Elektrochemische Eigenschaften von 6-Methoxy-2,5-dimethyl-2H-isoindol-4,7-dion,einem antimikrobiell wirksamen Alkaloid ausReniera-Arten

Summary To determine the electronaffinity of 6-methoxy-2,5-dimethyl-2H-isoindole-4,7-dione — the first naturally-occurring isoindole alkaloid — the peak potential was measured by DPP.

Herrn Univ.-Prof. Dr. W. Fleischhacker mit besten Wünschen zum 60. Geburtstag gewidmet.     

Polarographic (DCP & DPP) Determination of Ellagic Acid in Strawberries & Pharmaceutical Formulations

Direct Current (DC) and Differential Pulse (DP) Polarographic methods have been developed for the qualitative as well as quantitative analysis of ellagic acid in plant products (i.e. strawberries) and pharmaceutical formulations (Ellagic insurance formula). Ellagic acid produces a well‐defined polarographic wave/peak in pyridine hydrochloride at pH 6.8 ± 0.1 with E_1/2 /Ep = ?1.298 V vs. SCE. The wave/peak height is found to be proportional to the concentration of ellagic acid. The developed procedure was used for the analysis of ellagic acid in an extract of strawberries (Fragaria × ananassa) and pharmaceutical formulations. Statistical treatment of the observed polarographic data revealed high accuracy and good precision of determination. The work has been supplemented by FTIR screening of the sample. The percentage of ellagic acid in pharmaceutical formulations was determined by the developed method, which is in close agreement with the labeled amount.     

Magnetic beads as versatile tools for electrochemical DNA and protein biosensing

Magnetic beads (MBs) are versatile tools in the separation of nucleic acids, proteins and other biomacromolecules, their complexes and cells. In this article recent application of MBs in electrochemical biosensing and particularly in the development of DNA hybridization sensors is reviewed. In these sensors MBs serve not only for separation but also as a platform for optimized DNA hybridization. A hybridization event is detected separately at another surface, which is an electrode. The detection is based either on the intrinsic DNA electroactivity or on various kinds of DNA labeling, including chemical modification, enzyme tags, nanoparticles, electroactive beads, etc., greatly amplifying the signals measured. In addition to DNA hybridization, other kinds of biosensing in combination with MBs, such as DNA-protein interactions, are reviewed.     

Discovery of dipeptidyl peptidase Ⅳ(DPP4) inhibitors based on a novel indole scaffold

Dipeptidyl peptidase Ⅳ(DPP4) inhibitors are proven in the treatment of type 2 diabetes.We designed and synthesized a series of novel indole compounds that selectively inhibit the activity of DPP4 over dipeptidyl peptidase 9(DPP9)(200 fold).We further co-crystallized DPP4 with indole sulfonamide(compound 1) to confirm a proposed binding mode.Good metabolic stability of the indole compounds represents another positive attribute for further development.