Antibacterial, tyrosinase, and DNA photocleavage studies of some triazolylnucleosides

Synthesis of 2-Amino-N'-aroyl(het)arylhydrazides, DNA Photocleavage, Molecular Docking and Cytotoxicity Studies against Melanoma CarB Cell Lines

Diacylhydrazine bridged anthranilic acids with aryl and heteroaryl domains have been synthesized as the open flexible scaffold of arylamide quinazolinones in order to investigate flexibility versus rigidity towards DNA photocleavage and sensitivity. Most of the compounds have been synthesized via the in situ formation of their anthraniloyl chloride and subsequent reaction with the desired hydrazide and were obtained as precipitates, in moderate yields. All compounds showed high UV-A light absorption and are eligible for DNA photocleavage studies under this "harmless" irradiation. Despite their reduced UV-B light absorption, a first screening indicated the necessity of a halogen at the p-position in relation to the amine group and the lack of an electron-withdrawing group on the aryl group. These characteristics, in general, remained under UV-A light, rendering these compounds as a novel class of UV-A-triggered DNA photocleavers. The best photocleaver, the compound 9, was active at concentrations as low as 2 μΜ. The 5-Nitro-anthranilic derivatives were inactive, giving the opposite results to their related rigid quinazolinones. Molecular docking studies with DNA showed possible interaction sites, whereas cytotoxicity experiments indicated the iodo derivative 17 as a potent cytotoxic agent and the compound 9 as a slight phototoxic compound.

Novel 3'-[4-fluoroaryl-(1,2,3-triazol-1-yl)]-3'-deoxythymidine analogues: Design, synthesis, characterization and their potential as anticancer agents

Novel 3'-[4-fluoroaryl-(1,2,3-triazol-1-yl)]-3'-deoxythymidine analogues (7a-l) were developed by the Cu alkyne-azide cycloaddition (CuAAC) reaction. The obtained lead compounds were confirmed by using ¹H NMR, ¹³C NMR, 2 D NMR, HRMS and their anticancer activities were screened against Huh-7 liver cancer cells and U87MG human glioblastoma cells. Among the synthesized fluorinated 1,2,3-triazolyl nucleosides, three compounds (7i, 7a-b) demonstrated promising anti-proliferative against Huh-7 and U87MG cell lines. Significantly, compound 7i has displayed remarkable promising anticancer activity with IC₅₀ value in the micromole range (22.41-24.92 µM) and (18.12-21.36 µM) against Huh-7 cancer cells and U87MG glioblastoma cells, respectively.

Anti-melanogenesis potential of a new series of Morita-Baylis-Hillman adducts in B16F10 melanoma cell line

Melanin is a natural polymer pigment which provides skin photoprotection against ultraviolet radiation. An excessive synthesis of melanin leads to hyperpigmentation disorders. Tyrosinase catalyzes the rate limiting steps on melanogenesis. Therefore, tyrosinase inhibitors have potential applications in medicine and cosmetic fields. We carried out herein the screening of a family of cyclic Morita-Baylis-Hillman adducts (MBH) to find out their effects on tyrosinase activity and on melanogenesis in murine melanoma B16F10 cell line. Kinetic analysis of tyrosinase inhibition showed that compounds 1a (2-hydroxymethyl) cyclohex-2-enone) and 3f (diethyl (1-(6-oxocyclohex-1-en-1-yl) ethyl-phosphonate) were competitive inhibitors, whereas the compound 2b (6-oxocyclohex-1-en-1-yl) ethyl acetate) was a non-competitive one. Additionally we have found that (1a, 2b and 3f) compounds had a strong melanogenesis inhibition effect in isobutylmethylxanthine (IBMX)-treated murine melanoma B16F10 cells when tested at low and non cytotoxic dose (10-50 µM), by attenuating the melanin production, intracellular tyrosinase activity and tyrosinase expression. Thus, we suggest that these compounds could be used as effective skin-whitening agents.