Examinando por Autor "Quispe, Cristina"

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    Ítem
    A new mulinane diterpenoid from the cushion shrub Azorella compacta growing in Perú
    (Medknow Publications, 2014-07) Salgado, Francisco; Areche, Carlos; Sepúlveda, Beatriz; Simirgiotis, Mario J.; Cáceres, Fátima; Quispe, Cristina; Quispe, Lina; Cano, Teresa
    Background: Azorella compacta is a rare yellow‑green compact resinous cushion shrub growing from the high Andes of southern Perú to northwestern Argentina, and which is a producer of biologically active and unique diterpenoids. Objective: This study investigated the secondary metabolites present in a Peruvian sample of Azorella compacta and the evaluation of gastroprotective activity of the isolated compounds in a gastric‑ induced ulcer model in mice. Material and Methods: Six secondary metabolites (diterpenoids 1‑6) present in the dichloromethane (DCM) extract of A. compacta growing in Perú were isolated by a combination of Sephadex LH‑20 permeation and silica gel chromatography and their chemical structures were elucidated by spectroscopic methods (NMR) and molecular modeling. The gastroprotective activity of the new compound 1 was evaluated on the HCl/EtOH‑induced gastric lesion model in mice and compared to the activity showed by the known compounds. Results: A new mulinane diterpene along with five known diterpenoids have been isolated from a Peruvian sample of A. compacta and the gastroprotective results show that compound 1 is less active than the other known mulinane diterpenoids isolated. Conclusions: A. compacta growing in Perú showed the presence of the new mulinane 1, which was poorly active in the HCl/EtOH‑induced gastric lesion model in mice. Indeed, the activity was lower than other diterpenoids (2‑6) showing an oxygenated function at C‑16 or/and C‑20, which confirm the role of an oxygenated group (OH or carboxylic acid) for the gastroprotective activity of mulinane compounds.
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    Ítem
    Fast detection of phenolic compounds in extracts of easter pears (pyrus communis) from the atacama desert by ultrahigh-performance liquid chromatography and mass spectrometry (UHPLC-Q/Orbitrap/MS/MS)
    (MDPI AG, 2016-01) Simirgiotis, Mario J.; Quispe, Cristina; Bórquez, Jorge; Areche, Carlos; Sepúlveda, Beatriz
    A small Chilean variety of pears growing in the town of Toconao, an oasis located at the northeastern edge of the Salar de Atacama, northern Chile, was studied by means of modern PDA and high resolution mass spectral data (UHPLC-PDA-HESI-orbitrap-MS/MS). In addition, the antioxidant features of the fruits were compared with the varieties Packhman’s Triumph and Abate Fetel and correlated with the presence of phenolic compounds. The non-pigmented phenolics were fingerprinted and related to the antioxidant capacities measured by the bleaching of the DPPH radical, the ferric reducing antioxidant power (FRAP), the superoxide anion scavenging activity assay (SA), and total content of phenolics and flavonoids measured by spectroscopic methods. The machine allowed a fast separation of 15 min employing a flow rate of 1 mL per minute and could accurately identify 25 compounds, including several isorhamnetin derivatives and phenolic acids, present in the peel and pulps of this Chilean variety for the first time. The compounds were monitored using a wavelength range of 210–800 nm. The native small Chilean pear showed the highest antioxidant activity measured as the bleaching of the DPPH radical, the ferric reducing antioxidant power and superoxide anion scavenging activity (8.61 ˘ 0.65 µg/mL, 712.63 ˘ 12.12 micromols trolox equivalents (µmol/TE)/100 g FW, and 82.89% ˘ 2.52% at 100 µg/mL, respectively).
  • Miniatura
    Ítem
    Phenolic Compounds in Chilean Mistletoe (Quintral, Tristerix tetrandus) Analyzed by UHPLC–Q/Orbitrap/MS/MS and Its Antioxidant Properties
    (MDPI AG, 2016) Simirgiotis, Mario J.; Quispe, Cristina; Areche, Carlos; Sepúlveda, Beatriz
    Mass spectrometry has become a method of choice to characterize bioactive compounds in biological samples because of its sensitivity and selectivity. Hybrid ultra-HPLC hyphenated with Orbitrap mass analyzer is an innovative state of the art technology that allows fast and accurate metabolomic analyses. In this work the metabolites of a Chilean mistletoe endemic to the VIII region of Chile were investigated for the first time using UHPLC mass analysis (UHPLC-PDA-HESI-Orbitrap MSn). The anthocyanins, together with the non-pigmented phenolics were fingerprinted and correlated with the antioxidant capacities measured by the bleaching of the DPPH radical, the ferric reducing antioxidant power (FRAP), the superoxide anion scavenging activity assay (SA), and total content of phenolics, flavonoids and anthocyanins measured by spectroscopic methods. Six anthocyanins were identified, and among them, the 3-O-glycosides of delphinidin and cyanidin were the major ones. In addition, several phenolic acids (including feruloylquinic acid, feruloyl glucose, chlorogenic acid) and several flavonols (luteolin, quercetin, apigenin, isorhamnetin and glycoside derivatives) were also identified. The mistletoe leaves showed the highest antioxidant activity as measured by the DPPH radical bleaching, ferric reducing antioxidant power and superoxide anion scavenging activity tests (13.38 ± 0.47 µg/mL, 125.32 ± 5.96 µmolTE/g DW and 84.06 ± 4.59 at 100 µg/mL, respectively).