This work describe products of reactions between four alpha-dicarbonyl compounds (diacetyl, pentan-2,3-dione, glyoxal, and methylglyoxal) or two alpha-hydroxy ketones, (acetoine and acetol) and amino acids present in wines. The results shows the formation of odorous products or strong-smelling additives resulting from the Maillard and Strecker reaction in a primarily aqueous medium, at low temp...

Peptoids (N-substituted glycines) are an important class of biomimetic oligomers that have made a significant impact in the areas of combinatorial drug discovery, gene therapy, drug delivery, and biopolymer folding in recent years. Sequence-specific peptoid oligomers are easily assembled from primary amines by the solid-phase submonomer method. However, most amines that contain heterocyclic nit...

A series of thieno[3,4-b]pyrazine-based oligomers were synthesized via Stille cross-coupling as models of electronic structure-function relationships in thieno[3,4-b]pyrazine-based conjugated materials. The prepared oligomers include two oligothieno[3,4-b]pyrazine series from monomer to trimer, as well as a series of mixed terthienyls in which the ratio of thieno[3,4-b]pyrazine to either thioph...

Several North American species of Pogonomyrmex harvester ants exhibit group foraging, whereas South American species are exclusively solitary foragers. The composition of the secretions of the poison and Dufour glands in the South American species, Pogonomyrmex vermiculatus, were analyzed, and the secretions and their components were tested as trail pheromones in laboratory bioassays. The major...

In this study the volatile composition of six samples dark chocolates varying in cocoa roasting time (30.5, 34.5 and 38.5 min) geographical origin (Ecuador Ghana) was characterized by headspace solid-phase microextraction (HS-SPME) followed gas chromatography-mass spectrometry (GC-MS). One hundred twenty-one different compounds were identified using a carboxen/polydimethylsiloxane (CAR-PDMS) fi...