To investigate the mechanism of compound AG-881 on inhibiting IDH1R132H mutant protein by molecular dynamics method.

The activated IDH1R132H protein structure and inactivated AG-881-IDH1R132H protein structure were constructed respectively and placed in a stereoscopic box. Molecular dynamics simulations were carried out on each system for 100 ns. The protein conformations of different systems were compared, and hydrogen bond analysis, energy analysis and principal component analysis (PCA), etc. were performed.

Substrate α-KG could stabilize IDH1R132H protein in the activated closed conformation. After AG-881 acted on the allosteric site of the protein at dimer interface, it made IDH1R132H in the open conformation of inactive state. In this process, amino acid residue Gln277 participated into the binding of AG-881. At the same time, hydrophobic occupation and hydrogen bond contributed mainly to the binding of AG-881 to IDH1R132H. In addition, halogen bond also played a certain role.

Molecular dynamics simulation can be used as an effective aid for allosteric inhibitor design, and the potential mechanism of AG-881 inhibiting IDH1R132H activity can be studied, which can further provide theoretical guidance for the development of new drugs targeting IDH1 mutant proteins.

To explore the neuroprotective effect of acteoside (ACT) on mouse model of MPTP-induced Parkinson's disease (PD) and its mechanism.

The PD mouse model was established by intraperitoneal injection of MPTP. The experimental mice were randomly divided into control group, model group and ACT group (100 mg·kg^-1), which were administrated by gavage for 14 d. After administration, behavioral evaluation and biochemical detection were performed to evaluate the neuroprotective effect of ACT on PD mice. Two-dimensional electrophoresis, mass spectrometry and Western blot were used to further explore the anti-PD mechanism of ACT.

After prophylactic administration of ACT, the pole climbing time of MPTP-induced PD mice was significantly shortened, swimming test score was improved, suspension duration was prolonged, and hind limb tension test score and cylinder test score were decreased. ACT could effectively improve the activities of SOD, CAT, and GSH-Px in the substantia nigra and striatum of MPTP-induced PD mice and reduce the content of MDA. The results of two-dimensional electrophoresis and Western blot showed that the expression of biliverdin reductase B (BLVRB) increased in the substantia nigra and striatum of PD mice induced by MPTP, while the expression of BLVRB decreased significantly after the administration of ACT.

ACT has neuroprotective effect on MPTP-induced PD mice, and its underlying mechanism may be related to the decrease of BLVRB expression and anti-oxidative stress of ACT.

To investigate the antibacterial effect of acetylkitasamycin dry suspension on Mycoplasma pneumoniae (MP) in vitro.

51 clinical isolates and 2 standard strains of MP from patients with respiratory tract infection stored in our laboratory from 2016 to 2019 were randomly selected for the research. Taking azithromycin and erythromycin as control drugs, the minimum inhibitory concentration (MIC) of acetylkitasamycin dry suspension against MP was determined using broth microdilution method.

Of all the 51 clinical isolates, there were 43 drug-resistant strains that contained the point mutations A2063G in V region of 23S rRNA domain, and there were 8 susceptible strains which had no mutations related to drug resistance. The MIC values of the acetyljithamycin dry suspension were 0.125 mg·L^-1 for the standard MP strains FH and M129; for the clinically resistant MP strains, the MIC was 8~32 mg·L^-1, the MIC₅₀ was 16 mg·L^-1, and the MIC₉₀ was 32 mg·L^-1; for clinically sensitive MP strains, the MIC was 0.063~0.125 mg·L^-1, and both MIC₅₀ and MIC₉₀ were 0.125 mg·L^-1. Erythromycin had a MIC range of 256~1 024 mg·L^-1 for clinically resistant MP strains, the MIC₅₀ was 512 mg·L^-1, and the MIC₉₀ was 1 024 mg·L^-1; azithromycin had a MIC range of 64~512 mg·L^-1 for clinically resistant MP strains, the MIC₅₀ was 256 mg·L^-1, and the MIC₉₀ was 512 mg·L^-1. The MIC values of erythromycin and azithromycin for clinically sensitive MP strains were <0.5 mg·L^-1.

MP showed different degrees of resistance to macrolide antibiotics. Acetylkitasamycin dry suspension had good bacteriostatic activity against sensitive MP strains in vitro, and the MIC value against resistant MP strains was low, and the clinical effect on MP infection need to be further studied.

To establish a method for determination of polymer impurities in penicillin sodium for injection.

Penicillin sodium was dissolved by water to prepare penicillin polymer stock solution. High performance size exclusion chromatography method (HPSEC) and column switching-LC/MSn method were used to separate and deduce the weak retention impurities in polymer impurity solution and the specificity of HPSEC method was evaluated. A RP-HPLC method for polymer analysis was established with a C₁₈ column, using gradient elution by the mixed solution [phosphate buffer solution (pH 3.4)-methanol (72∶14)] and acetonitrile, and the RP-HPLC method was validated.

4 polymers, their isomers, one dimer degradation and some small molecular impurities were identified in the polymer impurity solution. Polymer impurities were liable to be co-eluted with small molecular impurities by HPSEC method, which resulted in poor quantification accuracy and specificity. 3 indicative polymer impurities were detected by RP-HPLC method with effective specificity, including 2 dimers produced by different polymerized patterns.

HPSEC cannot effectively control the polymer impurities of penicillin sodium for injection. The established RP-HPLC method has good specificity and high sensitivity for the determination of impurities in penicillin sodium polymer for injection.

To improve the quality standards of Mongolian medicine Shashen Zhike Decoction Powder.

TLC method was used to establish the identification of Bistortae Rhizoma and Shikonin, and the identification of Glycyrrhizae Radix et Rhizoma was revised. The content determination of glycyrrhizic acid was established by reversed phase HPLC.

The TLC identification methods resulted in clear spots of Bistortae Rhizoma, Shikonin and Glycyrrhizae Radix Et Rhizoma, without interference for the negative control. Glycyrrhizic acid had good linear relationship in the range from 92.90 to 1 161.25 ng (r=0.999 9). The average recovery was 102.57%, and the RSD was 1.85% (n=9).

The method is simple, specific, stable and repeatable, and can be used for the quality evaluation and control of Shashen Zhike Decoction Powder.

To evaluate and compare the safety and efficacy of microecological live bacteria preparations Lactasin (Lactasin strain) and Biofermin (Biofermin strain) production strains at the genome level using high-throughput sequencing and bioinformatics technology, thus to provide basis for the quality research and consistency evaluation of strains used in the production of ecological live bacteria products.

Combined with a personalized database, DIAMOND retrieval strategy was used to find target genes and analyze their functions through sequence comparison.

The strains used for Lactasin and Biofermin production were both Enterococcus faecium. The genomes of the 2 strains had good collinearity, but a few of genes had rearrangements such as insertions, deletions, inversions, and translocations. The safety of the Biofermin strain was similar to the Lactasin strain in 6 aspects, including virulence genes, drug resistance genes, bacteriocin genes, biogenic amine genes, prophages and mobile genetic elements. In the evaluation of probiotic function of stress response genes, antimicrobial/antagonistic activity, antioxidant activity genes and adhesion genes, Biofermin strain was better than Lactasin strains.

In this paper, a quality evaluation method of strains for the production of microecological live bacteria products was initially established based on specific gene function analysis, and the quality research and quality evaluation system were also improved and perfected for microecological live bacteria products.