RPTOR mutation: a novel predictor of efficacious immunotherapy in melanoma.

Identifying biomarkers to evaluate the therapeutic effect of immune checkpoint inhibitors (ICIs) is crucial. Regulatory Associated Protein of MTOR Complex 1 (RPTOR), one of the genes in the mTOR pathway, plays a role in regulating tumor progression. However, the connection between RPTOR mutation and the efficacy of ICIs in melanoma remains unclear. The data of ICIs-treated melanoma patients in discovery (n = 384) and validation (n = 320) cohorts were obtained from cBioPortal databases. The genomic data in the two cohorts was used to investigate the connection between RPTOR mutation and immunotherapy efficacy. The underlying mechanisms were explored based on data from the The Cancer Genome Atlas (TCGA)-skin cutaneous melanoma (SKCM) cohort. Compared to melanoma patients with RPTOR wildtype (RPTOR-WT), RPTOR-mutation (RPTOR-Mut) patients achieved prolonged overall survival (OS) in both discovery cohort (median OS of 49.3 months vs. 21.7 months; HR = 0.41, 95% CI: 0.18-0.92; P = 0.026) and validation cohorts (not reached vs. 42.0 months; HR = 0.34, 95% CI: 0.11-1.06; P = 0.049). RPTOR-Mut melanoma patients exhibited a higher objective response rate (ORR) than RPTOR-WT patients in the discovery cohort (55.0% vs. 29.0%, P = 0.022). RPTOR-Mut patients exhibited higher TMB than RPTOR-WT patients in both discovery and validation cohorts (P < 0.001). RPTOR-Mut melanoma patients had an increased number of DNA damage response (DDR) mutations in TCGA-SKCM cohort. Immune cell infiltration analysis suggested that activated CD4 memory T cells were more enriched in RPTOR-Mut tumors. RPTOR-Mut melanoma patients had higher expression levels of immune-related genes than the RPTOR-WT patients. Our results suggest that RPTOR mutation could serve as a predictor of effective immunotherapy for melanoma.

Diastereoselective Synthesis of Dihydrobenzofuran-Fused Spiroindolizidines via Double-Dearomative [3 + 2] Cycloadditions.

Spiroindolizidine oxindoles represent a kind of privileged scaffold in many biologically active natural alkaloids. 2,3-Dihydrobenzofuran derivatives exhibit significant bioactivities in a variety of pharmaceuticals. Herein, we assembled these two privileged fragments into a small molecule via double-dearomative [3 + 2] cycloadditions with pyridinium ylides and 2-nitrobenzofurans. This protocol features remarkable advantages including wide substrate scope, mild condition, high level of diastereoselectivities and yields. Thus, a collection of spiroindolizidine-fused dihydrobenzofurans/indolines were facilely produced efficiently.

A NIR fluorescent probe for dual imaging of mitochondrial viscosity and FA in living cells and zebrafish.

Formaldehyde (FA) and viscosity play multiple roles in human health and diseases, and viscosity has great regional differences due to the diversity of subcellular organelles. However, it is challenging to achieve dual detection of viscosity and FA in subcellular organelles. Herein, we developed a near infrared (NIR) fluorescent probe FA-Cy, which can simultaneously monitor the viscosity and FA concentration of mitochondria in living cells. The probe could detect mitochondrial viscosity and exogenous and endogenous FA in living cells and zebrafish.

A lysosome-targeting fluorescent probe to visualize endogenous and exogenous methylglyoxal in live cells and zebrafish.

The development of a lysosome-targeting fluorescent probe to visualize endogenous and exogenous methylglyoxal (MGO) in live cells has important implications for associated diseases. Herein, a lysosome-targeting fluorescent probe MGO-Naph-A was designed and synthesized to detect MGO with high selectivity. The probe contained naphthalimide as the fluorescent group, o-phenylenediamine as the MGO recognition group, and morpholine as the lysosome targeting group. This fluorescent probe could detect endogenous and exogenous MGO in living cells by precisely targeting and staining lysosomes. It could also detect MGO in living zebrafish. The results showed that the probe MGO-Naph-A has the potential to visualize MGO in lysosomes.

Design, Synthesis, and Biological Evaluation of New 1H-Imidazole-2-Carboxylic Acid Derivatives as Metallo-ß-Lactamase Inhibitors.

As one of important mechanisms to ß-lactam antimicrobial resistance, metallo-ß-lactamases (MBLs) have been receiving increasing worldwide attentions. Ambler subclass B1 MBLs are most clinically relevant, because they can hydrolyze almost all ß-lactams with the exception of monobactams. However, it is still lacking of clinically useful drugs to combat MBL-medicated resistance. We previously identified 1H-imidazole-2-carboxylic acid as a core metal-binding pharmacophore (MBP) to target multiple B1 MBLs. Herein, we report structural optimization of 1H-imidazole-2-carboxylic acid and substituents. Structure-activity relationship (SAR) analyses revealed that replacement of 1H-imidazole-2-carboxylic acid with other structurally highly similar MBPs excepting thiazole-4-carboxylic acid resulted in decreased MBL inhibition. Further SAR studies identified more potent inhibitors to MBLs, of which 28 manifested IC50 values of 0.018 µM for both VIM-2 and VIM-5. The microbiological tests demonstrated that the most tested compounds showed improved synergistic effects; some compounds at 1 µg/ml were able to reduce meropenem MIC by at least 16-fold, which will be worth further development of new potent inhibitors particularly targeting VIM-type MBLs.

One-Pot Route from Halogenated Amides to Piperidines and Pyrrolidines.

Piperidine and pyrrolidine derivatives are important nitrogen heterocyclic structures with a wide range of biological activities. However, reported methods for their construction often face problems of requiring the use of expensive metal catalysts, highly toxic reaction reagents or hazardous reaction conditions. Herein, an efficient route from halogenated amides to piperidines and pyrrolidines was disclosed. In this method, amide activation, reduction of nitrile ions, and intramolecular nucleophilic substitution were integrated in a one-pot reaction. The reaction conditions were mild and no metal catalysts were used. The synthesis of a variety of N-substituted and some C-substituted piperidines and pyrrolidines became convenient, and good yields were obtained.

Continuous-Flow Synthesis of Nitro-o-xylenes: Process Optimization, Impurity Study and Extension to Analogues.

An efficient continuous-flow nitration process of o-xylene at pilot scale was demonstrated. The effects of parameters such as temperature, ratio of H2SO4 to HNO3, H2SO4 concentration, flow rate, and residence time on the reaction were studied. Under the optimal conditions, the yield of products reached 94.1%, with a product throughput of 800 g/h. The main impurities of this continuous-flow nitration process were also studied in detail. Compared with batch process, phenolic impurity decreased from 2% to 0.1%, which enabled the omission of the alkaline solution washing step and thus reduced the wastewater emission. The method was also successfully applied to the nitrification of p-xylene, toluene, and chlorobenzene with good yields.

Synthesis of osthol-based botanical fungicides and their antifungal application in crop protection.

Plant pathogenic fungi decrease the quality and productivity of plant production. The botanical fungicides have better biocompatibility and rapid biodegradation, little or no cross resistance, and the structural diversity, and thus are beneficial to deal with plant fungal diseases. Osthole has been widely used as the commercial botanical fungicide against powdery mildew in China. In this article, a series of osthole derivatives were synthesized, which respectively contain different substituents on the benzene ring, at the C8-position and pyrone ring. All the target compounds were evaluated in vitro for their antifungal activity against resistant phytopathogenic fungi. Colletotrichum fragariae, Strawberry Botrytis Cinerea, Kiwifruit Botrytis Cinerea, Kiwifruit brown Rots, which are common in fruit fungal diseases. The compound C4 was identified as the most promising candidate with the EC50 values at 38.7 µg/mL against Colletotrichum Fragariae, 14.5 µg/mL against Strawberry Botrytis Cinerea and 24.3 µg/mL against Kiwifruit Botrytis Cinerea, respectively, whereas the antifungal activity against resistant phytopathogenic fungi. of osthole is too low to be used (EC50 > 400 ppm). The results of mycelial relative conductivity determination, PI uptake and fluorescence spectroscopy indicated that the cell membrane of fungi is the key action site of C4. Besides, C4 has the potent inhibitory activity against both of plant and human pathogenic bacteria. Our studies showed that C4 was worthy for further attention as a promising botanical fungicide candidate in crop protection.

Synthesis, biological activities and docking studies of pleuromutilin derivatives with piperazinyl urea linkage.

Antibiotics resistance is becoming increasingly common, involving almost all antibiotics on the market. Diseases caused by drug resistant bacteria, such as MRSA, have high mortality and negatively affect public health. The development of new drugs would be an effective means of solving this problem. Modifications based on bioactive natural products could greatly shorten drug development time and improve success rate. Pleuromutilin, a natural product from the basidiomycete bacterial species, is a promising antibiotic candidate. In this study, a series of novel pleuromutilin derivatives possessing piperazinyl urea linkage were efficiently synthesised, and their antibacterial activities and bactericidal properties were evaluated via MIC, MBC and Time-kill kinetics assays. The results showed that all compounds exhibited potent activities against tested strains, especially MRSA strains with MIC values as low as 0.125 µg/mL; 8 times lower than that of marketed antibiotic Tiamulin. Docking studies indicate substituted piperazinyl urea derivatives could provide hydrogen bonds and initiate π-π stacking between molecules and surrounding residues.

Design and synthesis of tricyclic terpenoid derivatives as novel PTP1B inhibitors with improved pharmacological property and in vivo antihyperglycaemic efficacy.

Overexpression of protein tyrosine phosphatase 1B (PTP1B) induces insulin resistance in various basic and clinical research. In our previous work, a synthetic oleanolic acid (OA) derivative C10a with PTP1B inhibitory activity has been reported. However, C10a has some pharmacological defects and cytotoxicity. Herein, a structure-based drug design approach was used based on the structure of C10a to elaborate the smaller tricyclic core. A series of tricyclic derivatives were synthesised and the compounds 15, 28 and 34 exhibited the most PTP1B enzymatic inhibitory potency. In the insulin-resistant human hepatoma HepG2 cells, compound 25 with the moderate PTP1B inhibition and preferable pharmaceutical properties can significantly increase insulin-stimulated glucose uptake and showed the insulin resistance ameliorating effect. Moreover, 25 showed the improved in vivo antihyperglycaemic potential in the nicotinamide-streptozotocin-induced T2D. Our study demonstrated that these tricyclic derivatives with improved molecular architectures and antihyperglycaemic activity could be developed in the treatment of T2D.

4,6-Substituted-1H-Indazoles as potent IDO1/TDO dual inhibitors.

Indoleamine 2,3-dioxygenase 1 (IDO1) and tryptophan 2,3-dioxygenase (TDO) are constitutively overexpressed in many types of cancer cells and exert important immunosuppressive functions. In this article, a series of 4,6-substituted-1H-indazole derivatives were synthesized and evaluated the inhibitory activities against IDO1 and TDO, as well as their structure-activity relationships (SARs). Among these, compound 35 displayed the most IDO1 inhibitory potency with an IC50 value of 0.74 µM in an enzymatic assay and 1.37 µM in HeLa cells. Quantitative analysis of the Western blot results indicated that 35 significantly decreased the INFγ-induced IDO1 expression in a concentration-dependent manner. In addition, 35 showed promising TDO inhibition with an IC50 value of 2.93 µM in the enzymatic assay and 7.54 µM in A172 cells. Moreover, compound 35 exhibited in vivo antitumor activity in the CT26 xenograft model. These findings suggest that 1H-indazole derivative 35 is a potent IDO1/TDO dual inhibitor, and has the potential to be developed for IDO1/TDO-related cancer treatment.

Discovery of [1,2,4]Triazole Derivatives as New Metallo-ß-Lactamase Inhibitors.

The emergence and spread of metallo-ß-lactamase (MBL)-mediated resistance to ß-lactam antibacterials has already threatened the global public health. A clinically useful MBL inhibitor that can reverse ß-lactam resistance has not been established yet. We here report a series of [1,2,4]triazole derivatives and analogs, which displayed inhibition to the clinically relevant subclass B1 (Verona integron-encoded MBL-2) VIM-2. 3-(4-Bromophenyl)-6,7-dihydro-5H-[1,2,4]triazolo [3,4-b][1,3]thiazine (5l) manifested the most potent inhibition with an IC50 (half-maximal inhibitory concentration) value of 38.36 µM. Investigations of 5l against other B1 MBLs and the serine ß-lactamases (SBLs) revealed the selectivity to VIM-2. Molecular docking analyses suggested that 5l bound to the VIM-2 active site via the triazole involving zinc coordination and made hydrophobic interactions with the residues Phe61 and Tyr67 on the flexible L1 loop. This work provided new triazole-based MBL inhibitors and may aid efforts to develop new types of inhibitors combating MBL-mediated resistance.

Discovery of (5-Phenylfuran-2-yl)methanamine Derivatives as New Human Sirtuin 2 Inhibitors.

Human sirtuin 2 (SIRT2), a member of the sirtuin family, has been considered as a promising drug target in cancer, neurodegenerative diseases, type II diabetes, and bacterial infections. Thus, SIRT2 inhibitors have been involved in effective treatment strategies for related diseases. Using previously established fluorescence-based assays for SIRT2 activity tests, the authors screened their in-house database and identified a compound, 4-(5-((3-(quinolin-5-yl)ureido)methyl)furan-2-yl)benzoic acid (20), which displayed 63 ± 5% and 35 ± 3% inhibition against SIRT2 at 100 µM and 10 µM, respectively. The structure-activity relationship (SAR) analyses of a series of synthesized (5-phenylfuran-2-yl)methanamine derivatives led to the identification of a potent compound 25 with an IC50 value of 2.47 µM, which is more potent than AGK2 (IC50 = 17.75 µM). Meanwhile, 25 likely possesses better water solubility (cLogP = 1.63 and cLogS = -3.63). Finally, the molecular docking analyses indicated that 25 fitted well with the induced hydrophobic pocket of SIRT2.

Discovery and preliminary structure-activity relationship of 1H-indazoles with promising indoleamine-2,3-dioxygenase 1 (IDO1) inhibition properties.

Indoleamine 2,3-dioxygenase 1 (IDO1)-mediated kynurenine pathway of tryptophan degradation is identified as an important immune effector pathway in the tumor cells to escape a potentially effective immune response. IDO1 is an attractive target for anticancer therapy and the discovery of IDO1 inhibitors has been intensely ongoing in both academic research laboratories and pharmaceutical organizations. Our study discovered that 1H-indazole was a novel key pharmacophore with potent IDO1 inhibitory activity. A series of new 1H-indazole derivatives were synthesized and determined the enzyme inhibitory activities, and the compound 2g exhibited the highest activity with an IC50 value of 5.3µM. The structure-activity relationships (SARs) analysis of the 1H-indazole derivatives as novel IDO1 inhibitors indicated that the 1H-indazole scaffold is necessary for IDO1 inhibition, and the substituent groups at the both 4-position and 6-position largely affect inhibitory activity. The docking model exhibited that the effective interactions of 1H-indazoles with ferrous ion of heme and key residues of hydrophobic Pocket A and B ensured the IDO1 inhibitory activities. The study suggested that the 1H-indazole was a novel interesting scaffold for IDO inhibition for further development.

Direct synthesis of carbamates, thiocarbamates, and ureas from Boc-protected amines: a sustainable and efficient approach.

In the quest for sustainable and efficient synthetic methodologies within medicinal chemistry, the synthesis of carbamates and their derivatives holds a pivotal role due to their widespread application in bioactive compounds. This investigation unveils a novel methodology for the straightforward transformation of Boc-protected amines into carbamates, thiocarbamates, and ureas, utilizing tert-butoxide lithium as the sole base. This approach effectively obviates the necessity for hazardous reagents and metal catalysts, presenting marked enhancements compared to traditional synthetic pathways. Notably, the method demonstrates facile scalability to gram-level production. This study contributes to the advancement of sustainable synthetic methodologies, offering a more benign and efficient alternative for the synthesis of key chemical intermediates with implications for broad pharmaceutical and agrochemical applications.

L-Pipecolinic acid derived Lewis base organocatalyst for asymmetric reduction of N-aryl imines by trichlorosilane: effects of the side amide group on catalytic performances.

A series of N-formamides derived from pipecolinic acid have been synthesized and tested as Lewis base catalysts for the enantioselective reduction of N-aryl imines by trichlorosilane. Through the investigation of the structure-efficacy relationship between the side amide group and catalytic performance, several highly effective catalysts were discovered. In particular, arylamido-type catalyst 5i and non-arylamido-type catalyst 6c exhibited high reactivity and enantioselectivity, furnishing the reduction of a wide variety of N-aryl imines with high isolated yields (up to 98%) and ee values (up to 96%) under mild conditions. Moreover, these two catalysts complement each other in terms of their tolerances to nonaromatic ketimines and non-methyl ketimines.

Heparin-Mimetic Chitooligosaccharides-Based Monoliths Obtained from C/W Emulsions: Hemocompatibility and Toxin Removal Ability.

Hemoperfusion (HP) is one of the most prominent therapies for treating uremia, hyperbilirubinemia, and acute drug toxicity. The comprehensive performance of currently used porous HP adsorbents needs to be improved due to the impediment to their synthesis strategy. Herein, green carbon dioxide-in-water high internal phase emulsions (C/W HIPEs) were utilized and emulsified with poly(vinyl alcohol) (PVA) for the formation of a heparin-mimetic chitosan oligosaccharides/poly(acrylamide-co-sodium 4-styrenesulfonate) [COS/P(AM-co-SSS)] monolith, which exhibited good mechanical properties, stable swelling performance, hydrophilic properties, anticoagulant effect, and low hemolysis. It showed a strong toxin adsorption capacity (415.2 mg/g for creatinine, 199.3 mg/g for urea, 279.5 mg/g for bilirubin, and 160 mg/g for tetracycline). The adsorption process of porous COS/P(AM-co-SSS) followed the pseudo-second-order kinetic and Langmuir isotherm models. Moreover, the porous materials had a strong electrostatic force on creatinine. The removal of creatinine by simulated in vitro blood perfusion was 80.2% within 30 min. This work provides a green preparation strategy for developing novel HP materials, highlighting their potential application value in blood and environmental purification.

Synthesis and Biological Activities of Oxazolidinone Pleuromutilin Derivatives as a Potent Anti-MRSA Agent.

A series of pleuromutilin derivatives containing an oxazolidinone skeleton were synthesized and evaluated in vitro and in vivo as antibacterial agents. Most of the synthesized derivatives exhibited potent antibacterial activities against three strains of Staphylococcus aureus (including MRSA ATCC 33591, MRSA ATCC 43300, and MSSA ATCC 29213) and two strains of Staphylococcus epidermidis (including MRSE ATCC 51625 and MSSE ATCC 12228). Compound 28 was the most active antibacterial agent in vitro (MIC = 0.008-0.125 µg·mL-1) and exhibited a significant bactericidal effect, low cytotoxicity, and weak inhibition (IC50 = 20.66 µmol·L-1) for CYP3A4, as well as exhibited less possibility to cause bacterial resistance. Furthermore, in vivo activities indicated that the compound was effective in reducing MRSA load in a murine thigh infection model. Moreover, it clearly facilitated the healing of MRSA skin infection and inhibited the secretion of the TNF-α, IL-6, and MCP-1 inflammatory factors in serum. These results suggest that oxazolidinone pleuromutilin is a promising therapeutic candidate for drug-resistant bacterial infections.

Case Report: Response to crizotinib treatment in a patient with advanced non-small cell lung cancer with LDLR-ROS1 fusion.

C-ros oncogene 1 (ROS1) fusion is a pathogenic driver gene in non-small cell lung cancer (NSCLC). Currently, clinical guidelines from the National Comprehensive Cancer Network (NCCN) have recommended molecular pathologic tests for patients with NSCLC, including the detection of the ROS1 gene. Crizotinib is a small molecule tyrosine kinase inhibitor of anaplastic lymphoma kinase (ALK), ROS1, and mesenchymal-epithelial transition (MET). In recent years, the efficacy of crizotinib in NSCLC patients with ROS1 fusion has been reported. Here, a 77-year-old woman was diagnosed with stage IVA lung adenocarcinoma harboring a novel low-density lipoprotein receptor (LDLR)-ROS1 fusion variant. This novel LDLR-ROS1 fusion was identified by targeted DNA next-generation sequencing (NGS) panel and then verified by RNA fusion panel based on amplicon sequencing. This patient benefited from subsequent crizotinib therapy and achieved progression-free survival of 15 months without significant toxic symptoms. Our case report recommended a promising targeted therapeutic option for patients with metastatic NSCLC with LDLR-ROS1 fusion and highlighted the importance of genetic testing for accurate treatment.

Design, Synthesis, and Biological Activity of Thioguanine-Modified Pleuromutilin Derivatives.

Antibiotic overuse has caused the increasingly serious problem of bacterial drug resistance, with numerous marketed antibiotics exhibiting significantly reduced activity against drug-resistant bacteria. Therefore, there is urgent demand for the development of novel antibiotics. Pleuromutilin is a tricyclic diterpene exhibiting antibacterial activity against Gram-positive bacteria and is currently considered the most promising natural antibiotic. In this study, novel pleuromutilin derivatives were designed and synthesized by introducing thioguanine units, and their antibacterial activities against drug-resistant strains were evaluated in vitro and in vivo. Compound 6j was observed to have a rapid bactericidal effect, low cytotoxicity, and potent antibacterial activity. The in vitro results suggest that 6j has a significant therapeutic effect on local infections, and its activity is equal to that of retapamulin, an anti-Staphylococcus aureus pleuromutilin derivative.