α-Aminoisobutyric Acid Leads a Fluorescent syn-bimane LASER Probe Across the Blood-brain Barrier.

Penetration of the blood brain barrier (BBB) by appropriate fluorescent probes remains a challenge in optical imaging and diagnostics. We designed, synthesized and observed the in vivo BBB penetration of a LASER syn-bimane probe. Results demonstrate that the Aib transporter unit in our probe may lead a fluorescent bimanyl moiety across the BBB.

Antimicrobial benzodiazepine-based short cationic peptidomimetics.

Antimicrobial peptides (AMPs) appear to be good candidates for the development of new antibiotic drugs. We describe here the synthesis of peptidomimetic compounds that are based on a benzodiazepine scaffold flanked with positively charged and hydrophobic amino acids. These compounds mimic the essential properties of cationic AMPs. The new design possesses the benzodiazepine scaffold that is comprised of two glycine amino acids and which confers flexibility and aromatic hydrophobic 'back', and two arms used for further synthesis on solid phase for incorporation of charged and hydrophobic amino acids. This approach allowed us a better understanding of the influence of these features on the antimicrobial activity and selectivity. A novel compound was discovered which has MICs of 12.5 µg/ml against Staphylococcus aureus and 25 µg/ml against Escherichia coli, similar to the well-known antimicrobial peptide MSI-78. In contrast to MSI-78, the above mentioned compound has lower lytic effect against mammalian red blood cells. These peptidomimetic compounds will pave the way for future design of potent synthetic mimics of AMPs for therapeutic and biomedical applications.