Repositorio Digital Ikiam (Univ. Regional Amazónica)
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Diagnóstico molecular de COVID-19: Experiencia desde el laboratorio
Get PDFEl mundo, tal y como lo
conocíamos hasta hace
pocos meses, ha cam
-
biado y el impacto se ha
dado prácticamente en
todos los ámbitos sociales y profe
-
sionales. Muchas de las actividades
que estábamos desarrollando o que
teníamos planeadas, se han tenido
que posponer o culminar de manera
prematura
Production of the bioactive plant‐derived triterpenoid morolic acid in engineered Saccharomyces cerevisiae
Get PDFMorolic acid is a plant‐derived triterpenoid that possesses pharmacological properties such as cytotoxicity, as well as anti‐HIV, anti‐HSV, anti‐inflammatory, and antidiabetic effects. The significant therapeutic properties of morolic acid are desirable in the context of pharmacological and drug development research, but the low accessibility of morolic acid from natural resources limits its applications. In the present study, we developed a microbial system for the production of morolic acid. Using a combinatorial biosynthesis approach, a novel production pathway was constructed in Saccharomyces cerevisiae by co‐expressing BfOSC2 (germanicol synthase) from Bauhinia forficata and CYP716A49 (triterpene C‐28 oxidase) from Beta vulgaris. Moreover, we reconstructed the cellular galactose regulatory network by introducing a chimeric transcriptional activator (fusion of Gal4dbd.ER.VP16, GEV) to overdrive the genes under the control of the galactose promoter. We also overexpressed truncated HMG1, encoding feedback‐inhibition‐resistant form of 3‐hydroxy‐3‐methylglutaryl‐coenzyme A reductase 1 and sterol‐regulating transcription factor upc2‐1, to increase the isoprenoid precursors in the mevalonate pathway. Using this yeast system, we achieved morolic acid production up to 20.7 ± 1.8 mg/L in batch culture. To our knowledge, this is the highest morolic acid titer reported from a heterologous host, indicating a promising approach for obtaining rare natural triterpenoids. This article is protected by copyright. All rights reserved
Ketone Body Metabolism: Love and Survival
Get PDFThe following story tells the details of the ketone body metabolism, focusing on the needs of the brain in prolonged fasting conditions. This literary composition highlights the use of ketone bodies as an important metabolic adaptation that avoids excessive protein degradation and allows for greater survival. The liver produces ketone bodies that are released into the bloodstream and exported to the brain, which then absorbs and transforms them into acetyl‐CoA. These molecules with central role in metabolism generate energy through the Krebs cycle, electron transport chain, and oxidative phosphorylation. This tale is a valuable tool for biochemistry teachers and students because it can help with a deeper understanding of the physiological roles of ketone bodies and their metabolism. © 2019 International Union of Biochemistry and Molecular Biology, 48(1):82–83, 2020
An egg-shell bifunctional CeO2-modified NiPd/Al2O3 catalyst for petrochemical processes involving selective hydrogenation and hydroisomerization
Get PDFThe catalytic performance during the 1-butyne hydrogenation using two reduced Al2O3-supported Pd-based catalysts was carried out in a total recirculation system with an external fixed-bed reactor. The lab-prepared egg-shell NiPd/CeO2-Al2O3 catalyst (NiPdCe) with Pd loading = 0.5 wt%, Ni/Pd atomic ratio = 1 and CeO2 loading = 3 wt% was synthesized and characterized, and it was compared with an egg-shell Al2O3-supported Pd based commercial catalyst (PdCC). The reduced catalysts were characterized by X-ray diffraction, X-ray photoelectron spectroscopy, and high-resolution transmission electron microscopy. The textural characteristics and ammonia temperature-programmed desorption profiles of the fresh (unreduced) catalysts were also obtained. Both catalysts show high 1-butyne conversion and selectivity to 1-butene, but the catalysts also present important differences between hydroisomerizing and hydrogenating capabilities. NiPdCe catalyst shows higher capability for hydroisomerization reactions, while the PdCC catalyst exhibits higher hydrogenating capability. The observed catalytic performances can be interesting for some industrial processes and can provide a guideline for the development of a Pd-based catalyst with specific catalytic properties
Wildlife roadkill patterns in a fragmented landscape of the Western Amazon
Get PDFOne of the most evident and direct effects of roads on wildlife is the death of animals
by vehicle collision. Understanding the spatial patterns behind roadkill helps to plan
mitigation measures to reduce the impacts of roads on animal populations. However,
although roadkill patterns have been extensively studied in temperate zones, the potential
impacts of roads on wildlife in the Neotropics have received less attention
and are particularly poorly understood in the Western Amazon. Here, we present
the results of a study on roadkill in the Amazon region of Ecuador; a region that is
affected by a rapidly increasing development of road infrastructure. Over the course
of 50 days, in the wet season between September and November 2017, we searched
for road-killed vertebrates on 15.9 km of roads near the city of Tena, Napo province,
for a total of 1,590 surveyed kilometers. We recorded 593 dead specimens,
predominantly reptiles (237 specimens, 40%) and amphibians (190, 32%), with birds
(102, 17%) and mammals (64, 11%) being less common. Recorded species were assigned
to three functional groups, based on their movement behavior and habitat
use (“slow,” “intermediate,” and “fast”). Using Ripley's K statistical analyses and 2D
HotSpot Identification Analysis, we found multiple distinct spatial clusters or hotspots,
where roadkill was particularly frequent. Factors that potentially determined
these clusters, and the prevalence of roadkill along road segments in general, differed
between functional groups, but often included land cover variables such as native
forest and waterbodies, and road characteristics such as speed limit (i.e., positive effect
on roadkill frequency). Our study, which provides a first summary of species that
are commonly found as roadkill in this part of the Amazon region, contributes to a
better understanding of the negative impacts of roads on wildlife and is an important
first step toward conservation efforts to mitigate these impacts
Percepción sobre cambio climático en cuatro comunidades orientadas a la ganadería bovina en la zona central de los Andes Ecuatorianos
Get PDFEl presente documento analizó la percepción de pequeños ganaderos de cuatro comunidades de la zona
centro Andina del Ecuador, a cerca del conocimiento sobre el Cambio Climático (CC), y disponibilidad para
aceptar capacitación y acciones para enfrentar el CC. Se ejecutó una encuesta de percepciones en 188
hogares de pequeños productores asentados en las comunidades; Pilahuín, Tamboloma (Tungurahua) y San
Rafael y Chuquipogyo (Chimborazo). El estudio analizó las principales características socio demográficas y
del sistema productivo ganadero, principalmente la percepción que poseen los pequeños ganaderos sobre el
CC. Los resultados muestran la mayoría de los productores solo cuentan con educación básica y más del
60% no entienden ni tienen idea en lo referente al cambio climático. Sin embargo, la mayoría de ellos (70%)
perciben que el clima ha cambiado en sus zonas en los últimos años. Aunque alrededor del 90% no han
adoptado prácticas de adaptación al CC, la mayoría de ellos (80%) están dispuestos a adoptar estas prácticas
si reciben algún tipo de apoyo de organizaciones nacionales o internacionales con competencias en el tema.
Finamente el documento brinda conclusiones y recomendaciones para tomadores de decisiones hacia el
desarrollo de capacidades locales para promover una ganadería sostenible y resiliente al cambio climático
Heterogenization of Co II and CuII complexes containing a terpyridine-based Schiff base macrocyclic ligand on thiol- functionalized mesostructured silica
Get PDFHexagonal mesoporous MCM-41-type molecular sieve has been functionalized with (3-mercaptopropyl)trimethoxysilane and used to heterogenize two large Co(II)- and Cu(II)-complexes containing a terpyridine-based Schiff base macrocyclic ligand. First, thiol groups were linked to the siliceous surface of the mesoporous host via grafting process. Some samples were characterized by FTIR, ICP-AES, SA-XRD, N2 physisorption, 13C-MAS-NMR, XPS and EPR. This set of characterization techniques confirmed a successful functionalization process, and also confirmed that the used experimental procedure allowed the heterogenization of Co(II)- and Cu(II)-complexes inside the pores of the functionalized host, retaining the mesoporous structure. The homo- and heterogeneous catalysts were active for cyclopentene oxidation. Co@MCM(F) sample was reported in this article as the best catalyst due to its higher activity and selectivity, as well as its low loss of catalytic activity after reuse
Etnofarmacología de Kalanchoe pinnata en Amazonía: uso medicinal de " chugri yuyu "
Get PDFKalanchoe pinnata pertenece a la familia
Crassulaceae, siendo una hierba suculenta de 0,3 a
1,2 m de altura, nativa de Madagascar y con
distribución tanto en Asia como América [1]. En la
región amazónica los pueblos indígenas Achuar, A’i
Cofán, Kichwa, Secoya y Siona usan las hojas
maceradas o cocinadas como analgésico,
antibacterial, anticancerígeno, antiinflamatorio y
antitumoral. La planta registra 13 nombres
vernáculos, uno en achuar chicham “pákipanga”; uno
en a’ingae “sebachuccaque”; nueve nombres en
kichwa “chugri yuyu”, “kibi yuyu”, “llaga panka”,
“llagaspanga”, “pahuipanga”, “paichi panga”,
“palahuanda” “paquingana” y “racu-panga”; uno en
paicoca “soma iko”, y uno en castellano “espíritu
santo” [2
Identification of Oleandrin and other Cardenolides with Anticancer Activity in Methanolic Extracts from Plants of the Apocynaceae Family
Get PDFCardenolides are a family of steroid-type compounds, which due to their biological activity,
have become consolidated as possible anticancer agents. The Apocynaceae family is the
main source of these compounds, of which about 25% show anticancer activity. In this
research, six species of the Apocynaceae family present in the Ecuadorian Amazon were
considered: Himatanthus tarapotensis, Himatanthus bracteatus, cf. Aspidorperma
excelsum, Rauvolfia praecox y Tabernamontana sananho; being Nerium oleander the
model specie. In the methanolic extracts of these six species was evaluated the presence
of oleandrin and other cardenolides, as well as the cytotoxic activity in two cancer cell lines,
HeLa and D-384. It was found that the species H. tarapotensis, H. bracteatus, and cf A.
excelsum possess cardenolides, among them oleandrin. Furthermore, these extracts
showed strong cytotoxic activity in the evaluated cell lines without producing marked
hemolytic effects. The cytotoxic activity shown by H. tarapotensis, H. bracteatus and cf. A.
excelsum is greater than N. oleander and can be attributed to an additive or synergistic
effect between cardenolides and another family of compounds such as triterpenoids,
indole alkaloids or iridoids reported in Apocynaceaes. The results obtained confirm the
potential that plant can present in the search for new agents against complex diseases
Notes on the breeding behaviour and nesting preferences of Blackish nightjar (Nyctipolus nigrescens) in the Napo province in eastern Ecuad
Get PDFWe describe the first breeding record of a Blackish nightjar (Nyctipolus nigrescens) in a pasture habitat dominated by tropical grasses (Figure 1(a–d)) located at the buffer zone of the Colonso-Chalupas Biological Reserve, in the Napo province in eastern Ecuador. The record was made during the wet season at the study area (March – June) and helps to fill a gap of observa-tions on reproductive and breeding behaviour strate-gies of this species.N. nigrescens are nocturnal insectivores that inhabit rocky outcrops, granite formations, sparsely vegetated open areas, trails and quiet roads and around rivers [1–3]. This species is endemic to the neotropical region and its distribution ranges from Brazilian Amazonia to the southern Guianas and from south-eastern Colombia to eastern Ecuador and northern Bolivia in which it occurs from sea level to approximately 1200 m a.s.l. [1–3]. In Ecuador, N. nigrescens occurs in non- inundated lowland forests above 300 m in elevation and in the eastern Andean foothills, being classified as “uncommon to rare” [4,5]. Since caprimulgids are mostly nocturnal and have cryptic behaviour, not a great deal of literature is available on their breeding strategies [6]. Still, N. nigrescens is one of the best described Caprimulgidae regarding behaviour and breeding due to its large distribution range [7]. So far, breeding records have been documented in Ecuador [8,9], Brazil [10], Surinam [11,12], the Guianas [13,14] with also the documented double brood in French Guiana [15] and aberrant coloured juveniles in Ecuador [9]