0000000000928801
AUTHOR
M. Ferrugia
Atractyligenin chemistry. Part 4: Synthesis of the 15β-ol epimer of atractyligenin
The oxidation with PCC of atractyligenin 3, the aglicone of the toxic glycoside 1 isolated from Atractylis gummifera L., led to the 15-oxo-derivative 6, together with a small amount of 2,15-dioxoderivative 5, with a selective oxidation of the allylic 15-OH group of the molecule. Further reduction with NaBH4 and KOH hydrolysis gave stereoselectively the 15β-ol epimer of atractiligenin 9.
Volatile profiles of Sicilian prickly pear (Opuntia ficus indica) by SPME-GC/MS analysis
The aroma compounds present in the headspace of homogenized slurries of fresh prickly pears (Opuntia ficus-indica) from Sicilian cultivars were determined. Solid Phase Microextraction (SPME) followed by Gas-chromatography/Mass Spectrometry (GC/MS) analysis was used to characterize the volatile compounds. The volatile flavour profiles of the three cultivars investigated (red, white and yellow) showed significant differences. The aromatic profile of peeled prickly pears stored for one day was different from the one of the fresh samples, mainly due to the occurrence of some oxidative and hydrolytic reactions
Interactions of tryptophan and serotonin with biomembrane models: Binding to reversed micellar systems of ionic and non ionic surfactants
The interactions of Tryptophan (TRP) and Serotonin (5-HT), with water-containing sodium bis (2-ethylhexyl) sulfosuccinate (AOT), didodecyldimethylammonium bromide (DDAB) and tetraethylene glycol monododecyl ether (C12E4) reversed micelles have been investigated by UV absorption spectroscopy. Our results suggest that independently of the nature of the surfactant and the amount of the water encapsulated into the micellar core, TRP and 5-HT are solubilized in the micellar phase, preferring to be located in a shallow region constituted by the hydrated surfactant head groups. This is due to the amphiphilic nature of TRP and 5-HT and the biological implications are discussed.
1H-NMR and FT-IR study of the state of melatonin confined in membrane models: location and interactions of melatonin in water free lecithin and AOT reversed micelles
The state of melatonin confined either in dry lecithin or bis(2-ethylhexyl) sulfosuccinate sodium salt (AOT) reversed micelles has been investigated by H-1-NMR and FT-IR spectroscopies as a function of the melatonin to surfactant molar ratio (R). The analysis of experimental results leads to hypothesize that, independently of R and the surfactant nature and as a consequence of anisotropic melatonin/surfactant interactions, melatonin is totally solubilized in reversed micelles and mainly located by opportune orientation in the nanodomain constituted by the surfactant head groups. The absence of significant spectral changes related to the protons linked to the first carbon atoms of surfactant…