Inhibition of HIV-1 reverse transcriptase by aryl-substituted naphto- and anthraquinones

Raman spectra-based structural classification analysis of quinoidal and derived molecular systems

This work reports a classification analysis method based on the vibrational Raman spectra of 38 quinones and related structures, spectrally ordering and classifying the compounds. The molecular systems are relevant for chemical and biological processes, with applications in pharmacology, toxicology and medicine. The classification strategy uses a combination of principal component analysis with K-means clustering methods. Both theoretical simulations and experimental data are analysed, thus establishing their spectral characteristics, as related to their chemical structures and properties. The protocol introduced here should be broadly applicable in other molecular and solid state systems.

Ionically Crosslinked Chitosan Membranes Used as Drug Carriers for Cancer Therapy Application

The aim of this paper was to prepare, by the freeze-drying method, ionically crosslinked chitosan membranes with different contents of pentasodium tripolyphosphate (TPP) and loaded with 1,4-naphthoquinone (NQ14) drug, in order to evaluate how the physical crosslinking affects NQ14 release from chitosan membranes for cancer therapy application. The membranes were characterized by Fourier transform infrared spectroscopy (FTIR), wide-angle X-ray diffraction (WAXD), scanning electron microscopy (SEM), swelling degree, and through in vitro drug release and cytotoxicity studies. According to the results, the molecular structure, porosity and hydrophilicity of the chitosan membranes were affected by TPP concentration and, consequently, the NQ14 drug release behavior from the membranes was also affected. The release of NQ14 from crosslinked chitosan membranes decreased when the cross-linker TPP quantity increased. Thus, depending on the TPP amount, the crosslinked chitosan membranes would be a potential delivery system to control the release of NQ14 for cancer therapy application. Lastly, the inhibitory potential of chitosan membranes ionically crosslinked with TPP and loaded with NQ14 against the B16F10 melanoma cell line was confirmed through in vitro cytotoxicity studies assessed via MTT assay. The anti-proliferative effect of prepared membranes was directly related to the amount of cross-linker and among all membranes prepared, such that one crosslinked with 0.3% of TPP may become a potential delivery system for releasing NQ14 drug for cancer therapy.

Investigation of the antimicrobial and anticancer activity of aminonaphthoquinones

In this study, we report on the inhibitory activity of synthesized aminonaphthoquinones against two bacterial and one fungal species to determine their antimicrobial properties. A minimum inhibitory concentration (MIC) of 7.8 μg/mL was obtained against the fungus, Candida albicans, which was better than that of Amphotericin B (MIC = 31.25 μg/mL). Escherichia coli (Gram -), was inhibited at a MIC of 23.4 μg/mL and Staphylococcus aureus (Gram +) at a MIC of 31.3 μg/mL. The aminonaphthoquinones were also screened against HCT116 colon, PC3 prostate and HepG2 liver cancer cell lines to evaluate their cytostatic effects. They had potent activity (GI₅₀  = 5.87-9.90 μM) which was about three-6-fold better than that of parthenolide (GI₅₀  = 25.97 μM) against the prostate cancer cell line. These compounds were generally more selective for cancer cells than for normal human lung fetal fibroblasts (WI-38).

Synthesis of Selenium-Quinone Hybrid Compounds with Potential Antitumor Activity via Rh-Catalyzed C-H Bond Activation and Click Reactions

In continuation of our quest for new redox-modulating catalytic antitumor molecules, selenium-containing quinone-based 1,2,3-triazoles were synthesized using rhodium-catalyzed C-H bond activation and click reactions. All compounds were evaluated against five types of cancer cell lines: HL-60 (human promyelocytic leukemia cells), HCT-116 (human colon carcinoma cells), SF295 (human glioblastoma cells), NCIH-460 (human lung cells) and PC3 (human prostate cancer cells). Some compounds showed good activity with IC50 values below 1 µM. The cytotoxic potential of the naphthoquinoidal derivatives was also evaluated in non-tumor cells, exemplified by L929 cells. Overall, these compounds represent promising new lead derivatives and stand for a new class of chalcogenium-containing derivatives with potential antitumor activity.

Aromatase inhibitory activity of 1,4-naphthoquinone derivatives and QSAR study

A series of 2-amino(chloro)-3-chloro-1,4-naphthoquinone derivatives (1-11) were investigated for their aromatase inhibitory activities. 1,4-Naphthoquinones 1 and 4 were found to be the most potent compounds affording IC₅₀ values 5.2 times lower than the reference drug, ketoconazole. A quantitative structure-activity relationship (QSAR) model provided good predictive performance (R²_CV = 0.9783 and RMSE_CV = 0.0748) and indicated mass (Mor04m and H8m), electronegativity (Mor08e), van der Waals volume (G1v) and structural information content index (SIC2) descriptors as key descriptors governing the activity. To investigate the effects of structural modifications on aromatase inhibitory activity, the model was employed to predict the activities of an additional set of 39 structurally modified compounds constructed in silico. The prediction suggested that the 2,3-disubstitution of 1,4-naphthoquinone ring with halogen atoms (i.e., Br, I and F) is the most effective modification for potent activity (1a, 1b and 1c). Importantly, compound 1b was predicted to be more potent than its parent compound 1 (11.90-fold) and the reference drug, letrozole (1.03-fold). The study suggests the 1,4-naphthoquinone derivatives as promising compounds to be further developed as a novel class of aromatase inhibitors.

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.

Understanding cancer and the anticancer activities of naphthoquinones – a review

Naphthoquinone moieties are present in drugs such as doxorubicin which are used clinically to treat solid cancers.

Anticancer activity and SAR studies of substituted 1,4-naphthoquinones

In this paper, we report the structure-activity relationship studies of substituted 1,4-naphthoquinones for its anticancer properties. 1,4-Naphthoquinone, Juglone, Menadione, Plumbagin and LLL12.1 were used as lead molecules to design PD compounds. Most of the PD compounds showed improved antiproliferative activity in comparison to the lead molecule in prostate (DU-145), breast (MDA-MB-231) and colon (HT-29) cancer cell lines. PD9, PD10, PD11, PD13, PD14 and PD15 were found to be the most potent compound with an IC₀ value of 1-3 μM in all cancer cell lines. Fluorescent polarization assay was employed to study the inhibition of STAT3 dimerization by PD compounds. PD9 and PD18 were found to be potent STAT3 dimerization inhibitors.

Elucidation of structure–activity relationships for 2- or 6-substituted-5,8-dimethoxy-1,4-naphthoquinones

1,4-Naphthoquinones have already been recognized to possess a wide range of biological activities. We have developed quantitative structure activity relationships (QSAR) for different series of 2- or 6-substituted-5,8-dimethoxy-1,4-naphthoquinones to understand the chemical-biological interaction governing antiproliferative/cytotoxic activities against L1210 cells. QSAR results have shown that these activities of 2- or 6-substituted-5,8-dimethoxy-1,4-naphthoquinones depend largely on their hydrophobicity.