Low IC50 Values Research Articles

Metabolic Fingerprinting of Different Sideritis Taxa Infusions and Their Neurogenic Activity.

Over the last years, Sideritis extracts were shown to improve memory. However, their potential to promote the generation of new neurons, starting with the neuronal differentiation of neural stem cells, remains unexplored. Therefore, the present study aimed to evaluate the neurogenic effects of different Sideritis infusions in neural stem and precursor cells and their impact on cell viability. Moreover, the metabolic fingerprints were recorded using LC-DAD, LC-HRESIMS, and GC-MS. The neurogenic potential of infusions of the eight Sideritis taxa tested was as potent as the classical neuronal inducer combination of retinoic acid and valproic acid. Further cytotoxicity assays revealed that the IC50 values of the extracts were between 163 and 322 µg/mL. Hierarchical cluster analyses of the metabolic fingerprints unveiled that the two Sideritis taxa with the lowest IC50 values were the most divergent in the analytical techniques used. As the analysis focused on polyphenols, it is reasonable to assume that these compounds are responsible for the effect on the cell viability of SH-SY5Y neuroblastoma cells. This study is the first report on the neurogenic potential of Sideritis taxa and might support the use of Sideritis herbal preparations in the context of neurodegenerative diseases.

In Silico and In Vitro Evaluation of Some Amidine Derivatives as Hit Compounds towards Development of Inhibitors against Coronavirus Diseases.

Coronaviruses, including SARS-CoV-2, SARS-CoV, MERS-CoV and influenza A virus, require the host proteases to mediate viral entry into cells. Rather than targeting the continuously mutating viral proteins, targeting the conserved host-based entry mechanism could offer advantages. Nafamostat and camostat were discovered as covalent inhibitors of TMPRSS2 protease involved in viral entry. To circumvent their limitations, a reversible inhibitor might be required. Considering nafamostat structure and using pentamidine as a starting point, a small set of structurally diverse rigid analogues were designed and evaluated in silico to guide selection of compounds to be prepared for biological evaluation. Based on the results of in silico study, six compounds were prepared and evaluated in vitro. At the enzyme level, compounds 10-12 triggered potential TMPRSS2 inhibition with low micromolar IC50 concentrations, but they were less effective in cellular assays. Meanwhile, compound 14 did not trigger potential TMPRSS2 inhibition at the enzyme level, but it showed potential cellular activity regarding inhibition of membrane fusion with a low micromolar IC50 value of 10.87 µM, suggesting its action could be mediated by another molecular target. Furthermore, in vitro evaluation showed that compound 14 inhibited pseudovirus entry as well as thrombin and factor Xa. Together, this study presents compound 14 as a hit compound that might serve as a starting point for developing potential viral entry inhibitors with possible application against coronaviruses.

Bioconversion of a Peanut Oil Processing By-Product into a Novel α-Glucosidase Inhibitor: Hemi-Pyocyanin

Hemi-pyocyanin (HPC) is a heterocyclic nitrogenous compound with some reported potential medical effects. The current report aimed to investigate the potential use of organic industrial waste for the production of HPC via microbial fermentation. The novel antidiabetic activity of HPC was also accessed and reported in this work. A peanut oil processing by-product (groundnut cake) was screened as the best substrate for Pseudomonas aeruginosa TUN03 conversion to obtain high-yield HPC. This compound was further produced in a 14 L bioreactor system on a large scale (6 L per pilot) and reached higher productivity (35.1 μg/mL) in a shorter time course of cultivation (8 h) compared to fermentation on a small scale in flasks (19.5 μg/mL; 3 days of fermentation). On assessing its activity, HPC demonstrated potent inhibition against α-glucosidase, an antidiabetic enzyme, with a low IC50 value (0.572 mg/mL) and a maximum inhibition rate of 100%. In an in silico study, HPC was found to inhibit α-glucosidase with a good binding energy score (−9.0 kcal/mol) via interaction with amino acids Lys156, Leu313, and Arg315 at the active site, and three bonds (1 H-acceptor and 2 pi-H) were generated. The data from five Lipkin’s rules and ADMET-based pharmacokinetics and pharmacology revealed that HPC possesses drug-like properties and good ADMET properties within the required allotted limitations. The data obtained in the current work highlighted the potential application of groundnut cakes for the eco-friendly and scaled-up production of HPC, a new anti-α-glucosidase agent that should be further investigated for type 2 diabetes management.

Comprehensive analysis and molecular map of Hippo signaling pathway in lower grade glioma: the perspective toward immune microenvironment and prognosis.

The activation of YAP/TAZ transcriptional co-activators, downstream effectors of the Hippo/YAP pathway, is commonly observed in human cancers, promoting tumor growth and invasion. The aim of this study was to use machine learning models and molecular map based on the Hippo/YAP pathway to explore the prognosis, immune microenvironment and therapeutic regimen of patients with lower grade glioma (LGG). SW1783 and SW1088 cell lines were used as in vitro models for LGG, and the cell viability of the XMU-MP-1 (a small molecule inhibitor of the Hippo signaling pathway) treated group was evaluated using a Cell Counting Kit-8 (CCK-8). Univariate Cox analysis on 19 Hippo/YAP pathway related genes (HPRGs) was performed to identify 16 HPRGs that exhibited significant prognostic value in meta cohort. Consensus clustering algorithm was used to classify the meta cohort into three molecular subtypes associated with Hippo/YAP Pathway activation profiles. The Hippo/YAP pathway's potential for guiding therapeutic interventions was also investigated by evaluating the efficacy of small molecule inhibitors. Finally, a composite machine learning models was used to predict individual patients' survival risk profiles and the Hippo/YAP pathway status. The findings showed that XMU-MP-1 significantly enhanced the proliferation of LGG cells. Different Hippo/YAP Pathway activation profiles were associated with different prognostic and clinical features. The immune scores of subtype B were dominated by MDSC and Treg cells, which are known to have immunosuppressive effects. Gene Set Variation Analysis (GSVA) indicated that subtypes B with a poor prognosis exhibited decreased propanoate metabolic activity and suppressed Hippo pathway signaling. Subtype B had the lowest IC50 value, indicating sensitivity to drugs that target the Hippo/YAP pathway. Finally, the random forest tree model predicted the Hippo/YAP pathway status in patients with different survival risk profiles. This study demonstrates the significance of the Hippo/YAP pathway in predicting the prognosis of patients with LGG. The different Hippo/YAP Pathway activation profiles associated with different prognostic and clinical features suggest the potential for personalized treatments.

The Photodynamic Anticancer and Antibacterial Activity Properties of a Series of meso-Tetraarylchlorin Dyes and Their Sn(IV) Complexes.

A series of tetraarylchlorins with 3-methoxy-, 4-hydroxy- and 3-methoxy-4-hydroxyphenyl meso-aryl rings (1-3-Chl) and their Sn(IV) complexes (1-3-SnChl) were synthesized and characterized so that their potential utility as photosensitizer dyes for use in photodynamic therapy (PDT) and photodynamic antimicrobial chemotherapy (PACT) can be assessed. The photophysicochemical properties of the dyes were assessed prior to in vitro PDT activity studies against MCF-7 breast cancer cells through irradiation with Thorlabs 625 or 660 nm LED for 20 min (240 or 280 mW·cm-2). PACT activity studies were performed against both planktonic bacteria and biofilms of Gram-(+) S. aureus and Gram-(-) E. coli upon irradiation with Thorlabs 625 and 660 nm LEDs for 75 min. The heavy atom effect of the Sn(IV) ion results in relatively high singlet oxygen quantum yield values of 0.69-0.71 for 1-3-SnChl. Relatively low IC50 values between 1.1-4.1 and 3.8-9.4 µM were obtained for the 1-3-SnChl series with the Thorlabs 660 and 625 nm LEDs, respectively, during the PDT activity studies. 1-3-SnChl were also found to exhibit significant PACT activity against planktonic S. aureus and E. coli with Log10 reduction values of 7.65 and >3.0, respectively. The results demonstrate that the Sn(IV) complexes of tetraarylchlorins merit further in depth study as photosensitizers in biomedical applications.

Pluronic F127 and P104 Polymeric Micelles as Efficient Nanocarriers for Loading and Release of Single and Dual Antineoplastic Drugs.

The potential application of biodegradable and biocompatible polymeric micelles formed by Pluronic F127 and P104 as nanocarriers of the antineoplastic drugs docetaxel (DOCE) and doxorubicin (DOXO) is presented in this work. The release profile was carried out under sink conditions at 37 °C and analyzed using the Higuchi, Korsmeyer-Peppas, and Peppas-Sahlin diffusion models. The cell viability of HeLa cells was evaluated using the proliferation cell counting kit CCK-8 assay. The formed polymeric micelles solubilized significant amounts of DOCE and DOXO, and released them in a sustained manner for 48 h, with a release profile composed of an initial rapid release within the first 12 h followed by a much slower phase the end of the experiments. In addition, the release was faster under acidic conditions. The model that best fit the experimental data was the Korsmeyer-Peppas one and denoted a drug release dominated by Fickian diffusion. When HeLa cells were exposed for 48 h to DOXO and DOCE drugs loaded inside P104 and F127 micelles, they showed lower IC50 values than those reported by other researchers using polymeric nanoparticles, dendrimers or liposomes as alternative carriers, indicating that a lower drug concentration is needed to decrease cell viability by 50%.

Design, Synthesis, Characterization and Biological Activities of Novel S‐(Acyloxy)butyl‐N,N‐Diethyldithiocarbamate Compounds

AbstractIn this study, S‐(Acyloxy)butyl‐N,N‐Diethyldithiocarbamate compounds (P1‐P7) were synthesized by s‐alkylation of N,N‐diethyldithiocarbamate sodium trihydrate with 4‐chlorobutylcarboxylates. P1–P7 were characterized by full infrared, NMR spectroscopy and elemental analyses. Additionally, the impacts of these compounds were investigated on some metabolic enzymes and then compared to the reference compounds. It was observed that the DEDTCA esters generally had lower IC50 and Ki values. Among them, P4 and P6 molecules had lower IC50 with 112.47 and 111.55 μM; and Ki values: 105.53±7.17 and 102.06±5.08 μM against AChE, respectively. Furthermore, molecular docking simulations approved the binding interaction patterns and structural orientations of N,N‐diethyldithiocarbamic acid derivatives within the binding sites of AChE, BChE and α‐glucosidase. Taken together, the compound P6 performs strong distant bond interactions against tacrine for AChE and BChE enzymes within the scope of in silico study. The compound P4, on the other hand, exhibits good interactions with the target by making hydrophobic, pi‐sulfur and pi‐sigma bonds as well as hydrogen bonds compared to acarbose as standard compound against α‐glucosidase. These can be further analyzed as potent candidate compounds in biological studies of the respective enzymes.

Dual gatekeepers-modified mesoporous organic silica nanoparticles for synergistic photothermal-chemotherapy of breast cancer

HypothesisConstruction of dual gatekeepers-functionalized mesoporous organic silica nanoparticles (MONs) with both physical and chemical mechanisms for modulated drug delivery properties provides one solution to the extracellular stability vs. intracellular high therapeutic efficiency of MONs that hold great potential for clinical translations. ExperimentsWe reported herein facile construction of diselenium-bridged MONs decorated with dual gatekeepers, i.e., azobenzene (Azo)/polydopamine (PDA) for both physical and chemical modulated drug delivery properties. Specifically, Azo can act as a physical barrier to block DOX in the mesoporous structure of MONs for extracellular safe encapsulation. The PDA outer corona serves not only as a chemical barrier with acidic pH-modulated permeability for double insurance of minimized DOX leakage in the extracellular blood circulation but also for inducing a PTT effect for synergistic PTT and chemotherapy of breast cancer. FindingsAn optimized formulation, DOX@(MONs-Azo3)@PDA resulted in approximately 1.5 and 2.4 fold lower IC50 values than DOX@(MONs-Azo3) and (MONs-Azo3)@PDA controls in MCF-7 cells, respectively, and further mediated complete tumor eradication in 4T1 tumor-bearing BALB/c mice with insignificant systematic toxicity due to the synergistic PTT and chemotherapy with enhanced therapeutic efficiency.

Bioactive compounds and mechanism of Xianglian pill in the treatment of gastric cancer: Network pharmacology analysis and experimental validation

Ethnopharmacological relevanceGastric cancer (GC) affects people's quality of life because of its high incidence rate and mortality. The Xianglian Pill (XLP) is a traditional Chinese medicine (TCM) prescription used to treat gastrointestinal (GI） diseases. Its anti-tumor effect has been found in recent years, but it's bioactive compounds and mechanism of action in treating GC are remain unknown. Aim of the studyThis study reveals the bioactive compounds and mechanisms of XLP in the treatment of GC through network pharmacology analysis and experimental verification. Materials and methodsThe main compounds in XLP were searched and the active compounds with anti-GC activity were selected. Compounds targets and GC- related targets were predicted, and common targets were obtained. Subsequently, a protein-protein interaction (PPI) network of common targets is constructed, while GO and KEGG enrichment analyses were performed on common targets. Finally, the anti-GC effects of active compounds in XLP were verified in GC cell lines MGC-803 and HGC-27 by wound healing assay, cell cycle assay, cell apoptosis assay and western blotting (WB) assay. ResultsA total of 33 active compounds of XLP were obtained. MTT assay showed that dehydrocostus lactone (DHL) and berberrubine (BRB) had lower IC50 value in GC cells HGC-27 and MGC-803, and has a less inhibitory effect on normal gastric epithelial cells. Further, 73 common targets were obtained after the total target of DHL and BRB intersected with GC. Among them, CASP3, AKT1, SRC, STAT3,and CASP9 were the most associated genes in the PPI network. GO and KEGG enrichment analyses indicated that apoptosis played a major role in the biological processes and signaling pathways involved. Moreover, the in vitro experiment revealed that DHL and BRB inhibited GC cell viability via inducing cell cycle arrest at G2/M phase, and promoting cell apoptosis by up-regulating the caspase3 expression and down-regulating the expression of Bcl2/Bax. ConclusionsDHL and BRB are the two main anti-GC active compounds in XLP, and their mechanism is mainly to inhibit cell cycle and promote cell apoptosis.

A novel water-soluble thiosemicarbazone Schiff base ligand and its complexes as potential anticancer agents and cellular fluorescence imaging.

A novel fluorescent ligand (H2LCl⋅1.5CH3OH, 1) was synthesized and metal complexes of 1 with Mn(II), Fe(III), Ni(II), Cu(II), and Zn(II) were obtained as Mn(HL)2Cl2 (2), Fe(HL)2Cl3⋅3H2O (3), Ni(L)(HL)Cl⋅8H2O (4), Cu(HL)Cl2⋅4H2O (5), Zn(H2L)Cl3 (6), respectively. These compounds were identified by spectroscopic methods, elemental analysis, molar conductivity, and single-crystal X-ray crystallography. According to the crystal structure of 4 nickel (II), center is surrounded by two ligands in a distorted octahedral geometry. The ligand and its complexes are soluble in water and have excellent stability. In vitro anti-proliferative activity of these compounds was evaluated against human breast adenocarcinoma (MCF-7) and human lipo-sarcoma (SW-872) as cancer cells and human fibroblasts (HFF-2) as normal cells by MTT assay. Interestingly, complex 5 exhibited excellent activity against both cancer cells with low IC50 value 22.18 ± 0.35μg/mL (35.66 ± 0.56μM) for SW-872 and 79.41 ± 3.54μg/mL (127.6 ± 5.69μM) for MCF-7 among the compounds and in comparison with paclitaxel (PTX) which acts finely. Morphological changes were evaluated by flow cytometry that revealed apoptosis is the main cause of cell death. Likewise, cell cycle studies indicated the cell cycle arrest in the G1 and S phases for complex 5 against MCF-7 and SW-872 cancer cells, while complex 6 could arrest the MCF-7 and SW-872 cells in G2 and G1 phases, respectively. All of the compounds are fluorescent which enabled us to monitor the uptake and intracellular distribution in living human cancer cells by fluorescence microscopy.

Novel advances in parainfluenza virus 3 neutralization through antibodies targeting hemagglutinin-neuraminidase.

Abstract Parainfluenza virus 3 (PIV3) remains to be a global burden to infants, the elderly, and immunocompromised individuals. With no approved therapeutics or vaccines, PIV3 continues to cause a large portion of the lower respiratory illness hospitalizations in young children. Similar to other paramyxoviruses, PIV3 utilizes two structural proteins, the fusion (F) protein and the hemagglutinin-neuraminidase (HN) protein, for viral fusion and entry. Here, we characterize newly identified human monoclonal antibodies (mAbs) targeting HN on the PIV3 virion, with EC 50values ranging from 9ng/mL to 21ng/mL. The mAbs were tested for neutralization of PIV3 and all were determined to have an IC 50values ranging from 11ng/mL to 450ng/mL. Utilizing biolayer interferometry, we conducted a competitive epitope mapping study and found the mAbs targeted three major epitopes on the HN protein with some competitive binding between multiple sites, suggesting these epitopes are within close proximity of each other. mAbs binding to one particular site had significantly low IC 50values ranging from 11ng/mL to 120ng/mL. We have established a PIV3 infection model in Golden Syrian hamsters and are currently testing mAbs from each epitope for prevention of viral replication in the lungs and airways. Due to the similarities between the HN protein amongst different parainfluenza virus subtypes, we plan to study the potential cross-neutralizing capabilities of these mAbs against other parainfluenza virus subtypes. Supported by grants from NIH (R01 AI143865)

Bioactive compounds and in vitro evaluation of antioxidant capacities, antimicrobial properties, and effectiveness of cytotoxicity of three edible mushrooms from Egypt

Many edible mushrooms have been evaluated as new therapeutic alternatives with various activities. We focused this work to estimate the antioxidant, antimicrobial and cytotoxicity effects of three edible aqueous mushroom extracts: Agaricus bisporus (white button mushroom), Pleurotus ostreatus (pearl oyster mushroom), and Pleurotus pulmonarius (Phoenix mushroom). The biochemical analysis of extracts revealed marked variations for total carbohydrate, protein, phenolic, and flavonoid contents. The three extracts were tested for antioxidant activities using 2,2-diphenyl-1-picryl-hydrazyl-hydrate (DPPH) radical scavenging assay. Pleurotus ostreatus had a potential antioxidant capacity with lowest IC50 value (13.26 µg/mL). Distinct variable degrees of antimicrobial activity were detected against five reference microbial strains, exerting the minimum inhibitory concentration (MIC) ranging from 28 to 89 mg/ml. Agaricus bisporus exhibited the highest cytotoxicity against EAC cells with cell viability 68% and showed an evidenced inhibitory action against human breast cancer cell lines (MCF-7) based on Sulforhodamine B (SRB) assay.

In vitro antioxidant and anticancer potential of Annona squamosa L. Extracts against breast cancer

Various ailments have long been treated with plant-based remedies. This research aims to determine which compounds are present in Annona squamosa L. leaves and seeds extracts, as well as their antioxidant and anticancer potential. Annona squamosa L. hexane, methanol, and aqueous extracts were analysed for their phytochemical content, and results showed the existence of many useful compounds. The DPPH assay was used to measure the antioxidant activity. In particular, the low IC50 values revealed that the plant extracts under study possessed remarkable antioxidant activities. Antioxidant phytochemicals such alkaloid, flavonoid, phenol, oil, phytosterol, coumarin, and saponins may be responsible for these benefits. This research shows that extracts of Annona squamosa L. have a high antioxidant activity and promise as a dietary supplement and possible medicinal agent. MTT assay was used to test for anticancer characteristics. Cell viability was assessed for each extract using a negative control and a positive control (Cisplatin). Both the Annona squamosa L. (seeds) methanolic extract and the Annona squamosa L. (leaves) water extract showed substantial efficacy in this investigation against the MCF-7 breast cancer cell line. It follows that extracts of Annona squamosa L. (leaves) and (seeds) could be used to create a natural medicine for breast cancer treatment.

Synthesis and Investigation of Anti-Inflammatory Activity of New Thiourea Derivatives of Naproxen.

The aim of the study was a synthesis and investigation of the dose-dependent anti-inflammatory effect of new thiourea derivatives of naproxen with selected aromatic amines and esters of aromatic amino acids. The results of the in vivo study indicate that derivatives of m-anisidine (4) and N-methyl tryptophan methyl ester (7) showed the most potent anti-inflammatory activity four hours after injection of carrageenan, with the percentage of inhibition of 54.01% and 54.12%, respectively. In vitro assays of COX-2 inhibition demonstrated that none of the tested compounds achieved 50% inhibition at concentrations lower than 100 µM. On the other hand, the aromatic amine derivatives (1-5) accomplished significant inhibition of 5-LOX, and the lowest IC50 value was observed for compound 4 (0.30 μM). High anti-edematous activity of compound 4 in the rat paw edema model, together with potent inhibition of 5-LOX, highlight this compound as a promising anti-inflammatory agent.

Essential Oil of Origanum vulgare var. aureum L. from Western Romania: Chemical Analysis, In Vitro and In Silico Screening of Its Antioxidant Activity

This investigation aims to assess the chemical composition and antioxidant properties of Origanum vulgare var. aureum L. essential oil (OEO). The oil was obtained with a 0.34% (v/w dried weight) yield and investigated by gas chromatography-mass spectrometry (GC–MS) analysis. The main compounds of the OEO were found to be gamma-terpinene (22.96%), para-cymene (14.72%), germacrene (11.64%), beta-trans-ocimene (9.81%), and cis-beta-ocimene (7.65%). Furthermore, individual antioxidant assays 1,1-diphenyl-2-picrylhydrazyl (DPPH) and [2,2′-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium] (ABTS) radical scavenging activities and beta-carotene/linoleic acid bleaching were carried out. OEO demonstrated better scavenging effects on the DPPH (IC50 93.12 ± 0.03 μg/mL) and ABTS (IC50 27.63 ± 0.01 μg/mL) assays (significantly lower IC50 values; p ≤ 0.001) than ascorbic acid (IC50 127.39 ± 0.45 μg/mL). In the beta-carotene/linoleic acid bleaching assay, the OEO exhibited a higher Relative antioxidant activity (RAA %) (82.36 ± 0.14%) but lower compared with butylated hydroxyanisole (BHA) (100%), with no significant differences (p > 0.05) observed. According to molecular docking results, the first two main compounds of the OEO, para-cymene, and gamma-terpinene, may potentially contribute to the biological antioxidant activity of the oil by inhibiting ROS (reactive oxygen species)-producing enzymes such as lipoxygenase and xanthin oxidase. These experimental data suggest that OEO could represent a valuable new natural antioxidant source with functional properties in the food or pharmaceutical industries.

Broadly neutralizing antibodies against Omicron variants of SARS-CoV-2 derived from mRNA-lipid nanoparticle-immunized mice

The COVID-19 pandemic continues to threaten human health worldwide as new variants of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) emerge. Currently, the predominant circulating strains around the world are Omicron variants, which can evade many therapeutic antibodies. Thus, the development of new broadly neutralizing antibodies remains an urgent need. In this work, we address this need by using the mRNA-lipid nanoparticle immunization method to generate a set of Omicron-targeting monoclonal antibodies. Five of our novel K-RBD-mAbs show strong binding and neutralizing activities toward all SARS-CoV-2 variants of concern (Alpha, Beta, Gamma, Delta and Omicron). Notably, the epitopes of these five K-RBD-mAbs are overlapping and localized around Y453 and F486 of the spike protein receptor binding domain (RBD). Chimeric derivatives of the five antibodies (K-RBD-chAbs) neutralize Omicron sublineages BA.1 and BA.2 with low IC50 values ranging from 5.7 to 12.9 ng/mL. Additionally, we performed antibody humanization on broadly neutralizing chimeric antibodies to create K-RBD-hAb-60 and -62, which still retain excellent neutralizing activity against Omicron. Our results collectively suggest that these five therapeutic antibodies may effectively combat current and emerging SARS-CoV-2 variants, including Omicron BA.1 and BA.2. Therefore, the antibodies can potentially be used as universal neutralizing antibodies against SARS-CoV-2.

Organyltellurium(IV) complexes incorporating Schiff base ligand derived from 2-hydroxy-1-naphthaldehyde: Preparation, spectroscopic investigations, antimicrobial, antioxidant activities, DFT, MESP, NBO, molecular docking and ADMET evaluation

In this article, the synthesis of 1-(((2-nitrophenyl)imino)methyl)naphthalen-2-ol (H2NA) Schiff base and its organyltellurium(IV) complexes were carried out and investigated via numerous spectral and physical methods like FT-IR, MS, 1HNMR , 13CNMR , UV–Vis, EDX, Powder XRD, TG-DTG and molar conductance measurements. The spectroscopic characterization results elucidate the bidentate nature of the Schiff base and distorted square pyramidal geometry of the complexes. Further, the compounds were theoretically investigated via quantum chemical computations to justify the experimental results. The thermal analysis results indicate the dehydrated nature of the complexes. In vitro biological evaluations (antioxidant and antimicrobial) indicates that the biological efficiency of the Schiff base was enhanced on complex formation. The antioxidant activity revealed the highest scavenging ability of the 3a, 3b and 3d complexes among the synthesized compounds with lowest IC50 value. While, the antimicrobial examination indicates the more inhibition property of 3c, 3e and 3f complexes against all the tested microbes. The in silico, molecular docking simulation of the compounds on the active site of Pseudomonas aeruginosa (2UV0) indicates promising interactions and advocates the good biological response against 2UV0. The FMO studies also supports the more bioactivity of complexes as compared to Schiff base which carried out on B3LYP/6–31G*. MESP of the compounds displayed their most reactive regions. The hyper-conjugative interactions and stabilization energy of the compounds have been estimated via NBO analysis. The predicted ADMET profiles of the compounds align with Lipinski's and other restrictive rules indicating their potential to act as effective inhibitors.

Series of Organotin(IV) Compounds with Different Dithiocarbamate Ligands Induced Cytotoxicity, Apoptosis and Cell Cycle Arrest on Jurkat E6.1, T Acute Lymphoblastic Leukemia Cells.

The discovery of cisplatin has influenced scientists to study the anticancer properties of other metal complexes. Organotin(IV) dithiocarbamate compounds are gaining attention as anticancer agents due to their potent cytotoxic properties on cancer cells. In this study, a series of organotin compounds were assessed for their toxic effects on the Jurkat E6.1 cell line. WST-1 assay was used to determine the cytotoxic effect of the compounds and showed that six out of seven organotin(IV) dithiocarbamate compounds exhibited potent cytotoxic effects toward T-lymphoblastic leukemia cells, Jurkat E6.1 with the concentration of IC50 ranging from 0.67-0.94 µM. The apoptosis assay by Annexin V-FITC/PI staining showed that all tested compounds induced cell death mainly via apoptosis. Cell cycle analysis assessed using RNase/PI staining showed that organotin(IV) dithiocarbamate compounds induced cell cycle arrest at different phases. In conclusion, the tested organotin(IV) dithiocarbamate compounds demonstrated potent cytotoxicity against Jurkat E6.1 cells via apoptosis and cell cycle arrest at low IC50 value. However, further studies on the mechanisms of action are required to probe the possible potential of these compounds on leukemia cells before they can be developed into anti-leukemic agents.

Design and synthesis of 2-amino-4,6-diarylpyrimidine derivatives as potent α-glucosidase and α-amylase inhibitors: structure–activity relationship, in vitro, QSAR, molecular docking, MD simulations and drug-likeness studies

In the present study, a series of 2-amino-4,6-diarylpyrimidine derivatives was designed, synthesized, characterized and evaluated for their in vitro α-glucosidase and α-amylase enzyme inhibition assays. The outcomes proved that this class of compounds exhibit considerable inhibitory activity against both enzymes. Among the target compounds, compounds 4p and 6p demonstrated the most potent dual inhibition with IC50 = 0.087 ± 0.01 μM for α-glucosidase; 0.189 ± 0.02 μM for α-amylase and IC50 = 0.095 ± 0.03 μM for α-glucosidase; 0.214 ± 0.03 μM for α-amylase, respectively as compared to the standard rutin (IC50 = 0.192 ± 0.02 μM for α-glucosidase and 0.224 ± 0.02 μM for α-amylase). Remarkably, the enzyme inhibition results indicate that test compounds have stronger inhibitory effect on the target enzymes than the positive control, with a significantly lower IC50 value. Moreover, these series of compounds were found to inhibit α-glucosidase activity in a reversible mixed-type manner with IC50 between 0.087 ± 0.01 μM to 1.952 ± 0.26 μM. Furthermore, molecular docking studies were performed to affirm the binding interactions of this scaffold to the active sites of α-glucosidase and α-amylase enzymes. The quantitative structure–activity relationship (QSAR) investigations showed a strong association between 1p–15p structures and their inhibitory actions (IC50) with a correlation value (R 2) of 0.999916. Finally, molecular dynamic (MD) simulations were carried out to assess the dynamic behavior, stability of the protein–ligand complex, and binding affinity of the most active inhibitor 4p. The experimental and theoretical results therefore exposed a very good compatibility. Additionally, the drug-likeness assay revealed that some compounds exhibit a linear association with Lipinski’s rule of five, indicating good drug-likeness and bioactivity scores for pharmacological targets. Communicated by Ramaswamy H. Sarma

Abstract 6314: Novel granzyme B-based fusion constructs targeting FRα on liquid and solid tumors

Abstract Folate receptor α (FRα) has been an attractive therapeutic target for many decades because it is highly overexpressed on several solid tumors and demonstrates low or restricted distribution on healthy tissues. Additionally, high expression of FRα has been associated with tumor progression and thus poor prognosis of cancer patients. Therefore, utilizing FRα to effectively locate tumor cells for targeted therapy using antibody drug conjugates, small molecule drug conjugates, radioimmunoconjugates or chimeric antigen receptor T cells, has been extensively investigated. Although some of the mentioned targeted therapies have shown promising preclinical results, their clinical utility has been limited due to associated toxicities in healthy tissues. We generated two new fusion constructs targeting FRα and containing active human granzyme B (GrB) as the cytotoxic payload. We used as binding domains two different scFvs targeting the FRα from antibodies previously used in clinical trials. These human scFvs (mov003 and mov018) were fused to the human serine protease GrB through an engineered human IgG heavy-chain fragment (designated as Fc) which contains a dimerization domain for longer half-life. The cytotoxicity of the constructs against a panel of cell lines expressing various levels of FRα showed a specific cytotoxic effect with an IC50 in the low nanomolar range (5-100 nM), particularly exhibiting very low IC50 values against breast and ovarian cell lines. FRα negative cells demonstrated IC50 levels in the micromolar range. Immunofluorescence studies demonstrated that the fusion constructs targeting FRα are efficiently internalized and effectively delivered the active serine protease to the cytosol. In vitro stability assays over 96 hours showed that both constructs are highly stable in mouse serum. Additionally, recent publications suggested that FRα is significantly associated with acute myeloid leukemia (AML) and might serve as a therapeutic target. We assessed the cytotoxic efficacy of GrB-based constructs on a panel of FRα+ AML cell lines and have found that these cell lines were very sensitive (IC50 in the low nanomolar range). Furthermore, evaluation of GrB fusion efficacy in two AML cell lines resistant to Bcl-2 inhibitor Venetoclax showed IC50s to be similar or lower than their parental cell lines. These results, therefore, demonstrate no cross-resistance to GrB. The safe and effective profile of these drugs together with their unique mechanism of action makes them ideal candidates for advancing pre-clinical development and may offer a potential new strategy for treatment of solid tumors and particularly Venetoclax relapsed AML patients, ineligible for intensive chemotherapy. In vivo efficacy studies to compare the two constructs are warranted and will help to identify the optimal therapeutic for further clinical consideration. Research conducted, in part, by the Clayton Foundation for Research. Citation Format: Ana Alvarez-Cienfuegos, Lawrence H. Cheung, Khalid A. Mohamedali, Natalia Baran, Marina Konopleva, Michael G. Rosenblum. Novel granzyme B-based fusion constructs targeting FRα on liquid and solid tumors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 6314.