Antidiabetic, antioxidant, and anti-obesity effects of phenylthio-ethyl benzoate derivatives, and molecular docking study regarding α-amylase enzyme.

In addition to their wide therapeutic application, benzoates and benzoic acid derivatives are the most commonly utilized food preservatives. The purpose of this study was to estimate the antioxidant, anti-diabetic, and anti-obesity activities of four 2-(phenylthio)-ethyl benzoate derivatives utilizing standard biomedical assays. The results revealed that the 2a compound has potent antidiabetic activity through the inhibition of α-amylase and α-glycosidase with IC50 doses of 3.57 ± 1.08 and 10.09 ± 0.70 µg/ml, respectively, compared with the positive control acarbose (IC50 = 6.47 and 44.79 µg/ml), respectively. In addition, by utilizing the ß-carotene linoleic acid and DPPH methods, the 2a compound showed the highest antioxidant activity compared with positive controls. Moreover, the 2a compound showed potential anti-lipase activity with an IC50 dose of 107.95 ± 1.88 µg/ml compared to orlistat (IC50 = 25.01 ± 0.78 µg/ml). A molecular docking study was used to understand the interactions between four derivatives of (2-(phenylthio)-ethyl benzoate with α-amylase binding pocket. The present study concludes that the 2a compound could be exploited for further antidiabetic, antioxidant, and anti-obesity preclinical and clinical tests and design suitable pharmaceutical forms to treat these global health problems.

Synthesis and biological testing of novel pyridoisothiazolones as histone acetyltransferase inhibitors.

We present a combination of database screening, synthesis and in vitro testing to identify novel histone acetyltransferase (HAT) inhibitors. The National Cancer Institute compound collection (NCI) and several commercial databases were filtered by similarity-based virtual screening to find new HAT inhibitors. Employing the recombinant HAT p300/CBP-associated factor (PCAF) and two different histone substrates for screening, pyridoisothiazolones were identified as inhibitors of human PCAF. Due to the limited solubility of the initial hits, we synthesized and tested them on PCAF. The compounds inhibit the proliferation of cancer cells. In summary, valuable chemical tools and potential lead candidates for new anticancer agents directed against HATs as new targets have been identified.

Molecular docking, chemo-informatic properties, alpha-amylase, and lipase inhibition studies of benzodioxol derivatives.

Currently, available therapies for diabetes could not achieve normal sugar values in a high percentage of treated patients. In this research project, a series of 17 benzodioxole derivatives were evaluated as antidiabetic agents; that belong to three different groups were evaluated against lipase and alpha-amylase (α-amylase) enzymes. The results showed that 14 compounds have potent inhibitory activities against α-amylase with IC50 values below 10 µg/ml. Among these compounds, 4f was the most potent compound with an IC50 value of 1.11 µg/ml compared to the anti-glycemic agent acarbose (IC50 6.47 µg/ml). On the contrary, these compounds showed weak or negligible activities against lipase enzyme. However, compound 6a showed the best inhibitory anti-lipase activity with IC50 44.1 µg/ml. Moreover, all the synthesized compounds were undergone Molinspiration calculation, and the result showed that all compounds obeyed Lipinski's rule of five. Molecular docking studies were performed to illustrate the binding interactions between the benzodioxole derivatives and α-amylase enzyme pocket. Related to the obtained results it was clear that the carboxylic acid, benzodioxole ring, halogen or methoxy substituted aryl are important for the anti-amylase activities. The potent inhibitory results of some of the synthesized compounds suggest that these molecules should go further in vivo evaluation. It also suggests the benzodioxole derivatives as lead compounds for developing new drug candidates.

A Multi-step Virtual Screening Protocol for the Identification of Novel Non-acidic Microsomal Prostaglandin†E2 Synthase-1 (mPGES-1) Inhibitors.

Microsomal prostaglandin E2 synthase-1 (mPGES-1) is a potential therapeutic target for the treatment of inflammatory diseases and certain types of cancer. To identify novel scaffolds for mPGES-1 inhibition, we applied a virtual screening (VS) protocol that comprises molecular docking, fingerprints-based clustering with diversity-based selection, protein-ligand interactions fingerprints, and molecular dynamics (MD) simulations with molecular mechanics Poisson-Boltzmann surface area (MM-PBSA) calculations. The hits identified were carefully analyzed to ensure the selection of novel scaffolds that establish stable interactions with key residues in the mPGES-1 binding pocket and inhibit the catalytic activity of the enzyme. As a result, we discovered two promising chemotypes, 4-(2-chlorophenyl)-N-[(2-{[(propan-2-yl)sulfamoyl]methyl}phenyl)methyl]piperazine-1-carboxamide (6) and N-(4-methoxy-3-{[4-(6-methyl-1,3-benzothiazol-2-yl)phenyl]sulfamoyl}phenyl)acetamide (8), as non-acidic mPGES-1 inhibitors with IC50 values of 1.2 and 1.3 µm, respectively. Minimal structural optimization of 8 resulted in three more compounds with promising improvements in inhibitory activity (IC50 : 0.3-0.6 µm). The unprecedented chemical structures of 6 and 8, which are amenable to further derivatization, reveal a new and attractive approach for the development of mPGES-1 inhibitors with potential anti-inflammatory and anticancer properties.

Pteryxin - A promising butyrylcholinesterase-inhibiting coumarin derivative from Mutellina purpurea.

Pteryxin is a dihydropyranocoumarin derivative found in Apiaceae family. In this study, pteryxin, which was previously isolated from the fruits of Mutellina purpurea, was investigated for its inhibitory potential against acetylcholinesterase (AChE) and butyrylcholinesterase (BChE), which are the key enzymes in the pathology of Alzheimer's disease (AD). The compound was tested in vitro using ELISA microplate reader at 100 µg/ml and found to cause 9.30 ± 1.86% and 91.62 ± 1.53% inhibition against AChE and BChE, respectively. According to our results, pteryxin (IC50 = 12.96 ± 0.70 µg/ml) was found to be a more active inhibitor of BChE than galanthamine (IC50 = 22.16 ± 0.91 µg/ml; 81.93± 2.52% of inhibition at 100 µg/ml). Further study on pteryxin using molecular docking experiments revealed different possible binding modes with both polar and hydrophobic interactions inside the binding pocket of BChE. Top docking solution points out to the formation of two hydrogen bonds with the catalytic residues S198 and H438 of BChE as well as a strong π - π stacking with W231. Therefore, pteryxin as a natural coumarin seems to be a strong BChE inhibitor, which could be considered as a lead compound to develop novel BChE inhibitors for AD treatment.

From cosubstrate similarity to inhibitor diversity--inhibitors of ADP-ribosyltransferases from kinase inhibitor screening.

ADP-ribosyltransferases (ADP-RTs) use NAD(+) to transfer an ADP-ribosyl group to target proteins. Although some ADP-RTs are bacterial toxins only few inhibitors are known. Here we present the development of fluorescence-based assays and a focussed library screening using kinase inhibitors as a new approach towards inhibitors of ADP-RTs. Different screening setups were established using surrogate small molecule substrates or the quantitation of the cofactor NAD(+). Proof-of-principle screening experiments were performed using a kinase inhibitor library in order to target the NAD(+) binding pockets. This led to the discovery of structurally different lead inhibitors for the mono-ADP-ribosyltransferases Mosquitocidal toxin (MTX) from Bacillus sphaericus SSII-1, C3bot toxin from Clostridium botulinum and CDTa from Clostridium difficile. The interaction of the inhibitors with the toxin proteins was analyzed by means of docking and binding free energy calculations. Binding at the nicotinamide subpocket, which shows a significant difference in the three enzymes, is used to explain the selectivity of the identified inhibitors and offers an opportunity for further development of potent and selective inhibitors.