Discovery of Novel EGFR Inhibitor Targeting Wild-Type and Mutant Forms of EGFR: In Silico and In Vitro Study

Targeting L858R/T790M and L858R/T790M/C797S mutant EGFR is a critical challenge in developing EGFR tyrosine kinase inhibitors to overcome drug resistance in non-small cell lung cancer (NSCLC). The discovery of next-generation EGFR tyrosine kinase inhibitors (TKIs) is therefore necessary. To this end, a series of furopyridine derivatives were evaluated for their EGFR-based inhibition and antiproliferative activities using computational and biological approaches. We found that several compounds derived from virtual screening based on a molecular docking and solvated interaction energy (SIE) method showed the potential to suppress wild-type and mutant EGFR. The most promising PD13 displayed strong inhibitory activity against wild-type (IC50 of 11.64 ± 1.30 nM), L858R/T790M (IC50 of 10.51 ± 0.71 nM), which are more significant than known drugs. In addition, PD13 revealed a potent cytotoxic effect on A549 and H1975 cell lines with IC50 values of 18.09 ± 1.57 and 33.87 ± 0.86 µM, respectively. The 500-ns MD simulations indicated that PD13 formed a hydrogen bond with Met793 at the hinge region, thus creating excellent EGFR inhibitory activity. Moreover, the binding of PD13 in the hinge region of EGFR was the major determining factor in stabilizing the interactions via hydrogen bonds and van der Waals (vdW). Altogether, PD13 is a promising novel EGFR inhibitor that could be further clinically developed as fourth-generation EGFR-TKIs.

Discovery of novel anti-tumor compounds targeting PARP-1 with induction of autophagy through in silico and in vitro screening

Poly (ADP-ribose) polymerase 1 (PARP-1) is a critical enzyme involved in DNA damage repair and recombination, and shows great potential for drug development in the treatment of cancers with defective DNA repair. The anti-tumor activities of PARP-1 inhibitors are regulated by both inhibition activities and allosteric mechanisms of PARP-1, and may also be involved in an autophagy-mediated process. Screening PARP-1 inhibitors with potential allosteric mechanisms and induced autophagy process could achieve elevated potency toward cancer cell killing. In this study, we tried to discover novel anti-tumor compounds targeting PARP-1 by computer simulations and in vitro screening. In order to filter PARP-1 inhibitors that could affect the folding state of the helix domain (HD) on PARP-1, the free energy contribution of key residues on HD were systematically analyzed using the ligand-binding crystal structures and integrated into in silico screening workflow for the selection of 20 pick-up compounds. Four compounds (Chemdiv codes: 8012-0567, 8018-6529, 8018-7168, 8018-7603) were proved with above 40% inhibitory ratio targeting PARP-1 under 20 μM, and further performed binding mode prediction and dynamic effect evaluation by molecular dynamics simulation. Further in vitro assays showed that compounds 8018-6529 and 8018-7168 could inhibit the growth of the human colorectal cancer cell (HCT-116) with IC50 values of 4.30 and 9.29 μM and were accompanied with an induced autophagy process. Taken together, we discover two novel anti-tumor compounds that target PARP-1 with an induced autophagy process and provide potential hit compounds for the anti-cancer drug development.

New derivatives of a natural nordentatin

New derivatives were obtained from natural nordentatin (1) previously isolated from the methanol fraction of Clausena excavata by an acylation method. Herein, we report ten new pyranocoumarin derivatives 1a–1j. Their structures were elucidated based on UV-vis, FT-IR, NMR, and DART-MS data. The α-glucosidase inhibition and anticancer activities of nordentatin (1) and its derivatives were also evaluated. The α-glucosidase inhibition assay exhibited that the derivatives 1b, 1d, 1e, 1f, 1h, 1i, and 1j possess higher inhibitory activity for α-glucosidase with IC50 values of 1.54, 9.05, 4.87, 20.25, 12.34, 5.67, and 2.43 mM, whereas acarbose was used as the positive control, IC50 = 7.57 mM. All derivatives exhibited a weak cytotoxicity against a cervical cancer (HeLa) cell line with the IC50 between 0.25 and 1.25 mM. They also showed moderate to low growth inhibition of a breast cancer (T47D) cell line with IC50 values between 0.043 and 1.5 mM, but their activity was lower than that of the parent compound, nordentatin (1) (IC50 = 0.041 mM).

Synthesis and characterization of new 4-aryl-2-(2-oxopropoxy)-6-(2,5-dichlorothiophene)nicotinonitrile and their furo[2,3-b]pyridine derivatives: Assessment of antioxidant and biological activity

A new series of furo[2,3-b]pyridine derivatives bearing aryl substituents were synthesized in two steps, where, the cyano-(2H)-pyridones (1a-l) were converted to the corresponding nicotinonitriles (2a-l), followed by the Thorpe-Ziegler ring cyclization to the furo[2,3-b]pyridine derivatives (3a-l). All new compounds were characterized by 1D-NMR experiments (1H and 13C) and 2D-NMR experiments (COSY, HMBC and HSQC), as well as ESI-MS and HR-ESI-MS data. The new compounds were screened for their antioxidant activities by 2,2-diphenyl-1-picryl-hydrazylhydrate (DPPH) free radical assay. The highest radical scavenging effect was observed for nicotinonitriles 2d, 2h and 2l and furo[2,3-b]pyridines 3b, 3f and 3j by methanolic solvent at 4.0 mg/mL concentration. Remarkably, all nicotinonitriles and furo[2,3-b]pyridine exhibited a significant radical scavenging activity after 24 and 48 hours compared with 0.5 hour.

Current anti-diabetic agents and their molecular targets: A review

Diabetes mellitus is a medical condition characterized by the body's loss of control over blood sugar. The frequency of diagnosed cases and consequential increases in medical costs makes it a rapidly growing chronic disease that threatens human health worldwide. In addition, its unnerving statistical projections are perilous to both the economy of the nation and man's life expectancy. Type-I and type-II diabetes are the two clinical forms of diabetes mellitus. Type-II diabetes mellitus (T2DM) is illustrated by the abnormality of glucose homeostasis in the body, resulting in hyperglycemia. Although significant research attention has been devoted to the development of diabetes regimens, which demonstrates success in lowering blood glucose levels, their efficacies are unsustainable due to undesirable side effects such as weight gain and hypoglycemia. Over the years, heterocyclic scaffolds have been the basis of anti-diabetic chemotherapies; hence, in this review we consolidate the use of bioactive scaffolds, which have been evaluated for their biological response as inhibitors against their respective anti-diabetic molecular targets over the past five years (2012-2017). Our investigation reveals a diverse target set which includes; protein tyrosine phosphatase 1 B (PTP1B), dipeptidly peptidase-4 (DPP-4), free fatty acid receptors 1 (FFAR1), G protein-coupled receptors (GPCR), peroxisome proliferator activated receptor-γ (PPARγ), sodium glucose co-transporter-2 (SGLT2), α-glucosidase, aldose reductase, glycogen phosphorylase (GP), fructose-1,6-bisphosphatase (FBPase), glucagon receptor (GCGr) and phosphoenolpyruvate carboxykinase (PEPCK). This review offers a medium on which future drug design and development toward diabetes management may be modelled (i.e. optimization via structural derivatization), as many of the drug candidates highlighted show promise as an effective anti-diabetic chemotherapy.