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- Phytochemical profile and anticholinesterase and antimicobial activities of supercritical versus conventional extracts of Satureja montanaPublication . Silva, Filipa; Martins, A.; Salta, J.; Neng, N. R.; Nogueira, J.; Mira, Delfina; Gaspar, Natália; Justino, Jorge; Grosso, C.; Urieta, J. S.; Palavra, A. M. S.; Rauter, A. P.Winter savory Satureja montana is a medicinal herb used in traditional gastronomy for seasoning meats and salads. This study reports a comparison between conventional (hydrodistillation, HID, and Soxhlet extraction, SE) and alternative (supercritical fluid extraction, SFE) extraction methods to assess the best option to obtain bioactive compounds. Two different types of extracts were tested, the volatile (SFE-90 bar, second separator vs HID) and the nonvolatile fractions (SFE-250 bar, first and second separator vs SE). The inhibitory activity over acetyl- and butyrylcholinesterase by S. montana extracts was assessed as a potential indicator for the control of Alzheimer's disease. The supercritical nonvolatile fractions, which showed the highest content of (+)-catechin, chlorogenic, vanillic, and protocatechuic acids, also inhibited selectively and significantly butyrylcholinesterase, whereas the nonvolatile conventional extract did not affect this enzyme. Microbial susceptibility tests revealed the great potential of S. montana volatile supercritical fluid extract for the growth control and inactivation of Bacillus subtilis and Bacillus cereus, showing some activity against Botrytis spp. and Pyricularia oryzae. Although some studies were carried out on S. montana, the phytochemical analysis together with the biological properties, namely, the anticholinesterase and antimicrobial activities of the plant nonvolatile and volatile supercritical fluid extracts, are described herein for the first time.
- Alkyl deoxy-arabino-hexopyranosides: synthesis, surface properties, and biological activitiesPublication . Silva, Filipa; Goulart, Margarida; Justino, Jorge; Neves, Ana; Santos, F.; Caio, J.; Lucas, S.; Newton, A.; Sacoto, D.; Barbosa, E.; Santos, M. S.; Rauter, A. P.Octyl and dodecyl glycosides possessing 2-deoxy-arabino-hexopyranoside moieties belonging to the D-and L-series in their alpha- and beta-forms were synthesized by reaction of an acetyl protected glycal with octanol or dodecanol, catalyzed by triphenylphosphine hydrobromide, followed by deprotection. Their surface properties were studied and discussed in terms of the adsorption and aggregation parameters, pC(20), CMC, and gamma(CMC). The antimicrobial activities were assessed using the paper disk diffusion and broth dilution methods. Both the octyl and dodecyl 2-deoxy beta-D-glycosides inhibited significantly Enterococcus faecalis, a microbe also highly susceptible to dodecyl 2,6-dideoxy-alpha-L-arabino-hexopyranoside. This compound was particularly active against Bacillus cereus and Bacillus subtilis, presenting for both Bacillus species a minimal inhibitory concentration of the same order of magnitude and a minimal lethal concentration even smaller than that obtained for chloramphenicol, a bioactivity which remained unaltered after 1 year solution storage at 4 degrees C. In addition, activity over Listeria monocytogenes was also observed. Direct cytotoxicity and genotoxicity of the glycosides were determined by proliferative index (mitotic index) evaluation in peripheral human lymphocytes of healthy donors. All compounds induced acute toxicity effects, and the response was dose dependent for the alpha-anomer of both the alkyl 2-deoxy-arabino-hexopyranosides and for the corresponding dodecyl beta-anomer, what suggests that non-toxic but still bioactive concentrations may be found for these compounds