Syntheses and properties of second-generation V-shaped xanthene dyes with piperidino groups

Recent Advances in Heterocyclic Nanographenes and Other Polycyclic Heteroaromatic Compounds

This review surveys recent progress in the chemistry of polycyclic heteroaromatic molecules with a focus on structural diversity and synthetic methodology. The article covers literature published during the period of 2016-2020, providing an update to our first review of this topic (Chem. Rev. 2017, 117 (4), 3479-3716).

Synthesis and Properties of V-Shaped Xanthene Dyes with Tunable and Predictable Absorption and Emission Wavelengths

V-shaped xanthene dyes capable of predicting absorption and emission wavelengths are described. These dyes were synthesized by bridging a xanthene ring and an aryl moiety of fluorescein through ether covalent bonds. These dyes showed longer absorption and emission wavelengths than those of the parent fluorescein. Furthermore, substituents introduced on the aryl moiety mainly affected the lowest unoccupied molecular orbital energy level of the molecule. Therefore, the Hammett substituent constants could be used to predict the absorption and emission wavelengths of the compound.

Heterocyclization of 2-(2-phenylhydrazono)cyclohexane-1,3-dione to Synthesis Thiophene, Pyrazole and 1,2,4-triazine Derivatives with Anti-Tumor and Tyrosine Kinase Inhibitions

BACKGROUND

Recently tetrahydrobenzo[b]thiazole derivatives acquired a special attention due to their wide range of pharmacological activities especially the therapeutic activities. Through the market it was found that many pharmacological drugs containing the thiazole nucleus were known.

OBJECTIVE

This work aimed to synthesize target molecules not only possess anti-tumor activities but also kinase inhibitors. The target molecules were obtained starting from the arylhydrazonocyclohexan-1,3-dione followed by their heterocyclization reactions to produce anticancer target molecules.

METHODS

The arylhydrazone derivatives 3a-c underwent different heterocyclization reactions to produce thiophene, thiazole, pyrazole and 1,2,4-triazine derivatives. The anti-proliferative activity of twenty six compounds among the synthesized compounds toward the six cancer cell lines namely A549, H460, HT-29, MKN-45, U87MG, and SMMC-7721 was studied.

RESULTS

Anti-proliferative evaluations, tyrosine and Pim-1 kinase inhibitions were perform for most of the synthesized compounds where the varieties of substituent through the aryl ring and the thiophene moiety afforded compounds with high activities.

CONCLUSION

The compounds with high anti-proliferative activity towards the cancer cell lines showed that compounds 3b, 3c, 5e, 5f, 8c, 9c, 11c, 12c, 14e, 14f and 16c were the most cytotoxic compounds. Further tests of the latter compounds toward the five tyrosine kinases c-Kit, Flt-3, VEGFR-2, EGFR, and PDGFR and Pim-1 kinase showed that compounds 3c, 5e, 5f, 8c, 9c, 12c, 14e, 14f and 16c were the most potent of the tested compounds toward the five tyrosine kinases and compounds 6d, 11a, 20b and 21e were of the highest inhibitions towards Pim-1 kinase. Pan Assay Interference Compounds (PAINS) for the most cytotoxic compounds showed zero PAINS alert and can be used as lead compounds.

Textile finishing dyes and their impact on aquatic environs

In the present review, we have been able to describe the different families of dyes and pigments used in textile finishing processes (Yarns, fabrics, nonwovens, knits and rugs) such as dyeing and printing. These dyes are reactive, direct, dispersed, indigo, sulphur and vats. Such that their presence in the liquid effluents resulting from the textile washing constitutes a serious risk, in the absence of their purification, for the quality of receiving aquatic environments. Indeed, the presence of these dyes and pigments can cause a significant alteration in the ecological conditions of the aquatic fauna and flora, because of the lack of their biodegradability. This has a negative impact on the equilibrium of the aquatic environment by causing serious dangers, namely the obvious dangers (Eutrophication, under-oxygenation, color, turbidity and odor), the long-term dangers (Persistence, bioaccumulation of carcinogenic aromatic products and formation of by-products of chlorination), mutagenicity and carcinogenicity.

Rhodols - synthesis, photophysical properties and applications as fluorescent probes

The formal replacement of one dialkylamino group in rhodamines with a hydroxyl group transforms them into rhodols. This apparently minor difference is not as small as one may think; rhodamines belong to the cyanine family whereas rhodols belong to merocyanines. Discovered in the late 19th century, rhodols have only very recently begun to gain momentum in the field of advanced fluorescence imaging. This is in part due to the increased understanding of their photophysical properties, and new methods of synthesis. Rationalization of how the nature and arrangement of polar substituents around the core affect the photophysical properties of rhodols is now possible. The emergence of so-called π-expanded and heteroatom-modified rhodols has also allowed their fluorescence to be bathochromically shifted into regions applicable for biological imaging. This review serves to outline applicable synthetic strategies for the synthesis of rhodols, and to highlight important structure-property relationships. In the first part of this Review, various synthetic methods leading to rhodols are presented, followed by structural considerations and an overview of photophysical properties. The second part of this review is entirely devoted to the applications of rhodols as fluorescent reporters in biological imaging.