Furan Analog of the Alkaloid Dubiamine Based on 5-Hydroxymethylfurfurol

Chemistry of Natural Compounds -     

Synthesis of New Methanofullerenes with Phthalimide Fragment

Bromo- and chloromethyl ketones based on N-phthalyl-substituted amino acids have been synthesized via the Arndt–Eistert reaction. The products [2+1] cycloaddition to the fullerene scaffold has afforded the monoadducts of fullerene C60.     

Synthesis of pharmacologically active hydrogels based on combined silicon and titanium polyolates

The target synthesis of new biologically active hydrogels based on combined silicon and titanium polyolates was carried out. The optimum conditions for hydrogel formation and their composition were determined. The type of hydrogels and mechanisms of gelation depend on the nature of polyols: gels based on combined silicon and titanium polyethylene glycolates are polymeric and formed via the polycondensation mechanism, whereas gels based on combined silicon and titanium glycerolates are colloidal and formed via the coagulation-condensation mechanism. The combined hydrogels based on silicon dimethyl glycerolates and titanium tetraglycerolate exhibit enhanced transcutaneous, wound healing, and regenerating activity.     

Antiradical activity of 5-amino-1,3,6-trimethyluracil in the radical chain oxidation of ethylbenzene as the model system

The antiradical activity of 5-amino-1,3,6-trimethyluracil was quantitatively measured in the initiated radical chain oxidation of ethylbenzene as the model system. The rate constant of the reaction of 5-amino-1,3,6-trimethyluracil with the ethylbenzene peroxyl radical at 333 K was found: k ₇ = (2.1 ± 0.3) × 10⁵ L mol^?1 s^?1. The kinetics of 5-amino-1,3,6-trimethyluracil consumption in the course of the radical chain oxidation of ethylbenzene was studied. The stoichiometric inhibition factor was determined to be f = 2.     

Synthesis of 5-(hydroxy-, chloro-, bromomethyl)furan-2-enones Based on Fructose and their Antioxidant Activity

Chemistry of Natural Compounds - New enones were synthesized from 5-hydroxymethylfurfurol (5-HMF) and its derivatives using Wittig reactions of various phosphoranes. The synthesized enones were...     

Kinetics of the radical-chain oxidation of methyl oleate inhibited by 5-amino-6-methyluracil and 5-amino-1,3,6-trimethyluracil

Kinetics and Catalysis - The effects of 5-amino-6-methyluracil (AMU) and 5-amino-1,3,6-trimethyluracil (ATMU) on the rate of oxygen uptake in methyl oleate (MO) radical-chain oxidation initiated by...     

Inhibiting effect of 5-amino-5-methyluracil and its derivatives on the free-radical oxidation of 1,4-dioxane

The antiradical activity of 5-amino-6-methyluracil in the initiated radical-chain oxidation of 1,4-dioxane as a model system was studied quantitatively. The rate constant k ₇ of its reaction with the peroxyl radical of 1,4-dioxane was measured to be (5.6 ± 1.8) × 10⁵ L mol^?1 s^?1 at 333 K. The effect of the methyl substituents in the 1- and 3-positions of the uracil ring and in the amino group on the rate constant of inhibition was studied. The strengths of all N-H bonds in the 5-amino-6-methyluracil and its derivatives were calculated in the G3MP2B3 approximation and were compared with the measured rate constants of inhibition. By the example of the reaction of 5-amino-6-uracil with i-PrO ₂ ^?? , different attack pathways of the peroxyl radical at the N-H bonds of uracil were analyzed in the UB3LYP/6-311+G(d,p) approximation. The lowest activation barrier (5.8 kJ/mol) was observed for peroxyl radical attack on the (C⁵)N-H bonds. The site responsible for the inhibition activity of the compound is the amino group.     

Synthesis of Tetrahydroisoquinoline-Alkaloid Analogs with a Diphenyloxide Fragment

Chemistry of Natural Compounds - New synthetic benzylisoquinoline-alkaloid analogs based on the diaryl ether hernandial were prepared under Pictet–Spengler reaction conditions.