“…The most amply studied class of dipolar spiro-σ-complexes 44 is represented by derivatives of tropolone, aminotropone, aminothiotropone, and aminotroponeimine, formed on coupling these compounds with highly electrophilic aromatic and heterocyclic substrates. , In general, compounds of type 44 serve as intermediates in nucleophilic rearrangements caused by fast 45 ( 46 ) ⇌ 44 ⇌ 45 ( 46 ) migration of aryl and heterocyclic groups, activated by strong electron-withdrawing substituents or electronegative heteroatoms in the ring (Scheme ). 36 …”
Section: Dipolar Spiro-σ-complexesmentioning
confidence: 99%
“…The kinetics of the rearrangements was studied using dynamic 1 H NMR technique. 102d,e,g Rate constants and energy barriers to the racemization reaction are summarized in Table . It may be seen that the enantiomerization reaction is a rather fast process, the lifetimes of the ring-opened isomers 45 are very short, and their equilibrium amounts are too low to cause noticeable changes in the UV−vis absorption spectra of the spiro-σ-complexes.…”
“…The most amply studied class of dipolar spiro-σ-complexes 44 is represented by derivatives of tropolone, aminotropone, aminothiotropone, and aminotroponeimine, formed on coupling these compounds with highly electrophilic aromatic and heterocyclic substrates. , In general, compounds of type 44 serve as intermediates in nucleophilic rearrangements caused by fast 45 ( 46 ) ⇌ 44 ⇌ 45 ( 46 ) migration of aryl and heterocyclic groups, activated by strong electron-withdrawing substituents or electronegative heteroatoms in the ring (Scheme ). 36 …”
Section: Dipolar Spiro-σ-complexesmentioning
confidence: 99%
“…The kinetics of the rearrangements was studied using dynamic 1 H NMR technique. 102d,e,g Rate constants and energy barriers to the racemization reaction are summarized in Table . It may be seen that the enantiomerization reaction is a rather fast process, the lifetimes of the ring-opened isomers 45 are very short, and their equilibrium amounts are too low to cause noticeable changes in the UV−vis absorption spectra of the spiro-σ-complexes.…”
“…The membrane-stabilizing and antioxidant effects of mexidol [1,2] suggest that the lymphotropic mechanism of its action is due to modification of the microenvironment of membrane receptors on cell surface. This treatment can modify the protein conformation and capacity to bind bioactive substances.…”
Single parenteral administration of dimephosphon, mexidol, and ketorolac produces a lymphotropic effect. Dimephosphon directly affects the lymph system by increasing the number of functioning lymph capillaries and contractile activity of the walls and valves of small intestinal mesenteric lymphangions in rats, which leads to stimulation of lymph circulation. Mexidol and ketorolac increased only lymph flow rate in the thoracic lymph duct, which attested to their indirect effect of the lymph system (presumably associated with stimulation of lymph formation). Despite these differences in the mechanisms of lymphotropic effect, all these drugs activate lymph drainage and, hence, transporting function of the lymph system.
“…Mexidol promotes a decrease in oxygen consumption, thus stimulating the adaptive compensatory functions of the body [1][2][3][5][6][7][8][9][10]12,13]. Mexidol inhibits free radical LPO processes, increases activities of antioxidant enzymes, and produces positive effects on the physicochemical characteristics of membranes by increasing the content of polar lipid fractions (phosphatidylserine and phosphatidylinositol) and reducing the cholesterol/phospholipid ratio and viscosity of the lipid bilayer.…”
Single injection of mexidol (drug with antioxidant and membranotropic effects) to animals with reactive fever produces a multicomponent effect on the lymph circulation. The drug increased the number of functioning lymph capillaries and contractile activity of wall and valvular leaflets in rat small intestinal mesenteric lymphangion, accelerated lymph drainage, thus stimulating lymph formation and lymph flow.
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