Lichens and fungi. Part V. Dehydration rearrangements of 7-hydroxyhopanes

Surface enhancement Raman spectroscopy and density functional theory study of silver nanoparticles synthetized with d‐glucose

“…[29][30][31][32][33][34][35] In the present work, the initial concentration of α-D-glucose in the synthesis was 0.0345% (w/v), whereas in the literature, the concentration of the monosaccharides was higher than 20% (w/v). [27,29,[31][32][33][34][35] High concentration of D-glucose can lead to interactions by the solute molecules through van der Waals forces or hydrogen bonds, producing changes in the Raman shift. [36] Moreover, the wavenumbers obtained experimentally were carried out in an alkaline medium (pH 10.00), whereas the measurement of normal modes obtained from the literature was done in distilled water.…”

“…Wavenumbers shown in Table 1 suggest α-D-glucose, β-D-glucose, and also D-gluconate anion are adsorbed on the silver surface of the AgNPs, because the wavenumbers present in the experiments correspond to those found in literature for these species. [29][30][31][32][33][34][35] Small discrepancies are observed and can be attributed to the different concentration of the carbohydrate present in the sample with respect to that used in literature. [29][30][31][32][33][34][35] In the present work, the initial concentration of α-D-glucose in the synthesis was 0.0345% (w/v), whereas in the literature, the concentration of the monosaccharides was higher than 20% (w/v).…”

“…[29][30][31][32][33][34][35] Small discrepancies are observed and can be attributed to the different concentration of the carbohydrate present in the sample with respect to that used in literature. [29][30][31][32][33][34][35] In the present work, the initial concentration of α-D-glucose in the synthesis was 0.0345% (w/v), whereas in the literature, the concentration of the monosaccharides was higher than 20% (w/v). [27,29,[31][32][33][34][35] High concentration of D-glucose can lead to interactions by the solute molecules through van der Waals forces or hydrogen bonds, producing changes in the Raman shift.…”

“…[36] Moreover, the wavenumbers obtained experimentally were carried out in an alkaline medium (pH 10.00), whereas the measurement of normal modes obtained from the literature was done in distilled water. [26][27][28][29][30][31][32] On the other hand, there is evidence about a slight shift in wavenumbers between conventional Raman measurements and SERS. [37,38] It should be noted that the wavenumbers found in literature for the D-gluconate anion are in solid state, leading to possible differences.…”

Raman imaging processed cheese and its components

“…Components such as fat, protein and calcite content have been quantified in milk powder samples using multivariate analysis, [2,3] while other substances often present in foods, such as carbohydrates and carotenoid dyes, have been shown to produce distinct Raman signatures, making them suitable for identification using the technique. [4][5][6][7][8] Not only is Raman spectroscopy useful for identifying the desirable components in dairy products, but undesirable constituents such as adulterants or bacteria have also been shown to be discernable in several studies as well. [9][10][11][12][13] Features such as the structure and content of milk fat globules have also been investigated.…”