Virtual Screening, Molecular Dynamics Simulation, and Bioactivity Assessment Validate T13074 as a Dual-Target EGFR/c-Met Inhibitor.

OBJECTIVES: The objective of this study is to identify dual-target inhibitors against EGFR/c-Met through virtual screening, dynamic simulation, and biological activity evaluation. This endeavor is aimed at overcoming the challenge of drug resistance induced by L858R/T790M mutants. METHODS: Active structures were gathered to construct sets of drug molecules. Next, property filtering was applied to the drug structures within the compound library. Active compounds were then identified through virtual screening and cluster analysis. Subsequently, we conducted MTT antitumor activity evaluation and kinase inhibition assays for the active compounds to identify the most promising candidates. Furthermore, AO staining and JC-1 assays were performed on the selected compounds. Ultimately, the preferred compounds underwent molecular docking and molecular dynamics simulation with the EGFR and c-Met proteins, respectively. RESULT: The IC50 of T13074 was determined as 2.446 µM for EGFRL858R/T790M kinase and 7.401 nM for c-Met kinase, underscoring its potential in overcoming EGFRL858R/T790M resistance. Additionally, T13074 exhibited an IC50 of 1.93 µM on the H1975 cell. Results from AO staining and JC-1 assays indicated that T13074 induced tumor cell apoptosis in a concentration-dependent manner. Notably, the binding energy between T13074 and EGFR protein was found to be -90.329 ± 16.680 kJ/mol, while the binding energy with c-Met protein was -139.935 ± 17.414 kJ/mol. CONCLUSION: T13074 exhibited outstanding antitumor activity both in vivo and in vitro, indicating its potential utility as a dual-target EGFR/c-Met inhibitor. This suggests its promising role in overcoming EGFR resistance induced by the L858R/T790M mutation.

Expression, purification, and biological activity evaluation of cathepsin L in mammalian cells.

Cathepsin L (CTSL) could cleave and activate SARS-CoV-2 Spike protein to promote viral entry, making it a hopeful therapeutic target for COVID-19 prevention and treatment. So CTSL inhibitors are considered to be a promising strategy to SARS-CoV-2 infection. CTSL has previously been expressed in inclusion body in Escherichia coli. In order to prepare CTSL with high purity and activity in soluble active form, we transformed HEK-293T cells with a recombinant mammalian expression plasmid. CTSL was purified to a purity about 95%, found to migrate at approximately 43 kDa and exhibited substrate specificity against Z-Phe-Arg-AMC with specific activity of no less than 85 081 U/mg, characteristic of active CTSL. Although eukaryotic purified CTSL is commercially available, our study for the first time reported the details of the expression, purification, and characterization of active, recombinant CTSL in eukaryocyte system, which laid an experimental foundation for the establishment of high-throughput screening model for anti-coronavirus drugs targeting CTSL.

Discovery a series of novel inhibitors of human dihydroorotate dehydrogenase: Biological activity evaluation and molecular docking.

Human dihydroorotate dehydrogenase (hDHODH) is a key enzyme that catalyzes the de novo synthesis of pyrimidine. In recent years, various studies have shown that inhibiting this enzyme can treat autoimmune diseases such as rheumatoid arthritis (RA) and cancer. This study designed and synthesized a series of novel thiazolidone hDHODH inhibitors. Through biological activity evaluation, Compound 14 was found to have high inhibitory activity, with an IC50 value reaching nanomolar level. Preliminary structure-activity relationship studies found that the carboxyl group in R1 and the naphthalene in R2 are key factors in improving activity. Through molecular docking, the binding mode between inhibitors and proteins was elucidated. This study provides an important reference for further optimizing hDHODH inhibitors.

Synthesis and biological evaluation of novel pteridin-7(8H)-one derivatives as potent CDK2 inhibitors.

Cyclin-dependent kinase 2 (CDK2) is considered as an important target in the research of antitumor drugs. Taking the CDK2/4/6 inhibitor Ebvaciclib as the positive control and an in-house library compound (23) as the lead compound, three classes of 30 target compounds with pteridin-7(8H)-one as the core structure were designed to establish structure-activity relationships (SAR). In general, SAR of pteridin-7(8H)-one CDK2 inhibitors is systematically described in this paper, resulting in the discovery of two compounds (KII-17 and KII-21) with further research value. After the above compounds were tested for CDK2/4/6 kinase selectivity, we found that compound KII-21 was about 3 and 4 times more selective to CDK2-cyclinE2 than CDK4-cyclinD1 and CDK6-cyclinD3, respectively. This work also provides a reference basis for the subsequent research on CDK2 inhibitors.

Synthesis and Evaluation of 2-Amine-4-oxyphosaniline Pyrimidine Derivatives as EGFR L858R/T790M/C797S Mutant Inhibitors.

Epidermal growth factor receptor (EGFR) C797S mutation leads to Osimertinib drug resistance by disturbing the covalent biding of Michael acceptor group to the Cys797 residue in the ATP biding cleft. In this manuscript, a class of 2-amine-4-oxyphosaniline pyrimidine derivatives were designed, synthesized and evaluated as new noncovalent reversible EGFR inhibitors against L858R/T790M/C797S (CTL) triple mutant. The kinases inhibitiory activity evaluation showed that four compounds exhibited significant inhibitory activities against CTL (IC50 < 30 nM). In particularly, the most promising compound 7a showed excellent enzymatic inhibitory activity against CTL with IC50 value of 9.9 nM, which was more potent than control compound Osimertinib. Moreover, cell proliferation assays indicated that 7a effectively inhibited H1975-EGFR L858R/T790M/C797S with IC50 value of 0.33 µM. Furthermore, compound 7a displayed good metabolic stabilities in human, rat and mouse liver microsomes, and the putative biding mode of compound 7a with ATP was revealed by molecular docking study. These findings strongly indicated that compound 7a was a promising L858R/T790M/C797S mutant EGFR inhibitor.

[Comprehensive evaluation system for quality of Chinese medicinal decoction pieces based on "experience-ingredients-activity-electronic sensing"].

Quality evaluation of Chinese medicinal decoction pieces is vital for the development of the downstream industries, and is an important channel for implementing the strategy of "higher quality, higher price, and priority for the high quality" for traditional Chinese medicine. At the moment, the quality of Chinese medicinal decoction pieces is mainly evaluated based on chemical component examination. Considering the weak preliminary research foundation and poor research conditions, traditional experience-based evaluation is undervalued in the quality rating of Chinese medicinal decoction pieces. However, traditional experience is a summary of the quality of Chinese medicinal materials based on clinical experience, which thus can be a potential basis for the quality evaluation of the decoction pieces. It is a challenge in the evaluation of Chinese medicinal decoction pieces to objectify the traditional experience-based evaluation from multiple aspects such as chemistry, effect, and characterization via modern techniques. Therefore, this study developed the "experience-ingredients-activity-electronic sensing" evaluation system for Chinese medicinal decoction pieces on the basis of experience-based assessment, chemical ingredients that can truly reflect the traditional experience, biological effect assessment, and electronic sensory evaluation, which is expected to quantify the traditional experience of quality evaluation of Chinese medicinal decoction pieces via chemistry, biology, and sensory simulation. The evaluation system can serve as a reference for clinical experience-based quality evaluation of Chinese medicinal decoction pieces.

Comprehensive evaluation system for quality of Chinese medicinal decoction pieces based on "experience-ingredients-activity-electronic sensing" / 中国中药杂志

Quality evaluation of Chinese medicinal decoction pieces is vital for the development of the downstream industries, and is an important channel for implementing the strategy of "higher quality, higher price, and priority for the high quality" for traditional Chinese medicine. At the moment, the quality of Chinese medicinal decoction pieces is mainly evaluated based on chemical component examination. Considering the weak preliminary research foundation and poor research conditions, traditional experience-based evaluation is undervalued in the quality rating of Chinese medicinal decoction pieces. However, traditional experience is a summary of the quality of Chinese medicinal materials based on clinical experience, which thus can be a potential basis for the quality evaluation of the decoction pieces. It is a challenge in the evaluation of Chinese medicinal decoction pieces to objectify the traditional experience-based evaluation from multiple aspects such as chemistry, effect, and characterization via modern techniques. Therefore, this study developed the "experience-ingredients-activity-electronic sensing" evaluation system for Chinese medicinal decoction pieces on the basis of experience-based assessment, chemical ingredients that can truly reflect the traditional experience, biological effect assessment, and electronic sensory evaluation, which is expected to quantify the traditional experience of quality evaluation of Chinese medicinal decoction pieces via chemistry, biology, and sensory simulation. The evaluation system can serve as a reference for clinical experience-based quality evaluation of Chinese medicinal decoction pieces.

Design, Synthesis and Biological Evaluation of the Quinazoline Derivatives as L858R/T790M/C797S Triple Mutant Epidermal Growth Factor Receptor Tyrosine Kinase Inhibitors.

Inhibition of the epidermal growth factor receptor (EGFR) has been proved to be one of the most promising strategies for the treatment of non-small cell lung cancers. A series of 2-aryl-4-amino substituted quinazoline derivatives were designed and synthesized with the purpose to overcome L858R/T790M/C797S (CTL) triple mutant drug resistance and the biological activity for inhibition of CTL kinases and EGFR wild type (WT) were evaluated. Three compounds (20, 24 and 27) showed excellent inhibitory activities against EGFR kinases triple mutant CTL (IC50 < 1 µM) and high selectivity (IC50: WT/CTL >10000). Cell line evaluation showed that the most potent compound 27 was significantly potent against H1975-EGFR L858R/T790M (IC50 = 3.3 µM) and H1975-EGFR L858R/T790M/C797S (IC50 = 1.2 µM). Compound 27 also exhibited good microsomes stabilities in human, rat and mouse liver species, but low bioavailability. This work would be very useful for discovering new quinazoline derivatives as tyrosine kinase inhibitors targeting triple mutant L858R/T790M/C797S.

Establishment of Jinzepaishi Granules fingerprint and evaluation of its anti-inflammatory activity for cyclooxygenase-2 / 中草药

Objective To establish HPLC fingerprints of Jinzepaishi Granules from ten different batches and a preliminary method for its anti-inflammatory biological activity titer detection, and construct a dose-effect relationship between cyclooxygenase-2 (COX-2) and Jinzepaishi Granules for scientific evaluation and effective control of granules quality. Methods The HPLC method was used to analyze the similarity of common peaks in different batches of granules and assigned 19 common peaks to herbs. The fingerprints were further analyzed by the chemometric method of hierarchical clustering analysis and principal component analysis (PCA). The EIA method was used to determine the half-inhibitory concentration (IC50) of Jinzepaishi Granules. Results The similarity of HPLC fingerprints of all the ten batches was ≥ 0.955, which were consistent with the results of cluster analysis and PCA. Jinzepaishi Granules had a significant inhibitory effects on COX-2 with a IC50 of 10.272 mg/mL, which demonstrated a significant dose-effect relationship. Conclusion The multiple quality control system of chemical fingerprinting and biological activity detection has the characteristics of high efficiency, rapidness, accuracy, sensitivity, and good reproducibility. It can effectively evaluate the anti-inflammatory biological activity of Jinzepaishi Granules and achieve more scientific and reasonable control of its quality. It also provides a reference for the establishment of more scientific quality control for other Chinese materia medica preparations.

Evaluation and screening for biological activity of components in Chinese materia medica / 中草药

Biological activity evaluation of Chinese materia medica (CMM) composition is one of the main means to explore the active components of CMM. This paper, from the three aspects of whole animal, cellular, and molecular, discusses systematically the technical progress in this area over the past 10 years and the screening of new active ingredients from CMM and monomer compounds based on new technology. At the same time, the different technical strengths and weaknesses have been analyzed in the hope of providing the information and ideas for the research on the new drugs of CMM.