Alkaloids of Phaedranassa dubia (Kunth) J.F. Macbr. and Phaedranassa brevifolia Meerow (Amaryllidaceae) from Ecuador and its cholinesterase-inhibitory activity.

Alzheimer's disease is considered the most common cause of dementia and, in an increasingly aging population worldwide, the quest for treatment is a priority. Amaryllidaceae alkaloids are of main interest because of their cholinesterase inhibition potential, which is the main palliative treatment available for this disease. We evaluated the alkaloidal profile and the in vitro inhibitory activity on acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) of bulb alkaloid extract of Phaedranassa dubia and Phaedranassa brevifolia collected in Ecuador. Using gas chromatography coupled to mass spectrometry (GC-MS), we identified typical Amaryllidaceae alkaloids in these species, highlighting the presence of lycorine-type alkaloids in P. dubia and haemanthamine/crinine-type in P. brevifolia. The species P. dubia and P. brevifolia showed inhibitory activities against AChE (IC50 values of 25.48 ± 0.39 and 3.45 ± 0.29 µg.mL-1, respectively) and BuChE (IC50 values of 114.96 ± 4.94 and 58.89 ± 0.55 µg.mL-1, respectively). Computational experiments allowed us to understand the interactions of the alkaloids identified in these samples toward the active sites of AChE and BuChE. In silico, some alkaloids detected in these Amaryllidaceae species presented higher estimated binding free energy toward BuChE than galanthamine. This is the first study about the alkaloid profile and biological potential of P. brevifolia species.

Niobium on BEA Dealuminated Zeolite for High Selectivity Dehydration Reactions of Ethanol and Xylose into Diethyl Ether and Furfural.

In this work, we investigated the role of solid-state dealumination by (NH4)2SiF6 (25% Al removal and 13% Si insertion), the impregnation of niobium (10, 18, and 25 wt. %) on dealuminated *BEA (DB) zeolite and their catalytic properties in ethanol and xylose transformations. Among all the studied catalysts, 18%Nb-DB showed increased mesoporosity and external areas. A leveling effect in the number and strength of the proposed two sites (Brønsted and Lewis) present in the catalyst (n1 = 0.24 mmol g-1, -ΔH1 = 49 kJ mol-1, and n2 = 0.20 mmol g-1, -ΔH2 = 42 kJ mol-1) in the catalyst 18%Nb-DB, might be responsible for its good activity. This catalyst presented the highest selectivity for diethyl ether, DEE (97%) with 61% conversion after 50 ethanol pulses at 230 °C (turnover number, TON DEE = 1.15). These features allowed catalytically fruitful bonding of the ethanol molecules to the neighboring sites on the channels, facilitating bimolecular ether formation through a possible SN2 mechanism. The same catalyst was active and selective for transformation of xylose at 180 °C, showing 64% conversion and 51% selectivity for furfural (TON Furfural = 24.7) using water as a green solvent.

Anestesia de roedores sigmodontinos en condiciones de campo / Anesthesia in Sigmodontinae Rodents Living out in the Countryside

Resumen Algunas investigaciones de mamíferos silvestres requieren del uso de métodos que faciliten la manipulación de los individuos en condiciones de campo, sin afectar negativamente a los animales o a los investigadores. Dentro de estos métodos, se encuentra la inmovilización química, la cual no ha sido muy documentada en roedores silvestres de la subfamilia Sigmodontinae (Cricetidae). Por ello, en esta investigación se evaluó el uso de éter dietílico inhalado para manipular roedores sigmodontinos en campo, comparando el tiempo de inducción y el tiempo de recuperación de la anestesia entre especies, sexos y tipos de ambientes. Se capturaron y anestesiaron un total de 289 individuos de seis especies en el Parque Nacional Natural Chingaza. El tiempo de inducción de la anestesia fue diferente entre Microryzomys minutus, Neomicroxus bogotensis, Thomasomys laniger y Thomasomys niveipes (F3; 552 = 9,36; p < 0,05); de igual forma, el tiempo de recuperación de la anestesia fue diferente entre dichas especies (H = 9,59; p = 0,022). No se encontraron diferencias en los tiempos de inducción y recuperación de la anestesia entre sexos, ni entre ambientes. La mortalidad total fue de 4,5 %. No se observaron secreciones mucosas, vómito o complicaciones cardíacas o respiratorias en los individuos anestesiados. Los individuos fueron recapturados y no se evidenciaron alteraciones en su comportamiento o aspecto físico que indicaran una afectación por la anestesia o manipulación en capturas previas. La anestesia inhalada con éter dietílico puede ser una opción rápida y segura para inmovilizar y manipular sigmodontinos durante procedimientos cortos en campo dentro de estudios poblacionales o programas de monitoreo en vida silvestre.

Abstract Some researches in wild mammals require methods that enable to handle the animals living in wild conditions, without affecting negatively the animals, or the researchers. These methods include the chemical immobilization, which has not been enough documented when handling wild rodents of the Sigmodontinae subfamily (Cricetidae). Therefore, this research evaluated the use of diethyl ether when handling Sigmodontinae rodents out in the countryside. It compared the induction time to the anesthesia recovery time between species, genders, and type of environments. A total of 289 animals were caught and anesthetized from six species in the Chingaza National Natural Park. The anesthesia induction times were different between Microryzomys minutus, Neomicroxus bogotensis, Thomasomys laniger y Thomasomys niveipes (F3; 552 = 9.36; p < 0.05). Likewise, the anesthesia recovery times were different between the same species (H = 9.59; p = 0.022). No difference was found in the induction times and the anesthesia recovery times between genders, neither for the types of environment. Total mortality was 4.5%. None mucosal secretions, vomit, or cardiac/respiratory complications were observed in the anesthetized animals. These subjects were caught again and they did not show any alterations in their behavior or physical aspect indicating affection derived either from the anesthesia or the previous handling under captivation. Anesthesia with diethyl ether can be a quick and safe choice when it comes to immobilize and handle Sigmodontinae rodents during short procedures out in the countryside, when carrying out population studies or wildlife monitoring programs.

Effects of partial replacement of maize in the diet with crude glycerin and/or soyabean oil on ruminal fermentation and microbial population in Nellore steers.

The objective of this study was to determine whether a combination of crude glycerin (CG) and soyabean oil (SO) could be used to partially replace maize in the diet of Nellore steers while maintaining optimum feed utilisation. Eight castrated Nellore steers fitted with ruminal and duodenal cannulas were used in a double 4×4 Latin square design balanced for residual effects, in a factorial arrangement (A×B), when factor A corresponded to the provision of SO, and factor B to the provision of CG. Steers feed SO and CG showed similar DM intake, DM, organic matter and neutral-detergent fibre digestibility to that of steers fed diets without oil and without glycerine (P>0·05). Both diets with CG additions reduced the acetate:propionate ratio and increased the proportion of iso-butyrate, butyrate, iso-valerate and valerate (P<0·05). Steers fed diets containing SO had less total N excretion (P<0·001) and showed greater retained N expressed as % N intake (P=0·022). SO and CG diet generated a greater ruminal abundance of Prevotella, Succinivibrio, Ruminococcus, Syntrophococcus and Succiniclasticum. Archaea abundance (P=0·002) and total ciliate protozoa were less in steers fed diets containing SO (P=0·011). CG associated with lipids could be an energy source, which is a useful strategy for the partial replacement of maize in cattle diets, could result in reduced total N excretion and ruminal methanogens without affecting intake and digestibility.