Browsing by Author "Gutierrez, Margarita"

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    Antiplatelet, anticoagulant, and fibrinolytic activity in vitro of extracts from selected fruits and vegetables
    (LIPPINCOTT WILLIAMS & WILKINS, 2011) Torres Urrutia, Constanza; Guzman, Luis; Schmeda Hirschmann, Guillermo; Moore Carrasco, Rodrigo; Alarcon, Marcelo; Astudillo, Luis; Gutierrez, Margarita; Carrasco, Gilda; Yuri, Jose A.; Aranda, Eduardo; Palomo, Ivan
    A diet rich in fruits and vegetables is known to decrease the risk of cardiovascular disease. However, the information regarding the antithrombotic activity (antiplatelet, anticoagulant, and fibrinolytic) of fruits and vegetables is scarce. The aim of this study was to assess the antithrombotic activity of extracts from fruits and vegetables widely consumed in central Chile. The study included samples of 19 fruits and 26 vegetables, representative of the local diet. The extracts prepared from each sample included an aqueous (juice or pressed solubles) and/or methanol-soluble fraction. The extracts were evaluated for antiplatelet, anticoagulant, and fibrinolytic activity in vitro at a final concentration of 1 mg/ml. The antiplatelet activity was assessed by platelet aggregation inhibition; anticoagulant activity was measured by the prothrombin time (PT), diluted prothrombin time (dPT), activated partial thromboplastin time (APTT), kaolin clotting time (KCT), and thrombin time. The fibrinolytic effect was determined with the euglobin clot lysis time and fibrin plate methods. Extracts of green beans and tomatoes inhibited platelet aggregation induced by ADP and arachidonic acid, in a concentration-dependent manner. The methanolic extracts of grapes prolonged the PT and dPT. Finally, extracts of raspberry prolonged the APTT and also presented fibrinolytic activity. In conclusion, from a screening that included a variety of fruits and vegetables, we found antiplatelet activity in green beans and tomatoes, anticoagulant activities in grapes and raspberries, whereas fibrinolytic activity was observed only in raspberries. Further investigations are necessary to advance in knowledge of the active compounds of these fruits and vegetables and their mechanisms of action. Blood Coagul Fibrinolysis 22:197-205 (c) 2011 Wolters Kluwer Health vertical bar Lippincott Williams & Wilkins.
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    Furanyl chalcone derivatives as efficient singlet oxygen quenchers. An experimental and DFT/MRCI study
    (PERGAMON-ELSEVIER SCIENCE LTD, 2020) Diaz Uribe, Carlos; Vallejo, William; Florez, Jiress; Trilleras, Jorge; Gutierrez, Margarita; Rodriguez Serrano, Angela; Schott, Eduardo; Zarate, Ximena
    This study reports the antioxidant activity against singlet oxygen (O-1(2)) of five newly synthesized furanyl chalcones (FCs) (E)-3 (5-(4 chlorophenyl)furan-2-yl)-1-arylprop-2-en-1-ones (3a-e). Their structural difference is based on the aryl substituent as follows (Ar): 3a = -C6H4-OCH3, 3b = -C6H3-(1,2-OCH3), 3c = -C6H4OC6H4, 3d = - C10H6-(OCH3) and 3e = -C4H3O. We used a Claisen-Schmidt condensation involving a 5-(4-chlorophenyl)furan-2-carbaldehyde and the corresponding ketones under ultrasonic irradiation. Their property to O-1(2) quenching was analyzed in terms of the rate constant for the process (k(Q) at 25 degrees C) determined by the Stern-Volmer model in ethanol. For the compounds 3c, 3d and 3e, the k(Q) values are slightly larger respect to 3a and 3b. The FCs 3c behaves as the best quencher (k(Q )of 8.44 (+/- 0.09) x 10(7) M-1 s(-1)). Geometry analysis and electronic structure calculations have been performed in the framework of Density Functional Theory (DFT) and DFT/Multi-Reference Configuration Interaction (DFT/MRCI) methods. According to DFT/MRCI, a physical quenching of O-1(2) from the ground states of the FCs may not likely induce a spontaneous energy transfer processes but a chemical quenching mechanism may dominate the kinetics. (C) 2020 Elsevier Ltd. All rights reserved.
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    Toward the cholinesterase inhibition potential of TADDOL derivatives: Seminal biological and computational studies
    (2022) Constantino, Andrea R.; Charbe, Nitin Bharat; Duarte, Yorley; Gutierrez, Margarita; Giordano Villatoro, Ady; Prasher, Parteek; Dua, Kamal; Mandolesi, Sandra; Zacconi, Flavia C. M.
    Alzheimer's disease (AD) is a degenerative neurological disease characterized by gradual loss of cognitive skills and memory. The exact pathogenesis involved still remains unrevealed, but several studies indicate the involvement of an array of different enzymes, underlining the multifactorial character of the disease. Inhibition of these enzymes is therefore a powerful approach in the development of AD treatments, with promising candidates, including acetylcholinesterase (AChE), butyrylcholinesterase (BuChE), and monoamine oxidase. Interestingly, AChE is the target of a major pesticide family (organophosphates), with several reports indicating an intersection between the pesticide's activity and AD. In this study, various TADDOL derivatives were synthesized and their in vitro activities as AChE/BuChE inhibitors as well as their antioxidant activities were studied. Molecular modeling studies revealed the capability of TADDOL derivatives to bind to AChE and induce inhibition, especially compounds 2b and 3c furnishing IC50 values of 36.78 +/- 8.97 and 59.23 +/- 5.31 mu M, respectively. Experimental biological activities and molecular modeling studies clearly demonstrate that TADDOL derivatives with specific stereochemistry have an interesting potential for the design of potent AChE inhibitors. The encouraging results for compounds 2b and 3c indicate them as promising scaffolds for selective and potent AChE inhibitors.