2022 is the third year of the global COVID-19 pandemic, and its troubles on new drug discovery are gradually apparent. 37 new drugs were approved by the FDA's Center for Drug Evaluation and Research (CDER) last year, down from the peak of 50 new drug approvals in 2021. Notably, first-in-class drugs still occupy a dominant position this year, with a total of 21 drugs. Among them, 7 are first-in-class small molecule drugs. Although the total number of new drug approvals in 2022 sharply decreased, some first-in-class small molecule drugs were regarded as significant, including mitapivat, the first oral activator targeting the pyruvate kinase (PK); mavacamten, the first selective allosteric inhibitor targeting the myocardial β myosin ATPase; deucravacitinib, the first deuterated allosteric inhibitor targeting the tyrosine kinase 2 (TYK2); and lenacapavir, the first long-acting inhibitor targeting the HIV capsid. Generally, the research of first-in-class drugs needs to focus on difficult clinical problems and can treat some specific diseases through novel targets and biological mechanisms. There are tremendous challenges in the research processes of new drugs, including biological mechanism research, target selection, molecular screening, lead compound identification and druggability optimization. Therefore, the success of first-in-class drugs development has prominent guidance significance for new drug discovery. This review briefly describes the discovery background, research and development process and therapeutic application of 3 first-in-class small molecule drugs to provide research ideas and methods for more first-in-class drugs.

Breast cancer has become the most prevalent malignant tumor among women, putting the health of women at serious risk. Screening for lead compounds in the active ingredients of plant that are effective and less toxic continues to be an important strategy for treating breast cancer. Gerbeloid J, a coumarin isolated from Gerbera piloselloides (L.) Cass., showed significant anti-cancer activity. But there is no report on the effect and mechanism of gerbeloid J on cycle and apoptosis of breast cancer. By using the CCK-8, clone formation, and PI staining assays, the effects of gerbeloid J on the proliferation of MCF-7 and MDA-MB-231 cells were assessed in this study. The effects of gerbeloid J on the apoptosis and mitochondrial function of MCF-7 and MDA-MB-231 cells were assessed using DAPI, Annexin V/TO-PRO-3, Rhod-2 AM, TMRM, DCFDA staining assays, and Western blot. The results demonstrated that gerbeloid J regulated the P21/CDC25C/CDK-1/cyclin B1 pathway and arrested the cell cycle at G2/M phase to suppressed the proliferation of MCF-7 and MDA-MB-231 cells. Additionally, gerbeloid J induced apoptosis through the stimulation of mitochondrial calcium excess, reduction of mitochondrial membrane potential, and promotion of ROS generation, and its mechanism was related to the activation of mitochondrial apoptotic pathway. In conclusion, by regulating the P21/CDC25C/CDK-1/cyclin B1 pathway and activating the mitochondrial apoptosis pathway, gerbeloid J could cause breast cancer cell cycle arrest and apoptosis, which might offer a promising candidate for the creation of new drugs against breast cancer.

With the development of small-molecule immunotherapy drugs, its combination with the programmed cell death ligand 1/programmed cell death protein 1 (PD-L1/PD-1) antibodies would provide a new opportunity for cancer treatment. Therefore, targeting PD-L1/PD-1 axis by small-molecule drug is an attractive approach to enhance antitumor immunity and considered as the next generation of tumor immunotherapy. In the present study, we investigated the anti-tumor role of salvianolic acid B (SAB) by regulating the PD-L1 level in tumors. Changes of total PD-L1 and membrane PD-L1 levels were determined by Western blot, flow cytometry and PD-1/PD-L1 interaction assays. The expression of mRNA level of PD-L1 was detected by real-time PCR. The cytotoxicity of activated peripheral blood mononuclear cell (PBMC) cells toward co-cultured tumor cells was measured by cell impedance assay and crystal violet experiment. Surface plasma resonance technique was used to analyze the direct interaction between SAB and ubiquitin carboxyl-terminal hydrolase 2 (USP2). The antitumor effect of SAB in vivo was examined by C57BL/6 mice bearing MC38 xenograft tumor (all animal experiments were conducted in accordance with the Animal Ethics Committee of the Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences). Western blot and flow cytometry assay showed that SAB can significantly downregulate the abundance of PD-L1 in RKO and PC3 cells in dose- and time-dependent manner. PD-1/PD-L1 binding assay revealed that SAB reduces the binding of tumor cells to recombinant PD-1 protein. Mechanism studies revealed that SAB can bind directly to USP2 protein and inhibit its activity, thus promote the ubiquitin-proteasome pathway degradation of PD-L1 proteins. In addition, Cell impedance and crystal violet staining indicated that SAB enhances the killing activity of co-cultured PBMC cells toward tumor cells. MC38 tumor transplanted mouse experiments revealed that SAB treatment displayed significant suppression in the growth of MC38 tumor xenografts in C57BL/6 mice with an inhibition rate of 63.2% at 20 mg·kg^-1. Our results demonstrate that SAB exerts its anti-tumor activity by direct binding and inhibiting the activity of USP2 and reducing the PD-L1 level. Our study provides an important material basis and scientific basis for the potential application of SAB in tumor immunotherapy drug targeting USP2-PD-L1 axis.

Mannitol-calcium chloride metal organic framework (MOF) cocrystal significantly improved the tabletability of β-mannitol and could be developed as a new tablet filler. However, mannitol monomer was found in the product during the scale-up production of the excipient, which significantly affected the functional properties of the excipient. In this study, we intend to quantify the multi-component eutectic system of mannitol-calcium chloride. In this experiment, the MOF cocrystal excipient mannitol-calcium chloride cocrystal was used as the model compound, and infrared spectrum was collected. Based on partial least squares regression (PLSR) method, the abnormal bands were removed and the spectrum was preprocessed by normalization. The quantitative correction model of mannitol-calcium chloride MOF cocrystal content in cocrystal excipients was established and compared by two different variable screening methods, genetic algorithm (GA) and competitive adaptive reweighting algorithm (CARS). Two different variable screening methods, GA method and CARS method, were used to screen out 160 and 14 variables, respectively. The mannitol-calcium chloride cocrystal model established by CARS-PLSR method had the best performance, and the average relative error (MRE) and corrected root mean square error (RMSEC) of the model were 0.008 8 and 0.892 5, respectively, the determination coefficient (R²) of the model was increased from 0.978 3 to 0.994 4. The quantitative method of eutectic system established in this study has high prediction accuracy, fast detection speed and good stability, which is of great significance for optimizing the preparation process conditions and quality control methods of such eutectic excipients.

The bactericidal mechanism of carbon monoxide (CO) and the feasibility of CO-releasing molecules as anti-infective drugs were summarized by consulting scientific literature, combined with our own research work. Anaerobic bacteria are usually tolerant to high concentration of CO, and some can even grow with CO as sole carbon or energy source, but most pathogenic bacteria are sensitive to CO. In view of the difficulty of gaseous CO in controlling the applying dose and the action site, CO release molecules were synthesized. CO release molecules not only have higher bactericidal activities against common pathogenic bacteria than gaseous CO, but also have the ability to kill antibiotics-resistant bacteria and destroy their biofilms. CO mainly binds with heme-Fe²⁺ in cells, interrupting the electron transfer of respiration chains, which would result in the generation of reactive oxygen species. CO can also disturb intracellular ion balance, which further triggers free radical reactions. Due to its diverse acting targets, uneasy to induce drug resistance, and synergistic effect with other antibiotics, CO is expected to be the next generation of anti-infection drugs.

The aim of this paper is to explore the key anti-fatigue active components in the saponin-like composition of American ginseng. The anti-fatigue activity of western ginseng samples was evaluated using a zebrafish model; metabolomics techniques were used to identify the main saponins in western ginseng from different origins; the active substances and relevant targets of the anti-fatigue effect of western ginseng were initially screened by constructing a PPI protein interaction network between western ginseng saponins and disease targets, and the key active ingredients were screened using a molecular docking method; finally, the anti-fatigue activity of the key active ingredients was evaluated using a zebrafish, animal experiment was approved by the Ethics Committee of Shandong Academy of Medical Sciences (SYXK20220005). The anti-fatigue activity of the key active ingredients was evaluated using a zebrafish model. The results of the zebrafish activity evaluation showed that there were significant differences in the activities of the western ginseng samples from the two origins, and a total of 10 different saponins were identified as possibly related to the anti-fatigue activity after further metabolomic testing and pattern discrimination. The core anti-fatigue targets were screened with the help of component-disease target PPI, combined with pharmacophore-like parameters and molecular docking techniques, and pseudoginsenoside F11 was found to have good binding activity to five of the targets. Finally, the zebrafish model revealed that pseudoginsenoside F11 exhibited significant anti-fatigue activity. This study used metabolomics and zebrafish model to screen the key active substances of pseudoginsenoside F11 for its anti-fatigue activity, which will provide a reference for further research on the anti-fatigue of pseudoginsenosides.

Nine compounds were isolated from the crude extract of the solid culture of endophyte Trichoderma atroviride B7 of Colquhounia coccinea var. mollis by silica gel column chromatography, Sephadex LH-20 gel column chromatography, and HPLC. They were identified as atroviridanol (1), 3-oxo-3-[(2-phenylethyl) amino]-propanoic acid (2), N-(2′-phenylethyl)-acetamide (3), neoechinulin A (4), echinulin (5), gancidin W (6), N-isobutyl-3-methylbutanamide (7), 5-acetamido-1-pentanol (8), and N-2-methylpropyl-2-methylbutenamide (9) by NMR, HR-MS, and so on. Among them, compound 1 is a new compound, and compounds 2-9 are firstly isolated from Trichoderma spp.

This study mainly explores the role of myeloid differentiation primary response protein 88 (MyD88) in tumorigenesis and development, to identify active compounds targeting MyD88. CRISPR/Cas9 system and xenograft tumor model were used to detect the effect of MyD88 deletion on tumor growth, and the experimental animal ethics review number was PZSHUTCM200828006. Microscale thermophoresis technology (MST) was used to identify compounds directly bind to MyD88 and further detect the impact of candidate small molecules on cell proliferation. Results showed that depletion of MyD88 significantly inhibited xenograft tumor growth of colon cancer, pancreatic cancer and skin cancer and the activity of NF-κB signaling pathway. MST showed that nordihydroguaiaretic acid (NDGA) bound to MyD88, with the binding dissociation constant K_d of 14.61 µmol·L^-1. NDGA inhibited NF-κB reporting system activation and phosphorylation of p65, the key factor in NF-κB signal pathway. In addition, the results of colony formation assay showed that NDGA suppressed the proliferation of tumor cells. The above results show that, MyD88 is a potential therapeutic target for colon cancer, pancreatic cancer and skin cancer, NDGA directly binds to MyD88 and inhibits the activity of NF-κB signaling pathway, as well as inhibits the proliferation of pancreatic cancer, skin cancer and colon cancer cells.

With the rapid development of nanotechnology, the research and development of nanomedicines have become one of the development directions of drug innovation. Nanomedicines have special physical and chemical properties, such as nanoscale effects and nanostructure effects, so they have special biological properties, which may change the pharmacokinetic profiles such as absorption and tissue distribution of drug molecules, and thus affect their safety and effectiveness. There are many special concerns on the non-clinical safety evaluation of nanomedicines at the basis of ordinary drug because of the particularity of nanomedicines. On August 25, 2021, China issued Guidance on Non-clinical Safety Evaluation for Nanomedicines(interim). This article interprets comprehensively the guidance, focuses on the key points of non-clinical safety evaluation for nanomedicines, and expounds combined with some cases, aiming to provide reference for drug researchers.

Dihydroflavonol 4-reductase (DFR) plays an essential role in the biosynthesis of anthocyanin and regulation of plant flower color. Based on the transcriptome data of Cistanche tubulosa (Schenk) Wight, a full-length cDNA sequence of CtDFR gene was cloned by reverse transcription-polymerase chain reaction (RT-PCR). CtDFR contains an open reading frame (ORF) of 1 263 bp which encodes 420 amino acids with a predicted molecular weight of 47.5 kDa. The sequence analysis showed that CtDFR contains a nicotinamide adenine dinucleotide phosphate (NADPH) binding domain and a specific substrate binding domain. The expression analysis indicated that CtDFR was highly expressed in red and purple flowers, and the relative expression levels were 4.04 and 19.37 times higher than those of white flowers, respectively. The recombinant CtDFR protein was expressed in E.coli BL21 (DE3) using vector pET-28a-CtDFR and was purified. In vitro enzyme activity analysis, CtDFR could reduce three types of dihydroflavonols including dihydrokaempferol, dihydroquercetin, and dihydromyricetin to leucopelargonidin, leucocyanidin and leucodelphinidin. Subcellular localization analysis showed that CtDFR was mainly localized in the cytoplasm. These results demonstrate that CtDFR plays an important role in regulation of flower color in C. tubulosa and make a valuable contribution for the further investigation on the regulation mechanism of C. tubulosa (Schenk) Wight flower color.