A Review of FDA-Approved Anti-HIV-1 Drugs, Anti-Gag Compounds, and Potential Strategies for HIV-1 Eradication.

Acquired immunodeficiency syndrome (AIDS) is an enormous global health threat stemming from human immunodeficiency virus (HIV-1) infection. Up to now, the tremendous advances in combination antiretroviral therapy (cART) have shifted HIV-1 infection from a fatal illness into a manageable chronic disorder. However, the presence of latent reservoirs, the multifaceted nature of HIV-1, drug resistance, severe off-target effects, poor adherence, and high cost restrict the efficacy of current cART targeting the distinct stages of the virus life cycle. Therefore, there is an unmet need for the discovery of new therapeutics that not only bypass the limitations of the current therapy but also protect the body's health at the same time. The main goal for complete HIV-1 eradication is purging latently infected cells from patients' bodies. A potential strategy called "lock-in and apoptosis" targets the budding phase of the life cycle of the virus and leads to susceptibility to apoptosis of HIV-1 infected cells for the elimination of HIV-1 reservoirs and, ultimately, for complete eradication. The current work intends to present the main advantages and disadvantages of United States Food and Drug Administration (FDA)-approved anti-HIV-1 drugs as well as plausible strategies for the design and development of more anti-HIV-1 compounds with better potency, favorable pharmacokinetic profiles, and improved safety issues.

Ligand-based design and synthesis of new trityl histamine and trityl cysteamine derivatives as SIRT2 inhibitors for cancer therapy.

The relentless pursuit of novel therapeutic agents against cancer has led to the identification of multiple molecular targets, among which Sirtuin 2 (SIRT2) has garnered significant attention. This study presents an extensive SAR study of our reported trityl scaffold-based SIRT2 inhibitors. This study encompasses a range of different medicinal chemistry approaches to improve the activity of the lead compounds TH-3 and STCY1. The rationally designed and synthesized structures were confirmed using NMR and high-resolution mass spectroscopy before performing SIRT2 inhibition assay, NCI60 cytotoxicity test, and cell cycle analysis. Indeed, our strategies afforded hitherto unreported SIRT2 inhibitors with high activity, particularly 2a, 4a, 7c, and 7f. Remarkably, the presence of a lipophilic para substitution on the phenyl group of a freely rotating or a locked trityl moiety enhanced activity SIRT2 inhibition. Concomitantly, the synthesized compounds showed prominent activity against different cancer lines from the NCI60 assay. Of interest, compound 7c stands out as a potent and highly selective antiproliferative agent against leukemia and colon cancer panels. Furthermore, 7c treatment resulted in cell cycle arrest in MCF-7 cells at G2 phase and did not cause in vitro DNA cleavage.

HIV-1 Gag MA domain binds to cardiolipin in a binding mode distinct from virus assemble mediator PI(4,5)P2.

The human immunodeficiency virus type 1 (HIV-1) Gag protein is responsible for facilitating HIV-1 virion assembly and budding. Our study demonstrates that cardiolipin (CL), a component found in the inner mitochondrial membrane, exhibits the highest binding affinity to the N-terminal MA domain of the HIV-1 Gag protein within the lipid group of host cells. To assess this binding interaction, we synthesized short acyl chain derivatives of CL and employed surface plasmon resonance (SPR) analysis to determine the dissociation constants (Kd) for CL and the MA domain. Simultaneously, we examined the Kd of D-myo-phosphatidylinositol 4,5-bisphosphate (PI(4,5)P2 ) derivatives, known to play a crucial role in virion formation. Among all the derivatives, Tetra-C7 -CL exhibited the lowest Kd value (Kd = 30.8 ± 6.9 µM) for MA binding on the CL analog-immobilized sensorchip, indicating a higher affinity. Similarly, the Kd value of Di-C7 -PIP2 (Kd = 36.6 ± 4.7 µM) was the lowest on the PI(4,5)P2 analog-immobilized sensorchip. Thus, Tetra-C7 -CL binds to the MA domain using a distinct binding mode while displaying a comparable binding affinity to Di-C7 -PIP2. This discovery holds significant implications for comprehending the virological importance of CL-MA domain binding, such as its subcellular distribution, including mitochondrial translocation, and involvement in viral particle formation in concert with PI(4,5)P2 . Furthermore, this study has the potential to contribute to the development of drugs in the future.

An ADAM17 selective inhibitor promotes glucose uptake by activating AMPK.

AMPK activation promotes glucose and lipid metabolism. Here, we found that our previously reported ADAM17 inhibitor SN-4 activates AMPK and promotes membrane translocation and sugar uptake of GLUT4. AMPK inhibitor dorsomorphin reversed this effect of SN-4, confirming that the effect is mediated by AMPK activation. In addition, SN-4 inhibited lipid accumulation in HepG2 under high glucose conditions by promoting lipid metabolism and inhibiting lipid synthesis. Although lactic acidosis is a serious side effect of biguanides such as metformin, SN-4 did not affect lactate production. Furthermore, SN-4 was confirmed to inhibit the release of TNF-α, a causative agent of insulin resistance, from adipocytes. In diabetes treatment, it is important to not only regulate blood sugar levels but also prevent complications. Our findings reveal the therapeutic potential of SN-4 as a new antidiabetic drug that can also help prevent future complications.

Structural Characterization of TRAF6 N-Terminal for Therapeutic Uses and Computational Studies on New Derivatives.

Tumor necrosis factor receptor-associated factors (TRAFs) are a protein family with a wide variety of roles and binding partners. Among them, TRAF6, a ubiquitin ligase, possesses unique receptor binding specificity and shows diverse functions in immune system regulation, cellular signaling, central nervous system, and tumor formation. TRAF6 consists of an N-terminal Really Interesting New Gene (RING) domain, multiple zinc fingers, and a C-terminal TRAF domain. TRAF6 is an important therapeutic target for various disorders and structural studies of this protein are crucial for the development of next-generation therapeutics. Here, we presented a TRAF6 N-terminal structure determined at the Turkish light source "Turkish DeLight" to be 3.2 Å resolution at cryogenic temperature (PDB ID: 8HZ2). This structure offers insight into the domain organization and zinc-binding, which are critical for protein function. Since the RING domain and the zinc fingers are key targets for TRAF6 therapeutics, structural insights are crucial for future research. Separately, we rationally designed numerous new compounds and performed molecular docking studies using this template (PDB ID:8HZ2). According to the results, 10 new compounds formed key interactions with essential residues and zinc ion in the N-terminal region of TRAF6. Molecular dynamic (MD) simulations were performed for 300 ns to evaluate the stability of three docked complexes (compounds 256, 322, and 489). Compounds 256 and 489 was found to possess favorable bindings with TRAF6. These new compounds also showed moderate to good pharmacokinetic profiles, making them potential future drug candidates as TRAF6 inhibitors.

Turkish Plants, Including Quercetin and Oenothein B, Inhibit the HIV-1 Release and Accelerate Cell Apoptosis.

The introduction of combined anti-retroviral therapy (cART) in 1996, along with a continual breakthrough in anti-human immunodeficiency virus-1 (HIV-1) drugs, has improved the life expectancies of HIV-1-infected individuals. However, the incidence of drug-resistant viruses between individuals undergoing cART and treatment-naïve individuals is a common challenge. Therefore, there is a requirement to explore potential drug targets by considering various stages of the viral life cycle. For instance, the late stage, or viral release stage, remains uninvestigated extensively in antiviral drug discovery. In this study, we prepared a natural plant library and selected candidate plant extracts that inhibited HIV-1 release based on our laboratory-established screening system. The plant extracts from Epilobium hirsutum L. and Chamerion angustifolium (L.) Holub, belonging to the family Onagraceae, decreased HIV-1 release and accelerated the apoptosis in HIV-1-infected T cells but not uninfected T cells. A flavonol glycoside quercetin with oenothein B in Onagraceae reduced HIV-1 release in HIV-1-infected T cells. Moreover, extracts from Chamerion angustifolium (L.) Holub and Senna alexandrina Mill. inhibited the infectivity of progeny viruses. Together, these results suggest that C. angustifolium (L.) Holub contains quercetin with oenothein B that synergistically blocks viral replication and kills infected cells via an apoptotic pathway. Consequently, the plant extracts from the plant library of Turkey might be suitable candidates for developing novel anti-retroviral drugs that target the late phase of the HIV-1 life cycle.

Harnessing Oleanolic Acid and Its Derivatives as Modulators of Metabolic Nuclear Receptors.

Nuclear receptors (NRs) constitute a superfamily of ligand-activated transcription factors with a paramount role in ubiquitous physiological functions such as metabolism, growth, and reproduction. Owing to their physiological role and druggability, NRs are deemed attractive and valid targets for medicinal chemists. Pentacyclic triterpenes (PTs) represent one of the most important phytochemical classes present in higher plants, where oleanolic acid (OA) is the most studied PTs representative owing to its multitude of biological activities against cancer, inflammation, diabetes, and liver injury. PTs possess a lipophilic skeleton that imitates the NRs endogenous ligands. Herein, we report a literature overview on the modulation of metabolic NRs by OA and its semi-synthetic derivatives, highlighting their health benefits and potential therapeutic applications. Indeed, OA exhibited varying pharmacological effects on FXR, PPAR, LXR, RXR, PXR, and ROR in a tissue-specific manner. Owing to these NRs modulation, OA showed prominent hepatoprotective properties comparable to ursodeoxycholic acid (UDCA) in a bile duct ligation mice model and antiatherosclerosis effect as simvastatin in a model of New Zealand white (NZW) rabbits. It also demonstrated a great promise in alleviating non-alcoholic steatohepatitis (NASH) and liver fibrosis, attenuated alpha-naphthol isothiocyanate (ANIT)-induced cholestatic liver injury, and controlled blood glucose levels, making it a key player in the therapy of metabolic diseases. We also compiled OA semi-synthetic derivatives and explored their synthetic pathways and pharmacological effects on NRs, showcasing their structure-activity relationship (SAR). To the best of our knowledge, this is the first review article to highlight OA activity in terms of NRs modulation.

Cryogenic X-ray crystallographic studies of biomacromolecules at Turkish Light Source "Turkish DeLight".

X-ray crystallography is a robust and powerful structural biology technique that provides high-resolution atomic structures of biomacromolecules. Scientists use this technique to unravel mechanistic and structural details of biological macromolecules (e.g., proteins, nucleic acids, protein complexes, protein-nucleic acid complexes, or large biological compartments). Since its inception, single-crystal cryocrystallography has never been performed in Türkiye due to the lack of a single-crystal X-ray diffractometer. The X-ray diffraction facility recently established at the University of Health Sciences, Istanbul, Türkiye will enable Turkish and international researchers to easily perform high-resolution structural analysis of biomacromolecules from single crystals. Here, we describe the technical and practical outlook of a state-of-the-art home-source X-ray, using lysozyme as a model protein. The methods and practice described in this article can be applied to any biological sample for structural studies. Therefore, this article will be a valuable practical guide from sample preparation to data analysis.

Gypsogenin Battling for a Front Position in the Pentacyclic Triterpenes Game of Thrones on Anti-Cancer Therapy: A Critical Review-Dedicated to the Memory of Professor Hanaa M. Rady.

In the last decade, gypsogenin has attracted widespread attention from medicinal chemists by virtue of its prominent anti-cancer potential. Despite its late identification, gypsogenin has proved itself as a new anti-proliferative player battling for a frontline position among other classic pentacyclic triterpenes such as oleanolic acid, glycyrrhetinic acid, ursolic acid, betulinic acid, and celastrol. Herein, we present the most important reactions of gypsogenin via modification of its four functional groups. Furthermore, we demonstrate insights into the anti-cancer activity of gypsogenin and its semisynthetic derivatives and go further by introducing our perspective to judiciously guide the prospective rational design. The present article opens a new venue for a better exploitation of gypsogenin chemical entity as a lead compound in cancer chemotherapy. To the best of our knowledge, this is the first review article exploring the anti-cancer activity of gypsogenin derivatives.

Structural Characterization of Zinc(II)/Cobalt(II) Complexes of Chiral N-(Anthracen-9-yl)methyl-N,N-bis(2-picolyl)amine and Evaluation of DNA Photocleavage Activity.

We designed and synthesized a chiral ligand N-(anthracen-9-ylmethyl)-1-(pyridin-2-yl)-N-(pyridin-2-ylmethyl)ethanamine (APPE) DNA photocleavage agent to investigate the effects of chirality of bis(2-picolyl)amine on the DNA photocleavage activity of metal complexes. The structures of ZnII and CoII complexes in APPE were analyzed via X-ray crystallography and fluorometric titration. APPE formed metal complexes with a 1 : 1 stoichiometry in both the crystalline and solution states. Fluorometric titration was used to show that the ZnII and CoII association constants of these complexes (log Kas) were 4.95 and 5.39, respectively. The synthesized complexes were found to cleave pUC19 plasmid DNA when irradiated at 370 nm. The DNA photocleavage activity of the ZnII complex was higher than that of the CoII complex. The absolute configuration of the methyl-attached carbon did not affect DNA cleavage activity and, unfortunately, an achiral APPE derivative without the methyl group (ABPM) was found to perform DNA photocleavage more effectively than APPE. One reason for this may be that the methyl group suppressed the structural flexibility of the photosensitizer. These results will be useful for the design of new photoreactive reagents.

The unique activity of saponin: Induction of cytotoxicity in HTLV-1 infected cells.

Infection with the retrovirus human T-cell leukemia virus type 1 (HTLV-1) sometimes causes diseases that are difficult to cure. To find anti-HTLV-1 natural compounds, we opted to screen using the HTLV-1-infected T-cell line, MT-2. Based on our results, an extract of the pulp/seeds of Akebia quinata Decaisne fruit killed MT-2 cells but did not affect the Jurkat cell line that was not infected with virus. To determine the active ingredients, seven saponins with one-six sugar moieties were isolated from A. quinata seeds, and their activities against the two cell lines were examined. Both cell lines were killed in a similar manner by Akebia saponins A and B. Further, Akebia saponins D, E, PK and G did not exhibit cytotoxicity. Akebia saponin C had a similar activity to the extract found in the screening. This compound was found to enhance Gag aggregation, induce the abnormal cleavage of Gag, suppress virion release, and preferentially kill HTLV-1 infected cells; however, their relationship remains elusive. Our findings may lead to the development of new therapies for infectious diseases based on the removal of whole-virus-infected cells.

New insight into the bioactivity of substituted benzimidazole derivatives: Repurposing from anti-HIV activity to cell migration inhibition targeting hnRNP M.

Drug repurposing is a distinguished approach for drug development that saves a great deal of time and money. Based on our previous successful repurposing of a compound BMMP from anti-HIV-1 therapy to anti-cancer metastatic activity, we adopted the same techniques for repurposing benzimidazole derivatives considering MM-1 as a lead compound. An extensive structure-activity relationship (SAR) study afforded three promising compounds, MM-1d, MM-1h, and MM-1j, which inhibited cell migration in a similar fashion to BMMP. These compounds suppressed CD44 mRNA expression, whereas only MM-1h further suppressed mRNA expression of the epithelial-mesenchymal transition (EMT) marker zeb 1. Using benzimidazole instead of methyl pyrimidine as in BMMP resulted in better affinity for heterogeneous nuclear ribonucleoprotein (hnRNP) M protein and higher anti-cell migration activity. In conclusion, our study identified new agents that surpass the affinity of BMMP for hnRNP M and have anti-EMT activity, which makes them worthy of future attention and optimization.

Rapid and efficient ambient temperature X-ray crystal structure determination at Turkish Light Source.

High-resolution biomacromolecular structure determination is essential to better understand protein function and dynamics. Serial crystallography is an emerging structural biology technique which has fundamental limitations due to either sample volume requirements or immediate access to the competitive X-ray beamtime. Obtaining a high volume of well-diffracting, sufficient-size crystals while mitigating radiation damage remains a critical bottleneck of serial crystallography. As an alternative, we introduce the plate-reader module adapted for using a 72-well Terasaki plate for biomacromolecule structure determination at a convenience of a home X-ray source. We also present the first ambient temperature lysozyme structure determined at the Turkish light source (Turkish DeLight). The complete dataset was collected in 18.5 min with resolution extending to 2.39 Å and 100% completeness. Combined with our previous cryogenic structure (PDB ID: 7Y6A), the ambient temperature structure provides invaluable information about the structural dynamics of the lysozyme. Turkish DeLight provides robust and rapid ambient temperature biomacromolecular structure determination with limited radiation damage.

Difference in the Inhibitory Effect of Thiol Compounds and Demetallation Rates from the Zn(II) Active Site of Metallo-ß-lactamases (IMP-1 and IMP-6) Associated with a Single Amino Acid Substitution.

Gram-negative bacteria producing metallo-ß-lactamases (MBLs) have become a considerable threat to public health. MBLs including the IMP, VIM, and NDM types are Zn(II) enzymes that hydrolyze the ß-lactam ring present in a broad range of antibiotics, such as N-benzylpenicillin, meropenem, and imipenem. Among IMPs, IMP-1 and IMP-6 differ in a single amino acid substitution at position 262, where serine in IMP-1 is replaced by glycine in IMP-6, conferring a change in substrate specificity. To investigate how this mutation influences enzyme function, we examined lactamase inhibition by thiol compounds. Ethyl 3-mercaptopropionate acted as a competitive inhibitor of IMP-1, but a noncompetitive inhibitor of IMP-6. A comparison of the crystal structures previously reported for IMP-1 (PDB code: 5EV6) and IMP-6 (PDB code: 6LVJ) revealed a hydrogen bond between the side chain of Ser262 and Cys221 in IMP-1 but the absence of hydrogen bond in IMP-6, which affects the Zn2 coordination sphere in its active site. We investigated the demetallation rates of IMP-1 and IMP-6 in the presence of chelating agent ethylenediaminetetraacetic acid (EDTA) and found that the demetallation reactions had fast and slow phases with a first-order rate constant (kfast = 1.76 h-1, kslow = 0.108 h-1 for IMP-1, and kfast = 14.0 h-1 and kslow = 1.66 h-1 for IMP-6). The difference in the flexibility of the Zn2 coordination sphere between IMP-1 and IMP-6 may influence the demetallation rate, the catalytic efficiency against ß-lactam antibiotics, and the inhibitory effect of thiol compounds.

Scaffold Hopping and Structural Modification of NSC 663284: Discovery of Potent (Non)Halogenated Aminobenzoquinones.

The development of new anticancer drugs is still ongoing as a solution to the unsatisfactory results obtained by chemotherapy patients. Our previous studies on natural product-based anticancer agents led us to synthesize a new series of Plastoquinone (PQ) analogs and study their anticancer effects. Four members of PQ analogs (PQ1-4) were designed based on the scaffold hopping strategy; the design was later completed with structural modification. The obtained PQ analogs were synthesized and biologically evaluated against different cancer genotypes according to NCI-60 screening in vitro. According to the NCI results, bromo and iodo-substituted PQ analogs (PQ2 and PQ3) showed remarkable anticancer activities with a wide-spectrum profile. Among the two selected analogs (PQ2 and PQ3), PQ2 showed promising anticancer activity, in particular against leukemia cell lines, at both single- and five-dose NCI screenings. This compound was also detected by MTT assay to reveal significant selectivity between Jurkat cells and PBMC (healthy) compared to imatinib. Further in silico studies indicated that PQ2 was able to occupy the ATP-binding cleft of Abl TK, one of the main targets of leukemia, through key interactions similar to dasatinib and imatinib. PQ2 is also bound to the minor groove of the double helix of DNA. Based on computational pharmacokinetic studies, PQ2 possessed a remarkable drug-like profile, making it a potential anti-leukemia drug candidate for future studies.

New Insights into the Structural Requirements of Isatin-Derived Pro-Apoptotic Agents against Acute Myeloid Leukemia.

Searching for bioactive compounds within the huge chemical space is like trying to find a needle in a haystack. Isatin is a unique natural compound which is endowed with different bio-pertinent activities, especially in cancer therapy. Herein, we envisaged that adopting a hybrid strategy of isatin and α,ß-unsaturated ketone would afford new chemical entities with strong chemotherapeutic potential. Of interest, compounds 5b and 5g demonstrated significant antiproliferative activities against different cancer genotypes according to NCI-60 screening. Concomitantly, their IC50 against HL-60 cells were 0.38 ± 0.08 and 0.57 ± 0.05 µM, respectively, demonstrating remarkable apoptosis and moderate cell cycle arrest at G1 phase. Intriguingly, an impressive safety profile for 5b was reflected by a 37.2 times selectivity against HL-60 over PBMC from a healthy donor. This provoked us to further explore their mechanism of action by in vitro and in silico tools. Conclusively, 5b and 5g stand out as strong chemotherapeutic agents that hold clinical promise against acute myeloid leukemia.

Design, semi-synthesis and examination of new gypsogenin derivatives against leukemia via Abl tyrosine kinase inhibition and apoptosis induction.

Chronic myelogenous leukemia (CML) is characterized by Philadelphia translocation arising from Bcr-Abl fusion gene, which encodes abnormal oncoprotein showing tyrosine kinase (TK) function. Certain mutations in kinase domain, off-target effects and resistance problems of current TK inhibitors require the discovery of novel Abl TK inhibitors. For this purpose, herein, we synthesized new gypsogenin derivatives (6a-l) and evaluated their anticancer effects towards CML cells along with healthy cell line and different leukemic cells. Among these compounds, compound 6l was found as the most active anti-leukemic agent against K562 CML cells compared to imatinib exerting less cytotoxicity towards PBMCs (healthy). This compound also revealed significant anti-leukemic effects against Jurkat cell line. Besides, compound 6l enhanced apoptosis in CML cells with 52.4 % when compared with imatinib (61.8 %) and inhibited Abl TK significantly with an IC50 value of 13.04 ± 2.48 µM in a large panel of kinases accentuating Abl TK-mediated apoptosis of compound 6l in CML cells. Molecular docking outcomes showed that compound 6l formed mainly crucial interactions in the ATP-binding cleft of Abl TK similar to that of imatinib. Ultimately, in silico pharmacokinetic evaluation of compound 6l indicated that this compound was endowed with anti-leukemic drug candidate features.

Identification of New L-Heptanoylphosphatidyl Inositol Pentakisphosphate Derivatives Targeting the Interaction with HIV-1 Gag by Molecular Modelling Studies.

The HIV-1 Gag protein binds to the host cell membrane and assembles into immature particles. Then, in the course of immature virion budding, activated protease cleaves Gag into its main components: MA, CA, NC, and p6 proteins. The highly basic residues of MA predominantly interact with the acidic head of phosphatidyl-inositol-4,5-bisphosphate (PI(4,5)P2) inserted into the membrane. Our research group developed L-Heptanoylphosphatidyl Inositol Pentakisphosphate (L-HIPPO) and previously confirmed that this compound bound to the MA more strongly than PI(4,5)P2 and inositol hexakisphosphate (IP6) did. Therefore, herein we rationally designed eight new L-HIPPO derivatives based on the fact that the most changeable parts of L-HIPPO were two acyl chains. After that, we employed molecular docking for eight compounds via Maestro software using high-resolution crystal structures of MA in complex with IP6 (PDB IDs: 7E1I, 7E1J, and 7E1K), which were recently elucidated by our research group. The most promising docking scores were obtained with benzene-inserted compounds. Thus, we generated a library containing 213 new aromatic group-inserted L-HIPPO derivatives and performed the same molecular docking procedure. According to the results, we determined the nine new L-HIPPO derivatives most effectively binding to the MA with the most favorable scoring functions and pharmacokinetic properties for further exploration.

In Vitro Cytotoxicity Evaluation of Plastoquinone Analogues against Colorectal and Breast Cancers along with In Silico Insights.

Colorectal cancer (CRC) and breast cancer are leading causes of death globally, due to significant challenges in detection and management. The late-stage diagnosis and treatment failures require the discovery of potential anticancer agents to achieve a satisfactory therapeutic effect. We have previously reported a series of plastoquinone analogues to understand their cytotoxic profile. Among these derivatives, three of them (AQ-11, AQ-12, and AQ-15) were selected by the National Cancer Institute (NCI) to evaluate their in vitro antiproliferative activity against a panel of 60 human tumor cell lines. AQ-12 exhibited significant antiproliferative activity against HCT-116 CRC and MCF-7 breast cancer cells at a single dose and further five doses. MTT assay was also performed for AQ-12 at different concentrations against these two cells, implying that AQ-12 exerted notable cytotoxicity toward HCT-116 (IC50 = 5.11 ± 2.14 µM) and MCF-7 (IC50 = 6.06 ± 3.09 µM) cells in comparison with cisplatin (IC50 = 23.68 ± 6.81 µM and 19.67 ± 5.94 µM, respectively). This compound also augmented apoptosis in HCT-116 (62.30%) and MCF-7 (64.60%) cells comparable to cisplatin (67.30% and 78.80%, respectively). Molecular docking studies showed that AQ-12 bound to DNA, forming hydrogen bonding through the quinone scaffold. In silico pharmacokinetic determinants indicated that AQ-12 demonstrated drug-likeness with a remarkable pharmacokinetic profile for future mechanistic anti-CRC and anti-breast cancer activity studies.

In Vitro and In Silico Study to Assess Toxic Mechanisms of Hybrid Molecules of Quinone-Benzocaine as Plastoquinone Analogues in Breast Cancer Cells.

We managed to obtain three different series of 2,3-dimethyl-1,4-benzoquinones, named nonhalogenated and halogenated (brominated and chlorinated) PQ analogues, via the molecular hybridization strategy. Sixteen of eighteen hybrid molecules were selected by the National Cancer Institute (NCI) of Bethesda for their in vitro antiproliferative potential against the full NCI 60 cell line panel. The hybrid molecules (BrPQ5, CIPQ1, and CIPQ3) showed good growth inhibition at 10 µM concentration, particularly against breast cancer cell lines. As per the results obtained from in vitro antiproliferative evaluation, cytotoxic activities of the hybrid molecules (BrPQ5, CIPQ1, and CIPQ3) were evaluated with an 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay in T47D and MCF7 breast cancer and human umbilical vein endothelial (HUVEC) cells. Molecules exhibited cytotoxic activity, and especially, CIPQ1 showed remarkable cytotoxic activity and good selectivity on T47D and MCF7 cells. Furthermore, CIPQ1 could inhibit cell proliferation, cause apoptotic cell death and disturb the cell cycle in T47D and MCF7 cells. Additionally, CIPQ1 caused oxidative stress induction in both cells, more so in T47D. In vitro study results indicated that the anticancer activity of CIPQ1 was more prominent in T47D cells than in MCF7 cells. The compound CIPQ1 showed a prominent binding with JNK3 in silico. Thus, the obtained hybrid molecules via the molecular hybridization strategy of two important pharmacophores could be useful in the discovery of novel antiproliferative agents, and CIPQ1 could be considered a promising drug candidate.