6-Methoxy-2-Naphthoate as a Standard Chromophore for Chiroptical Studies by Fluorescence-Detected Exciton-Coupled Circular Dichroism.

被引量：- 发表：2024

Chiral Chemopolymorphism in the Monoterpenes of Pistacia palaestina Leaves and Galls.

Pistacia palaestina Boiss. is a common tree in the Mediterranean maquis. The leaves of this plant accumulate defensive monoterpenes, whose levels greatly increase in galls induced by the aphid Baizongia pistaciae. We previously found a significant chemopolymorphism in monoterpene content among individual trees, but the chirality of these monoterpenes was unknown. Although most plant species specifically accumulate one enantiomeric form of a given compound, P. palaestina individuals display chemopolymorphism in the chirality of the key monoterpenes accumulated. We report here a marked enantiomeric variation for the limonene, α- and β-pinene, camphene, sabinene, δ-3-carene, and terpene-4-ol content in leaves and galls of nine different naturally growing P. palaestina trees. Interestingly, insect-induced gall monoterpene composition is an augmentation of the specific enantiopolymorphism originally displayed by each individual tree.

被引量：- 发表：2024

Observation of the Liquid-Liquid Phase Separation of FUS-LC Using Vacuum-Ultraviolet Circular Dichroism Spectroscopy.

To reveal the structural mechanism by which the low-complexity domain of the fused in sarcoma protein (FUS-LC) mediates liquid-liquid phase separation (LLPS), we conducted a vacuum-ultraviolet circular dichroism (VUV-CD) spectroscopic study, a technique to analyze the secondary structures of proteins. The VUV-CD measurements were performed at the BL12 VUV-CD station at the Hiroshima Synchrotron Radiation Center (HiSOR) in Japan. CD spectra were measured between 180 and 260 nm while controlling the temperature of samples from 37°C to 5°C to obtain the LLPS of FUS-LC. The CD spectrum obtained at 37°C exhibited a large negative peak at 195 nm and a small negative shoulder near 220 nm. The peak intensity around 195 nm decreased as the sample temperature decreased. The spectral changes originated from the LLPS formation.

被引量：- 发表：2024

Inherently Chiral Oligomers Based on Indole-Benzothiophene Core.

In recent years, transductors of chiral information based on conducting polymers have gained considerable attention. In particular, inherently chiral materials, which allow differentiation between the antipodes of a chiral analyte in terms of energetic variations, are highly desired. In this work, we successfully synthesized a novel inherently chiral oligomer based on an indole-benzothiophene core, namely, 2-([2,2'-bithiophen]-5-yl)-3-(2-([2,2'-bithiophen]-5-yl)benzo[b]thiophen-3-yl)-N-methylindole (BTIndT4). The electrochemical characterization evidences a stabilization of electrogenerated radical cations due to the presence of the indole group, which guides the oligomerization, producing well-ordered polymeric matrices. Furthermore, the in situ electrochemical conductance analysis demonstrates a simultaneous intrachain and interchain transfer of charge carriers. Finally, the highly efficient enantiorecognition capabilities of the antipodes of the oligo-BTIndT4 films toward the enantiomers of tryptophan and 3,4-dihydroxyphenylalanine (DOPA), as model chiral analytes, were demonstrated.

被引量：- 发表：2024

First Principles Simulations of Optical Rotation of Chiral Molecular Crystals.

In this work, we present simulations of the optical rotation (OR) for five molecular crystals at density functional theory level with periodic boundary conditions (DFT-PBC). Calculations are compared with experimental measurements and show semi-quantitative agreement with experimental data for three of the crystals: tartatic acid, benzil, and pentaerythritol. For the other two crystals, aspartic acid and glutamic acid, the calculated data are in qualitative agreement with, but two orders of magnitude smaller than, the experimental data. We provide some arguments that support the theoretical predictions and suggest that the experiments should be revisited. We also find that the position of H centers provided in experimental X-ray data is not sufficiently reliable for simulating OR, and better results are obtained when H atoms are allowed to relax while keeping heavier elements fixed at the experimental positions. Comparison with molecular cluster calculations with a better functional and a larger basis set indicate that the role of intermolecular interactions (reproduced with the PBC technique) is as or more important than the choice of model chemistry. Despite the current limitations in the level of theory that can be employed, these simulations provide a promising avenue to investigate the effect of intermolecular interactions on this sensitive electronic property of molecules and materials.

被引量：- 发表：2024