RESUMEN
Crocins in commercial liquid saffron extracts (Saffr'activ®) were identified using high-performance liquid chromatography (HPLC) with a diode array detector (DAD) and mass spectrometry (MS). The impact of storage on the qualities of the saffron extract were studied with HPLC-DAD-MS by exposing trans-4-GG crocin to environmental factors. Light and temperature induced degradation after only one week. Trans-4-GG crocin was totally hydrolyzed when stored at 60 °C and exposed to light. A quick and reliable method using HPLC-DAD was then developed to improve quantification of crocins in commercial liquid saffron extracts. An internal standard quantification method that uses a response factor, corrected with the molecular weight of each crocin, improved results for old saffron extracts.
Asunto(s)
Carotenoides/análisis , Cromatografía Líquida de Alta Presión/métodos , Crocus/química , Espectrometría de Masas/métodos , Extractos Vegetales/análisis , Aire , Carotenoides/química , Análisis de los Alimentos/métodos , Almacenamiento de Alimentos/métodos , Luz , Extractos Vegetales/química , Vitamina A/análogos & derivados , Vitamina A/químicaRESUMEN
Capitalizing on a recently reported iminosugar-based aza-crown (ISAC) accessed by a double Staudinger azaWittig coupling reaction, we have expanded the structural diversity of this new family of sweet cyclam analogs. Replacement of the two secondary amines linking the iminosugar units by two amide bonds obtained a cyclodimerization by with BOP and DIPEA led to a macrocycle that did not demonstrate efficient Zn2+ chelation unlike the parent ISAC. Introduction of two pyrene moieties on the secondary amines of the parent ISAC yielded a new fluoroionophore that selectively binds Hg2+ in methanol.
Asunto(s)
Quelantes/síntesis química , Compuestos Corona/química , Colorantes Fluorescentes/síntesis química , Glicopéptidos/síntesis química , Iminoazúcares/química , Quelantes/química , Colorantes Fluorescentes/química , Glicopéptidos/química , Conformación MolecularRESUMEN
A new family of chiral C2 symmetric tetraazamacrocycles, coined ISAC for IminoSugar Aza-Crown, incorporating two iminosugars adopting a 4C1 conformation is disclosed. Multinuclear NMR experiments on the corresponding Cd2+ complex show that the ISAC is a strong chelator in water and its tetramine cavity adopts a conformation similar to that of the parent Cd-cyclam complex. Similar behavior is observed with Cu2+ in solution, with enhanced stability compared to the Cu-cyclam complex.