Structural analysis, vibrational spectra and coordinated normal of 2R-(−)-6-hydroxytremetone

Vibrational and structural study of onopordopicrin based on the FTIR spectrum and DFT calculations

“…The very strong IR bands at 1771 and 1718 cm À1 are easily assigned to the C@O stretching modes according to the values reported for similar compounds [1,[3][4][5][6]9,11,38,39]. Note that the Raman intensities of these bands are lower than the expected because the O atoms belonging to the C27@O28 and C39@O40 groups are involved in DET LP!r à charge transfers, as observed in Table S4.…”

“…The in-plane and out-of-plane deformation modes are predicted to occur in the expected regions reported for similar molecules [1][2][3]5,6,[9][10][11][12]38,39]: 1396-1246 and 898-894 cm À1 , respectively.…”

“…As part of our investigations on compounds that contain rings in their structures and exhibit important biological activities [1][2][3][4][5][6][7][8][9][10][11][12][13], in this work, we studied the structural and vibrational properties of onopordopicrin (OP), a sesquiterpene lactone isolated from the weed Centaurea tweediei. Onopordopicrin exhibits antimicrobial and cytotoxic activities, especially against human-derived macrophages [14] and against epidermoid carcinoma cells [15].…”

Structure of dimethylphenyl betaine hydrochloride studied by X-ray diffraction, DFT calculation, NMR and FTIR spectra

“…The overestimation of the computed wavenumbers is quite systematic and can be corrected by applying appropriate scaling factors or scaling equations [23][24][25][26][27][28][29][30][31][32][33][34][35]. In as recommended by Alcolea Palafox [28], was used to obtain the predicted frequencies, which are listed as m scaleq in Table 4.…”

“…The vibrational band assignments of 3 and 3a were made using Gauss-View molecular visualization program [36] and data from Refs. [33,34].…”