808.143 5) of binding molecular of CA and CS was detected by CSI-MS, indicating CA could chemically bond with CS. Furtherly, the antibacterial experiments found the antibacterial ability of CS against Klebsiella pneumonia was significantly reduced (P < 0.01) by CA in mixed solution. Finally, molecular docking technology showed CA and CS have a common target of penicillin binding protein 3 (PBP3), suggesting that the phenomenon of CA reduced the antibacterial ability of CS may be related to the competitive binding of two components with PBP3. Our studies have shown that CA could spontaneously chemically bond to CS and reduced its antibacterial ability, providing scientific data for molecular interaction evaluation of CA and CS.

Method for the detection of human immunoglobulin Fc function based on surface plasmon resonance: preliminary establishment and validation / 中国输血杂志

【Objective】 To establish a method for detecting human immunoglobulin Fc function based on surface plasmon resonance technology. 【Methods】 Based on the characteristic that FcγRI can be binded to the Fc segment of IgG, the affinity constant of the sample was detected by surface plasmon resonance, and its Fc function was the KD ratio of the sample to the standard. The method was validated for specificity/specificity, precision and robustness. The method and the pharmacopoeia method were used to detect the Fc function of 30 human immunoglobulins, and the correlation and consistency of the detection results were analyzed. 【Results】 The method validation results showed that this method has strong specificity/specificity (t values were 0.15, 0.22, both P>0.05), good precision (CV value 5.37%~10.69%) and good robustness (CV value 10.06%). The detection results of this method and the pharmacopoeia method have high correlation (r=0.96, P<0.05) and high consistency (Bias-2.060, 95% Limits of Agreement-5.628~1.508). 【Conclusion】 A method for detecting human immunoglobulin Fc function based on surface plasmon resonance has been successfully established.

Study on the substance basis of "property-taste-efficacy" of Liquorice and Rhizoma chinensis based on supramolecular system induced by weak bond / 药学学报

It is a common understanding that turbidity and precipitation of traditional Chinese medicine are easy to occur in the process of decocting. At present, our research group found that the cause of "multi-phase of traditional Chinese medicine decoction" mainly came from the interaction between the effective components of traditional Chinese medicine, especially the interaction of acid and base components. For example, the Liquorice and Rhizoma chinensis was a supramolecular system formed by a large number of active components in the decoction (>30%), and could stably exist in the decoction system. In this study, the supramolecular part was extracted, and the morphology of the supramolecular part was characterized by scanning electron microscopy and dynamic light scattering. It was observed that the supramolecular particles were uniform in size and regular in shape. The main components of supramolecular sites were identified by liquid mass spectrometry (LC-MSn). The results of UV and IR spectra showed that the chemical components of Liquorice and Rhizoma chinensis in the co-decocting process collided with each other, and weak bonds were formed between the functional groups of the molecules, which then induced the aggregation to form supramolecules. Thereafter, Through the diarrhea model of mice, sensory evaluation and antibacterial activity evaluation found that Liquorice and Rhizoma chinensis decocted together enhanced the antibacterial activity of Rhizoma, and compatibility "reconcile" Rhizoma "big bitter cold" property compared with single decoction group and interval administration group. All animal experiments were approved by the Animal Ethics Committee of Beijing University of Chinese Medicine, and the relevant regulations of Beijing University of Chinese Medicine on experimental animals were strictly followed. In this study, supramolecular chemistry method was used to preliminarily discuss the scientific connotation of "increasing efficiency and decreasing toxicity" of Liquorice and Rhizoma chinensis combined decoction from three perspectives of "property, efficacy and taste", and provide new ideas for the basic research of "reconcile" compatibility of Liquorice.

New qualities control strategy of Scutellaria baicalensis by isothermal titration calorimetry / 中国中药杂志

It has been focused on that there will be precipitates when decoction of Scutellariat Radix mixed with Coptidis Rhizoma. Precipitation was derived from interaction between acidic and basic compounds. This study was based on the interaction between active ingredients after compatibility, strived to explore whether it was feasible to judge the qualities of different Scutellariat Radix by isothermal titration calorimetry (ITC), build a new method established to characterize the qualities of traditional Chinese medicine by taking a series of active ingredients as index. We selected Scutellariat Radix (including three batches of different Scutellariat Radix bought from market and immature Scutellariat Radix which usually was used as adulterant) in different batches as the samples. First, we used ITC to determine the binding heat of the reactions between berberine and the decoctions of different Scutellariat Radix. The test showed that the binding heat of berberine titrated Scutellariat Radix was Scutellariat Radix A (－317.20 μJ), Scutellariat Radix B (－292.83 μJ), Scutellariat Radix C (－208.95 μJ) and immature Scutellariat Radix (－21.53 μJ), respectively. We chose deionized water titrated by berberine (2.51 μJ) as control. The heat change of berberine titrated immature Scutellariat Radix was much less than berberine titrated Scutellariat Radix. Then we determined the absorbance of different decoctions of Scutellariat Radix by UV Spectrophotometry on the maximum absorption wavelength, and the result is： Scutellariat Radix A (0.372), Scutellariat Radix B (0.333), Scutellariat Radix C (0.272), immature Scutellariat Radix (0.124). The absorbance of immature Scutellariat Radix was also less than Scutellariat Radix. The result of ITC assay was corresponded to UV spectrophotometry test. In conclusion, ITC could be used to characterize the quality of Scutellariat Radix. The new method to characterize the qualities of traditional Chinese medicine by taking a kind of active ingredients as index building by ITC was simple, scientific and feasible.

Microbial interactions: ecology in a molecular perspective

ABSTRACT The microorganism-microorganism or microorganism-host interactions are the key strategy to colonize and establish in a variety of different environments. These interactions involve all ecological aspects, including physiochemical changes, metabolite exchange, metabolite conversion, signaling, chemotaxis and genetic exchange resulting in genotype selection. In addition, the establishment in the environment depends on the species diversity, since high functional redundancy in the microbial community increases the competitive ability of the community, decreasing the possibility of an invader to establish in this environment. Therefore, these associations are the result of a co-evolution process that leads to the adaptation and specialization, allowing the occupation of different niches, by reducing biotic and abiotic stress or exchanging growth factors and signaling. Microbial interactions occur by the transference of molecular and genetic information, and many mechanisms can be involved in this exchange, such as secondary metabolites, siderophores, quorum sensing system, biofilm formation, and cellular transduction signaling, among others. The ultimate unit of interaction is the gene expression of each organism in response to an environmental (biotic or abiotic) stimulus, which is responsible for the production of molecules involved in these interactions. Therefore, in the present review, we focused on some molecular mechanisms involved in the microbial interaction, not only in microbial-host interaction, which has been exploited by other reviews, but also in the molecular strategy used by different microorganisms in the environment that can modulate the establishment and structuration of the microbial community.

Microbial interactions: ecology in a molecular perspective

ABSTRACT The microorganism-microorganism or microorganism-host interactions are the key strategy to colonize and establish in a variety of different environments. These interactions involve all ecological aspects, including physiochemical changes, metabolite exchange, metabolite conversion, signaling, chemotaxis and genetic exchange resulting in genotype selection. In addition, the establishment in the environment depends on the species diversity, since high functional redundancy in the microbial community increases the competitive ability of the community, decreasing the possibility of an invader to establish in this environment. Therefore, these associations are the result of a co-evolution process that leads to the adaptation and specialization, allowing the occupation of different niches, by reducing biotic and abiotic stress or exchanging growth factors and signaling. Microbial interactions occur by the transference of molecular and genetic information, and many mechanisms can be involved in this exchange, such as secondary metabolites, siderophores, quorum sensing system, biofilm formation, and cellular transduction signaling, among others. The ultimate unit of interaction is the gene expression of each organism in response to an environmental (biotic or abiotic) stimulus, which is responsible for the production of molecules involved in these interactions. Therefore, in the present review, we focused on some molecular mechanisms involved in the microbial interaction, not only in microbial-host interaction, which has been exploited by other reviews, but also in the molecular strategy used by different microorganisms in the environment that can modulate the establishment and structuration of the microbial community.

Molecular Interaction between the Glucocorticoid Receptor and MAPK Signaling Pathway: A novel link in Modulating the Anti-inflammatory Role of Glucocorticoids.

Glucocorticoids (GCs) have a broad spectrum of life-sustaining functions and play an important role in health and diseases. At pharmacologic doses, GCs are potent immunosuppressive and anti-inflammatory agents. Inflammation and its related diseases present a huge ever increasing burden on the health and disease management. A plausible link of inflammation with aging, cardiovascular diseases and cancer makes matter even worst and calls for a better understanding to resolve the mechanisms associated with the cause and cure of inflammation. Understanding the physiological and molecular interlinks is an utmost importance in designing novel therapeutic strategies in combating inflammation. Advancement in research related to the mitogen-activated protein kinase (MAPK) signaling pathway and its regulation on inflammation has open up new and promising avenues in targeting inflammation as well as understanding the anti-inflammatory property of GCs. Molecular interaction between the ligand-activated glucocorticoid receptor (GR) and the MAPK signaling at different junctions inhibit the latter and thus may account for the anti-inflammatory role of GCs. Therapeutic application of GCs in combination with the recently added class of GR modulators having greater transrepresssion over transactivation (dissociative property) might overcome the clinical side effects associated with GCs.

Model flavoproteins : Interaction of ribofIavin-5'-monophosphate with poly-( α –L-lysine) and poly-( α -L-histidine).

The interactions of flavin mononucleotide (riboflavin-5'-monophosphate) with two polypeptides, poly-(α-L-lysine) and poly-(α-L-histidine) in water and 0.05 Μ phosphate buffer were studied by measuring circular dichroism in the pH range 3 to 11. The interation of flavin mononucleotide with the two polypeptides was due to hydrophobic as well as ionic associations and was further influenced by the involvement of the ribityl side chain. The results of the present study have shown that small changes in the environmental conditions of the interacting molecules could modify their mode of interaction considerably.