Poly[3-(3,4-dihydroxyphenyl)glyceric acid] from Stems of <Emphasis Type="Italic">Symphytum asperum</Emphasis> and <Emphasis Type="Italic">S. caucasicum</Emphasis>

Two high-molecular-weight (>1000 kDa) water-soluble preparations were isolated from stems of Symphytum asperum and S. caucasicum. Their basic component was established as poly[hydroxy-1-carboxy-2-(3,4-dihydroxyphenyl)ethylene], analogous to that of high-molecular-weight (>1000 kDa) preparations from roots of these same plants, using IR and NMR spectral data. __________ Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 303–305, July–August, 2005. An erratum to this article is available at .     

Ruthenium complexes with ferrocene-based P,C,P pincer ligand

First ruthenium complexes with a ferrocene-based pincer ligand were synthesized. The cyclometallation of 1,3-bis[(di-tert-butylphosphino)methyl]ferrocene with RuCl₂(DMSO)₄ in 2-methoxyethanol afforded the RuCl(CO)[{2,5-(Bu^t ₂PCH₂)₂C₅H₂}Fe(C₅H₅)](RuCl(CO) ) complex (5). Complex 5 reversibly binds CO to form the RuCl(CO)₂ complex (6). The analogous reaction in the presence of NaBAr′₄ (Ar′ = 3,5-(CF₃)₂C₆H₃) produced the cationic complex {Ru(CO)₂ }BAr′₄ (7). The structures of complexes 5 and 7 were established by single-crystal X-ray diffraction. The X-ray diffraction study revealed an agostic interaction between one of the C-H bonds of the axial (exo-oriented with respect to the ferrocene iron atom) tert-butyl group and the Ru atom in complexes 5 and 7. Dedicated to Academician G. A. Abakumov on the occasion of his 70th birthday. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 1695–1701, September, 2007.     

Synthesis and Antiviral Activity of Modified 5α-Steroids

Chemistry of Natural Compounds -     

Chemical modification of oximes with N-protected amino acids

The modification of oximes, including 5α-steroids, with N-protected amino acids, in solution phase, using benzotriazole methodology is reported.     

Poly[3-(3,4-dihydroxyphenyl)glyceric acid], a new biologically active polymer from Symphytum asperum Lepech. and S. caucasicum Bieb. (Boraginaceae)

Two high-molecular water-soluble preparations with high anticomplementary, antioxidant, antilipoperoxidant and antiinflammatory activities were isolated from the roots of Symphytum asperum and S. caucasicum. Their main chemical constituent was found to be poly[oxy-1-carboxy-2-(3,4-dihydroxyphenyl)ethylene], according to IR and NMR spectroscopy. The Symphytum high-molecular preparations can modulate in vitro B- chronic lymphocytic leukaemia (B-CLL) cells apoptosis and cell cycle progression.     

Poly[3-(3,4-dihydroxyphenyl)glyceric acid] from <Emphasis Type="Italic">Symphytum officinale</Emphasis> roots and its biological activity

Two high-molecular-weight (>1000 kDa) water-soluble biopolymers, the main component of which was poly[3-(3,4-dihydroxyphenyl)glyceric acid] or poly[oxy-1-carboxy-2-(3,4-dihydroxyphenyl)ethylene] according to IR and NMR spectroscopy, were isolated from roots of Symphytum officinale. They exhibit antioxidant activity as expressed in a decrease of active oxygen species (AOS) by interfering directly in their formation process by polymorphonuclear neutrophils (PMN) and binding directly AOS. Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 9–12, January–February, 2009.     

Preliminary investigation of water-soluble polysaccharides from Georgian plants

Water-soluble polysaccharides have been isolated from nine representatives of the Georgian flora belonging to seven families. According to preliminary results two of them contained glucomannans and the others contained acid arabinogalactans. A more detailed study of a polysaccharide from the fruit of the mistletoeViscum album has permitted it to be assigned to the class of pectin substances.Tbilisi State University. N. D. Zelinskii Institute of Organic Chemistry, Academy of Sciences of the USSR, Moscow. Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 330–335, May–June, 1989.