Different pyridine substituted cruciform fluorophores (XF) were prepared and their optical properties were studied. Upon protonation of the pyridine nitrogen, the XFs with a para or ortho substitution pattern show similar bathochromic shifts in the emission, whereas the meta XF features a smaller bathochromic shift in emission wavelength. The color changes of XFs in the presence of carboxylic acids were used to identify them by digital photography. Data extraction of the photographs is performed by a combination of a large RGB color space, a standard white balance, the transformation of RGB values into u 0 v 0 values and MANOVA statistics, improving the recognition of analytes by pyridine XFs. We discuss in this paper factors that determine the quality of the extraction of color information from digital photograph.

Miniproteins are scaffolds for the development of alternative non-immunoglobin binding agents for medical applications. This peptide format features high tolerance to sequence mutagenesis, excellent proteolytic stability, and fast blood pool clearance. Herein we present the total chemical synthesis of the disulfide-constrained scaffold Min-23 and its functionalization for in vitro and in vivo application. Optimized solid-phase peptide chemistry and oxidative folding strategies were developed to engineer this miniprotein with native-like disulfide configuration. High levels of serum stability and proteolytic resistance, as well as a beneficial pharmacokinetic profile for diagnostic imaging, were determined by using radiolabeling techniques such as positron emission tomography. The reported achievements highlight Min-23 as a promising scaffold for the development of novel recognition molecules for medical application.

No abstract

We developed a series of new conjugated cruciform fluorophores (XF) featuring imine groups. The condensation of an XF containing aldehyde functionalities and selected primary amines leads to several XF-imine derivatives. Upon addition of Cu(2+) or Zn(2+) ions to solutions of the imine XFs in different solvents, a red-shifted emission is detected, resulting in an altered emission color. The imine acts as a simple modular metallo-reactive fluorophore.