Evaluation of pigments from methanolic extract of Tagetes erecta and Beta vulgaris as antioxidant and antibacterial agent

The Total Phenolic Content (TPC), antioxidant and antibacterial activities of methanolic extract of Marigold flower (MF) (Tagetes erecta) and Beet root (BR) (Beta vulgaris) were examined. The present work reveals that MF contained greater amount of TPC (42.5 mg/g GAE) as compared to BR (39.4 mg/g GAE). Methanolic extract of MF exhibited excellent DPPH free radical scavenging power (IC₅₀ 0.0716 mg/mL) and reducing power at 1 mg/mL concentration. Similar results have been obtained in FTC and TBA method. The results of antibacterial test indicated that the methanolic extract of MF and BR is significantly effective against both type of Gram-negative (Escherichia coli, Shigella dysenteriae) and Gram-positive (Bacillus subtilis, Staphylococcus aureus) bacterial strains. Therefore, the present study suggests that the Marigold and BR are promising source of herbal medicinal products with noteworthy antioxidant and antibacterial activity.     

Redox-induced η5 ⇔ η3 haptotropy of the fluorenyl ligand in 9-substituted η5-fluorenylmanganesetricarbonyl complexes

It has been shown by cyclic voltammetry in THF within the –90 to 40 °C temperature range that fluorenyl (⁵-9-R-C₁₃H₈)Mn(CO)₃ complexes (R=Bu^t (3) and Ph (4)) undergo two-electron reduction to form allyl type [(³-9-R-C₁₃H₈)Mn(CO)₃]^2– dianions as final products. At low temperatures complexes3 and4 are reduced in two one-electron steps according to the EEC-scheme. The first step is reversible and corresponds to the formation of 19-radical anions 3^–. and 4^–.. TheE ⁰ values for redox pairs3 ^0/–. and4 ^0/–. are –1.88 and –1.73 V, respectively. The further reduction of radical anions3 ^–. and4 ^–. at more negative potentials is accompanied by fast ^{5 3} haptocoordination of the fluorenyl ligand to form 18-dianions [(³-9-R-C₁₃H₈)Mn(CO)₃]^2–. These dianions obtained by the reduction of complexes3 and4 by the radical anion of pyrene are stable at –80 °C and are characterized by their IR spectra. At room temperature the ^{5 3} hapticity change is a fast and reversible process occurring at the step of 19-radical anions3 ^–. and4 ^–. and leading to the electron deficient 17-species [(³-9-R-C₁₃H₈)Mn(CO)₃]^–., which are reduced easier than the initial complexes. As a result, complexes3 and4 are reduced to the corresponding dianions [(³-9-R-C₁₃H₈)Mn(CO)₃]^2– at room temperature in one reversible two-electron step according to the ECE-scheme. Reactivities of 19e^–-species of the isomeric ⁵- and ⁶-fluorenylmanganesetricarbonyl complexes are compared.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp. 1347–1353, July, 1995.The work was financially supported by the Russian Foundation for Basic Research (Project No. 93-03-05209) and the International Science Foundation (Grant No. REV 000).     

Oxidation of isomeric η6- and η5-fluorenylchromiumtricarbonyl anions

The oxidation of the carbon-centered [(⁶-C₁₃H₉)Cr(CO)₃]^– anion (1 ^–) results in formation of (-⁶:⁶-9,9-bifluorenyl)bis-chromiumtricarbonyl (3) due to coupling of the intermediate carbon-centered radical (1^.). The oxidation of the metal-centered anion [(⁵-C₁₃H₉)Cr(CO)₃]^– (2 ^–), which is isomeric to the 1^– anion, gives an equilibrium mixture of the chromium-centered radical {(⁵-C₁₃H₉)Cr(CO)₃}^. (2 ^.) and its dimer [(⁵-C₁₃H₉)Cr(CO)₃]₂ (6). Radical2 ^. readily reacts with MeI and the solvent (THF); the resulting derivatives, (⁵-C₁₃H₉)Cr(CO)₃R (R=Me (10); R=H (7)), undergo fast ricochet inter-ring ⁵⁶ rearrangements into (⁶-9R-C₁₃H₉)Cr(CO)₃ (R=CH₃ (9); R=H (4)).Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp. 1354–1358, July, 1995.The authors are grateful to D. V. Zagorevskii who recorded the mass spectra. This study was financially supported by the Russian Foundation for Basic Research (Grant No. 94-03-05209) and the International Science Foundation (Grant Nos. MQ 4000 and REV 000).     

Sulfamic acid andN-alkylsulfamates in the synthesis of nitro derivatives of guanidine and aminofurazan

TheN-nitro derivatives of the products of the condensation of formaldehyde with sulfamic acid derivatives and guanidine, nitroguanidine, 3,4-diaminofurazan, and 3-amino-4-methylfurazan have been synthesized.Deceased.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 4, pp. 719–721, April, 1995.     

An improved procedure for the synthesis of N-bromoacetyl-β-glycopyranosylamines, derivatives of mono- and disaccharides

An improved procedure for the synthesis of N-bromoacetyl--glycopyranosylamines from the corresponding -glycosylamines was developed. The procedure is applicable to a wide range of derivatives of monosaccharides (hexoses, 2-acetamido-2-deoxyhexoses, hexuronamides, and 6-deoxyhexoses) and some disaccharides. For the derivatives of pentoses and 2-deoxyhexoses, the use of the corresponding -glycosylammonium carbamates was found to be more convenient. N-Bromoacetyl--glycopyranosylamines derived from D-mannose, L-rhamnose, D-glucuronamide, 2-deoxy-D-arabino-hexose, 2-deoxy-D-lyxo-hexose, and melibiose were obtained for the first time.     

Synthesis and some properties of phosphorus-substituted azomethines

A series of phosphorus(iii)-substituted azomethines and enamines were synthesized by the reaction of lithium salts of aldimines and ketimines with derivatives of phosphorus(iii) acids. Some properties of the compounds synthesized were studied. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 339–346, February, 1998.     

Oxidation of theexo- andendo-phenylcyclohexadienyl iron complexes Fe(η5-6-PhC6H6) (η5- C5H5)

The roe of oxidatively induced homolyhc scission a the C(sp³)-H bonds in the iron phenykychhexadienyl complexes Fe(⁵-6-PhC₆H₆)(⁵-C₅H₅) (1) depends on the spatial orientation of the Ph substitutent. In the case of the (1 _endo ⁺) radical cation this process, resulting in the cationic biphenyl complex (Fe(⁶ -C₆H₅C₆H₅)(⁵-C₅H₅)]⁺ (2 ⁺), is fast and proceeds for several minutes. In the case of the more stable radical cation (1 _exo ⁺) the formation of 2⁺ is slow and takes tens minutes to complete.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp. 1698–1700, July, 1996.     

Synthesis of new organophosphorus‐substituted mono‐ and bis(trimethylsilyl)amines with PCH2N fragments and their derivatives

Convenient procedures for the synthesis of new organophosphorus‐substituted mono‐ and bis(trimethylsilyl)amines with PCH₂N moiety are proposed, starting from trimethylsilyl esters of organophosphorus acids, as well as 1,3,5‐trialkylhexahydro‐1,3,5‐triazines and N‐alkoxymethyl bis(trimethylsilyl)amines as aminomethylating reagents. Certain properties of the resulting compounds are presented. © 2010 Wiley Periodicals, Inc. Heteroatom Chem 21:71–77, 2010; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20580     

Synthesis of bis‐ and tris‐organophosphorus substituted amines and amino acids with PCH2N Fragments

The aminomethylation of the derivatives of trivalent organophosphorus acids, containing PH and POSiMe₃ fragments with various bis‐ and tris(alkoxymethyl)amines and bis(alkoxymethyl)amino acids, is proposed as a convenient method for the synthesis of new bis‐ and trisphosphorylated amines and amino acids as well as their derivatives with four and five coordinated phosphorus. Also the three‐components systems of phosphorous acid, paraformaldehyde, and amines are thoroughly investigated via the treatment of reaction mixtures with bis(trimethylsilyl)amine. © 2010 Wiley Periodicals, Inc. Heteroatom Chem 21:430–440, 2010; View this article online at wileyonlinelibrary.com . DOI 10.1002/hc.20616