A novel and easy two-step,microwave-assisted method for the synthesis of halophenyl pyrrolo[2,3-b]quinoxalines via their pyrrolo precursors. Evaluation of their bioactivity

A novel, two-step, facile route for the synthesis of pyrrolo[2,3-b]quinoxalines via 2,3-dioxopyrroles, enhanced by microwave irradiation, is presented. The newly synthesized 2,3-dioxo-5-halophenyl pyrrolo precursors 4a–c as well as the non-aromatized ethyl 2-(4-halophenyl)-1-methyl-2,4-dihydro-1H-pyrrolo[2,3-b]quinoxaline-3-carboxylates 6a–c and the aromatized ethyl 2-(4-halophenyl)-1-methyl-1H-pyrrolo[2,3-b]quinoxaline-3-carboxylates 7a–c were evaluated for their antioxidant, cytostatic, and antiviral properties. Most of them proved to be potent hydroxyl radical scavengers and inhibited in vitro lipid peroxidation. The compounds showed moderate antiproliferative activity, while 6a inhibited vaccinia virus at an EC₅₀ value of 2 μM, and 4c and 6c inhibited Sindbis virus at EC₅₀ values of 4 μM.     

Radionuclide activities and elemental concentrations in sediments from a polluted marine environment (Saronikos Gulf-Greece)

The levels and depth distributions of the natural radionuclides ²³⁸U, ²³²Th, ²²⁶Ra, ⁴⁰K and the man-made ¹³⁷Cs were analyzed by γ-ray spectrometry, while the concentrations of 26 chemical elements were measured by INAA in sediment samples collected from the organic mud layer that covers the Keratsini–Psitalia strait, Saronikos gulf (Greece). The average activity concentration values of ²²⁶Ra, ²³²Th and ⁴⁰K were lower when compared, whereas that of ²³⁸U was comparable to the average Greek and world values. The elemental contamination of the sediments was estimated on the basis of the calculated EF values. The results revealed high EF values of As, Br, Cr, Ni, Sb, Se, Zn ranging from 160 for Br to 10 for Cr, whose main sources are probable related to contaminated sewage outfall from the area of Athens and the Piraeus Harbour.