Browsing by Author "Costa, Maria do Céu"
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- Characterization of laurel fruit oil from Madeira Island, PortugalPublication . Castilho, Paula C.; Costa, Maria do Céu; Rodrigues, Ana; Partidário, AnaThe fixed oil extracted from Laurus spp. fruit from Madeira Island, Portugal, is used in local traditional medicine for a wide variety of health complaints. Physical properties, density and refractive index, as well as the TAG FA composition, sterols, and waxes were determined. The oil was found to have an un usually high content of volatiles (ca. 10%), with trans-ocimene and germacrene D predominating. Oleic (30%) and linoleic (20%) acids were the main unsaturated FA, whereas lauric (18%) and palmitic (up to 22.5%) acids were the main saturated FA in the neutral lipid fraction. The oil had a sterol content on the same order as olive oil, with β-sitosterol (84%) predominating. Two sesquiterpene lactones, dehydrocostuslactone and costunolide, accounted for 5% of the overall composition. Madeira laurel oil is not currently used as an edible oil because of its very strong flavor. Its claimed medicinal properties have not yet been vali dated, and this is the first report on the characterization of the commercial product.
- Characterization of triacylglycerols in Madeira laurel oil by HPLC-atmospheric pressure chemical ionization-MSPublication . Castilho, Paula C.; Costa, Maria do Céu; Rodrigues, Ana; Branco, Pedro Costa; Costa, MafalaaMadeira laurel oil was fractionated by liquid ex traction combined with TLC, and TAGs were analyzed by HPLC coupled with atmospheric pressure chemical ionization-MS (APCI-MS). Eluted molecular species compositions of the eluted TAG in the complex natural mixture were determined by GC identification of FAME and by LC-atmospheric pressure chemi cal ionization (APCI)-MS analysis of the lipid. The APCI-MS spectra of most TAG exhibited [M + H]+ and [M − RCOO]+ ions, which defined the M.W. and the molecular association of fatty acyl residues, respectively. Despite the relatively high de gree of saturation, with a saturated/unsaturated ratio of 0.70, no totally saturated TAG nor mixed asymmetric TAG with two sat urated FA (SSM or SSU, where S is saturated, M is monounsatu rated, and U is unsaturated) were found. This type of molecular structure provides a possible explanation for the relatively low m.p. (12–15°C) and also the high oxidative resistance observed.
- Direct identification and quantitative determination of costunolide and dehydrocostuslactone in the fixed oil of Laurus novocanariensis by13C-NMR spectroscopyPublication . Ferrari, Bernard; Castilho, Paula; Tomi, Félix; Rodrigues, Ana Isabel; Costa, Maria do Céu; Casanova, JosephThe fixed oil of Laurus novocanariensis (previously L. azorica) contains mostly glycerides together with minor non-saponifiable compounds. The direct identification and quantitative determination of costunolide and dehydrocostuslactone, two sesquiterpene lactones components of the oil that exhibit biological activities, is described. The analysis was carried out using 13C-NMR spectroscopy (signal acquisition with inverse gated decoupling of protons; diglyme as internal standard) without separation, derivatisation or any sample preparation.