Simulation of Solvatochromic Phenomena in Xanthione Using Explicit Solvent Methods.

Xanthione is a sulfated polycyclic aromatic hydrocarbon which exhibits unique anti-Kasha properties and substantial sensitivity to its medium. Due to this sensitivity however, this makes xanthione-based systems very difficult to simulate. Further, xanthione's is understood to be come more photostable in the presence of a highly polar medium, however whether these photophysical properties could be taken advantage of for certain applications remains to be seen.

Small molecule-based regulation of gene expression in human astrocytes switching on and off the G-quadruplex control systems.

A great deal of attention is being paid to strategies seeking to uncover the biology of the four-stranded nucleic acid structure G-quadruplex (G4) via their stabilization in cells with G4-specific ligands. The conventional definition of chemical biology implies that a complete assessment of G4 biology can only be achieved by implementing a complementary approach involving the destabilization of cellular G4s by ad hoc molecular effectors. We report here on an unprecedented comparison of the cellular consequences of G4 chemical stabilization by pyridostatin (PDS) and destabilization by phenylpyrrolocytosine (PhpC) at both transcriptome- and proteome-wide scales in patient-derived primary human astrocytes.

Breaking the blue barrier of nucleobase fluorescence emission with dicyanovinyl-based uracil molecular rotor probes.

Dicyanovinyl-modified uracil produces fluorescent molecular rotors (FMR) that display massively red-shifted emission and huge Stokes shifts. They are exemplified by DCVSU - an intrinsically fluorescent nucleobase analog (IFNA) with the longest emission wavelength of 592 nm (DMSO) reported thus far which also shows strong polarity sensitivity and large Stokes shift ( = 181 nm). The IFNAs exhibited typical molecular rotor response to solvent viscosity with brightnesses ( × ) of up to 8700 cm M.

Radiation-Driven Destruction of Thiophene and Methyl-Substituted Thiophenes.

Thiophene and two derivatives (2-methylthiophene and 3-methylthiophene) have been detected on the surface of Mars with the Sample Analysis at Mars instrument suite onboard NASA's Curiosity rover. Thiophene could serve as a secondary chemical biosignature since the secondary biosynthesis of thiophene is considered an important production pathway. However, it is critical to understand the abiotic formation and destruction of thiophene and its derivatives since these pathways could affect the molecules' stabilities on planetary surfaces over geological timescales.