Organic Spectroscopy

Spectroscopic impact on protein and carbohydrate inherent molecular structures of barley, oat and corn combined with wheat DDGS

“…Chemical functional groups were identified according to previous literature [9,28,31,35]. The regions of specific interest in this present study included the protein amide I, II lignin, secondary protein structures of α-helix and β-sheet, cellulosic compounds (CeC) and nonstructural carbohydrate (NSC with component peaks 1-3).…”

Biflavonoids from an Ethno-Medicinal Plant Ochna holtzii Gilg

“…The structure of compound 1 was confirmed from the analysis of its HMBC spectrum. The 1 H and 13 C NMR spectra of the compound closely compared with the spectral data of lophirone C [14], a compound isolated previously from Ochnaafzelii. The main difference was the presence of two quaternary carbon signals at δ156.2 and 114.5 at positions α 2 and β 2 , respectively, in compound 1, indicating a complete furene ring, while in lophirone C, the two carbon signals were aliphatic at δ 88.6 and 57.6, respectively, as shown in (Table 1 (8) of these appeared in the aromatic region.Eight of the ten signals (1D and 2D NMR) were very similar to those of α,β-unsaturated olefin moiety and B1 and B2 aromatic rings of lophirone C [14] and dehydrolophirone C. The main difference was absence in compound 3 of aromatic C-H signals corresponding to the para-disubstituted ring A 2 ( Table 1).…”

“…The UV spectrum exhibited absorption peaks at λ max 201, 223 and 274 nm, characteristic of compounds with highly conjugated system [13]. EI-MS (70eV) gave m/z at 526 [ H COSY spectrum, the aromatic protons were distributed into one para-disubstituted, three ortho, para-trisubstituted aromatic ring systems and a dehydrobenzofuran moiety.…”

Estudo do comportamento térmico dos compostos de Ag+ e Pb2+ com o ligante 1,4-bis(3-carbóxi-3-oxo-prop-1-enil)benzeno

“…Em comparação com o espectro de FT-IR do ácido1,4-bis(3-carbóxi-3-oxo-prop-1-enil)benzeno, verifica-se o deslocamento das bandas de absorção do estiramento do grupo carboxilato desse ligante [13] para menor nú-mero de onda, com sobreposição à banda de absorção da carbonila cetônica. Esta observação evidencia que, além da coordenação predominante do ânion carboxilato ao íon metálico, ocorre também coordenação da carbonila, indicando caráter bidentado para os terminais -OC-COO-do ligante, com a formação de anéis de cinco membros nesses terminais [1][2][3][4][5][6][16][17][18][19].…”