Screening of Antimicrobial Ingredients in Forsythia Leaves Using Target Constituent Knock-out/Knock-in Strategy and Evaluation of the Combination Effects with Antibiotics

To screen and identify the antimicrobial ingredients of Forsythia suspensa leaves (FL). A screening method based on a constituent knock-out/knock-in strategy was conducted. The antimicrobial activities of FL components against seven commonly infective strains were determined using the Oxford cup method. Their antimicrobial effects when used in combination with common antibiotics were investigated by a checkerboard titration method. Two of the seven strains, Staphylococcus aureus and methicillin-resistant S. aureus (MRSA), were considered to be the most sensitive to the inhibitory effect of FL. The main antimicrobial components in FL were forsythoside I and forsythoside A. The co-administration of vancomycin with forsythoside A was found to have a significant synergistic inhibiting effect on MRSA. Some phenylethanol glycoside components play a major contribution to the antimicrobial effect of FL. This provides a reference for the research and development of FL for both medicinal and food purposes.

Quality control strategies of medicine food homology materials based on fingerprint profiling and chemometrics: Citri Reticulata Pericarpium as an example

The study aimed to provide a reliable and feasible strategy for the comprehensive quality control of medicine food homology materials (MFHM). The high performance liquid chromatography (HPLC) fingerprints and Fourier transform mid-infrared (FT-MIR) quantized fingerprints were successfully developed to comprehensively evaluate overall quality of Citri Reticulata Pericarpium (CRP) by applying comprehensive quantified fingerprint method (CQFM). All samples were well distinguished and divided into 5 grades. In addition, through principal component analysis (PCA) and partial least squares discriminant analysis (PLS-DA), the identification ability of HPLC fingerprints and FT-MIR fingerprints on CRP with different storage years was discussed. The results showed that HPLC fingerprints combined with PCA had good discrimination ability, and the PLS-DA model established by the preprocessed FT-MIR fingerprint data could accurately distinguish and predict the storage period of CRP. Finally, based on 1, 1-diphenyl-2-picrylhydrazyl radical (DPPH•) scavenging assay, combined with bivariate correlation analysis, the fingerprint-activity relationship of offline antioxidant activity of CRP samples with the fingerprints peak were studied. In general, the comprehensive strategies provide a reliable and scientific reference scheme for the quality control of MFHM in the future.

Quality grade evaluation and related antioxidant activity research of different medicinal parts of Catalpa fruit

Catalpa fruit is a traditional Chinese medicine used in the treatment of diuresis and detumescence; however one-sided quantitative or qualitative investigation limits its overall quality evaluation. Hence, this study proposed to qualitatively and quantitatively evaluate the quality consistency of Catalpa fruit from the perspectives of chromatography and spectroscopy. First, the fusion fingerprints of 15 batches of Catalpa fruit pericarp and 15 batches of Catalpa fruit seed were established by high performance liquid chromatography (HPLC) and ultraviolet (UV) spectroscopy in equal weights, respectively, to avoid the unilaterality of a single analytical technique. The different medicinal parts of Catalpa fruit were graded and evaluated based on a systematically quantified fingerprint method, and the quality of the pericarp and seed was further investigated. The results revealed that the quality of most pericarp and seed samples was within the acceptable level range (grade ≤ 5), and that seed quality was clearly superior to pericarp quality. Furthermore, according to the research findings, the content of p-hydroxybenzoic acid in Catalpa fruit pericarp was generally higher than that in Catalpa fruit seed, while the content of catalposide was generally lower than that in Catalpa fruit seed. Additionally, the fingerprint-efficacy relationship with HPLC was discussed by binary correlation analysis, which indicated that catalposide had the strongest antioxidant activity. This study demonstrated that the analytical techniques based on chromatographic fingerprinting, spectral fingerprinting and antioxidant activity provided new theoretical foundation as well as technical guidance for Catalpa fruit quality control and rational utilization.