Effect of Extraction Method and Solvent Power on Polyphenol and Flavonoid Levels in Hyphaene Thebaica L Mart (Arecaceae) (Doum) Fruit, and its Antioxidant and Antibacterial Activities

Purpose: To evaluate the influence of extraction method and solvent type on extractable polyphenols and flavonoids in Doum Hyphaene Thebaica L. Mart. (Arecaceae) fruit, as well as to examine the antioxidant and antibacterial activities of the fruit extracts.Methods: The extraction procedures were performed separately in an ultrasonic bath or shaking water bath for 30 min (70 °C for ethanol and 60 °C for methanol) at agitation speed of 50 Hz and 70 rpm, respectively. The antioxidant potential of the extracts was investigated using â-carotene bleaching, 2,2- diphenylpicrylhydrazyl (DPPH) and reducing power ability assays. In vitro antibacterial activity of the extracts against Staphylococcus aureus, Listeria monocytogenes, Escherichia coli, and Salmonella typhi was assessed using agar disc diffusion assay.Results: Total polyphenol content (TPC) and total flavonoid content (TFC), as well as antioxidant capacity were maximized using methanol as the extraction solvent, particularly with the ultrasonic method. The half  maximal inhibitory concentration (IC50) values of the methanol/ultrasonic (MU), methanol/water bath (MW), ethanol/ultrasonic (EU), and   ethanol/water bath (EW) extracts in the DPPH assay were 107.6 126.7, 172.7, and 196.3 ìg/mL, respectively. The extracts showed strong antibacterial activity against Staphylococcus aureus and Salmonella typhi, while MU extract inhibited the growth of all pathogenic bacteria used in this study.Conclusion: The antioxidant and antibacterial activities of Doum fruit extracts are significantly affected by the type of extracting solvent and equipment used. The findings further demonstrate that MU extract had stronger antioxidant and antibacterial activity than the other extracts.Keywords: Doum fruit, Hyphaene thebaica, Ultrasonic extraction, Antioxidant, Phenolic, Flavonoid, Antibacteria

The role of E1-E2 interplay in multiphonon Coulomb excitation

In this work we study the problem of a charged particle, bound in a harmonic-oscillator potential, being excited by the Coulomb field from a fast charged projectile. Based on a classical solution to the problem and using the squeezed-state formalism we are able to treat exactly both dipole and quadrupole Coulomb field components. Addressing various transition amplitudes and processes of multiphonon excitation we study different aspects resulting from the interplay between E1 and E2 fields, ranging from classical dynamic polarization effects to questions of quantum interference. We compare exact calculations with approximate methods. Results of this work and the formalism we present can be useful in studies of nuclear reaction physics and in atomic stopping theory.Comment: 10 pages, 6 figure