Identifying highly effective coumarin-based novel cholinesterase inhibitors by in silico and in vitro studies.

Inhibition of high cholinesterase levels including acetylcholinesterase (AChE) and butyrylcholinesterase (BChE), is one of the most important strategies for the treatment of Alzheimer's disease (AD). Clinically limited drugs are used in the treatment of AD, so there is a need to find new effective inhibitors today. Therefore, in this study, synthesized six coumarin carboxamides (A1, A2, B1-B4) were evaluated against AChE and BChE by combined in silico and in vitro studies. The in vitro assessment of studied compounds revealed that A1, A2, B3, and B4 showed highest inhibition potential against AChE and BChE. As demonstrated with our structure activity relationship (SAR) study, the promising inhibition result of AChE at nanomolar concentrations was obtained with heterocyclic amines including pyrrolidine and N-methyl piperazine moieties for tertiary amide substituted coumarin compounds B3 and B4, displaying KI values of 9.78 nM and 8.07 nM, respectively. Thus, compounds B3 and B4 had around 5.7- and 6.9-fold more potency compared to the reference molecule, neostigmine. Moreover, coumarin-3-carboxamide derivative A1 bearing benzylmorpholine moiety on coumarin scaffold at position 3 displayed stronger inhibition potential against BChE. Furthermore, in order to better understand their molecular mechanisms in these targets, we conducted molecular docking and MD simulations. Our promising preclinical results show that the lead compounds A1, A2, B3 and B4 have high potential as effective inhibitors for the treatment of AD.

Novel inhibitors of eukaryotic elongation factor 2 kinase: In silico, synthesis and in vitro studies.

Eukaryotic elongation factor 2 kinase (eEF2K) is an unusual alpha kinase whose expression is highly upregulated in various cancers and contributes to tumor growth, metastasis, and progression. More importantly, eEF2K expression is associated with poor clinical outcome and shorter patient survival in breast, lung and ovarian cancers. Therefore, eEF2K is an emerging molecular target for development of novel targeted therapeutics and precision medicine in solid cancers. Currently, there are not any available potent and specific eEF2K inhibitors for clinical translation. In this study, we designed and synthesized a series of novel compounds with coumarin scaffold with various substitutions and investigated their effects in inhibiting eEF2K activity using in silico approaches and in vitro studies in breast cancer cells. We utilized an amide substitution at position 3 on the coumarin ring with their pharmacologically active groups containing pyrrolidine, piperidine, morpholine and piperazine groups with (CH2)2 bridged for aliphatic amides. Due to their ability to form covalent binding to the target enzyme, we also investigated the effects of boron containing groups on functionalized coumarin ring (3 compounds) and designed novel aliphatic and aromatic derivatives of coumarin scaffolds (10 compounds) and phenyl ring with boron groups (4 compounds). The Glide/SP module of the Maestro molecular modeling package was used to perform in silico analysis and molecular docking studies. According to our combined results, structure activity relationship (SAR) was performed in detail. Among the newly designed, synthesized, and tested compounds, our in vitro findings revealed that several compounds displayed a highly effective eEF2K inhibition at submicromolar concentrations in in vitro breast cancer cells. In conclusion, we identified novel compounds that can be used as eEF2K inhibitors and that they should be further evaluated by in vivo preclinical tumor models studies for antitumor efficacy and clinical translation.

Prodrugs for nitroreductase-based cancer therapy-3: Antitumor activity of the novel dinitroaniline prodrugs/Ssap-NtrB enzyme suicide gene system: Synthesis, in vitro and in silico evaluation in prostate cancer.

Prodrugs for targeted tumor therapies have been extensively studied in recent years due to not only maximising therapeutic effects on tumor cells but also reducing or eliminating serious side effects on healthy cells. This strategy uses prodrugs which are safe for normal cells and form toxic metabolites (drugs) after selective reduction by enzymes in tumor tissues. In this study, prodrug candidates (1-36) containing nitro were designed, synthesized and characterized within the scope of chemical experiments. Drug-likeness properties of prodrug candidates were analyzed using DS 2018 to investigate undesired toxicity effects. In vitro cytotoxic effects of prodrug canditates were performed with MTT assay for human hepatoma cells (Hep3B) and prostate cancer cells (PC3) and human umbilical vein endothelial cells (HUVEC) as healthy control. Non-toxic compounds (3, 5, 7, 10, 12, 15, 17, 19 and 21-23), and also compounds (1, 2, 5, 6, 9, 11, 14, 16, 20 and 24) which had low toxic effects, were selected to examine their suitability as prodrug canditates. The reduction profiles and kinetic studies of prodrug/Ssap-NtrB combinations were performed with biochemical analyses. Then, selected prodrug/Ssap-NtrB combinations were applied to prostate cancer cells to determine toxicity. The results of theoretical, in vitro cytotoxic and biochemical studies suggest 14/Ssap-NtrB, 22/Ssap-NtrB and 24/Ssap-NtrB may be potential prodrug/enzyme combinations for nitroreductase (Ntr)-based prostate cancer therapy.

In vitro and in silico studies of nitrobenzamide derivatives as potential anti-neuroinflammatory agents.

Communicated by Ramaswamy H. Sarma.

PRODRUGS FOR NITROREDUCTASE BASED CANCER THERAPY- 2: Novel amide/Ntr combinations targeting PC3 cancer cells.

The use of nitroreductases (NTR) that catalyze the reduction of nitro compounds by using NAD(P)H in GDEPT (Gene-directed enzyme prodrug therapy) studies which minimize toxicity at healthy cells and increases concentration of drugs at cancer cells is remarkable. Discovery of new prodrug/NTR combinations is necessary to be an alternative to known prodrug candidates such as CB1954, SN23862, PR-104A. For this aim, nitro containing aromatic amides (A1-A23)2 were designed, synthesized, performed in silico ADMET and molecular docking techniques in this study. Prodrug candidates were studied on reduction potentials with Ssap-NtrB by HPLC system. Also, cyototoxic properties and prodrug ability of these amides were investigated using different cancer cell lines such as Hep3B and PC3. As a result of theoretical and biological studies, combinations of A5, A6 and A20 with Ssap-NtrB can be suggested as potential prodrugs/enzyme combinations at NTR based cancer therapy compared with CB1954/NfsB.

Hyaluronic acid and hyaluronic acid: Sucrose nanogels for hydrophobic cancer drug delivery.

Porous and biodegradable hyaluronic acid (HA) nanogel and their copolymeric forms with sucrose (Suc), HA:Sucrose (HA:Suc) nanogels, were synthesized by employing glycerol diglycidyl ether (GDE) as crosslinker with a single step reaction in surfactant-free medium. The size of the nanogels was determined as 150 ±â€¯50 nm in dried state from SEM images and found to increase to about 540 ±â€¯47 nm in DI water measured with DLS measurements. The surface areas of HA and HA:Suc nanogels were measured as 18.07 ±â€¯2.4 and 32.30 ±â€¯6.1 m2/g with porosities of 3.58 ±â€¯1.8, and 9.44 ±â€¯3.1 nm via BET analysis, respectively. The zeta potentials for HA and HA:Suc nanogels were measured as -33 ±â€¯1.4 and - 30 ±â€¯1.2 mV, respectively. The thermal degradation of both types of nanogels revealed similar trends, while hydrolytic degradation of the nanogels was about 22.7 ±â€¯0.2 wt% in 15 days. Both HA and HA:Suc nanogels were stable in blood up to 250 µg/mL concentration with approximately 0.5 ±â€¯0.1% hemolysis ratio and 76 ±â€¯12% blood clotting indices, respectively. Finally, these nanogels were used as a sustained slow-release or long-term delivery system over 2 days for a hydrophobic cancer drug, 3­((E)­3­(4­hydroxyphenyl)acryloyl)­2H­chromen­2­on (A#) established by our group. The nanogels successfully delivered the model drug A at 10.43 ±â€¯2.12 mg/g for 2 days.

Biological evaluation and molecular docking studies of nitro benzamide derivatives with respect to in vitro anti-inflammatory activity.

A series of nitro substituted benzamide derivatives were synthesized and evaluated for their potential anti-inflammatory activities in vitro. Firstly, all compounds (1-6) were screened for their inhibitory capacity on LPS induced nitric oxide (NO) production in RAW264.7 macrophages. Compounds 5 and 6 demonstrated significantly high inhibition capacities in a dose-dependent manner with IC50 values of 3.7 and 5.3µM, respectively. These two compounds were also accompanied by no cytotoxicity at the studied concentrations (max 50µM) in macrophages. Molecular docking analysis on iNOS revealed that compounds 5 and 6 bind to the enzyme more efficiently compared to other compounds due to having optimum number of nitro groups, orientations and polarizabilities. In addition, 5 and 6 demonstrated distinct regulatory mechanisms for the expression of the iNOS enzyme at the mRNA and protein levels. Specifically, both suppressed expressions of COX-2, IL-1ß and TNF-α significantly, at 10 and 20µM. However, only compound 6 significantly and considerably decreased LPS-induced secretion of IL-1ß and TNF-α. These results suggest that compound 6 may be a multi-potent promising lead compound for further optimization in structure and as well as for in vivo validation studies.

Comparative study of antioxidant properties and total phenolic content of the extracts of Humulus lupulus L. and quantification of bioactive components by LC-MS/MS and GC-MS.

In this research, antioxidant activities of various extracts obtained from Humulus lupulus L. were compared by DPPH, ABTS, FRAP, and CUPRAC assays. The amount of total phenolic components determined by the Folin-Ciocalteu reagent was found to be highest for 25% aqueous ethanol (9079 ± 187.83 mg Ferulic acid equivalent/100 g extract) and methanol-1 (directly) (8343 ± 158.39 mg Ferulic acid equivalent/100 g extract) extracts. The n-hexane extract of H. lupulus exhibited the greatest with DPPH (14.95 ± 0.03 µg Trolox equivalent/g sample). The highest phenolic content in the ethanolic extract could be the major contributor to its highest CUPRAC activity (3.15 ± 0.44 mmol Trolox equivalent/g sample). Methanol-2 (n-hexane, acetone, and methanol) and methanol-3 (n-hexane, dichloromethane, ethylacetate, and methanol) extracts, respectively, exhibited the most potent ABTS (7.35 ± 0.03 mM Trolox equivalent) and FRAP (1.56 ± 0.35 mmol Fe(2+)/g sample) activities. Some of the components from the crude extracts were determined by LC-MS/MS and GC-MS analyses. Comparative screening of antioxidant activities of H. lupulus extracts and quantification of some major components by LC-MS/MS, qualitatively analysis of the reported ones which were optimal under negative ion SIM mode and coinjection, are going to be valuable for food and health applications.