Extended Reichardt's Dye-Synthesis and Solvatochromic Properties.

Three new pyridinium-phenolate dyes based on the benchmark solvatochromic dye Betaine 30 were synthesised. The dyes contained phenylene spacers between the donor and acceptor groups. Their UV-Vis absorption spectra were measured, with the dyes showing strong negative solvatochromic behaviour comparable to that of Betaine 30. These results stood in contrast to the behaviour of the π-extended dye Betaine 21, originally reported in 1963. This dye was synthesised and found to be significantly more solvatochromic than previously reported but prone to degrade. All π-extended dyes synthesised were found to be unstable in certain solvents. Although the increased distance between donor and acceptor did not enhance solvatochromism to the extent predicted, it was still determined that the reduced planarity caused by a phenylene spacer is not as detrimental as believed.

Protection of Boronic Acids Using a Tridentate Aminophenol ONO Ligand for Selective Suzuki-Miyaura Coupling.

Boronic acid protecting group chemistry powerfully enhances the versatility of Suzuki-Miyaura cross-coupling. Prominent examples include trifluoroborate salts, N-methyliminodiacetic acid (MIDA) boronates, and 1,8-diaminonaphthalene boronamides. In this work, we present a bis(2-hydroxybenzyl)methylamine (BOMA) ligand that forms tridentate complexes with boronic acids much like the MIDA ligand but the deprotection is facilitated by organic acids. The BOMA boronates showed considerable stability in both aqueous base and acid, and a variety of chemoselective reactions were performed on these boronates, including selective Suzuki-Miyaura coupling, palladium-catalyzed borylation, ester hydrolysis, alkylation, lithiation-borylation, and oxidative hydroxydeboronation.

Overview of the therapeutic potential of piplartine (piperlongumine).

Piplartine (piperlongumine, 5,6-dihydro-1-[(2E)-1-oxo-3-(3,4,5-trimethoxyphenyl)-2-propenyl]-2(1H)-pyridinone) is a biologically active alkaloid/amide from peppers, as from long pepper (Piper longum L. - Piperaceae). Long pepper is one of the most widely used in Ayurvedic medicine, which is used to treat many diseases, including tumors. The purpose of the current paper is to address to the chemical structure establishment and to systematically survey the published articles and highlight recent advances in the knowledge of the therapeutic potential of piplartine, establishing new goals for future research. The reported pharmacological activities of piplartine include cytotoxic, genotoxic, antitumor, antiangiogenic, antimetastatic, antiplatelet aggregation, antinociceptive, anxiolytic, antidepressant, anti-atherosclerotic, antidiabetic, antibacterial, antifungal, leishmanicidal, trypanocidal, and schistosomicidal activities. Among the multiple pharmacological effects of piplartine, its anticancer property is the most promising. Therefore, the preclinical anticancer potential of piplartine has been extensively investigated, which recently resulted in one patent. This compound is selectively cytotoxic against cancer cells by induction of oxidative stress, induces genotoxicity, as an alternative strategy to killing tumor cells, has excellent oral bioavailability in mice, inhibits tumor growth in mice, and presents only weak systemic toxicity. In summary, we conclude that piplartine is effective for use in cancer therapy and its safety using chronic toxicological studies should be addressed to support the viability of clinical trials.