Synthesis of Mesodiphenylhelianthrene from 1-Aminoanthraquinone and the Structural Elucidation of Its Endoperoxide Species after Irradiation.

A safe, five-step synthetic route to yield the reliable chemical actinometer, mesodiphenylhelianthrene (MDH), is reported from a commercially available compound. Full characterization of the intermediates of the synthetic route and the final product MDH are presented together with four crystal structures of intermediates and MDH. The usage of the actinometer is described, and finally, the structure of the endoperoxide species (MDHPO), which is formed after irradiation of MDH, has been elucidated experimentally and theoretically.

Thiolation and Carboxylation of Glutathione Synergistically Enhance Its Lead-Detoxification Capabilities.

The natural tripeptide glutathione (GSH) is a ubiquitous compound harboring various biological tasks, among them interacting with essential and toxic metal ions. Yet, although weakly binding the poisonous metal lead (Pb), GSH poorly detoxifies it. ß-Mercaptoaspartic acid is a new-to-nature novel amino acid that was found to enhance the Pb-detoxification capability of a synthetic cyclic tetrapeptide. Aiming to explore the advantages of noncanonical amino acids (ncAAs) of this nature, we studied the detoxification capabilities of GSH and three analogue peptides, each of which contains at least one ncAA that harbors both free carboxylate and thiolate groups. A thorough investigation that includes in vitro detoxification and mechanistic evaluations, metal-binding affinity, metal selectivity, and computational studies shows that these ncAAs are highly beneficial in additively enhancing Pb binding and reveals the importance of both high affinity and metal selectivity in synergistically reducing Pb toxicity in cells. Hence, such ncAAs join the chemical toolbox against Pb poisoning and pollution, enabling peptides to strongly and selectively bind the toxic metal ion.

Long-Term Near-Infrared Signal Tracking of the Therapeutic Changes of Glioblastoma Cells in Brain Tissue with Ultrasound-Guided Persistent Luminescent Nanocomposites.

The blood-brain barrier (BBB) is a physical barrier that selectively prevents certain substances from entering the brain through the blood. The BBB protects the brain from germs and causes difficulty in intracranial treatment. The chemotherapy drug temozolomide (TMZ), embedded in nanobubbles (NBs) and combined with persistent luminescent nanoparticles (PLNs), has been used to treat glioblastoma (GBM) effectively through image tracking. Through ultrasound induction, NBs produce cavitation that temporarily opens the BBB. Additionally, the PLNs release near-infrared emission and afterglow, which can penetrate deep tissues and improve the signal-to-noise ratio of bioimages. In this work, the nanosystem crossed the BBB for drug delivery and image tracking over time, allowing the enhancement of the drug's therapeutic effect on GBM. We hope that this nanosystem can be applied to the treatment of different brain diseases by embedding different drugs in NBs.