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Nitrification inhibitors are widely used in agriculture to mitigate nitrous oxide (N2O) emission and increase crop yield. However, no concrete information on their mitigation of N2O emission is available under soil and environmental conditions as in Pakistan. A field experiment was established using a silt clay loam soil from Peshawar, Pakistan, to study the effect of urea applied in combination with a nitrification inhibitor, nitrapyrin (2-chloro-6-tri-chloromethyl pyridine), and/or a plant growth regulator, gibberellic acid (GA3), on N2O emission and the nitrogen (N) uptake efficiency of maize. The experimental design was a randomized complete block with five treatments in four replicates: control with no N (CK), urea (200 kg N ha–1) alone, urea in combination with nitrapyrin (700 g ha–1), urea in combination with GA3 (60 g ha–1), and urea in combination with nitrapyrin and GA3. The N2O emission, yield, N response efficiency, and total N uptake were measured during the experimental period. The treatment with urea and nitrapyrin reduced total N2O emission by 39%–43% and decreased yield-scaled N2O emission by 47%–52%, relative to the treatment with urea alone. The maize plant biomass, grain yield, and total N uptake increased significantly by 23%, 17%, and 15%, respectively, in the treatment with urea and nitrapyrin, relative to the treatment with urea alone, which was possibly due to N saving, lower N loss, and increased N uptake in the form of ammonium; they were further enhanced in the treatment with urea, nitrapyrin, and GA3 by 27%, 36%, and 25%, respectively, probably because of the stimulating effect of GA3 on plant growth and development and the reduction in biotic and abiotic stresses. These results suggest that applying urea in combination with nitrapyrin and GA3 has the potential to mitigate N2O emission, improve N response efficiency, and increase maize yield. UCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Básicas::Centro en Investigación en Contaminación Ambiental (CICA)

Araujia sericifera is a native perennial, climbing laticiferous shrub from South America that is currently naturalized in many other countries. Previous data describe promising properties for A. sericifera, but no systematic study of its bioactive compounds and possible medicinal applications has been conducted to date. In the present study, aerial parts of A. sericifera (leaves, stems, and fruits) were explored by combining GC-MS and NMR spectroscopy analysis for both nonpolar (hexane) and polar (methanol) extracts. The hexanic extracts contained high amounts of pentacyclic triterpenes including two new metabolites, 3-tigloyl germanicol (18) and 3-tigloyl lupeol (19). The methanolic extracts revealed the presence of luteolin-7-glucoside (24), trigonelline (22), and conduritol F (23) as the main constituents. A multivariate study of a meaningful number of extracts allowed us to determine the distribution of compounds inside the plant. A cytotoxic evaluation in vitro showed that both leaf and fruit hexanic extracts presented a moderate activity against human breast carcinoma cell lines (MDA-MB-453 and MCF-7) and human colon carcinoma cell line (HCT-116) by the MTS [3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium] assay.

This work provides an evaluation of an ultrasound-assisted, combined extraction, centrifugation and ultrafiltration process for the optimal recovery of polyphenols. A purple sweet potato (PSP) extract has been obtained using ultrasonic circulating extraction equipment at a power of 840 W, a frequency of 59 kHz and using water as solvent. Extract ultrafiltration, using polyethersulfone (PES), was carried out for the recovery of polyphenol, protein and anthocyanin. Pre-treatment, via the centrifugation of purple sweet potato extract at 2500 rpm over 6 min, led to better polyphenol recovery, with satisfactory protein removal (reused for future purposes), than PSP extract filtration without centrifugation. Results showed that anthocyanin was efficiently recovered (99%) from permeate. The exponential model fit well with the experimental ultrafiltration data and led to the calculation of the membrane's fouling coefficient. The optimization of centrifugation conditions showed that, at a centrifugation speed of 4000 rpm (1195× g) and duration of 7.74 min, the optimized polyphenol recovery and fouling coefficient were 34.5% and 29.5 m-1, respectively. The removal of proteins in the centrifugation process means that most of the anthocyanin content (90%) remained after filtration. No significant differences in the intensities of the HPLC-DAD-ESI-MS² peaks were found in the samples taken before and after centrifugation for the main anthocyanins; peonidin-3-feruloylsophoroside-5-glucoside, peonidin-3-caffeoyl-p-hydroxybenzoylsophoroside-5-glucoside, and peonidin-3-caffeoyl-feruloyl sophoroside-5-glucoside. This proves that centrifugation is an efficient method for protein removal without anthocyanin loss. This study considers this process an ultrasound-assisted extraction-centrifugation-ultrafiltration for purple sweet potato valorization in "green" technology.

The epicuticular wax (EW) layer is located on the surface of most of plants organs. It provides the cuticle with most of its properties and is the primary barrier against biotic and abiotic stress. Despite the importance of Olea europaea cultivation, few studies have characterized the EW covering leaves and olives, which could be involved in resistance to both infection and environmental conditions. In the present study, wide-ranging screening was carried out using direct-injection electrospray ionisation coupled to high-resolution mass spectrometry to analyse EW in developing olives of nine varieties. The proportions of EW fractions (wax esters (WEs), diacylglycerols, triacylglycerols (TAGs), triterpenic acids and aldehydes) strongly depended on the olive cultivar, and in only a few cases were they influenced by the sampling date. The specific compositions of the major fractions, WEs and TAGs, were strictly related to the cultivar, while the degree of unsaturation and the chain length of the WEs evolved throughout the four weeks prior to the olive colour turning.

El cadmio (Cd) proveniente de suelos afectados por intemperismo y actividades antropogénicas puede producir efectos tóxicos, asociados con la baja afinidad de las formas adsorbentes, la alta solubilidad y la movilidad. Es de gran importancia conocer los fenómenos de adsorción y los factores de movilidad de este elemento y predecir su posible toxicidad en suelos de la región altoandina de Colombia cuyo sistema de uso está cambiando a pasturas y cultivos con aplicación de fertilizantes fosfatados que contienen cadmio. Para determinar la influencia en la retención y el factor de movilidad de Cd en estos suelos de la subcuenca Rio Las Piedras, Departamento del Cauca (Colombia), utilizados en sistemas de bosque, cultivo de papa (Solanum tuberosum) y pastura de kikuyo (Pennisetum clandestinum) fueron caracterizados por sus pro-piedades físicas y químicas,encontrando alta acidez, presencia de alófanos, alto contenido de carbono orgánico, alta capacidad de intercambio catiónico, y baja densidad. Para determinar la influencia en la retención y el factor de movilidad de Cd, la calidad de la materia orgánica (M.O) fue evaluada mediante índices de humificación obtenidos por la caracterizaron de sus diferentes fracciones. La retención fue evaluada mediante isotermas de adsorción de Freundlich en ácidos húmicos en suelos de los tres sistemas de uso. Los valores encontrados de K (máxima capacidad de adsorción) y n (fuerza de retención) fueron, respectivamente, de 131.98 y 1.18 en suelos de bosque, 340.93 y 1.19 en cultivo, y 170.36 y 1.19 en pasturas. La calidad de la M.O. tiene un efecto significativo en estos procesos, así, una mejor calidad redunda en menor movilidad de Cd previniendo contaminación de aguas subterráneas y toxicidad por bioacumulación de cadmio. Cadmium from soils by weathering and anthropogenic activities can have produce toxic effects associate to low affinity of adsorbents forms, high solubility and mobility. It is very important to conduct studies leading to knowledge of adsorption phenomena and cadmium mobility factors and predict possible toxici-ty in High Andeansoils whose use is changing to pastures and crops with applications of phosphate fertilizer with presence of Cd in composition. High Andean soils subbasin Rio Las Piedras, (Department of Cauca), with systems of forest, crop and pasture were characterized by physical and chemical properties, highlighting strong acidity, presence of allophones, high in organic carbon, high cation exchange capacity, low density of soil. The quality of soil organic matter was assessed by different humification index obtained with the different fractions characterized to determine the influence on cadmium retention phe-nomenon and mobility factor. The retention was evaluated by Freundlich adsorption isotherms in humic acids and soils of the three systems. The K (maximum adsorption capacity) and n (retention force) values correspond to 131. 98 and 1.18 in forest soils, 340.93 and 1.19 for crop, 170.36 and 1.19 in pasture, and are lower than those of humic acids in the three systems. The quality of the organic matter has a significantly effect on these processes, better quality results in less mobility preventing groundwater contamination and bioaccumulation toxicity.

The seeds of Fevillea cordifolta have yielded 11 new fevicordin-type 29- norcucurbitacins 3-13, and two new cucurbitacin glycosides 14 and 15, which were isolated along with previous reported fevicordin A [2] and its glucoside [1]. Structure determinations are based on spectroscopic studies and on chemical interconversions. UCR::Vicerrectoría de Docencia::Ciencias Básicas::Facultad de Ciencias::Escuela de Química