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1.
Mar Pollut Bull ; 205: 116639, 2024 Jul 03.
Article in English | MEDLINE | ID: mdl-38964190

ABSTRACT

Oil spills, detected by SAR sensors as dark areas, are highly effective marine pollutants that affect the ocean surface. These spills change the water surface tension, attenuating capillary gravitational waves and causing specular reflections. We conducted a case study in the Persian Gulf (Arabian Sea to the Strait of Hormuz), where approximately 163,900 gal of crude oil spilled in March 2017. Our study examined the relationship between oil weathering processes and extracted backscatter values using zonal slices projected over SAR-detected oil spills. Internal backscatter values ranged from -22.5 to -23.5, indicating an oil chemical binding and minimal interaction with seawater. MEDSLIK-II simulations indicated increased oil solubilization and radar attenuation rates with wind, facilitating coastal dispersion. Higher backscatter at the spill edges compared to the core reflected different stages of oil weathering. These results highlight the complex dynamics of oil spills and their environmental impact on marine ecosystems.

2.
Arch Pharm (Weinheim) ; : e2400372, 2024 Jul 04.
Article in English | MEDLINE | ID: mdl-38963326

ABSTRACT

The Morita-Baylis-Hillman (MBH) reaction is a unique C-C bond-forming technique for the generation of multifunctional allylic alcohols (MBH adducts) in a single operation. In recent years, these MBH adducts have emerged as a novel class of compounds with significant biological potential, including anticancer, anti-leishmanial, antibacterial, antifungal, anti-herbicidal effects and activity against Chagas disease, and so on. The aim of this review is to assimilate the literature findings from 2011 onwards related to the synthesis and biological potential of MBH adducts, with an emphasis on their structure-activity relationships (SAR). Although insight into the biological mechanisms of action for this recently identified pharmacophore is currently in its nascent stages, the mechanisms described so far are reviewed herein.

3.
Bioorg Chem ; 150: 107608, 2024 Jun 29.
Article in English | MEDLINE | ID: mdl-38981210

ABSTRACT

The deployment of DNA damage response (DDR) combats various forms of DNA damage, ensuring genomic stability. Cancer cells' propensity for genomic instability offers therapeutic opportunities to selectively kill cancer cells by suppressing the DDR pathway. DNA-dependent protein kinase (DNA-PK), a nuclear serine/threonine kinase, is crucial for the non-homologous end joining (NHEJ) pathway in the repair of DNA double-strand breaks (DSBs). Therefore, targeting DNA-PK is a promising cancer treatment strategy. This review elaborates on the structures of DNA-PK and its related large protein, as well as the development process of DNA-PK inhibitors, and recent advancements in their clinical application. We emphasize our analysis of the development process and structure-activity relationships (SARs) of DNA-PK inhibitors based on different scaffolds. We hope this review will provide practical information for researchers seeking to develop novel DNA-PK inhibitors in the future.

4.
mSystems ; : e0131823, 2024 Jul 09.
Article in English | MEDLINE | ID: mdl-38980056

ABSTRACT

Estuarine and coastal ecosystems are of high economic and ecological importance, owing to their diverse communities and the disproportionate role they play in carbon cycling, particularly in carbon sequestration. Organisms inhabiting these environments must overcome strong natural fluctuations in salinity, nutrients, and turbidity, as well as numerous climate change-induced disturbances such as land loss, sea level rise, and, in some locations, increasingly severe tropical cyclones that threaten to disrupt future ecosystem health. The northern Gulf of Mexico (nGoM) along the Louisiana coast contains dozens of estuaries, including the Mississippi-Atchafalaya River outflow, which dramatically influence the region due to their vast upstream watershed. Nevertheless, the microbiology of these estuaries and surrounding coastal environments has received little attention. To improve our understanding of microbial ecology in the understudied coastal nGoM, we conducted a 16S rRNA gene amplicon survey at eight sites and multiple time points along the Louisiana coast and one inland swamp spanning freshwater to high brackish salinities, totaling 47 duplicated Sterivex (0.2-2.7 µm) and prefilter (>2.7 µm) samples. We cataloged over 13,000 Amplicon Sequence ariants (ASVs) from common freshwater and marine clades such as SAR11 (Alphaproteobacteria), Synechococcus (Cyanobacteria), and acI and Candidatus Actinomarina (Actinobacteria). We observed correlations with freshwater or marine habitats in many organisms and characterized a group of taxa with specialized distributions across brackish water sites, supporting the hypothesis of an endogenous brackish-water community. Additionally, we observed brackish-water associations for several aquatic clades typically considered marine or freshwater taxa, such as SAR11 subclade II, SAR324, and the acI Actinobacteria. The data presented here expand the geographic coverage of microbial ecology in estuarine communities, help delineate the native and transitory members of these environments, and provide critical aquatic microbiological baseline data for coastal and estuarine sites in the nGoM.IMPORTANCEEstuarine and coastal waters are diverse ecosystems influenced by tidal fluxes, interconnected wetlands, and river outflows, which are of high economic and ecological importance. Microorganisms play a pivotal role in estuaries as "first responders" and ecosystem architects, yet despite their ecological importance, they remain underrepresented in microbial studies compared to open ocean environments. This leads to substantial knowledge gaps that are important for understanding global biogeochemical cycling and making decisions about conservation and management strategies in these environments. Our study makes key contributions to the microbial ecology of estuarine and coastal habitats in the northern Gulf of Mexico. Our microbial community data support the concept of a globally distributed, core brackish microbiome and emphasize previously underrecognized brackish-water taxa. Given the projected worsening of land loss, oil spills, and natural disasters in this region, our results will serve as important baseline data for researchers investigating the microbial communities found across estuaries.

5.
Expert Opin Drug Discov ; : 1-24, 2024 Jul 12.
Article in English | MEDLINE | ID: mdl-38994606

ABSTRACT

INTRODUCTION: Abundant evidence suggests that the overexpression of CDK2-cyclin A/E complex disrupts normal cell cycle regulation, leading to uncontrolled proliferation of cancer cells. Thus, CDK2 has become a promising therapeutic target for cancer treatment. In recent years, insights into the structures of the CDK2 catalytic site and allosteric pockets have provided notable opportunities for developing more effective clinical candidates of CDK2 inhibitors. AREA COVERED: This article reviews the latest CDK2 inhibitors that have entered clinical trials and discusses the design and discovery of the most promising new preclinical CDK2 inhibitors in recent years. Additionally, it summarizes the development of allosteric CDK2 inhibitors and CDK2-targeting PROTACs. The review encompasses strategies for inhibitor and PROTAC design, structure-activity relationships, as well as in vitro and in vivo biological assessments. EXPERT OPINION: Despite considerable effort, no CDK2 inhibitor has yet received FDA approval for marketing due to poor selectivity and observed toxicity in clinical settings. Future research must prioritize the optimization of the selectivity, potency, and pharmacokinetics of CDK2 inhibitors and PROTACs. Moreover, exploring combination therapies incorporating CDK2 inhibitors with other targeted agents, or the design of multi-target inhibitors, presents significant promise for advancing cancer treatment strategies.

6.
Eur J Med Chem ; 275: 116617, 2024 Sep 05.
Article in English | MEDLINE | ID: mdl-38959729

ABSTRACT

Agents that cause apoptotic cell death by interfering with tubulin dynamics, such as vinblastine and paclitaxel, are an important class of chemotherapeutics. Unfortunately, these compounds are substrates for multidrug resistance (MDR) pumps, allowing cancer cells to gain resistance to these chemotherapeutics. The indolesulfonamide family of tubulin inhibitors are not excluded by MDR pumps and have a promising activity profile, although their high lipophilicity is a pharmacokinetic limitation for their clinical use. Here we present a new family of N-indolyl-3,4,5-trimethoxybenzenesulfonamide derivatives with modifications on the indole system at positions 1 and 3 and on the sulfonamide nitrogen. We synthesized and screened against HeLa cells 34 novel indolic benzenesulfonamides. The most potent derivatives (1.7-109 nM) were tested against a broad panel of cancer cell lines, which revealed that substituted benzenesulfonamides analogs had highest potency. Importantly, these compounds were only moderately toxic to non-tumorigenic cells, suggesting the presence of a therapeutic index. Consistent with known clinical anti-tubulin agents, these compounds arrested the cell cycle at G2/M phase. Mechanistically, they induced apoptosis via caspase 3/7 activation, which occurred during M arrest. The substituents on the sulfonamide nitrogen appeared to determine different mechanistic results and cell fates. These results suggest that the compounds act differently depending on the bridge substituents, thus making them very interesting as mechanistic probes as well as potential drugs for further development.


Subject(s)
Antineoplastic Agents , Apoptosis , Benzenesulfonamides , Cell Proliferation , Drug Screening Assays, Antitumor , Indoles , Sulfonamides , Humans , Sulfonamides/chemistry , Sulfonamides/pharmacology , Sulfonamides/chemical synthesis , Cell Proliferation/drug effects , Antineoplastic Agents/pharmacology , Antineoplastic Agents/chemistry , Antineoplastic Agents/chemical synthesis , Structure-Activity Relationship , Apoptosis/drug effects , Molecular Structure , Indoles/chemistry , Indoles/pharmacology , Indoles/chemical synthesis , Dose-Response Relationship, Drug , Nitrogen/chemistry , Cell Line, Tumor , HeLa Cells , Tubulin Modulators/pharmacology , Tubulin Modulators/chemistry , Tubulin Modulators/chemical synthesis
7.
Future Med Chem ; 16(12): 1255-1266, 2024.
Article in English | MEDLINE | ID: mdl-38989987

ABSTRACT

Aim: To synthesize novel more potent anti-diabetic agents. Methodology: A simple cost effective Hantzsch's synthetic strategy was used to synthesize 2-(2-arylidenehydrazinyl)thiazol-4(5H)-ones. Results: Fifteen new 2-(2-arylidenehydrazinyl)thiazol-4(5H)-ones were established to check their anti-diabetic potential. From alpha(α)-amylase inhibition, anti-glycation and anti-oxidant activities it is revealed that most of the compounds possess good anti-diabetic potential. All tested compounds were found to be more potent anti-diabetic agents via anti-glycation mode. The results of α-amylase and anti-oxidant inhibition revealed that compounds are less active against α-amylase and anti-oxidant assays. Conclusion: This study concludes that introduction of various electron withdrawing groups at the aryl ring and substitution of different functionalities around thiazolone nucleus could help to find out better anti-diabetic drug.


Diabetes is a most spreading chronicle disease effecting millions of peoples across the globe every year and this number increases day by day. To cure the human population from this dilemma, we had synthesized, characterized and evaluated the anti-diabetic behavior of our synthesized compounds. α-Amylase, in vitro anti-glycation and anti-oxidant assays were performed to find out good lead for Diabetes Mellitus. All tested compounds were found to be excellent anti-glycating agents with IC50 values far better than standard amino-guanidine (IC50 = 3.582 ± 0.002 µM). Compound 4m was most efficient glycation inhibitor (IC50 = 1.095 ± 0.002 µM). Cytotoxicity of all compounds was determined with in vitro hemolytic assay and found all compounds safe and bio-compatible to humans at all tested concentrations. The inhibition potential was also examined with theoretical docking studies to support our experimental results against human pancreatic alpha-amylase (HPA) and human serum albumin (HSA) proteins. All compounds showed excellent binding affinity with HSA active pockets however, only compound 4h and 4k binding affinity was good with HPA.


Subject(s)
Hypoglycemic Agents , Molecular Docking Simulation , Thiazoles , alpha-Amylases , Hypoglycemic Agents/chemistry , Hypoglycemic Agents/pharmacology , Hypoglycemic Agents/chemical synthesis , Thiazoles/chemistry , Thiazoles/pharmacology , Thiazoles/chemical synthesis , alpha-Amylases/antagonists & inhibitors , alpha-Amylases/metabolism , Antioxidants/pharmacology , Antioxidants/chemistry , Antioxidants/chemical synthesis , Humans , Structure-Activity Relationship , Molecular Structure
8.
Expert Opin Ther Pat ; : 1-25, 2024 Jul 03.
Article in English | MEDLINE | ID: mdl-38958471

ABSTRACT

INTRODUCTION: COX-2 is a crucial enzyme in the manufacture of prostaglandins. The enzyme's metabolites might have an important function as regulators of the inflammatory response and other medical conditions such as cancer. Selective COX-2 inhibitors are believed to enhance or reverse the response of cancer chemotherapeutics. AREAS COVERED: This study addresses the chemical structures as well as the antitumor activity of new COX-2 inhibitors produced in the recent five years, aiming to provide an insight into the mechanism of COX-2 induced PGE2 powerful signal in cancer development. EXPERT OPINION: The significance of selective COX-2 inhibitors as an efficient superfamily of compounds with anti-inflammatory, anti-Alzheimer's, anti-Parkinson's disease, and anticancer properties has piqued the passion of academics in the field of drug development. Long-term usage of selective COX-2 inhibitors, such as celecoxib has been proven in clinical trials to lower the incidence of several human malignancies. Furthermore, celecoxib has the potential to greatly increase the effectiveness of chemotherapy. Our extensive understanding of selective COX-2 inhibitor SAR may aid in the development of safer and more effective selective COX-2 inhibitors as cancer chemopreventive agents. This review focuses on the different structural classes of selective COX-2 inhibitors, with a particular emphasis on their SAR.

9.
Heliyon ; 10(11): e32043, 2024 Jun 15.
Article in English | MEDLINE | ID: mdl-38873672

ABSTRACT

In the realm of air-maritime SAR missions, technical errors are relatively rare compared to human errors due to the multifaceted nature of these missions that standard checklists may not fully encompass. Thus, prioritizing pilot training and implementing a systematic approach are vital to mitigate pilot errors in SAR missions. To mitigate and predict human errors during maritime SAR helicopter hoist tasks, SHERPA methodology is applied in this study. This analysis uncovered a comprehensive total of 54 potential errors, most applicable to countries utilizing rescue aircraft similar to those in Taiwan. The errors identified in this analysis suggest opportunities for enhancing the design of maritime SAR helicopter hoisting tasks through the application of SHERPA, with the potential to decrease their occurrence in the future.

10.
Mar Pollut Bull ; 204: 116549, 2024 Jul.
Article in English | MEDLINE | ID: mdl-38850755

ABSTRACT

Marine oil spills pose significant ecological and economic threats worldwide, requiring effective decision-making tools. In this study, the optimal parameters, and configurations for Deep Learning models in oil spill classification and segmentation using Sentinel-1 SAR imagery were identified. First, a new Sentinel-1 image dataset was created. Ninety CNN configurations were explored for classification by varying the number of convolutional layers, filters, hidden layers, and neurons in each layer. For segmentation tasks, MLP and U-Net models were evaluated with variations in convolutional layers, filters, and incorporation of IoU and Focal Loss. The results indicated that a CNN model with six layers, 32 filters, and two hidden layers achieved 99 % classification accuracy. For segmentation, the U-Net model with more layers and filters using Focal Loss achieved 99 % accuracy and 96 % IoU. Therefore, a CNN and U-Net framework was proposed that achieves an overall accuracy of 95 % and an IoU of 90 %.


Subject(s)
Deep Learning , Environmental Monitoring , Petroleum Pollution , Environmental Monitoring/methods , Neural Networks, Computer
11.
Bioorg Chem ; 150: 107536, 2024 Jun 05.
Article in English | MEDLINE | ID: mdl-38878751

ABSTRACT

Carboxylesterase 1 (CES1), a member of the serine hydrolase superfamily, is involved in a wide range of xenobiotic and endogenous substances metabolic reactions in mammals. The inhibition of CES1 could not only alter the metabolism and disposition of related drugs, but also be benefit for treatment of metabolic disorders, such as obesity and fatty liver disease. In the present study, we aim to develop potential inhibitors of CES1 and reveal the preferred inhibitor structure from a series of synthetic pyrazolones (compounds 1-27). By in vitro high-throughput screening method, we found compounds 25 and 27 had non-competitive inhibition on CES1-mediated N-alkylated d-luciferin methyl ester (NLMe) hydrolysis, while compound 26 competitively inhibited CES1-mediated NLMe hydrolysis. Additionally, Compounds 25, 26 and 27 can inhibit CES1-mediated fluorescent probe hydrolysis in live HepG2 cells with effect. Besides, compounds 25, 26 and 27 could effectively inhibit the accumulation of lipid droplets in mouse adipocytes cells. These data not only provided study basis for the design of newly CES1 inhibitors. The present study not only provided the basis for the development of lead compounds for novel CES1 inhibitors with better performance, but also offered a new direction for the explore of candidate compounds for the treatment of hyperlipidemia and related diseases.

12.
Pestic Biochem Physiol ; 202: 105943, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38879303

ABSTRACT

In this study, a new series of thiazolo[4,5-b]quinoxaline derivatives 3-8 were synthesized by treating 2,3-dichloroquinoxaline with thiosemicarbazone and thiourea derivatives under reflux conditions. The chemical structure of the newly designed derivatives was conducted using spectroscopic techniques. The insecticidal bioassay of the designed derivatives was evaluated against the 2nd and 4th larvae of S. litura after five days as toxicity agents via median lethal concentration (LC50) and the lethal time values (LT50). The results indicated that all the tested compounds had insecticidal effects against both instar larvae of S. litura with variable values. Among them, thiazolo[4,5-b]quinoxaline derivative 3 was the most toxic, with LC50 = 261.88 and 433.68 ppm against 2nd and 4th instar larvae, respectively. Moreover, the thiazolo[4,5-b]quinoxaline derivative 3 required the least time to kill the 50% population (LT50) of 2nd larvae were 20.88, 13.2, and 15.84 hs with 625, 1250, and 2500 ppm, respectively, while for the 4th larval instar were 2.75, 2.08, and 1.76 days with concentrations of 625, 1250, and 2500 ppm, respectively. Larvae's morphological and histological studies for the most active derivative 3 were investigated. According to SEM analysis, the exterior morphology of the cuticle and head capsule was affected. In addition, there were some histological alterations in the cuticle layers and the midgut tissues. Columnar cells began breaking down, and vacuolization occurred in the peritrophic membrane. Moreover, treating 4th S litura larvae hemolymph with compound 3 showed significant changes in biochemical analysis, such as total proteins, GPT, GOT, acetylcholinesterase (AChE), and alkaline phosphatase (AlP). Finally, the toxicity prediction of the most active derivative revealed non-corrosive, non-irritant to the eye, non-respiratory toxicity, non-sensitivity to the skin, non-hepatotoxic, and don't have toxicity on minnow toxicity and T. pyriformis indicating a good toxicity profile for human.


Subject(s)
Insecticides , Larva , Quinoxalines , Spodoptera , Animals , Insecticides/chemical synthesis , Insecticides/pharmacology , Insecticides/toxicity , Insecticides/chemistry , Quinoxalines/toxicity , Quinoxalines/pharmacology , Quinoxalines/chemical synthesis , Quinoxalines/chemistry , Larva/drug effects , Spodoptera/drug effects , Spodoptera/growth & development , Thiazoles/chemistry
13.
Future Med Chem ; : 1-13, 2024 Jun 28.
Article in English | MEDLINE | ID: mdl-38940467

ABSTRACT

Aim: The present study describes benzothiazole derived thiazolidinone based thiadiazole derivatives (1-16) as anti-Alzheimer agents. Materials & methods: Synthesis of benzothiazole derived thiazolidinone based thiadiazole derivatives was achieved using the benzothiazole bearing 2-amine moiety. These synthesized compounds were confirmed via spectroscopic techniques (1H NMR, 13C NMR and HREI-MS). These compounds were biologically evaluated for their anti-Alzheimer potential. Binding interactions with proteins and drug likeness of the analogs were explored through molecular docking and ADMET analysis, respectively. In the novel series, compound-3 emerged as the most potent inhibitor when compared with other derivatives of the series. Conclusion: The present study provides potent anti-Alzheimer's agents that can be further optimized to discover novel anti-Alzheimer's drugs.


[Box: see text].

14.
ACS Appl Bio Mater ; 2024 Jun 27.
Article in English | MEDLINE | ID: mdl-38934736

ABSTRACT

Protein cages are promising tools for the controlled delivery of therapeutics and imaging agents when endowed with programmable disassembly strategies. Here, we produced hybrid nanocomposites made of tobacco mosaic virus (TMV) and magnetic iron oxide nanoparticles (IONPs), designed to disrupt the viral protein cages using magnetically induced release of heat. We studied the effects of this magnetic hyperthermia on the programmable viral protein capsid disassembly using (1) elongated nanocomposites of TMV coated heterogeneously with magnetic iron oxide nanoparticles (TMV@IONPs) and (2) spherical nanocomposites of polystyrene (PS) on which we deposited presynthesized IONPs and TMV via layer-by-layer self-assembly (PS@IONPs/TMV). Notably, we found that the extent of the disassembly of the protein cages is contingent upon the specific absorption rate (SAR) of the magnetic nanoparticles, that is, the heating efficiency, and the relative position of the protein cage within the nanocomposite concerning the heating sources. This implies that the spatial arrangement of components within the hybrid nanostructure has a significant impact on the disassembly process. Understanding and optimizing this relationship will contribute to the critical spatiotemporal control for targeted drug and gene delivery using protein cages.

15.
Materials (Basel) ; 17(12)2024 Jun 17.
Article in English | MEDLINE | ID: mdl-38930318

ABSTRACT

Cancer is a major worldwide public health problem. Although there have already been astonishing advances in cancer diagnosis and treatment, the scientific community continues to make huge efforts to develop new methods to treat cancer. The main objective of this work is to prepare, using a green sol-gel method with coconut water powder (CWP), a new nanocomposite with a mixture of Gd3Fe5O12 and ZnFe2O4, which has never been synthesized previously. Therefore, we carried out a structural (DTA-TG and X-ray diffraction), morphological (SEM), and magnetic (VSM and hyperthermia) characterization of the prepared samples. The prepared nanocomposite denoted a saturation magnetization of 11.56 emu/g at room temperature with a ferromagnetic behavior and with a specific absorption rate (SAR) value of 0.5 ± 0.2 (W/g). Regarding cytotoxicity, for concentrations < 10 mg/mL, it does not appear to be toxic. Although the obtained results were interesting, the high particle size was identified as a problem for the use of this nanocomposite.

16.
Sensors (Basel) ; 24(12)2024 Jun 07.
Article in English | MEDLINE | ID: mdl-38931509

ABSTRACT

Oil spills are a major threat to marine and coastal environments. Their unique radar backscatter intensity can be captured by synthetic aperture radar (SAR), resulting in dark regions in the images. However, many marine phenomena can lead to erroneous detections of oil spills. In addition, SAR images of the ocean include multiple targets, such as sea surface, land, ships, and oil spills and their look-alikes. The training of a multi-category classifier will encounter significant challenges due to the inherent class imbalance. Addressing this issue requires extracting target features more effectively. In this study, a lightweight U-Net-based model, Full-Scale Aggregated MobileUNet (FA-MobileUNet), was proposed to improve the detection performance for oil spills using SAR images. First, a lightweight MobileNetv3 model was used as the backbone of the U-Net encoder for feature extraction. Next, atrous spatial pyramid pooling (ASPP) and a convolutional block attention module (CBAM) were used to improve the capacity of the network to extract multi-scale features and to increase the speed of module calculation. Finally, full-scale features from the encoder were aggregated to enhance the network's competence in extracting features. The proposed modified network enhanced the extraction and integration of features at different scales to improve the accuracy of detecting diverse marine targets. The experimental results showed that the mean intersection over union (mIoU) of the proposed model reached more than 80% for the detection of five types of marine targets including sea surface, land, ships, and oil spills and their look-alikes. In addition, the IoU of the proposed model reached 75.85 and 72.67% for oil spill and look-alike detection, which was 18.94% and 25.55% higher than that of the original U-Net model, respectively. Compared with other segmentation models, the proposed network can more accurately classify the black regions in SAR images into oil spills and their look-alikes. Furthermore, the detection performance and computational efficiency of the proposed model were also validated against other semantic segmentation models.

17.
Sensors (Basel) ; 24(12)2024 Jun 17.
Article in English | MEDLINE | ID: mdl-38931705

ABSTRACT

The simulation of microwave absorption and external thermal flow is an essential aspect of the vacuum thermal testing process for Synthetic Aperture Radar (SAR) antenna. This paper proposes a novel integrated method for simulating microwave absorption and external thermal flow, specifically designed for vacuum thermal testing. The method employs a non-woven fabric square pyramid assembly as the primary structure to establish a low electromagnetic scattering environment. External heat flow simulation is achieved by arranging carbon fiber heating wires between square cones. Through numerical analysis and experimental tests, the influence of the position of the carbon fiber heating wire on the uniformity of heat flow and reflectivity was revealed. A prototype system is developed based on these findings. The external thermal flow is adjustable in the range of 80-550 W/m2, with a uniformity better than 5%. The reflectivity in the L to X microwave frequency band is basically better than -25 dB, and in local frequency bands, it is better than -30 dB. The system has been successfully applied in SAR antenna component and satellite vacuum thermal tests, meeting all ground simulation test requirements and exhibiting significant potential for widespread application.

18.
Bioorg Med Chem ; 109: 117791, 2024 Jul 15.
Article in English | MEDLINE | ID: mdl-38870715

ABSTRACT

The flavonoid family is a set of well-known bioactive natural molecules, with a wide range of potential therapeutic applications. Despite the promising results obtained in preliminary in vitro/vivo studies, their pharmacokinetic and pharmacodynamic profiles are severely compromised by chemical instability. To address this issue, the scaffold-hopping approach is a promising strategy for the structural optimization of natural leads to discover more potent analogues. In this scenario, this Perspective provides a critical analysis on how the replacement of the chromon-4-one flavonoid core with other bioisosteric nitrogen/sulphur heterocycles might affect the chemical, pharmaceutical and biological properties of the resulting new chemical entities. The investigated derivatives were classified on the basis of their biological activity and potential therapeutic indications. For each session, the target(s), the specific mechanism of action, if available, and the key pharmacophoric moieties were highlighted, as revealed by X-ray crystal structures and in silico structure-based studies. Biological activity data, in vitro/vivo studies, were examined: a particular focus was given on the improvements observed with the new heterocyclic analogues compared to the natural flavonoids. This overview of the scaffold-hopping advantages in flavonoid compounds is of great interest to the medicinal chemistry community to better exploit the vast potential of these natural molecules and to identify new bioactive molecules.


Subject(s)
Flavonoids , Heterocyclic Compounds , Flavonoids/chemistry , Flavonoids/pharmacology , Flavonoids/chemical synthesis , Humans , Heterocyclic Compounds/chemistry , Heterocyclic Compounds/pharmacology , Heterocyclic Compounds/chemical synthesis , Chemistry, Pharmaceutical , Biological Products/chemistry , Biological Products/pharmacology , Biological Products/chemical synthesis , Molecular Structure , Structure-Activity Relationship , Animals
19.
Bioorg Med Chem ; 109: 117796, 2024 Jul 15.
Article in English | MEDLINE | ID: mdl-38879996

ABSTRACT

The USFDA granted regular approval to Osimertinib (AZD9291) on March 2017, for treating individuals with metastatic Non-Small Cell Lung Cancer having EGFR T790M mutation. Clinically, Osimertinib stands at the forefront for the treatment of patients with Non-Small Cell Lung Cancer. Osimertinib forms a covalent bond with the Cys797 residue and predominantly spares binding to WT-EGFR, thereby reducing toxicity and enabling the administration of doses that effectively inhibit T790M. However, a high percentage of patients treated with Osimertinib (AZD9291) developed a tertiary cysteine797 to serine797 (C797S) mutation in the EGFR kinase domain, rendering resistance to it. This comprehensive review sheds light on the chemistry, computational aspects, structural features, and expansive spectrum of biological activities of Osimertinib and its analogues. The in-depth exploration of these facets serves as a valuable resource for medicinal chemists, empowering them to design better Osimertinib analogues. This exhaustive study not only provides insights into improving potency but also emphasizes considerations for mutant selectivity and optimizing pharmacokinetic properties. This review acts as a guiding beacon for the strategic design and development of next-generation Osimertinib analogues.


Subject(s)
Acrylamides , Aniline Compounds , Antineoplastic Agents , Carcinoma, Non-Small-Cell Lung , ErbB Receptors , Lung Neoplasms , Mutation , Protein Kinase Inhibitors , Acrylamides/chemistry , Acrylamides/pharmacology , Aniline Compounds/chemistry , Aniline Compounds/pharmacology , Humans , Carcinoma, Non-Small-Cell Lung/drug therapy , Carcinoma, Non-Small-Cell Lung/pathology , ErbB Receptors/antagonists & inhibitors , ErbB Receptors/metabolism , ErbB Receptors/genetics , Lung Neoplasms/drug therapy , Lung Neoplasms/pathology , Protein Kinase Inhibitors/chemistry , Protein Kinase Inhibitors/pharmacology , Protein Kinase Inhibitors/chemical synthesis , Structure-Activity Relationship , Antineoplastic Agents/chemistry , Antineoplastic Agents/pharmacology , Antineoplastic Agents/chemical synthesis , Molecular Structure , Piperazines/chemistry , Piperazines/pharmacology , Indoles , Pyrimidines
20.
Virus Res ; 347: 199427, 2024 Jun 27.
Article in English | MEDLINE | ID: mdl-38917940

ABSTRACT

The hepatitis E virus (HEV) is infecting over 20 million people annually with a high morbidity especially in pregnant women and immune-suppressed individuals. While HEV genotype 1 (HEV-1) infects only humans, genotype 3 (HEV-3) is zoonotic and commonly transmitted from infected animals to humans. Whereas a few reverse genetics systems enabling targeted genome manipulations exist for HEV-3, those for HEV-1 are still very limited, mainly because of inefficient cell culture replication. Here, the generation of HEV-1 strain Sar55 and HEV-3 strain 47832mc by transfecting in vitro-transcribed and capped virus genomes into different cell lines was attempted. Culture supernatants of colon-derived colorectal adenocarcinoma cell line Caco-2 contained HEV-1 and HEV-3 capable of infecting Caco-2 cells. Density gradient centrifugation analyses of culture supernatants confirmed that HEV-1 particles were quasi-enveloped in analogy to HEV-3 and that non-virion-associated capsid protein was secreted from cells. Following transfection or infection of Caco-2 cells, HEV-1 consistently reached higher titers than HEV-3 in culture supernatants, but HEV-1 generated by transfection of Caco-2 cells was unable to efficiently infect hepatoma cell lines PLC/PRF/5 or HuH7-Lunet BLR. Taken together, our results indicate that HEV-1 is able to exert a complete replication cycle in Caco-2 cells. An efficient cell culture system for this genotype will be useful for studying species tropism, but further research is required to determine the significance of HEV-1 replication in colon-derived cells.

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