María Yolanda Ríos

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Ultra-short peptides 1-9 were designed and synthesized with phenylalanine, ornithine and proline amino acid residues and their effect on antimalarial activity was analyzed. On the basis of the IC(50) data for these compounds, the effects of nature, polarity, and amino acid sequence on Plasmodium berghei schizont cultures were analyzed too. Tetrapeptides(More)
The increased incidence of Multidrug-Resistant Mycobacterium tuberculosis (MDR-MT) requires the search for alternative antimycobacterial drugs. The main aim of this study was to evaluate the dichloromethane extract from Aristolochia brevipes (Rhizoma) and the compounds isolated from this extract against several mycobacterial strains, sensitive, resistant(More)
Two new cytotoxic isoflavans, (3S)-7-hydroxy-2',3',4',5', 8-pentamethoxyisoflavan (1) and (3S)-3',7-dihydroxy-2',4',5', 8-tetramethoxyisoflavan (2), were isolated from the bark and trunks of Eysenhardtia polystachya (Leguminosae), together with the known constituents stigmasterol, isoduartin, cuneatin, 7-hydroxy-2',4', 5'-trimethoxyisoflavone, and(More)
Heliopsis longipes is used as analgesic in Mexican traditional medicine. The present study assesses the possible antinociceptive effect of Heliopsis longipes and describes the pharmacological mechanism of action of the antinociceptive effect of affinin, identified as the one active principle in Heliopsis longipes acetone extract. Intraperitoneal(More)
Bioassay guided fractionation of an antimycobacterial extract of Foeniculum vulgare var dulce (Apiaceae) led to the isolation and characterization of 5-hydroxyfurano-coumarin. The chemical structure of this compound was elucidated by 1H and 13C (1D and 2D) Nuclear Magnetic Resonance (NMR) spectroscopy. In addition, the active fractions were analyzed by(More)
The plant Krameria pauciflora MOC et. Sessé ex DC. is used as an anti-inflammatory and antidiabetic in traditional medicine. The aim of this study was to evaluate the in vivo anti-inflammatory and antidiabetic effects of a methanol extract from the roots of K. pauciflora. Dichloromethane and ethyl acetate extracts obtained by partitioning the methanol(More)
Aqueous in situ one-pot N-Boc-deprotection-cyclization of N alpha-Boc-dipeptidyl-tert-butyl and methyl esters under microwave irradiation afforded 2,5-diketopiperazines (DKPs) in excellent yields. This protocol is rapid, safe, environmentally friendly, and highly efficient, and showed that the tert-butoxy moiety is also an excellent leaving group for these(More)
OBJECTIVE To establish the role of TRPV1 receptor in the antinociceptive effect of natural alkamides (i.e. affinin, longipinamide A, longipenamide A and longipenamide B) isolated from Heliopsis longipes (A. Gray) S.F. Blake and some related synthetic alkamides (i.e. N-isobutyl-feruloylamide and N-isobutyl-dihydroferuloylamide). METHODS The orofacial(More)
Herbivory activates the synthesis of allelochemicals that can mediate plant-plant interactions. There is an inverse relationship between the activity of xylophages and the abundance of epiphytes on Ipomoea murucoides. Xylophagy may modify the branch chemical constitution, which also affects the liberation of allelochemicals with defense and allelopathic(More)
Stansin 6 a tetrasaccharide resin glycoside isolated from the root of Ipomoea stans was evaluated as anticonvulsant and neuroprotective in kainic acid-induced seizures of rats. Intraperitoneal injection of kainic acid (10 mg/kg) induced typical behavioral seizures such as wet dog shakes and limbic seizures, and histopathological changes in the hippocampus(More)
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