RESUMEN
OBJECTIVE: To ascertain the essential oil phytochemicals of the leaf and to test for the antibacterial and antioxidant properties of dichloromethane crude extract of Barringtonia asiatica leaf. METHODS: The phytochemical screening of essential oils, extraction by hydrodistillation using the Clevenger apparatus, and analysis performed by gas chromatography equipped with a flame ionization detector (GC-FID). Antibacterial activity and the inhibition rate (mm) were determined using the agar disc method against four bacterial strains using tetracycline as positive control. The antioxidant potential of dichloromethane crude extract was investigated spectrophotometrically using 1,1-diphenyl-2-picrylhydrazyl. RESULTS: The essential oil properties were reasonable with major phytochemicals like uncineol 30.9%, eicosane 27.4%, eicosane 21.6%, and 4-propyl-guaiacol 14.05%. The antibacterial activity of the dichloromethane crude extract showed broad-spectrum activity against Salmonella typhi, Escherichia coli, Staphylococcus aureus, and Klebsiella pneumoniae with inhibition value ranges between 2.50 ± 0.10 mm and 5.00 ± 0.06 mm. The dichloromethane crude extract exhibited strong antioxidant activities when compared to the standard. CONCLUSIONS: These results suggest that the leaves of Barringtonia asiatica is composed of essential compound as well as antibacterial and antioxidant properties from the crude extract; these are possible due to the presence of some bioactive compounds in the crude extract. The species also showed a reasonable amount of natural products in the essential oils from the hydrodistillation which can as well be used in the cosmetics and food industries.
RESUMEN
We have developed a parameterization method which linearizes the relationship between local magnetic moment and the 3d L3/L2 "white line" ratio as observed in electron energy loss spectroscopy or X-ray near edge absorption spectroscopy. We first establish that the parameterization linearizes an existing theoretical result for ratio versus moment. We then test our method on data sets for which a white line ratio has been previously published by other authors, who have studied a series of compounds using a consistent deconvolution procedure. Finally, we apply our linearization method to the observed ratios of a series of 3d transition metals, and to the Cr L edges for a Au(x)Cr(1 - x) alloy. In addition we obtain, for the first time, experimental results on the Au L3 and L2 edge white lines of this alloy system. These results are consistent with a model in which the large local moment in this system is not limited to Cr dopants, but extends into the gold matrix.
