Examinando por Autor "Opazo, A."

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  • Miniatura
    Ítem
    Bioluminescence as a tool to evaluate hand washing during the training of professionals related to Public Health
    (Universidad Nacional Mayor de San Marcos, 2020) Contreras, S.; Caro, G.; Cuevas, J.; Barrientos, C.; Opazo, A.
    Health Care Associated Infections (HAS), Foodborne Illness and zoonoses generate high costs for public health. A simple and inexpensive measure, and with evidence of its effectiveness in their prevention is handwashing, a protocol established by the World Health Organization (WHO), that is taught in professional training programs to students of human and animal health, as well as those who process food. The aim of this descriptive and cross-sectional study was to evaluate handwashing by bioluminescence in students during their performance in practice centres, as well as their knowledge and attitude towards handwashing, by a survey involving 45 students from the Gastronomy, Nursing and Veterinary Medicine in their last cycle of academic training of a private higher education institution (Concepción, Chile). The students showed an adequate knowledge of handwashing (90%), but a bad attitude towards it (70% of favourable responses). Students gave greater importance to handwashing when they are observed, evaluated or when their classmates do it, showing a lack of awareness regarding the importance of doing it. The bioluminescence test indicated a significant reduction between before and after handwashing, from 2951±40 URL vs. 400.7±73 URL, respectively (p<0.0001), without significant differences between the careers. The measurement of ATP by bioluminescence is a simple and rapid method to evaluate the effectiveness of handwashing, being a tool that can be incorporated into disciplinary training in careers directly related to human-animal health.
  • Miniatura
    Ítem
    Oxidation of isodrimeninol with PCC yields drimane derivatives with activity against candida yeast by inhibition of lanosterol 14-alpha demethylase
    (MDPI AG, 2020-08) Marin, V.; Iturra, A.; Opazo, A.; Schmidt, B.; Heydenreich, M.; Ortiz, L.; Jiménez, V.A.; Paz, C.
    Candida species cause an opportunistic yeast infection called Candidiasis, which is responsible for more than 50,000 deaths every year around the world. Effective treatments against candidiasis caused by non-albicans Candida species such as C. glabrata, C. parapsilosis, C. aureus, and C. krusei are limited due to severe resistance to conventional antifungal drugs. Natural drimane sesquiterpenoids have shown promising antifungal properties against Candida yeast and have emerged as valuable candidates for developing new candidiasis therapies. In this work, we isolated isodrimeninol (C1) from barks of Drimys winteri and used it as starting material for the hemi-synthesis of four sesquiterpenoids by oxidation with pyridinium chlorochromate (PCC). The structure of the products (C2, C3, C4, and C5) was elucidated by 1D and 2D NMR spectroscopy resulting in C4 being a novel compound. Antifungal activity assays against C. albicans, C. glabrata, and C. krusei revealed that C4 exhibited an increased activity (IC50 of 75 µg/mL) compared to C1 (IC50 of 125 µg/mL) in all yeast strains. The antifungal activity of C1 and C4 was rationalized in terms of their capability to inhibit lanosterol 14-alpha demethylase using molecular docking, molecular dynamics simulations, and MM/GBSA binding free energy calculations. In silico analysis revealed that C1 and C4 bind to the outermost region of the catalytic site of 14-alpha demethylase and block the entrance of lanosterol (LAN) to the catalytic pocket. Binding free energy estimates suggested that C4 forms a more stable complex with the enzyme than C1, in agreement with the experimental evidence. Based on this new approach it is possible to design new drimane-type sesquiterpenoids for the control of Candida species as inhibitors of 14-alpha demethylase. © 2020 by the authors. Licensee MDPI, Basel, Switzerland.