Microwave-Assisted Extraction and HPLC-UV-CD Determination of (S)-usnic Acid in .

During the years, many usnic acid (UA) conjugates have been synthesized to obtain potent endowed with biological properties. Since ()-UA is less abundant in nature than ()-enantiomer, it is difficult to source, thus precluding a deeper investigation. Among the lichens producing UA, is a valuable (S)-UA source.

Enantiomeric Resolution and Absolute Configuration of a Chiral δ-Lactam, Useful Intermediate for the Synthesis of Bioactive Compounds.

During the past several years, the frequency of discovery of new molecular entities based on γ- or δ-lactam scaffolds has increased continuously. Most of them are characterized by the presence of at least one chiral center. Herein, we present the preparation, isolation and the absolute configuration assignment of enantiomeric 2-(4-bromophenyl)-1-isobutyl-6-oxopiperidin-3-carboxylic acid (-).