Dyes were used in Mexico since early pre-Hispanic periods for coloring of fibers, codex writing, and mural paintings, among other purposes. From the wide variety of Mexican dyes, only a handful has been studied at length. Moreover, few studies had been devoted to the identification of these substances in artistic or historical objects, in part, because of the lack of a suitable technique that complies with the nondestructive or microdestructive requirements that involves working with such objects. Surface-enhanced Raman spectroscopy (SERS) may provide the tool needed to identify the more than 20 dyes that can be found in Mexico and the first step would be acquiring their SERS spectra in laboratory conditions. To fulfill that goal, carminic acid, cochineal (Dactylopius coccus), achiote (Bixa orellana), muitle (Justicia spicigera), zacatlaxcalli (Cuscuta sp.), brazilwood (Caesalpinia echinata), and cempazuchitl (Tagetes erecta) SERS spectra were recorded in aqueous solution and directly on dyed wool fibers, using silver colloids as SERS substrate. Ag nanoparticles were prepared by chemical reduction with sodium citrate and characterized by UV-Vis spectroscopy and high resolution transmission electronic microscopy. Pure carminic acid was used for control SERS spectra and then samples of cochineal, achiote, muitle, zacatlaxcalli, brazilwood, and cempazuchitl were tested. Samples were prepared either by extraction from their natural sources or by dyeing the fibers; in both cases traditional recipes were followed. The acquired spectra may serve in future research as comparative references for the identification of the dyes present in cultural artifacts, and in the case of cempazuchitl, muitle, and zacatlaxcalli, these are probably the first reported Raman spectra of such plants.

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From the aerial parts of Salvia ballotiflora, eleven diterpenoids were isolated; among them, four icetexanes and one abietane (1–5) are reported for the first time. Their structures were established by spectroscopic means, mainly 1H- and 13C-NMR, including 1D and 2D homo- and hetero-nuclear experiments. Most of the isolated diterpenoids were tested for their antiproliferative, anti-inflammatory, and radical scavenging activities using the sulforhodamine B assay on six cancer cell lines, the TPA-induced ear edema test in mice, and the reduction of the DPPH assay, respectively. Some diterpenoids showed anti-proliferative activity, these being icetexanes 6 and 3, which were the most active with IC50 (μM) = 0.27 ± 0.08 and 1.40 ± 0.03, respectively, for U251 (human glioblastoma) and IC50 (μM) = 0.0.46 ± 0.05 and 0.82 ± 0.06 for SKLU-1 (human lung adenocarcinoma), when compared with adriamycin (IC50 (μM) = 0.08 ± 0.003 and 0.05 ± 0.003, as the positive control), respectively. Compounds 3 and 10 showed significant reduction of the induced ear edema of 37.4 ± 2.8 and 25.4 ± 3.0% (at 1.0 μmol/ear), respectively. Compound 4 was the sole active diterpenoid in the antioxidant assay (IC50 = 98. 4 ± 3.3), using α-tocopherol as the positive control (IC50 (μM) = 31.7 ± 1.04). The diterpenoid profile found is of chemotaxonomic relevance and reinforces the evolutionary link of S. ballotiflora with other members of the section Tomentellae.

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From the roots of some Mexican Salvia species, classified in subgenus Jungia, several diterpenoids belonging to abietane (i.e., 3-7), salvifolane (9-->20,10-->6)-diabeoabietane) (i.e., 2), and totarane (i.e., 10) carbocyclic skeletons were isolated together with two 20-nor- and one 6,7-secoabietane derivatives, 1 and 9, and 8, respectively. While compounds 2-10 were previously known from different sources, compound 1 is a new 20-norabietane derivative, whose structure was deduced by spectroscopic means and confirmed by X-ray-diffraction analysis. The phytogeographical significance of the distribution of 20-norabietanic diterpenoids in the genus suggested an evolutionary link between the Chinese and New-World Salvias. Compounds 2 and 8 were tested for cell-growth inhibition activity against several human cancer cell lines and human normal lymphocytes, while 2 showed a moderate cytotoxic activity, 8 exhibited a moderate yet selective activity against leukemia cell line.

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