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.

Exploration on rationality evaluation approach of drug combination medication based on sequential analysis and machine learning / 中国中药杂志

Drug combination is a common clinical phenomenon. However, the scientific implementation of drug combination is li-mited by the weak rational evaluation that reflects its clinical characteristics. In order to break through the limitations of existing evaluation tools, examining drug-to-drug and drug-to-target action characteristics is proposed from the physical, chemical and biological perspectives, combining clinical multicenter case resources, domestic and international drug interaction public facilities with the aim of discovering the common rules of drug combination. Machine learning technology is employed to build a system for evaluating and predicting the rationality of clinical drug combinations based on "drug characteristics-repository information-artificial intelligence" strategy, which will be debugged and validated in multi-center clinical practice, with a view to providing new ideas and technical references for the safety and efficacy of clinical drug use.

Antibacterial constituents from Melodinus suaveolens / 中国天然药物

To investigate the non-alkaloidal chemical constituents of the stems and leaves of Melodinus suaveolens and their antibacterial activities. Compounds were isolated and purified by repeated silica gel, Sephadex LH-20, RP18, and preparative HPLC. Their structures were elucidated by comparison with published spectroscopic data, as well as on the basis of extensive spectroscopic analysis. The antibacterial screening assays were performed by the dilution method. Fourteen compounds were isolated, and identified as lycopersene (1), betulinic aldehyde (2), 3β-acetoxy-22,23,24,25,26,27-hexanordammaran-20-one (3), 3a-acetyl-2, 3, 5-trimethyl-7a-hydroxy-5-(4,8,12-trimethyl-tridecanyl)-1,3a,5,6,7,7a-hexahydro-4-oxainden-1-one (4), 3β-hydroxy-28-norlup-20(29)-ene-17β-hydroperoxide (5), 3β-hydroxy-28-norlup-20(29)-ene-17α-hydroperoxide (6), β-sitosterol (7), 28-nor-urs-12-ene-3β, 17β-diol (8), α-amyrin (9), ergosta-4,6,8(14),22-tetraen-3-one (10), 3β-hydroxy-urs-11-en-28,13β-olide (11), betulin (12), obtusalin (13), and ursolic acid (14). Among the isolates, compounds 1, 2, 6, 8, 10, and 14 showed potent antibacterial activities against the four bacteria. This is the first report of the antibacterial activity of the constituents of Melodinus suaveolens.

Chemical constituents from stems and leaves of Cryptolepis buchananii / 中草药

Objective: To study the chemical constituents from the stems and leaves of Cryptolepis buchananii. Methods: Compounds were isolated and purified by chromatography on silica gel, Sephadex LH-20, ODS columns, and preparative HPLC. Their structures were identified by NMR and MS, as well as comparison on spectral data with literature values. Results: Thirteen compounds were obtained from the EtOAc fraction of methanol extract in the stems and leaves of C. buchananii and their structures were elucidated as isoscopoletin (1), (+)-3-hydroxy-β-ionone (2), (3R, 6R, 7E)-3-hydroxy-4, 7-megastigmadien-9-one (3), ficusic acid (4), (+)-pinoresinol (5), (+)-8-hydroxypinoresinol (6), (+)-syringaresinol (7), diaaurantiamide acetate (8), loliolide (9), (-)-balanophonin (10), chrysoeriol (11), 9-hydroxy-10E, 12Z-octadecadienoic acid methyl ester (12), and ficusesquilignan A (13). Conclusion: All the compounds are isolated from the plants of Cryptolepis R. Br. for the first time.