Objective To screen and prepare a broad-spectrum monoclonal antibody against Strep-tococcus pneumoniae ( S. pneumoniae) surface protein A ( PspA) and to evaluate its potential in clinical prac-tice. Methods Hybridoma cells were screened and inoculated into the abdominal cavities of BALB/c mice to prepare antibodies in ascites. Monoclonal antibodies were obtained by ammonium sulfate precipitation and protein A affinity chromatography and then identified by SDS-PAGE and Western blot. Their specificity, iso-forms and killing activities in vitro were analyzed. Results A broad-spectrum monoclonal antibody that rec-ognized PspA subclasses 2, 3 and 4 was obtained. Its in vitro killing rate against S. pneumoniae reached 40. 3％. Conclusions A broad-spectrum monoclonal antibody that could specifically bind to PspA was suc-cessfully prepared with a strong in vitro killing activity. This study provided reference for clinical diagnosis of S. pneumoniae-related diseases, quality assessment of S. pneumoniae vaccines and further research on mono-clonal antibody therapeutics.

We reported the discovery of six novel coumarins, toddasirins A-F (1-6), each endowed with modified isoprenyl or geranyl side chains, derived from the roots of Toddalia asiatica. Comprehensive structural elucidation was achieved through multispectroscopic analyses, single-crystal X-ray diffraction experiments, and advanced quantum mechanical electronic circular dichroism (ECD) calculations. Furthermore, the anti-inflammatory activity of these compounds was assessed. Notably, compounds 1-3 and 6 demonstrated notable inhibitory effects on nitric oxide (NO) production in lipopolysaccharide (LPS)-induced RAW 264.7 cells, with 50% inhibitory concentration (IC₅₀) values of 3.22, 4.78, 8.90, and 4.31 μmol·L^-1, respectively.
Mice ; Animals ; Coumarins/chemistry* ; Rutaceae/chemistry* ; Anti-Inflammatory Agents/pharmacology* ; Plant Extracts/chemistry* ; RAW 264.7 Cells ; Nitric Oxide ; Molecular Structure