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ABSTRACT: Six lycorine derivatives were prepared, characterized, and evaluated for their in vitro anti-Trichomonas vaginalis activity. Compounds bearing an acetyl (2), lauroyl (3), benzoyl (4 and 5), and p-nitrobenzoyl (6 and 7) groups were synthesized. The best activity was achieved with lycorine esterified at C-2 position with lauroyl group. Preliminary structure-activity relationship points that unprotected OH group at C-1 and C-2 is not necessary to the antiparasitic activity, and none of the derivative was less active than lycorine. The lycorine structural requisites required to kill this amitochondriate cell seem to be different in comparison with the derivatives most active against other parasites and tumor cell lines, both mitochondriated cells. This result is an important contribution with our ongoing studies regarding the mechanism of action of the Amaryllidaceae alkaloids on T. vaginalis cell death opening a new perspective to optimize this innovative pharmacological potential.
Chemical Biology & Drug Design 01/2012; 80(1):129-33. · 2.28 Impact Factor
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Chemistry of Natural Compounds 01/2010; 46(4):649-650. · 1.03 Impact Factor
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ABSTRACT: The treatment of neurological disorders and neurodegenerative diseases is related to the levels of acetylcholine (ACh) through the inhibition of acetylcholinesterase (AChE). Galanthamine, an important alkaloid isolated from the Amaryllidaceae family, is approved for the pharmacological treatment of Alzheimer's disease (AD) and acts by inhibiting the acetylcholinesterase (AChE) activity. In the present study, Ellman's method was used to verify the inhibition of AChE activity of some isoquinolines alkaloids such as galanthamine, montanine, hippeastrine and pretazettine. At the concentrations 1mM, 500 microm and 100 microm, galanthamine presented an AChE inhibition higher than 90%. Montanine inhibited, in a dose-dependent manner, more than 50% of the enzyme at 1mM concentration. With the concentrations 500 microm and 100 microm, 30-45% of AChE activity inhibition was detected. The alkaloids hippeastrine and pretazettine presented no significant inhibition of the AChE activity. The results demonstrate that montanine significantly inhibits AChE activity at the tested concentrations, suggesting the necessity of further investigations on this alkaloid use in treating neurological disorders.
Phytomedicine: international journal of phytotherapy and phytopharmacology 12/2009; 17(8-9):698-701. · 2.17 Impact Factor
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ABSTRACT: Strictosidinic acid 10mg/kg, isolated from Psychotria myriantha leaves, were administered intraperitoneally to Wistar male rats (n=5-6). After 60 minutes, striatum was dissected, homogenized and injected onto HPLC-ED chromatographic system. It was observed a 28.7% reduction in the 5-HT levels followed up by an increase of 5-HIAA levels (29.4%). Furthermore there was a decrease of 8.0% in DA levels and an increase in the levels of metabolites DOPAC (21.5%) and HVA (52.5%). The results indicate that strictosidinic acid has a promising effect in the central nervous system, justifying more studies about the central actions of Psychotria compounds.
Phytomedicine: international journal of phytotherapy and phytopharmacology 08/2009; 17(3-4):289-91. · 2.17 Impact Factor
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ABSTRACT: Infusions obtained from dried and fresh leaves of Blepharocalyx salicifolius were assessed in antibacterial (with S. aureus and E. coli), antiinflammatory, antinociceptive, antispasmodic and intestinal transit models. All samples analyzed showed significant antibacterial activity against Gram-positive and Gram-negative bacteria. The highest activity was observed with the dried leaves against E. coli. An infusion from fresh leaves inhibited the stimulating action of acetylcholine on intestinal musculature (average inhibition 45%). Other biological assays gave no significant results with doses up to 300 and 600 mg/kg for dried and fresh material, respectively. The essential oil obtained from fresh leaves by hydrodistillation (0.9%) was analyzed by GC and GC/MS, where 42 components were identified. The main components were 1,8-cineole (25.2%), linalool (20.4%) and ß-caryophyllene (22.9%).
09/2008; 39(4):308-311.
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ABSTRACT: The dichloromethane and n-butanol extracts obtained from fresh bulbs of Hippeastrum vittatum (Amaryllidaceae), collected in Southern Brazil, were evaluated for their cytotoxic activity in vitro against five human cell lines (HT29 colon adenocarcinoma, H460 non-small cell lung carcinoma, RXF393 renal cell carcinoma, MCF7 breast cancer, and OVCAR3 epithelial ovarian cancer), using the sulphorhodamine B assay. Both extracts showed potential antiproliferative activity. From CH(2)Cl(2) fraction, three alkaloids were isolated: lycorine, vittatine and montanine. The two last compounds were submitted to the antiproliferative assay and the highest level of cytotoxicity was found for the alkaloid montanine.
Phytomedicine: international journal of phytotherapy and phytopharmacology 03/2008; 15(10):882-5. · 2.17 Impact Factor
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ABSTRACT: The treatment of neurological disorders and neurodegenerative diseases is related to the levels of acetylcholine (ACh) through the inhibition of acetylcholinesterase (AChE). Galanthamine, an important alkaloid isolated from the Amaryllidaceae family, is approved for the pharmacological treatment of Alzheimer's disease (AD) and acts by inhibiting the acetylcholinesterase (AChE) activity. In the present study, Ellman's method was used to verify the inhibition of AChE activity of some isoquinolines alkaloids such as galanthamine, montanine, hippeastrine and pretazettine. At the concentrations 1 mM, 500 μm and 100 μm, galanthamine presented an AChE inhibition higher than 90%. Montanine inhibited, in a dose-dependent manner, more than 50% of the enzyme at 1 mM concentration. With the concentrations 500 μm and 100 μm, 30-45% of AChE activity inhibition was detected. The alkaloids hippeastrine and pretazettine presented no significant inhibition of the AChE activity. The results demonstrate that montanine significantly inhibits AChE activity at the tested concentrations, suggesting the necessity of further investigations on this alkaloid use in treating neurological disorders.
Phytomedicine.
