Quantification of Phenolic Component by LC-HESI-MS/MS and Evaluation of Antioxidant Activities of Crocus Ancyrensis (Ankara Çiğdemi) Extracts Obtained with Different Solvents

In this study, Crocus ancyrensis was extracted from different parts of the plants with various solvents and their antioxidant activities and phenolic contents were investigated in detail for the first time. The highest amount of total phenolic substance in all parts of the plant was determined in the stigmaless flower. In the DPPH and FRAP methods, the highest antioxidant activity was obtained from the water extraction from the plant. Rutin is the highest detected by LC MS/MS. Stigmaless flower extract in all solvents is attributed to the component that contributes the most to antioxidant capacity. p-hydroxy benzoic acid was detected as the highest phenolic component after rutin. When the antioxidant activity results were examined, it was determined that the highest activity was in the water extract. As a result, it is evaluated that rutin and p-hydroxybenzoic acid in the plant contribute to the antioxidant capacity.     

Enzymatic and insecticidal activities of the Amsacta moorei entomopoxvirus glycosyltransferase,AMV248

The family Poxviridae is divided into two subfamilies, the Chordopoxvirinae of vertebrates and the Entomopoxvirinae of invertebrates. The Amsacta moorei entomopoxvirus (AMEV, Entomopoxvirinae) has the potential to be used in gene therapy, as an expression vector, and as a biopesticide. It was suggested that AMV248 protein is a putative glycosyltransferase (GT) but was also shown to be an attachment protein to host receptors. GTs encoded by some other viruses catalyse the binding of sugars molecules to growth hormones of the host insects rendering the hormones inactive. Consequently, larval development is arrested and frequently results in larval mortality. In this study, AMV248 protein was shown to be a GT and the purified enzyme catalysed the production of uridine diphosphate (UDP) from the substrates UDP-glucose and UDP-N-acetylglucosamine. This AMEV enzyme may behave much like the ecdysteroid UDP-glucosyltransferase of baculoviruses. Various concentrations of the GT enzyme were tested for its insecticidal activity against gypsy moth Lymantria dispar (Linnaeus, 1758) (Lepidoptera: Lymantriidae), lackey moth Malacosoma neustria (Linnaeus, 1758) (Lepidoptera: Lasiocampidae), cotton bollworm Helicoverpa armigera (Hübner, 1808) (Lepidoptera: Noctuidae) and the greater wax moth Galleria mellonella (Linnaeus, 1758) (Lepidoptera: Pyralidae) larvae. It had varying deleterious effects on all test larvae but L. dispar was the most sensitive to the enzyme. While this enzyme exhibits properties with potential to be developed as an insecticide in biocontrol strategies, investigations are needed to ascertain its value in pest management.     

A new colorimetric DPPH• scavenging activity method with no need for a spectrophotometer applied on synthetic and natural antioxidants and medicinal herbs

2,2-Diphenyl-1-picrylhydrazyl (DPPH^?) radical scavenging, the most commonly used antioxidant method with more than seventeen thousand articles cited, is very practical; however, as with most assays, it has the major disadvantage of dependence on a spectrophotometer. To overcome this drawback, the colorimetric determination of the antioxidant activity using a scanner and freely available Image J software was developed. In this new method, the mixtures of solutions of DPPH^? and standard antioxidants or extracts of common medicinal herbs were dropped onto TLC plates, after an incubation period. The spot images were evaluated with Image J software to determine CSC₅₀ values, the sample concentrations providing 50% colour reduction, which were very similar with the SC₅₀ values obtained with spectrophotometric method. The advantages of the new method are the use of lower amounts of reagents and solvents, no need for costly spectrophotometers, and thus significantly lowered costs, and convenient implementation in any environment and situation.     

Radiation shielding parameters of some antioxidants using Monte Carlo method

In this paper, radiation shielding parameters such as mass attenuation coefficients and half value layer (HVL) of some antioxidants are investigated using MCNPX (version 2.4.0). The validation of the generated MCNPX simulation geometry for antioxidant structures is provided by comparing the results with standard WinXcom data for radiation mass attenuation coefficients of antioxidants. Very good agreement between W?NXCOM and MCNPX was obtained. The results from the validated geometry were used to calculate the shielding parameters of different antioxidants. The radiation attenuation properties of each antioxidant were compared with each other. The results showed that, on average, the highest and the lowest radiation mass attenuation coefficients were observed on hesperidin and delphinidin chloride, respectively. It can be concluded that Monte Carlo simulation is a strong tool and an alternate method where experimental investigations are not possible and a standard simulation setup can be used in further studies for different biological structures. It can also be concluded that the obtained results from this study are very useful for radiology and radiotherapy applications where antioxidants are frequently used.     

Exploring continuity equation via a modeling activity: in the context of crowd science

Abstract

Using problems from real life contexts which is related to learners’ environment or their culture plays an important role in their learning that concept. In this regard, science educators especially physics educators search for real-life domain of theoretical concepts for effective science teaching and they consider analogical and physical models as an opportunity in their instruction. In the presented activity, we worked with 66 senior pre-service science teachers from our science teaching methods course. We used crowd movements as a real-life domain of our analogical models to scientifically explain a stampede case, then utilized physical model to explore continuity equation. Real life problem based scenarios could be used while taking advantage of the 3?D modeling in teaching of scientific principle. As a result, we found that pre-service teachers were able to make scientific explanation for causes of stampedes by using modeling activity. High school teachers and upper-level instructors could benefit from including the modeling activity introduced in this study to help their students understand the concepts related to continuity equation by designing a physical model based on an analogical model. Via the physical model, students are able to make predictions, observations, interpretations and explanations of a complex and abstract scientific phenomenon.