Synthesis of new coumarin[1,3]oxazine derivatives of 7-hydroxy-6-isobornyl-4-methylcoumarin and their antioxidant activity.

In this work, we synthesized a series of new 9,10-dihydro-2H,8H-chromeno[8,7e][1,3]oxazine-2-on derivatives which incorporate isobornylcoumarin and 1,3-oxazine moieties. A structure-antioxidant activity relationship was analyzed. A comparative evaluation of their radical scavenging activity, antioxidant and membrane-protective properties was carried out in test with DPPH, as well as on the models of Fe /ascorbate-initiated lipid peroxidation and oxidative hemolysis of mammalian red blood cells.

Isobornylchalcones as Scaffold for the Synthesis of Diarylpyrazolines with Antioxidant Activity.

The pyrazoline ring is defined as a "privileged structure" in medicinal chemistry. A variety of pharmacological properties of pyrazolines is associated with the nature and position of various substituents, which is especially evident in diarylpyrazolines. Compounds with a chalcone fragment show a wide range of biological properties as well as high reactivity which is primarily due to the presence of an α, β-unsaturated carbonyl system.

Synthesis and Biological Evaluation of Novel Coumarins with tert-Butyl and Terpene Substituents.

Coumarins with terpene and tert-butyl substituents were synthesized via Pechmann condensation reaction. New derivatives were investigated in different model system for the exhibition of antioxidant, radical scavenging and membrane-protective activities. It has been found that 4-methylcoumarin derivatives with monoterpene moieties exhibit high antioxidant activities.

Effects of Siberian wildfires on the chemical composition and acidity of atmospheric aerosols of remote urban, rural and background territories.

Extensive forest fires occurred during the summer of 2012 in Siberia. This work presents the influence of long-range atmospheric smoke on the aerosol properties at urban, suburban and background sites, which are located 400-800 km from the fire source. The higher levels of submicron particles (PM1), organic (OC), secondary organic (SOC) and elemental (EC) carbon were observed at all sampling sites, whereas an increase in ionic species HCOO(-), K(+), NO3(-), and Cl(-) and a decrease in pH was higher at the background and suburban sites in comparison with the urban site.