Complex compounds based on a colchicine derivative

Complex compounds based on deacetyl-10-ethanolamino-10-demethoxycolchicine with Co, Mn, and Fe chlorides have been obtained, and their radiomodifying and antitumoral properties have been investigated.Tashkent State University, 700095, Tashkent, CIS, Vuzgorodok. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 728–730, September–October, 1996. Original article submitted November 5, 1994; revision submitted April 7, 1995.     

Synthesis of antitumoral agents from podophyllotoxin

Syntheses based on podophyllotoxin have led to the inclusion among antitumoral agents valuable in practice of the preparations etoposide(I) and teniposide(II). These compounds are, respectively, the 4,6-ethylidene and 4,6-thenylidene derivatives of 4-dimethylepipodophyllotoxin -D-glucopyranoside. A review has been made of methods of synthesizing (I) and (II) and for their experimental investigation. Some conclusions are given from the results of clinical trials. Although (I) and (II) have been accepted for practical use, their clinical activity is limited. The principles of the experimental selection of antitumoral agents are considered particularly. Considerations are expressed concerning the possibilities of improving the results of the search for antitumoral agents of plant origin.All-Union Oncological Scientific Center of the USSR Academy of Medical Sciences, Moscow. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 638–652, September–October, 1987.     

Synthesis of biologically active bromine derivatives of quercetin

The synthesis of a series of bromine derivatives of quercetin differing by the number of bromine atoms introduced is described. It has been shown that in the dynamics of the bromination process the deciding factors affecting the qualitative and quantitative compositions of the reaction products are the temperature regime and the ratio of the reactants. Thus, the use of equimolar amounts of the reactants in dioxane in the temperature interval from 20 to 25° C gives a monobromo derivative, while all other conditions give mixtures of bromo derivatives. The antiviral and antitumoral activities of the mono- and dibromo derivatives of quercetin have been studied.Al-Farabi Kazakh State National University, Almaty, fax (3272) 47 26 09. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 709–711, September–October, 1996. Original article submitted February 27, 1995.     

Biologically active polysaccharides from medicinal plants of the Far East

In a search for biologically active polysaccharides, we have investigated ten species of plants from six families of the flora of the Far East. By successive extractions with water and solutions of ammonium oxalate and of sodium hydroxide we have isolated polysaccharides from the roots and epigeal parts and have determined their qualitative and quantitative monosaccharide compositions. The polysaccharides obtained have been studied for immunostimulating, antitumoral, and antiviral activities.Pacific Ocean Institute of Bioorganic Chemistry, Far-Eastern Division of the Russian Academy of Sciences, Vladivostok, fax 7(4232) 31 40 50. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 197–201, March–April, 1997.     

Chemical modification of the natural flavonoid myricetin

A review is presented of our own results on the synthesis of nitro-, amino-, azo-, and bromo- derivatives of myricetin, as a result which 19 new derivatives have been obtained. The compounds synthesized are of interest as substances with potential antitumoral, antimicrobial, antifungal, antioxidant, and antitubercular activities.Institute of Phytochemistry Academy of Sciences of the Republic Kazakhstan, Karanganda, fax (83212) 511023; email arglabinphyto.karaganda.su. Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 27–37, January–February, 1999.     

Intramolecular cyclization of ortho-(cyclohex-2-enyl) anilines synthesis of ellipticine

A convenient method is proposed for the synthesis of the alkaloid ellipticine, which possesses a pronounced antitumoral activity. The interaction of 3-bromocyclohexene (1 equiv.) and 2,5-xylylidine (4 equiv., 150°C, 5 h) gave a mixture of hexa- and tetrahydrocarbazoles which was dehydrogenated in the presence of Pd/C to the key synthon 1,4-dimethylcarbazole. The formylation of the carbazole by the Vilsmeier-Haack reaction, interaction with 2,2-diethoxyethylamine, and reduction of the imine formed over Raney nickel led to 3-(2,2-diethoxyethylaminomethyl)-1,4-dimethylcarbazole, the boiling of the N-tosylate of which gave ellipticine in high yield.Institute of Organic Chemistry, Urals Branch, Russian Academy of Sciences, Ufa. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 549–554, September–October, 1992.     

Aromatic amino-claisen rearrangement in the synthesis of ellipticine

A convenient route is described for the preparation of 1,4-dimethylcarbazole — the key compound in the synthesis of the antitumoral alkaloid ellipticine. The interaction of 2,5-xylidine with 3-chlorocyclohexene led to N-(cyclohex-2-enyl)-2,5-xylidine (I), the two-hour heating of which at 140–150°C gave the product of an amino-Claisen rearrangement, 6-(cyclohex-2-enyl)-2,5-xylidine (II) with a yield of 82%. The intramolecular cyclization of compound (II) in polyphosphoric acid (130–140°C, 5 h) led to 5,6,7,8,12,13-hexahydro-1,4-dimethylcarbazole (III) in a yield of 75%. The dehydrogenation of substance (III) by boiling in trimethylbenzene in the presence of Pd/C gave 1,4-dimethylcarbazole (IV) with a yield of 87%. The conditions for performing the reactions and the physicochemical constants of the compounds obtained are given.Institute of Chemistry, Bashkir Scientific Center, Urals Branch, USSR Academy of Sciences, Ufa. Translated from Khimiya Prirodnykh Soedinenii, Vol. 6, pp. 816–818, November–December, 1989.     

Chemical modification of grosshemin in the lactone ring

Results are given on the antitumoral activity of grosshemin derivatives. A new grosshemin derivative has been obtained by the interaction of its acetate with hydroxylamine.Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 235–238, March-April, 1995. Original article submitted October 7, 1994.     

Phenolic compounds ofGeranium sanguineum

The chemical composition of the phenolic compounds of the epigeal part of blood-red geranium has been studied. The structure of the main substance of the polyphenolic complex of the plant has been established — bis(hexahydroxydiphenoyl)trigalloylglucose. The high antiviral and antitumoral activity of the total phenolic compounds of the geranium has been shown.A. A. Sadykov Institute of Bioorganic Chemistry, Academy of Sciences of the Republic of Uzbekistan, Tashkent, fax 627071. Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 40–44, January–February, 1994.     

Sesquiterpene lactones from plants of the family Asteraceae in the Kazakhstan flora and their biological activity

The results are generalized of the results of a study of 109 species of plants of the family Compositae (Asteraceae) growing on the territory of Kazakhstan. The promising nature is shown of the search for biologically active sesquiterpene -lactones among them. Fourteen new compounds of this series belonging to the germacranolides, eudesmanolides, guaianolides, and pseudogermanolides have been isolated and characterized by various methods. The results are given of biological tests of the lactones isolated and their derivatives. The artifeedant, antitumoral, antiviral, and growth-regulating activities of the sesquiterpene lactones are reported.Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 29–36 January–February, 1995. Original article submitted October 7, 1994.     

Synthesis and investigation of the antitumoral activity of shortened analogs of luliberin

With the aim of obtaining antitumoral drugs possessing a binary action mechanism, we have synthesized a series of shortened analogs of luliberin, including some containing a 1-carboxymethyl-5-fluorouracil residue. Their antitumoral and hormonal activities have been investigated.     

Preparation,characterization and in vitro antitumoral activity of a nanosize liposome complex encapsulated polyoxotungstate K6H2[CoW11TiO40]

The nanosize liposome complex-encapsulated polyoxotungstate K₆H₂[CoW₁₁TiO₄₀] has been prepared and structurally characterized by i.r., u.v.–vis and e.s.r. spectra. The particle size of the liposome complex-encapsulated K₆H₂[CoW₁₁TiO₄₀], is distributed in two uncontinuous limits in which 98.9% of particles distributed in the limit of 62.8–76.7 nm, average diameter, is 69.4 nm. The result shows that the polyoxotungstate retains the parent structure after being encapsulated by liposome, and that liposomal encapsulation increase the antitumoral activity of the polyoxometalate.     

Investigation of the structure and complex-formation of isomeric pyrrolophenanthridines and their quaternary salts by1H and13C NMR spectroscopies

It has been shown by NMR spectroscopy that quaternary salts of the isomeric pyrrolophenanthridine series from - self-associates of the stacking structure type in an aqueous medium. The changes in the protonic chemical shifts in DMSO and in water that have been found have enabled the structure of a - self-associate of a salt of the isomer showing the greatest antitumoral activity to be obtained. The order and the values of the self-association constants for the methosulfates of the pyrrolophenanthridines investigated have been calculated from the concentration dependences of the protonic CSs.D. I. Mendeleev Moscow Institute of Chemical Technology. Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 407–413, May–June, 1991.     

Phenolic compounds of sumac

The main component of the polyphenolic complex has been isolated from the leaves of two species of sumac (Rhus glabra andRh. typhina) and for this we have proposed the structure of 3,6-bis-O-digalloyl-1,2,4-tri-O-galloyl--D-glucose. A high interferon-inducing and antitumoral activity of the substance isolated has been found. In addition to catechins, 3,4,6-trihydroxyaurone has been tisolated from sumac stems.A. S. Sadykov Institute of Bioorganic Chemistry, Academy of Sciences of the Republic of Uzbekistan, Tashkent, fax 627071. Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 45–48, January–February, 1994.     

Oxomolybdenum(VI) and (V) complexes with 6–methyl-4–hydroxypyrimidinyl hydrazones

Dioxomolybdenum(VI) complexes [MoO2(L)H2O] and oxomolybdenum(V) complexes [Mo2O3(LH)2Cl2] (where LH2=hydrazones derived from 6–methyl-4–hydroxy-2–hydrazinopyrimidine with salicylaldehyde, 5–methyl-, 5–chloro-, 5–bromo-, 3–methoxy-salilcylaldehyde, or 2–hydroxy-1–naphthaldehyde) have been prepared and characterised by spectroscopic and physico-chemical methods. The MoVI complexes are diamagnetic octahedral structures, whilst the MoV complexes are paramagnetic and probably dimeric, via oxobridging.     

Use of ICP and XAS to determine the enhancement of gold phytoextraction by <Emphasis Type="Italic">Chilopsis linearis</Emphasis> using thiocyanate as a complexing agent

Under natural conditions gold has low solubility that reduces its bioavailability, a critical factor for phytoextraction. Researchers have found that phytoextraction can be improved by using synthetic chelating agents. Preliminary studies have shown that desert willow (Chilopsis linearis), a common inhabitant of the Chihuahuan Desert, is able to extract gold from a gold-enriched medium. The objective of the present study was to determine the ability of thiocyanate to enhance the gold-uptake capacity of C. linearis. Seedlings of this plant were exposed to the following hydroponics treatment: (1) 5 mg Au L^–1 (2.5×10^–5 mol L^–1), (2) 5 mg Au L^–1+10^–5 mol L^–1 NH₄SCN, (3) 5 mg Au L^–1+5×10^–5 mol L^–1 NH₄SCN, and (4) 5 mg Au L^–1+10^–4 mol L^–1 NH₄SCN. Each treatment had its respective control. After 2 weeks we determined the effect of the treatment on plant growth and gold content by inductively coupled plasma–optical emission spectroscopy (ICP–OES). No signs of shoot-growth inhibition were observed at any NH₄SCN treatment level. The ICP–OES analysis showed that addition of 10^–4 mol L^–1 NH₄SCN increased the concentration of gold by about 595, 396, and 467% in roots, stems, and leaves, respectively. X-ray absorption spectroscopy (XAS) studies showed that the oxidation state of gold was Au(0) and that gold nanoparticles were formed inside the plants.     

Synthesis of 5-glycopyranosylamino-pyrano[2,3-d]pyrimidin-2-one derivatives

Summary Three series of 3-substituted 5-glycopyranosylamino pyrano[2,3-d]pyrimidin-2-one derivatives,3 a–c,4 a–c, and5 a–c have been prepared by treatment of the corresponding 1,4-dihydro-6-glycopyranosylamino pyrimidin-4-ones1 a–c with malonic, methyl malonic and ethyl malonic acids, respectively.

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Synthese von Derivaten des 5-Glucopyranosylaminopyrano[2,3-d]pyrimidin-2-on

Zusammenfassung Es wurden drei Serien von 3-substituierten 5-Glucopyranosylaminopyrano[2,3-d]pyrimidin-2-onen (3 a–c,4 a–c und5 a–c) mittels Behandlung der entsprechenden 1,4-Dihydro-6-glucopyranosylamino-pyrimidin-4-one (1 a–c) mit Malon-, Methylmalon- bzw. Ethylmalonsäure dargestellt.

     

Radiation dose assessment for137Cs from fish in the Aegean Sea before and after the Chernobyl accident

The effective doses from fish in the Aegean Sea have been calculated for the nuclide¹³⁷Cs covering the period 1975–1982. The effective dose varies between 3×10^–5 and 10×10^–5 mSv y^–1 for adults and 14×10^–5 to 56×10^–5 mSv y^–1 for children, while the cumulative effective dose for the period 1975–1982 equals to 40.86×10^–5 and 229.57×10^–5 for both adults and children of 10 y old, respectively. When compared to doses derived from the Chernobyl accident /May 1986/ it was found that the additional dose incurred by Greek individuals in May 1986 was approximately equal to the cumulative dose of 8 y contribution period /1975–1982/ for adults and to a year's contribution for children of 10 y old.     

Photoreduction of rhenium(VII) in hydrochloric and sulfuric acids and their mixtures

Pulse photolysis has been used to investigate the photochemical reactions that take place in the series of oxochloride complexes of Re(VII), Re(VI), and Re(V) in concentrated hydrochloric and sulfuric acids and their mixtures. The kinetics of the formation and decay of the short-lived complex ReOCl ₅ ^– have been studied as a function, of the composition of the medium (the concentration of the acids and water). The causes of the stabilization of ReOC ₅ ^– in concentrated H₂SO₄ have been elucidated. It has been found that the anion radical Cl ₂ ^– formed in the photolysis of HCl oxidizes the complex ReOCl ₅ ^2– to ReOCl ₅ ^– .Translated from Teoreticheskaya i Éksperimental'naya Khimiya, Vol. 22, No. 3, pp. 296–302, May–June, 1986.     

Redox chemistry of [Fe2(CN)10]4−. Part 5. Reaction with thiourea

The reaction of the dimeric iron(III) complex [Fe2(CN)10]4– with a large excess of thiourea, tu, takes place in a series of stages, the first two of which have been examined in detail. The first stage is a one equivalent outer sphere electron transfer to form [Fe2– (CN)10]5– and the radical cation tu+· which dimerises to form the disulfide tu22+. There is kinetic evidence for the formation of a significant proportion of a precursor complex [Fe2(CN)10]4–·tu at high concentrations of tu. The second stage involves cleavage of the mixed valence dimer to yield [Fe(CN)5tu]2– and [Fe(CN)5H2O]3–. On standing, substitution of H2O by tu and oxidation by air occurs slowly, and finally all of the original iron is observed as [Fe(CN)5tu]2–.