Real time evolution of unprotected protonated galactosamine probed by IRMPD spectroscopy.

Conformational characterization of single α- and ß-epimers of galactosamine in solution still remains an intriguing task because of their flexibility and ability to interconvert. This difficulty was circumvented by recording several "snapshots" of the epimerization process by means of fast ESI vaporization of a galactosamine·HCl sample solution at different times. Consequently, the so generated gaseous mixtures were spectroscopically investigated and the specific conformational features of both α- and ß-epimers were assigned, despite the overlapping of several IR signals. Interestingly, from a comparison with time-resolved 1H-NMR data obtained for the same solutions, the catalyzing effect of the applied ESI technique in the anomerization process clearly emerges. Finally, the experimental data were supported using both the Density Functional Theory (DFT) and Block-Localized Wavefunction (BLW) approaches: the latter method was applied here for the first time for the investigation of charged species.

Scenedesmus dimorphus (Turpin) Kützing growth with digestate from biogas plant in outdoor bag photobioreactors.

Digestate coming from an Anaerobic Digestion unit in a Biogas Plant, feeded on cow manure and vegetable waste from markets, has been used. About 8-35 L polyethylene transparent bags have been employed as cultivation container, outdoor. Different aliquots of digestate, alone or mixed with commercial liquid fertiliser, were employed to cultivate in batch Scenedesus dimorphus, a freshwater green microalga, in the ENEA facilities of Casaccia Research Center, near Rome, Italy. The cultivation period was June-July 2013. The average daily yields of dry microalgae biomass varied from 20 mg/L/d to 60 mg/L/d, mean 38.2 mg/L/d. Final dry biomass concentration varied from 0.18 to 1.29 g/L, mean 0.55 g/L. S. dimorphus proved to be very efficient in removing N and P from the culture medium. Another fact emerged from these trials is that S. dimorphus inner composition resulted to be variable in response to the tested different culture conditions.

Reassessment of Melittis melissophyllum L. subsp. melissophyllum iridoidic fraction.

The analysis of the polar fraction of Melittis melissophyllum L. subsp. melissophyllum led to the identification of several iridoid glycosides: monomelittoside (1), melittoside (2), harpagide (3), acetyl-harpagide (4) and ajugoside (5). Compounds 3 and 4 are considered marker compounds for the genus and, as well as compounds 1, 2 and 5, were already evidenced in a previous study on the nominal species. It was noteworthy of the presence of allobetonicoside (6) which was never reported for this genus. The isolation of 6 is very relevant because of its allose residue on the structure. Allose has been often found in the species of the subfamily Lamioideae even if it mostly regarded flavonoids considered of chemotaxonomical relevance for some correlated genera of Lamiaceae. Same as allosyl-glycosidic flavonoids, the presence of allosyl-glycosidic iridoids may also be an additional chemosystematic evidence of botanical relationships among Lamiaceae species and genera.

Spectroscopic evidence for a gas-phase librating G-quartet-Na(+) complex.

The IRMPD spectrum of the G-quartet-Na(+) complex, in combination with an ab initio molecular dynamic simulation, revealed the presence of two metastable populations of conformers separated by a free energy barrier easily accessible at room temperature.

Phytochemical pattern of Gentiana species of Appennino in central Italy.

The molecular pattern of two Gentiana species, G. dinarica and G. lutea, present in a protected area of Appennino Centrale in Italy, was examined. Results were compared with literature data, examining the differences between the two species.