15th Anniversary of the synthesis of the first fluorine analogue of vitamin D3 chemical and biological aspects of the problem

A review of literature information and the results of investigations by the authors on methods of synthesis for, and the biological activity of, fluorine derivatives of vitamin D₃ expands traditional idea on their influence on the regulation of Ca and P metabolism in the organism. The review includes literature sources from 1974 to 1989.Institute of Bioorganic Chemistry and Petrochemistry, Academy of Sciences of the Ukrainian SSR, Kiev. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 707–732, November–December, 1990.     

Physalis withasteroids

The review gives a table of 47 withasteroids isolated from plants of the genusPhysalis. The biogenetic relationship between the different structures of the compounds is discussed on the basis of an analysis of literature material. An assignment of some C-methyl groups of the physalins is made.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 263–277, May–June, 1986.     

Brassinosteroids in the vegetable kingdom

This review gives literature information on the structure of brassinoids, which are natural plant growth regulators, and on their distribution in plants and their structure-biological activity relationships.Institute of Bioorganic Chemistry, Academy of Sciences of the Belorussian SSR, Minsk. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 159–173, March–April, 1991.     

Steroid alkaloids of the plant and animal Kingdoms

This review, which covers the literature for 1988–1996, gives new information on the occurrence of steroid alkaloids in Nature and discusses ecological and biogenetic aspects of their study.Deceased.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Republic of Uzbekistan, Tashkent, fax (371) 120 64 75. Translated from Khimiya Prirodnykh Soedinenii, No. 2 pp. 131–168, March–April, 1999.     

Vegetable tanning substances. Dependence of the tanning properties of extracts on their composition

Information is given on vegetable tanning substances, their classification, distribution in the plant world, and structure, and the dependence of their tanning properties on their composition, and also on methods of enriching tanning extracts. The review of literature sources includes publications from 1950 to 1989.A. S. Sadykov Institute of Bioorganic Chemistry, Uzbek SSR Academy of Sciences, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 293–307, May–June, 1990.     

Phytoecdysteroids of plants of the genusAjuga and their biological activity 1. Distribution and chemical structures of the compounds isolated

In this review, literature information on the structures of phytoecdysteroids, their distribution in plants, and their biological activities is generalized.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Republic of Uzbekistan, Tashkent, Fax (3712) 62 73 48. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 152–160, March–April, 1994.     

Ungernia alkaloids

The review is devoted to the study of the alkaloids of plants of the genusUngernia (Amaryllidaceae). It gives their characteristic reactions and information on the determination of their structures and stereochemistry and on the dynamics of the accumulation of alkaloids in the plants of the genusUngernia. A dependence of the physiological activity of the alkaloids on their structure is shown.Institute of the Chemistry of Plant Substances of the Academy of Sciences of the Uzbek, SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 749–767, November–December, 1980.     

Iridoids of plants of the genusGentiana from the family Gentianaceae

The review contains the results of an analysis of the literautre on the study of plants of the genusGentiana, family Gentianaceae Juss. The biological properties of the iridoid compounds are described. Their physicochemical constants are also given: the name of the substance, the melting point, the angle of rotation, details of the UV, IR and PMR spectra, and literature relating to them. The distribution of iridoid compounds in plants over the sections of the genusGentiana is given in the form of tables, and the material is discussed correspondingly.All-Union Scientific-Research Institute of Pharmacy, Moscow. Translated from Khimiya Prirodnikh Soedinenii, No. 1, pp. 3–11, January–February, 1987.     

Determination of organotin compounds in biological samples using accelerated solvent extraction,sodium tetraethylborate ethylation,and multicapillary gas chromatography–flame photometric detection

A method has been developed for species-selective analysis of organotin compounds in solid, biological samples. The procedure is based on accelerated solvent extraction (ASE) of analytes and includes extraction of the tin species with a methanol–water (90% methanol) solution of acetic acid/sodium acetate containing tropolone (0.03% w/v), their ethylation with NaBEt₄, and separation and detection by GC–FPD. The analytical procedure was optimized with an unspiked sample of harbor porpoise (Phocoena phocoena) liver. Effects of ASE operational variables (extraction temperature and pressure, solvent composition, number of static extraction steps) are discussed. Method detection limits (MDL) were in the range 6–10 ng(Sn) g^–1 dry weight and 7–17 ng(Sn) g^–1 dry weight for butyl- and phenyltin compounds, respectively. Recoveries were comparable with or better than those obtained by use of other procedures reported in the literature. The analytical procedure was validated by analysis of NIES No. 11 (fish tissue) certified reference material.     

Excess enthalpies of aqueous ternary solutions of urea and polyols at 25°C

The heats of dilution of nine ternary solutions of urea and polyols have been determined at 25°C. Excess enthalpies and their virial coefficients h _xy have been evaluated and compared with the data reported in the literature for mono- and polyfunctional alcohols and other oxygenated nonelectrolytes. The group additivity approach of Savage and Wood was applied and the contributions to the enthalpy coefficients, due to the water mediated interactions between urea and the functional groups –CH₂–, –OH, and –O– were determined. On the other hand, by using empirical combination rules among the cross- and self-enthalpic interaction coefficients it is possible to emphasize the large differences in the behavior (even in the presence of urea) of the polyols (and in particular of cyclitols) and of saccharides.     

Flavonoids in Leguminosae: analysis of extracts of T. pratense L., T. dubium L., T. repens L., and L. corniculatus L. leaves using liquid chromatography with UV, mass spectrometric and fluorescence detection

Reversed-phase LC on C-18 bonded silica with a methanol–ammonium formate gradient was used to determine the main flavonoids in leaves of four species of the Leguminosae family. The detection modes were diode-array UV absorbance, fluorescence, and (tandem) mass spectrometry. LC–UV was used for a general screening, sub-classification, and the calculation of total flavonoid contents. LC–FLU was included to identify isoflavones on the basis of their native fluorescence. Most structural information regarding aglycons, sugar moieties, and acidic groups was derived from LC–MS in both the full-scan and extracted-ion mode, using negative-ion atmospheric pressure chemical ionization. MS/MS did not provide much additional information, because the same fragments were observed as in full-scan MS.In T. pratense and T. repens, the main constituents were flavonoid glucoside–(di)malonates, while T. dubium and L. corniculatus mainly contained flavonoid (di)glycosides. Satellite sets comprising an aglycon, the glucoside and glucoside–malonates or –acetates, were abundantly present only in T. pratense. Generally speaking, the main aglycons and sugars in the four plant species are surprisingly different. In addition, while the results for T. pratense are similar to those reported in the literature, there is little agreement in the case of the other species. Finally, total flavonoid contents ranged from 50–65 mg/g for L. corniculatus and T. dubium, to 15 mg/g for T. pratense and only 1 mg/g for T. repens.     

Synthesis of protoberberine alkaloids

In this review an analysis is made of literature information on the synthesis of protoberberine alkaloids during 1980–1990.Institute of Chemistry of Plant Substances, Uzbekistan Republic Academy of Sciences, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 449–468, September–October, 1992.     

Study and prediction of alkylbenzenes’ vapour pressures

Vapour pressures of 1,4-di-tert-butylbenzene (379–1647 Pa), 1,3,5-tri-tert-butylbenzene (203.9–241 Pa), 1-methyl-3,5-di-tert-butylbenzene (16.7–435.8 and 1318–103,880 Pa), and 1,2,2-trimethylpropybenzene (36.3–287.4 Pa) have been measured using a transpiration method and an ebuliometric method. Based on the literature and obtained by the authors experimental data a comparative study of prediction capabilities of the following methods has been carried out: Ambrose–Walton's, Lee–Kesler's, Riedel's and the modification of Riedel's method made by Vetere.     

Chemical transformation of ecdysteroids: Latest advances

In this review the results of chemical transformations of ecdysteroids reported in the literature during 1986–1996 are discussed.Institute of Bioorganic Chemistry of the Belarus Academy of Sciences, 220141, Minsk, Zhodinskaya, 5/2. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 139–160, March–April, 1998.     

Thio-claisen rearrangement in the synthesis of sulfur-containing heterocyclic compounds (review)

The review is devoted to literature information on the mechanism of the thio-Claisen rearrangement of allyl aryl (heteryl) sulfides and their use in the synthesis of five- and six-membered sulfur-containing heterocyclic compounds, including derivatives of dihydrobenzothiophene and thiochromane.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 435–449, April, 1980.     

Experimental and calculated complex formation curves for mixed, dynamic and semi-dynamic, metal–ligand systems.: A differential pulse polarographic study of Cu–sarcosine–OH and Cd–MIDA–OH systems at a fixed ligand to metal ratio and varied pH

The Cu–sarcosine–OH and Cd–MIDA–OH systems have been studied by differential pulse polarography (DPP) at a fixed total ligand to total metal concentration ratio and varied pH at 298 K and μ=0.5 mol dm⁻³ in the background of NaNO₃. Both the metal–ligand systems show initially dynamic (labile), followed by semi-dynamic behaviour on the DPP time scale. It has been shown that the experimental and calculated DPP complex formation curves used previously only for labile metal–ligand systems can be employed for the modelling of all species formed in a solution and optimisation of their stability constants. The stability constants of ML and ML₂ complexes as log β were estimated for Cu^II and Cd^II as 7.75±0.02, 14.49±0.01 and 6.67 ±0.02, 12.00±0.02, respectively (all known hydroxide species of copper and cadmium, including polynuclear species, were incorporated into the metal–ligand–OH systems). The formation of the complex CuL₂(OH) is suggested also and its stability constant as log β has been estimated to be 16.2±0.2. Results reported here seem to be reasonable when compared with the literature data reported at 298 K and different ionic strengths.     

Photochemical isomers of tropolone alkaloids

This review, which covers the literature up to 1989, generalizes advances in the field of the study of the photochemical isomers of colchicine and tropolone alkaloids related to it. Information is given on their natural sources, methods of isolation, structure, and configuration, and photochemical and thermal interconversions. Characteristics distinguishing them from the topolone alkaloids in their UV, IR, mass, and²H and¹³C NMR spectra of the photochemical isomers are pointed out.Deceased.Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 147–165, March–April, 1990.     

Structure and biosynthesis of transferrin

The review gives a literature analysis of the state of the question of the structure and biosynthesis of transferrin with the results of modern investigations.Institute of Bioorganic Chemistry, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 291–305, May–June, 1985.     

Optimal Kinoshita wave functions for heliumlike atoms

An extensive optimization has been performed for the composition ofN terms, as well as the exponent and the mixing coefficients, of Kinoshita wave functions for heliumlike atoms with atomic numberZ. The optimalN-term Kinoshita functions have been constructed forN=1–10, 20, 30, 40, 50, 100 andZ=1(H^–)–10(Ne⁸⁺). The present results demonstrate that the optimal term selection dramatically improves the accuracy of the Kinoshita function: In the case of He, for example, the optimal 100-term Kinoshita function gives – 2.903 724 376 95 hartrees, which is only 8×10^–11 hartrees higher than the most accurate literature value.     

Crystal Chemistry of Rare-Earth Chalcogenides

Crystal structures of Ln–X, Ln–Ln'–X, Ln–M–X, and Ln–X–Z compounds (Ln and Ln' are rare-earth elements; M is subgroup I–VIIIa or II–Vb cation and Z is subgroup V–VIIb anion; X is S, Se, or Te) were systematized and analyzed using data obtained by us and data from the literature. The structures of binary Ln–X chalcogenides can be divided into 4 groups: derivatives of NaCl-type structures, structures with one small parameter b 4 Å, structures similar to those of oxides and pniktides, and derivatives of PbFCl-type structures. Triple Ln–Ln'–X chalcogenides have structures similar to those of the binary chalcogenides of the first, second, and third groups. It was shown that the crystal structure of Ln–M–X depends on the size of cation M, its formal charge, electronegativity value, and electronic structure. The crystal structures of the phases in the Ln–M–X and Ln–X–Z compounds were compared with binary chalcogenide structures. Different variants of structure characterization and their potentialities are considered. Special attention is given to the defect-containing and ordered structures and to elucidating the role of the cation and anion vacancies in the phase structures.