Results 161 to 170 of about 915 (185)

Squaric Acid Ester-Based Total Synthesis of Echinochrome A

The Journal of Organic Chemistry, 2002
The total synthesis of echinochrome A is described. Both key intermediates 5 and 8 were efficiently prepared from diisopropyl squarate 7. Nucleophilic addition of aryllithium 8 to 5, followed by thermal ring-expansion/cyclization of the 1,2-adduct 4, furnished hydroquinone 3. Oxidation and full deprotection of 3 gave the title compound.
Eduardo, Peña-Cabrera, Lanny S, Liebeskind   +1 more
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Effects of echinochrome on ventricular repolarization in acute ischemia

Journal of Electrocardiology, 2015
Myocardial ischemic electrophysiological alterations are associated with the generation of reactive oxygen species. However, electrophysiological effects of antioxidants are unclear. Our objective was to determine the effects of the antioxidant echinochrome on ventricular repolarization in a feline model of 30-min ischemia.Activation-recovery intervals
Ksenia, Sedova, Olesya, Bernikova, Jan, Azarov, Dmitry, Shmakov, Vladimir, Vityazev, Sergey, Kharin   +5 more
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Reaction of echinochrome trimethyl ether with aqueous ammonia

Russian Chemical Bulletin, 2010
Reaction of 7-ethyl-2,3,6-trimethoxynaphthazarin with NH3·H2O proceeds at the carbonyl groups at the C(4) atoms of the 1,4-naphthoquinonoid tautomeric forms. Methoxy group adjacent to ethyl group is the orienting substituent in this reaction.
G. I. Mel’man, V. A. Denisenko, V. Ph. Anufriev   +2 more
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Carrageenan gel beads for echinochrome inclusion: Influence of structural features of carrageenan

Carbohydrate Polymers, 2021
Carrageenan (CRG) and carrageenan/chitosan (CH) gel beads (CRG/CH) were prepared as a release delivery system for echinochrome A (Ech). According to spectral data, the Ech was dispersed in the polymer matrix, interacted with CRG, was not oxidised, and remained stable after encapsulation in CRG beads. Carrageenan beads containing Ech were coated with CH
Irina M, Yermak, Vladimir I, Gorbach, Ivan A, Karnakov, Viktoria N, Davydova, Evgeniya A, Pimenova, Dmitry А, Chistyulin, Vladimir V, Isakov, Valery P, Glazunov   +7 more
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Effect of Antioxidant Echinochrome A on Bleomycin-Induced Pulmonary Fibrosis

Bulletin of Experimental Biology and Medicine, 2015
We studied the protective effect of antioxidant echinochrome A on bleomycin-induced pulmonary fibrosis in rats at the early stages of postnatal ontogeny. Administration of echinochrome A was shown to reduce the severity of bleomycin-induced oxidative stress in the lungs, prevented the development of hypertrophy of interalveolar connective tissue and ...
O A, Lebed'ko, B Ya, Ryzhavskii, O V, Demidova   +2 more
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Cytotoxic activity of intermediates and side products of echinochrome synthesis

Chemistry of Natural Compounds, 2008
The cytotoxic activity of the principal intermediates and side products of echinochrome synthesis toward gametes of the sea urchin Strogylocentrotus intermedius was studied. Di-and trichloro naphthazarin derivatives with two vicinal Cl atoms were the most active.
N. D. Pokhilo, M. I. Kiseleva, V. V. Makhan’kov, V. Ph. Anufriev   +3 more
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7-Ethyl-2,3,5,6,8-pentahydroxy-1,4-naphthoquinone (echinochrome A): A DFT study of the antioxidant mechanism. 1. Interaction of echinochrome A with hydroperoxyl radical

Russian Chemical Bulletin, 2007
The molecular geometry and electronic structure of hydroxy-substituted naphthazarin (NZ)-7-ethyl-2,3,5,6,8-pentahydroxy-1,4-naphthoquinone (echinochrome A, (Et)NZ(β-OH)3, 1) were calculated by the B3LYP/6-311G(d) method. The influence of the (i) character of the β-OH groups dissociation and (ii) conformational mobility of molecule 1 and the anions ...
D. V. Berdyshev, V. P. Glazunov, V. L. Novikov   +2 more
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Molecular and crystal structure of the echinochrome complex with dioxane

Crystallography Reports, 2006
The molecular and crystal structures of a complex of echinochrome (2,3,5,6,8-pentahydroxy-7-ethyl-1,4-naphthoquinone) with dioxane are determined. The molecular complex 2(C12H10O7) · C4H8O2 crystallizes in the form of dark red transparent thin plates.
A. V. Gerasimenko, S. A. Fedoreyev, N. P. Mischenko   +2 more
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Liposome as Mucoadgesive Systems for Delivery Echinochrome-Carrageenan Complex

2021
Inclusion of drugs in liposomes offers the potential for localized and sustained delivery to mucosal surfaces. Liposomes are lipid vesicles that contain an aqueous solution of the active substance in their internal space or incorporate it into their shell.
V. I. Gorbach, V. P. Glazunov, V. N. Davydova, I. M. Yermak   +3 more
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Echinochrome Exhibits Antitumor Activity against Ehrlich Ascites Carcinoma in Swiss Albino Mice

Nutrition and Cancer, 2020
Background: Echinochrome (Ech) is a common pigment present in sea urchins, which has antioxidant, antimicrobial, antialgal, hypolipidemic and hypoglycemic activities.Purpose: The present investigation assessed the anticancer and antioxidant activities of Ech against the Ehrlich ascites carcinoma tumor model in mice.Methods: Forty female mice were ...
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