Raman and surface‐enhanced Raman spectroscopy for the analysis of Mexican yellow dyestuff

Abstract

In pre‐Hispanic Mesoamerica, pigments and dyes were used in the elaboration of a large variety of colored objects. Obtaining information regarding the objects' material composition is useful in restoration and preservation processes, as well as for recovering knowledge of its production technology and the context and history of the object. Yellow colors have been obtained from a large variety of Mexican natural resources. Although mineral yellow pigments, such as orpiment and oxides, are relatively easy to identify by nondestructive and noninvasive techniques (X‐ray fluorescence, Raman spectroscopy, fiber optics reflectance spectroscopy, and Fourier transform infrared spectroscopy), organic yellow colorants are difficult to analyze by these techniques. Therefore, most works dealing with the identification of yellow dyes use destructive methods such as liquid chromatography–mass spectrometry. The aim of this work is to elaborate a methodology based on Raman spectroscopy and surface‐enhanced Raman spectroscopy for the study of yellow colorants used in pre‐Hispanic and colonial Mexico, in order to aid in their identification by spectroscopic techniques. The yellow colorants selected for this work were extracted from local plants: zacatlaxcalli (Cuscuta tinctoria), old fustic (Maclura tinctoria), weld (Reseda luteola), marigold (Tagetes erecta), and xochipalli (Cosmos sulphureus).

Counteraction of Biofilm Formation and Antimicrobial Potential of Terminalia catappa Functionalized Silver Nanoparticles against Candida albicans and Multidrug-Resistant Gram-Negative and Gram-Positive Bacteria

“…Interestingly, earlier Raman spectroscopy reports suggest that -OH group positioned at 3 in flavonoids is most reactive in the presence of Ag-NPs and prompts native flavonoids to change their chemical structure readily [ 43 ]. The spectrum obtained from TCE-Ag-3 with the 785 nm laser was very similar to those obtained by Garcia-Bucio et al [ 44 ]. The bands at 1570, 1372, 946, 622, and 465 cm −1 in Figure 3 are pretty similar to those that have been reported for flavones like morin (C 15 H 10 O 7 ) corresponding to the bands at 1570 and 1372 cm −1 , luteolin (C 15 H 10 O 6 ) corresponding to 946 and 465 cm −1 , and chrysin (C 15 H 10 O 4 ) corresponding to 622 cm −1 in extract of Cuscuta tinctoria and T. catappa [ 43 , 44 , 45 ].…”

“…The spectrum obtained from TCE-Ag-3 with the 785 nm laser was very similar to those obtained by Garcia-Bucio et al [ 44 ]. The bands at 1570, 1372, 946, 622, and 465 cm −1 in Figure 3 are pretty similar to those that have been reported for flavones like morin (C 15 H 10 O 7 ) corresponding to the bands at 1570 and 1372 cm −1 , luteolin (C 15 H 10 O 6 ) corresponding to 946 and 465 cm −1 , and chrysin (C 15 H 10 O 4 ) corresponding to 622 cm −1 in extract of Cuscuta tinctoria and T. catappa [ 43 , 44 , 45 ]. Jones et al [ 46 ] have regarded certain bio-actives molecules viz quercetin, luteolin, phloretin, and morin as health beneficial flavonoids found in commonly consumed plant-based products.…”

“…The two prominent broad peaks at 1570 and 1372 cm –1 correspond to C=C and C=O stretching vibrations at ring B and A rings of morin (C 15 H 10 O 7 ) [ 41 ], whereas feeble signals at 946 and 465 cm −1 correspond to cyclic CH and COH bending in luteolin (C 15 H 10 O 6 ) structure [ 50 ]. The signals at 622 cm –1 correspond to δ (CCO) and δ (COC) vibrations in chrysin (C 15 H 10 O 4 ) rings [ 44 ]. Whereas, the weak signal at 213 cm −1 can be assigned to the Ag–N and Ag–O bonds stretching [ 50 , 51 ].…”

Recent advances in linear and nonlinear Raman spectroscopy. Part XIV

“…They conclude that this approach can be successfully used to investigate a wide variety of bioactive molecules encapsulated within polymeric templates, thus providing a sensitive and robust analytical tool not yet explored. Garcia‐Bucio et al [ 41 ] used Raman and SERS for the analysis of Mexican yellow colorants, used in pre‐Hispanic and colonial Mexico, to aid in their identification by spectroscopic techniques. The yellow colorants selected for this work were extracted from a variety of local plants.…”

In search of Humboldt’s colors: materials and techniques of a 17th-century lacquered gourd from Colombia

“…He believed the colorant to be obtained from Escobedia scabrifolia, a locally grown saffron-like root that is still used today in Colombian cuisine to color foods and drinks [74]. Yellow dyes are among the most difficult cultural heritage materials to characterize analytically, mostly due to the lack of adequate spectral databases to be used in identification studies and the fact that hundreds of plants can produce yellow extracts [75][76][77]. As observed in the case of red areas, XRF spectra acquired from yellow and golden portions of the decoration did not display any elements that could indicate Fig.…”