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Балтина, Л. А.; Murinov, Yu. I.; Ismagilova, A. F.; Davydova, V. A.; Zarudii, F. S.; Толстиков, Г. А.

doi:10.1023/a:1015192324213

Cited by 16 publications

(10 citation statements)

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“…A new class of triterpene glycopeptides in which the amide type of bonds intrinsic of natural glycoproteins is modeled [7,8] is of a special interest among GA derivatives as immunomodulators. It has been earlier shown that some GA glycopeptide derivatives containing three amino acid residues or their methyl esters possess high immunotropic and anti-HIV-1 activity [7][8][9][10][11][12].…”

Section: Introductionmentioning

confidence: 99%

Synthesis and biological activity of new glycyrrhizic acid conjugates with amino acids and dipeptides

et al. 2009

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New glycyrrhizic acid (GA) conjugates were synthesized with the use of tert-butyl esters of amino acids or benzyl esters of dipeptides; they contained two residues of L-amino acids (Met, Phe, Pro, and Ile or dipeptides Gly-Leu and Gly-Phe). Activation of GA carboxy groups was carried out with the help of N-hydroxysuccinimide, N,N'-dicyclohexylcarbodiimide, or N-hydroxybenzotriazole with dicyclohexylcarbodiimide. A proline-containing GA derivative is a low-toxic substance; it raises the level of agglutinins by 3.7 times in the blood of mice and 3 times that of hemolysins compared with the control. Dipeptide GA derivatives possess an expressed anti-HIV-1 activity in cultures of MT-4 cells and are 90-70 times less cytotoxic than azidothymidine. The selectivity index of the compounds exceeds those of GA by 110 and 34 times, respectively.

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Section: Introductionmentioning

confidence: 99%

Synthesis and biological activity of new glycyrrhizic acid conjugates with amino acids and dipeptides

et al. 2009

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“…Second, the authors who measure some parameters of GA complexes with various drugs indicate their unusual stability. ,,, The stability constant of GA complexes is in the range of 10 5 M -1 , which is 2 orders of magnitude higher than a mean stability constant of cyclodextrin complexes . Third, it was demonstrated also that application of glycyrrhizic acid together with other medicines strengthens their therapeutic action (sometimes, by orders of magnitude) and reduces side effects, e.g., the toxic action on the alimentary canal. ,,, Studies on the mechanisms of glycyrrhizic acid complexation are of practical and theoretical interest because physicochemical data on the structure and properties of its complexes are scarce. It is worth noting that at present progress in developing novel forms of medicines has been related not only to a search for new active substances but also to regulating the effect of already available preparations.…”

Section: Introductionmentioning

confidence: 99%

Host−Guest Complexes of Carotenoids with β-Glycyrrhizic Acid

et al. 2006

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The structure, stability, and reactivity of the host-guest complexes between a set of carotenoids and the triterpene glycoside, beta-glycyrrhizic acid (GA), were investigated by different physicochemical techniques: high-performance liquid chromatography, optical absorption, and fluorescence spectroscopy. It has been demonstrated recently that the molecular complexes of GA with a number of drugs are characterized by reduced toxicity and increased therapeutic activity of these drugs. In the present work it was found that carotenoids form 1:2 complexes with GA in aqueous solutions as well as in polar organic solvents, methanol, acetonitrile, and dimethylsulfoxide. We assume that the structure of the complex is a cycliclike dimer of GA encapsulating a carotenoid molecule. The stability constants in all solvents are near 10(4) M(-1). In addition, GA forms inclusion complexes with carotenoid radical cations, which results in their stabilization. Complex formation (a) decreases the rate of electron transfer from carotenoids to electron acceptors (Fe3+ or quinone) and (b) considerably increases the lifetime of the carotenoid-quinone charge-transfer complex and the yield of the major product (a carotenoid-quinone adduct). A thermodynamic study shows that hydrophobic interactions are the main driving force of the carotenoid-GA complex formation. These results are important for understanding both the nature of GA complexes and the influence of GA on the therapeutic activity of some drugs. Furthermore, carotenoid-GA complexes could be used for the design of artificial light-harvesting, photoredox, and catalytic systems.

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“…For example, it has been shown to decrease the required dosage of common antianginal nitrocompounds such as nitroglycerine; studies of GA complexes with sulfanilamides and oxytetracycline derivatives have demonstrated a notable increase of resistance toward common bacterial infections in laboratory animals . Also, complexes with 5-fluorouracil and rubomycin have been shown to be less toxic than initial antitumor drugs, while at the same time retaining their antitumor activity the required dosage of antiarrhythmic diterpenoid alkaloid , from monkshood−lappaconitine (Lap, Figure ).…”

Section: Introductionmentioning

confidence: 99%

Complexation of Lappaconitine with Glycyrrhizic Acid: Stability and Reactivity Studies

et al. 2005

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NMR and UV-vis spectroscopy have been used to study the complexation of antiarrhythmic alkaloid lappaconitine with an efficient complexing agent from licorice, glycyrrhizic acid, which is known to profoundly influence the therapeutic activity of the alkaloid in the complex. In MeOH, DMSO, or aqueous solutions, lappaconitine has been shown to form a stable complex with glycyrrhizic acid with 1:1 stoichiometry over a broad concentration range from 1 microM to 300 microM. The stability constant K(11) equals 2.0 x 10(5) M(-1) in aqueous solution. A similar complex of lappaconitine hydrobromide--the pharmaceutical formulation used in the treatment of arrhythmia--is 2 orders of magnitude less stable than pure lappaconitine. A notable decrease in the rate of the photoinduced electron-transfer reaction between lappaconitine in a complex with glycyrrhizic acid and tyrosine allows the suggestion of an explicit interrelation between the suppressed chemical reactivity of the bound alkaloid and the changes of its therapeutic efficiency.

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Cited by 16 publications

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Synthesis and biological activity of new glycyrrhizic acid conjugates with amino acids and dipeptides

Synthesis and biological activity of new glycyrrhizic acid conjugates with amino acids and dipeptides

Host−Guest Complexes of Carotenoids with β-Glycyrrhizic Acid

Complexation of Lappaconitine with Glycyrrhizic Acid: Stability and Reactivity Studies

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