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Analysis of non-anthocyanin phenolic compounds in wine samples using high performance liquid chromatography with ultraviolet and fluorescence detection A simple and rapid HPLC method with UV and fluorescence detection (FLD) for the separation of ten phenolic compounds including gallic acid, catechin, epicatechin, caffeic acid, coumaric, trans-piceid, cis-piceid, trans-resveratrol, cis-resveratrol and quercetin is reported. The UV and fluorescence detector in series provided a high selectivity for the determination of these compounds. Precisions, recoveries and LODs achieved for all the analytes were satisfactory. The proposed method was applied to the determination of these compounds in commercially available red wines.

The cyclic decapeptide gramicidin S (GS) was used as a model for the evaluation of four turn mimetics. For this purpose, one of the D‐Phe‐Pro two‐residue turn motifs in the rigid cyclic β‐hairpin structure of GS was replaced with morpholine amino acids (MAA 2–5), differing in stereochemistry and length of the side‐chain. The conformational properties of the thus obtained GS analogues (6–9) was assessed by using NMR spectroscopy and X‐ray crystallography, and correlated with their biological properties (antimicrobial and hemolytic activity). We show that compound 8, containing the dipeptide isostere trans‐MAA 4, has an apparent high structural resemblance with GS and that its antibacterial activity against a panel of Gram positive and ‐negative bacterial strains is better than the derivatives 6, 7 and 9.