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.

Titania Nanorods Embedded with 2-Bromo-3-(methylamino)naphthalene-1,4-dione for Dye-Sensitized Solar Cells

In a recent study, TiO₂ nanorod electrodes were prepared by the hydrothermal approach followed by calcination at various temperatures from 300 to 600 °C. The effects of calcination temperature on the morphological and structural properties were investigated. The novel analogue of aminonaphthoquinone(2R-(n-alkylamino)-1,4-naphthoquinone) photosensitizer, viz. BrA1, 2-bromo-3-(methylamino)naphthalene-1,4-dione was synthesized from 2,3-dibromonaphthalene-1,4-dione. X-ray crystallographic data collection and refinement confirm that BrA1 crystallizes in the triclinic space group P 1̅. After loading BrA1, the photosensitizer on the annealed TiO₂ nanorod (TiO₂NR) electrodes, the optical properties of the photoanodes showed broadbands in each of the UV and visible regions, which are attributed to the π →π* and n → π* charge-transfer transitions, respectively. The dye-sensitized solar cell (DSSC) system was formed by loading the BrA1 photosensitizer on TiO₂NR. The electrochemical impedance spectroscopy (EIS) analyses confirm that calcination temperature improves the charge transportation by lowering the resistance path during the photovoltaic process in TiO₂NR (400 °C) photoanode-based DSSCs due to the sufficient photosensitizer adsorption and fast electron injection. Due to the effective light harvesting by the BrA1 photosensitizer and charge transport through the TiO₂ nanorod, the power conversion efficiencies (PCE) of the TiO₂NR (400 °C/BrA1-based) DSSCs were improved for 2-bromo-3-(methylamino)naphthalene-1,4-dione.

Crystal structure of 2-chloro-3-((thiophen-2-ylmethyl)amino)naphthalene-1,4-dione, C30H20O4N2Cl2S2

C30H20O4N2Cl2S2, Orthorhombic, Pca21, a = 16.9808(14) Å, b = 7.5227(6) Å, c = 20.8027(16) Å, V = 2657.4(4) Å3, Z = 4, R gt (F) = 0.0642, wR ref(F 2) = 0.1809, T = 293 K.

Naphthoquinone based chemosensors for transition metal ions: experiment and theory

Naphthoquinone based chemosensors are studied for metal ion binding in methanol–water–triethylamine solvent mixtures. pH effect, M : L stoichiometry and competitive binding of metal ions is studied.