Acetone Serving as a Solvent and Interaction Partner Promotes the Direct Olefination of N-Tosylhydrazones under Visible Light.

The photochemistry of noncovalent interactions to promote organic transformations is an emerging approach to providing fresh opportunities in synthetic chemistry. Generally, the external substance is necessary to add as an interaction partner, thereby sacrificing the atom economy of the reaction. Herein, we describe a catalyst-free and noncovalent interaction-mediated strategy to access the olefination of N-tosylhydrazones using acetone as a solvent and an interaction partner. This protocol also features broad substrate scope, excellent functional group compatibility, and mild reaction conditions without transition metals. Moreover, the gram-scale synthesis of olefins and the generation of pharmaceutical intermediates highlighted its practical applicability. Lastly, mechanistic studies indicate that the reaction was initiated via noncovalent interactions between acetone and N-tosylhydrazone anion, which is also supported by density functional theory calculations.

Configuration-Specific Antibody for Bacterial Heptosylation: An Antiadhesion Therapeutic Strategy.

Alternative antibacterial therapies refractory to existing mechanisms of antibiotic resistance are urgently needed. One such attractive therapy is to inhibit bacterial adhesion and colonization. Ser O-heptosylation (Ser O-Hep) on autotransporters of Gram-negative bacteria is a novel glycosylation and has been proven to be essential for bacterial colonization. Herein, we chemically synthesized glycopeptides containing this atypical glycan structure and an absolute C6 configuration through the assembly of Ser O-Hep building blocks. Using glycopeptides as haptens, we generated first-in-class poly- and monoclonal antibodies, termed Anti-SerHep1a and Anti-SerHep1b, that stereoselectively recognize Ser O-heptosylation (d/l-glycero) with high specificity in vitro and in vivo. Importantly, these antibodies effectively blocked diffusely adhering Escherichia coli 2787 adhesion to HeLa cells and in mice in a dose- and Ser O-Hep-dependent manner. Together, these antibodies represent not only useful tools for the discovery of unknown serine O-heptosylated proteins bearing various C6 chiral centers but also a novel class of antiadhesion therapeutic agents for the treatment of bacterial infection.

Crizotinib-based proteolysis targeting chimera suppresses gastric cancer by promoting MET degradation.

As one of the common malignant cancer types, gastric cancer (GC) is known for late-stage diagnosis and poor prognosis. Overexpression of the receptor tyrosine kinase MET is associated with poor prognosis among patients with advanced stage GC. However, no MET inhibitor has been used for GC treatment. Like other tyrosine kinase inhibitors that fit the "occupancy-driven" model, current MET inhibitors are prone to acquired resistance. The emerging proteolysis targeting chimera (PROTAC) strategy could overcome such limitations through direct degradation of the target proteins. In this study, we successfully transformed the MET-targeted inhibitor crizotinib into a series of PROTACs, recruiting cereblon/cullin 4A E3 ubiquitin ligase to degrade the MET proteins. The optimized lead PROTAC (PRO-6 E) effectively eliminated MET proteins in vitro and in vivo, inhibiting proliferation and motility of MET-positive GC cells. In the MKN-45 xenograft model, PRO-6 E showed pronounced antitumor efficacy with a well-tolerated dosage regimen. These results validated PRO-6 E as the first oral PROTAC for MET-dependent GC.

Targeted Protein Degradation Technology and Nanomedicine: Powerful Allies against Cancer.

Targeted protein degradation (TPD) is an emerging therapeutic strategy with the potential of targeting undruggable pathogenic proteins. After the first proof-of-concept proteolysis-targeting chimeric (PROTAC) molecule was reported, the TPD field has entered a new era. In addition to PROTAC, numerous novel TPD strategies have emerged to expand the degradation landscape. However, their physicochemical properties and uncontrolled off-target side effects have limited their therapeutic efficacy, raising concerns regarding TPD delivery system. The combination of TPD and nanotechnology offers great promise in improving safety and therapeutic efficacy. This review provides an overview of novel TPD technologies, discusses their clinical applications, and highlights the trends and perspectives in TPD nanomedicine.

Discovery of the covalent SARS-CoV-2 Mpro inhibitors from antiviral herbs via integrating target-based high-throughput screening and chemoproteomic approaches.

The main proteases (Mpro ) are highly conserved cysteine-rich proteins that can be covalently modified by numerous natural and synthetic compounds. Herein, we constructed an integrative approach to efficiently discover covalent inhibitors of Mpro from complex herbal matrices. This work begins with biological screening of 60 clinically used antiviral herbal medicines, among which Lonicera japonica Flos (LJF) demonstrated the strongest anti-Mpro effect (IC50 = 37.82 µg/mL). Mass spectrometry (MS)-based chemical analysis and chemoproteomic profiling revealed that LJF extract contains at least 50 constituents, of which 22 exhibited the capability to covalently modify Mpro . We subsequently verified the anti-Mpro effects of these covalent binders. Gallic acid and quercetin were found to potently inhibit severe acute respiratory syndrome coronavirus 2 Mpro in dose- and time- dependent manners, with the IC50 values below 10 µM. The inactivation kinetics, binding affinity and binding mode of gallic acid and quercetin were further characterized by fluorescence resonance energy transfer, surface plasmon resonance, and covalent docking simulations. Overall, this study established a practical approach for efficiently discovering the covalent inhibitors of Mpro from herbal medicines by integrating target-based high-throughput screening and MS-based assays, which would greatly facilitate the discovery of key antiviral constituents from medicinal plants.

EnT-Mediated Amino-Sulfonylation of Alkenes with Bifunctional Sulfonamides: Access to ß-Amino Sulfone Derivatives.

ß-Amino sulfones are commonly found structural motifs in biologically active compounds. Herein, we report a direct photocatalyzed amino-sulfonylation reaction of alkenes for the efficicient production of important compounds by simple hydrolysis without the need for additional oxidants and reductants. In this transformation, the sulfonamides worked as bifunctional reagents, simultaneously generating sulfonyl radicals and N-centered radicals which were added to alkene in a highly atom-economical fashion with high regioselectivity and diastereoselectivity. This approach showed high functional group tolerance and compatibility, facilitating the late-stage modification of some bioactive alkenes and sulfonamide molecules, thereby expanding the biologically relevant chemical space. Scaling up this reaction led to an efficient green synthesis of apremilast, one of the best-selling pharmceuticals, demonstrating the synthetic utility of the applied method. Moreover, mechanistic investigations suggest that an energy transfer (EnT) process was in operation.

Neutrophils as potential therapeutic targets for breast cancer.

Breast cancer (BC) remains the foremost cause of cancer mortality globally, with neutrophils playing a critical role in its pathogenesis. As an essential tumor microenvironment (TME) component, neutrophils are emerging as pivotal factors in BC progression. Growing evidence has proved that neutrophils play a Janus- role in BC by polarizing into the anti-tumor (N1) or pro-tumor (N2) phenotype. Clinical trials are evaluating neutrophil-targeted therapies, including Reparixin (NCT02370238) and Tigatuzumab (NCT01307891); however, their clinical efficacy remains suboptimal. This review summarizes the evidence regarding the close relationship between neutrophils and BC, emphasizing the critical roles of neutrophils in regulating metabolic and immune pathways. Additionally, we summarize the existing therapeutic approaches that target neutrophils, highlighting the challenges, and affirming the rationale for continuing to explore neutrophils as a viable therapeutic target in BC management.

Green and efficient synthesis of pure ß-sulfonyl aliphatic sulfonyl fluorides through simple filtration in aqueous media.

A green and efficient method for the synthesis of ß-sulfonyl aliphatic sulfonyl fluorides was developed. This reaction works in aqueous media under mild and environmentally benign conditions without any ligand or additive. The efficiency of this method is demonstrated by isolating the desired products obtained through simple filtration.

The Discovery and Anti-Colorectal Cancer Activities of Cembranolides from the South China Sea Soft Coral Sinularia pendunculata.

A new cembranolide, namely, sinupendunculide A (1), along with eight known related compounds (2-9), was isolated from the South China Sea Soft coral Sinularia pendunculata. The structure of sinupendunculide A (1) was established by extensive spectroscopic analysis and X-ray diffraction experiments. In a bioassay, anti-colorectal cancer (CRC) activity was performed, and the results showed that several compounds exhibited cytotoxicity against RKO cells, and a preliminary structure-activity relationship was analysed. Meanwhile, the most effective compound 7 was proven to increase reactive oxygen species levels, which promoted cell apoptosis and inhibited cell proliferation.

[Strategy and challenge of innovative drug research and development from clinically effective ingredients of traditional Chinese medicine].

Novel drug discovery from the active ingredients of traditional Chinese medicine is the most distinctive feature and advantageous field of China, which has provided an unprecedented opportunity. However, there are still problems such as unclear functional substance basis, action targets and mechanism, which greatly hinder the clinical transformation of active ingredients in traditional Chinese medicine. Based on the analysis of the current status and progress of innovative drug research and development in China, this paper aimed to explore the prospect and difficulties of the development of natural active ingredients from traditional Chinese medicine, and to explore the efficient discovery of trace active ingredients in traditional Chinese medicine, and obtain drug candidates with novel chemical structure, unique target/mechanism and independent intellectual property rights, in order to provide a new strategy and a new model for the development of natural medicine with Chinese characteristics.

[Stapled anoplin peptide combined with photothermal therapy enhances oncolytic immunotherapy of triple-negative breast cancer].

This study constructed a nano-drug delivery system, A3@GMH, by co-delivering the stapled anoplin peptide(Ano-3, A3) with the light-harvesting material graphene oxide(GO), and evaluated its oncolytic immunotherapy effect on triple-negative breast cancer(TNBC). A3@GMH was prepared using an emulsion template method and its physicochemical properties were characterized. The in vivo and in vitro photothermal conversion abilities of A3@GMH were investigated using an infrared thermal imager. The oncoly-tic activity of A3@GMH against TNBC 4T1 cells was evaluated through cell counting kit-8(CCK-8), lactate dehydrogenase(LDH) release, live/dead cell staining, and super-resolution microscopy. The targeting properties of A3@GMH on 4T1 cells were assessed using a high-content imaging system and flow cytometry. In vitro and in vivo studies were conducted to investigate the antitumor mechanism of A3@GMH in combination with photothermal therapy(PTT) through inducing immunogenic cell death(ICD) in 4T1 cells. The results showed that the prepared A3@GMH exhibited distinct mesoporous and coated structures with an average particle size of(308.9±7.5) nm and a surface potential of(-6.79±0.58) mV. The encapsulation efficiency and drug loading of A3 were 23.9%±0.6% and 20.5%±0.5%, respectively. A3@GMH demonstrated excellent photothermal conversion ability and biological safety. A3@GMH actively mediated oncolytic features such as 4T1 cell lysis and LDH release, as well as ICD effects, and showed enhanced in vitro antitumor activity when combined with PTT. In vivo, A3@GMH efficiently induced ICD effects with two rounds of PTT, activated the host's antitumor immune response, and effectively suppressed tumor growth in 4T1 tumor-bearing mice, achieving an 88.9% tumor inhibition rate with no apparent toxic side effects. This study suggests that the combination of stapled anoplin peptide and PTT significantly enhances the oncolytic immunotherapy for TNBC and provides a basis for the innovative application of anti-tumor peptides derived from TCM in TNBC treatment.

Four-Dimensional Untargeted Profiling of N-Acylethanolamine Lipids in the Mouse Brain Using Ion Mobility-Mass Spectrometry.

N-Acylethanolamines (NAE) are a class of essential signaling lipids that are involved in a variety of physiological processes, such as energy homeostasis, anti-inflammatory responses, and neurological functions. NAE lipids are functionally different yet structurally similar and often have low concentrations in biological systems. Therefore, the comprehensive analysis of NAE lipids in complex biological matrices is very challenging. In this work, we developed an ion mobility-mass spectrometry (IM-MS) based four-dimensional (4D) untargeted technology for comprehensive analysis of NAE lipids. First, we employed the picolinyl derivatization to significantly improve ionization sensitivity of NAE lipids by 2-9-fold. Next, we developed a two-step quantitative structure-retention relationship (QSRR) strategy and used the AllCCS software to curate a 4D library for 170 NAE lipids with information on m/z, retention time, collision cross-section, and MS/MS spectra. Then, we developed a 4D untargeted technology empowered by the 4D library to support unambiguous identifications of NAE lipids. Using this technology, we readily identified a total of 68 NAE lipids across different biological samples. Finally, we used the 4D untargeted technology to comprehensively quantify 47 NAE lipids in 10 functional regions in the mouse brain and revealed a broad spectrum of the age-associated changes in NAE lipids across brain regions. We envision that the comprehensive analysis of NAE lipids will strengthen our understanding of their functions in regulating distinct physiological activities.

Stapled Helical Peptides Bearing Different Anchoring Residues.

A large proportion of protein-protein interactions (PPIs) occur between a short peptide and a globular protein domain; the peptides involved in surface interactions play important roles, and there is great promise for using peptide motifs to interfere with protein interactions. Peptide inhibitors show more promise in blocking large surface protein interactions compared to small molecule inhibitors. However, peptides have drawbacks including poor stability against circulating proteolytic enzymes and an intrinsic inability to penetrate cell membranes. Stapled helical peptides, by adopting a preformed, stable α-helical conformation, exhibit improved proteolytic stability and membrane permeability compared to linear bioactive peptides. In this review, we summarize the broad aspects of peptide stapling for chemistry, biophysics, and biological applications and specifically highlight the methodology by providing an inventory of different anchoring residues categorized into two natural amino acids, two nonnatural amino acids, or a combination of natural and nonnatural amino acids. Additional advantages of specific peptide stapling techniques, including but not limited to reversibility, bio-orthogonal reactivity, and photoisomerization, are also discussed individually. This review is expected to provide a broad reference for the rational design of druggable stapled peptides targeting therapeutic proteins, particularly those involved in PPIs, by considering the impact of anchoring residues, functional cross-linkers, physical staple length, staple components, and the staple motif on the biophysical properties of the peptides.

Coumarin-monoterpenes from Gerbera anandria (Linn.) Sch.-Bip and their neuroprotective activity.

Thirty-two undescribed coumarin-monoterpenes, including the first report of six pairs of enantiomeric and twenty congeners, were isolated from the petroleum ether extract of the stems of Gerbera anandria (Linn.) Sch.-Bip. Structurally, these compounds represented C3-substituted 5-methyl-4-hydroxycoumarin-monoterpenes. Among them, 1-7 and 10-24 were rare 5-methylcoumarin-monoterpenes formed through a furan ring. Their chemical structures and absolute configurations were determined by comprehensive analysis of spectroscopic data, including HRESIMS, 1D and 2D NMR spectroscopic data, Mosher's method, ECD calculations and single crystal X-ray diffraction. Furthermore, biological studies revealed that compounds 1-3, 3a, 5, 5a, 11-12, 21-22 and 26 had the neuroprotective effects on scopolamine-induced injury in PC12 cells. Notably, 3 exhibited the strongest neuroprotective activity with the cell viability values of 77.24%. Meanwhile, pretreatment with 3 significantly downregulate apoptosis and reactive oxygen species (ROS) production, as well as strengthen antioxidant enzyme activities (MDA and SOD). Moreover, pretreatment with 3 also could attenuate the down-regulation of HO-1 and Nrf2 induced by scopolamine. In conclusion, these results demonstrated that these compounds possessed the protective effects on scopolamine-injured PC12 cells through anti-apoptotic and anti-oxidant activities.

The adipokine orosomucoid alleviates adipose tissue fibrosis via the AMPK pathway.

The excess deposition of underlying extracellular matrix (ECM) in adipose tissue is defined as adipose tissue fibrosis that is a major contributor to metabolic disorder such as obesity and type 2 diabetes. Anti-fibrosis therapy has received much attention in the treatment of metabolic disorders. Orosomucoid (ORM) is an acute-phase protein mainly produced by liver, which is also an adipokine. In this study, we investigated the effects of ORM on adipose tissue fibrosis and the potential mechanisms. We showed that ORM1-deficient mice exhibited an obese phenotype, manifested by excessive collagen deposition in adipose tissues and elevated expression of ECM regulators such as metalloproteinases (MMP-2, MMP-13, MMP-14) and tissue inhibitors of metalloproteinases (TIMP-1, TIMP-2, TIMP-3). Administration of exogenous ORM (50 mg· kg-1· d-1, ip) for 7 consecutive days in high-fat diet (HFD)-fed mice and leptin receptor (LepR)-deficient db/db mice attenuated these abnormal expressions. Meanwhile, ORM administration stimulated AMP-activated protein kinase (AMPK) phosphorylation and decreased transforming growth factor-ß1 (TGF-ß1) level in adipose tissues of the mice. In TGF-ß1-treated 3T3-L1 fibroblasts, ORM (10 µg/mL) improved the impaired expression profiles of fibrosis-related genes, whereas a selective AMPK inhibitor dorsomorphin (1 µmol/mL) abolished these effects. Together, our results suggest that ORM exerts a direct anti-fibrosis effect in adipose tissue via AMPK activation. ORM is expected to become a novel target for the treatment of adipose tissue fibrosis.

Inhibition of drug-metabolizing enzymes by Jingyin granules: implications of herb-drug interactions in antiviral therapy.

Jingyin granules, a marketed antiviral herbal medicine, have been recommended for treating H1N1 influenza A virus infection and Coronavirus disease 2019 (COVID-19) in China. To fight viral diseases in a more efficient way, Jingyin granules are frequently co-administered in clinical settings with a variety of therapeutic agents, including antiviral drugs, anti-inflammatory drugs, and other Western medicines. However, it is unclear whether Jingyin granules modulate the pharmacokinetics of Western drugs or trigger clinically significant herb-drug interactions. This study aims to assess the inhibitory potency of the herbal extract of Jingyin granules (HEJG) against human drug-metabolizing enzymes and to clarify whether HEJG can modulate the pharmacokinetic profiles of Western drug(s) in vivo. The results clearly demonstrated that HEJG dose-dependently inhibited human CES1A, CES2A, CYPs1A, 2A6, 2C8, 2C9, 2D6, and 2E1; this herbal medicine also time- and NADPH-dependently inhibited human CYP2C19 and CYP3A. In vivo tests showed that HEJG significantly increased the plasma exposure of lopinavir (a CYP3A-substrate drug) by 2.43-fold and strongly prolonged its half-life by 1.91-fold when HEJG (3 g/kg) was co-administered with lopinavir to rats. Further investigation revealed licochalcone A, licochalcone B, licochalcone C and echinatin in Radix Glycyrrhizae, as well as quercetin and kaempferol in Folium Llicis Purpureae, to be time-dependent CYP3A inhibitors. Collectively, our findings reveal that HEJG modulates the pharmacokinetics of CYP substrate-drug(s) by inactivating CYP3A, providing key information for both clinicians and patients to use herb-drug combinations for antiviral therapy in a scientific and reasonable way.

In vivo and in vitro metabolism study of traditional Chinese medicine formula Dingkun Dan in rats by using ultra-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry.

Dingkun Dan (DKD), a reputable traditional Chinese medicine formula, has been used to treat gynecological diseases and showed significant clinical effects since ancient times. However, the application and development of DKD are seriously hampered by the unclear active substances. Structural characterization of compounds absorbed in vivo and their corresponding metabolites is significant for clarifying the pharmacodynamic material basis. In this study, an integrated strategy using ultra-performance liquid chromatography, coupled with quadrupole time-of-flight mass spectrometry and UNIFI™ software, was used to identify prototypes and metabolites after oral administration of DKD in rats. As a result, a total of 261 compounds, including 140 prototypes and 121 metabolites, were tentatively characterized in rat plasma, urine, and feces. The metabolic pathways of prototypes have been studied to clarify their possible transformation process in vivo. Moreover, an in vitro metabolism study was applied for verifying the metabolites under simulating the metabolic environment in vivo. This first systematic metabolic study of DKD is important for elucidating the metabolites and metabolic pathways and could provide a scientific basis for explaining the integrative mechanism in further pharmacology study.

Cytotoxic and antitumor peptides as novel chemotherapeutics.

Covering: up to 2020Treatment resistance and drug-induced refractory malignancies pose significant challenges for current chemotherapy drugs. There have been increasing research efforts aimed at developing novel chemotherapeutics, especially from natural products and related derivatives. Natural cytotoxic peptides, an emerging source of chemotherapeutics, have exhibited the advantage of overcoming drug resistance and displayed broad-spectrum antitumor activities in the clinic. This highlight examines the increasingly popular cytotoxic peptides from isolated natural products. In-depth review of several peptides provides examples for how this novel strategy can lead to the improved anti-tumor effects. The mechanisms and current application of representative natural cytotoxic peptides (NCPs) have also been discussed, with a particular focus on future directions for interdisciplinary research.

Ginsenoside Rb1 alleviates colitis in mice via activation of endoplasmic reticulum-resident E3 ubiquitin ligase Hrd1 signaling pathway.

Endoplasmic reticulum (ER) homeostasis is regulated by ER-resident E3 ubiquitin ligase Hrd1, which has been implicated in inflammatory bowel disease (IBD). Ginsenoside Rb1 (GRb1) is the major ginsenoside in ginseng with multiple pharmacological activities. In this study we investigated the role of Hrd1 in IBD and its regulation by GRb1. Two mouse colitis models were established to mimic human IBD: drinking water containing dextran sodium sulfate (DSS) as well as intra-colonic infusion of 2, 4, 6-trinitrobenzene sulfonic acid (TNBS). Colitis mice were treated with GRb1 (20, 40 mg·kg-1·d-1, ig) or a positive control drug sulfasalazine (500 mg·kg-1·d-1, ig) for 7 days. The model mice showed typical colitis symptoms and pathological changes in colon tissue. In addition to significant inflammatory responses and cell apoptosis in colon tissue, colon epithelial expression of Hrd1 was significantly decreased, the expression of ER stress markers GRP78, PERK, CHOP, and caspase 12 was increased, and the expression of Fas was increased (Fas was removed by Hrd1-induced ubiquitination). These changes were partially, or completely, reversed by GRb1 administration, whereas injection of Hrd1 inhibitor LS102 (50 mg·kg-1· d-1, ip, for 6 days) exacerbated colitis symptoms in colitis mice. GRb1 administration not only normalized Hrd1 expression at both the mRNA and protein levels, but also alleviated the ER stress response, Fas-related apoptosis, and other colitis symptoms. In intestinal cell line IEC-6, the expression of Hrd1 was significantly decreased by LPS treatment, but was normalized by GRb1 (200 µM). GRb1 alleviated LPS-induced ER stress and cell apoptosis in IEC-6 cells, and GRb1 action was inhibited by knockdown of Hrd1 using small interfering RNA. In summary, these results reveal a pathological role of Hrd1 in colitis, and provide a novel insight into alternative treatment of colitis using GRb1 activating Hrd1 signaling pathway.

Medicinal chemistry strategies to discover P-glycoprotein inhibitors: An update.

The presence of multidrug resistance (MDR) in malignant tumors is one of the primary causes of treatment failure in cancer chemotherapy. The overexpression of the ATP binding cassette (ABC) transporter, P-glycoprotein (P-gp), which significantly increases the efflux of certain anticancer drugs from tumor cells, produces MDR. Therefore, inhibition of P-gp may represent a viable therapeutic strategy to overcome cancer MDR. Over the past 4 decades, many compounds with P-gp inhibitory efficacy (referred to as first- and second-generation P-gp inhibitors) have been identified or synthesized. However, these compounds were not successful in clinical trials due to a lack of efficacy and/or untoward toxicity. Subsequently, third- and fourth-generation P-gp inhibitors were developed but dedicated clinical trials did not indicate a significant therapeutic effect. In recent years, an extraordinary array of highly potent, selective, and low-toxicity P-gp inhibitors have been reported. Herein, we provide a comprehensive review of the synthetic and natural products that have specific inhibitory activity on P-gp drug efflux as well as promising chemosensitizing efficacy in MDR cancer cells. The present review focuses primarily on the structural features, design strategies, and structure-activity relationships (SAR) of these compounds.