Secondary-ion mass spectra of pennogenin glycosides

LSIMS mass spectra of pennogenin glycosides have been studied; the most characteristic ions are (M+H–H₂O)⁺ (with glycerol as the liquid matrix) and (M+Na)⁺ (with glycerol +NaCl as matrix). In both cases the peaks of ions formed as the result of the successive elimination of the carbohydrate units, the breakdown of the bonds of the terminal pyranoses, the cleavage of the bonds of the rings D and E, and the peaks of the ions Agl⁺ and (Agl–H₂O)⁺ were observed.Institute of Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. All-Union Scientific-Research Institute for Agricultural Biotechnology, All-Union Academy of Agricultural Sciences, Moscow. Pacific Institute of Bioorganic Chemistry, Far Eastern Branch, Academy of Sciences of the USSR, Vladivostok. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 523–525, July–August, 1991.     

Features of the mass spectra of C18-diterpene alkaloids

Fragmentation under electron impact of eleven C₁₈-diterpene alkaloids with an oxygen function at C-4 has been investigated. The contributions of various modes of forming the (M - CH₃)⁺ ions have been determined. The mechanism of the appearance of the fragments (M - CH₃)⁺ and (M - OCH₃)⁺ at the expense of the methoxy groups at C-14 and C-16 has been considered. The characteristic nature of the parameters of the metastable peaks in the transitions to these daughter ions has been shown. Minor directions of the fragmentation of 3,4-epoxy- and 4-hydroxy bases have been characterized.Institute of the Chemistry of Plant Substances, Uzbek SSR Academy of Sciences, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 95–106, January–February, 1989.     

Dadi spectra of gossypol hexamethyl ethers and mixtures of them

The DADI spectra of the M⁺ ions of hexamethyl ethers of three tautomeric forms of gossypol and of mixtures of them have been studied. A specific fragmentation pathway of M⁺ for each form has been shown. On the basis of the results obtained, the amounts of the hexamethyl ethers of each tautomeric form produced in the methylation of gossypol have been found.Institute of Bioorganic Chemistry, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 38–42, January–February, 1980.     

Structural and dynamic investigations of aqueous clusters of Na+ and K+

Using computer modeling, we have studied Na⁺–24H₂O and K⁺–24H₂O clusters. We propose ion-water interaction potentials. We obtain structural, energy, and dynamic characteristics of the studied clusters. We show different mechanisms for exchange of water molecules surrounding the Na⁺ and K⁺ ions: single-particle in the case of Na⁺, and close to K⁺, along with single-particle exchange, a large percentage of multiparticle cooperative exchange of water molecules. This difference is explained by the different degrees of orientation of the water molecules surrounding these ions, by the presence of a unified deformed network of H bonds in the K⁺ cluster and its absence in the Na⁺ cluster. We propose a negative hydration mechanism for the K⁺ ion.Institute of General and Inorganic Chemistry, Russian Academy of Sciences. Institute of Physical Chemistry, Russian Academy of Sciences. Translated from Zhurnal Strukturnoi Khimii, Vol. 34, No. 2, pp. 96–104, March–April, 1993.     

V. Mass spectrometry of the alkaloids ofArundo donax

The mass spectra of alkaloids isolated from the epigeal part of the plant Arundo donax L. have been investigated. The main pathways of fragmentation under electron impact have been determined for arundine, ardine, donaxaridine, donaxarine, and donaxinine. An analogy has been found in the fragmentation of the M⁺ ions of donaxarine and donaxinine, the main pathway of their fragmentation consisting in the elimination of the elements of the N-methylpyrrolidone ring.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Republic of Uzbekistan, Tashkent, fax (3712) 89 14 75. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 217–220, March–April, 1996. Original article submitted September 25, 1995.     

Secondary-ion mass spectrometry of lycotetraosides of the spirostan and furostan series

The secondary-ion mass spectra of seven steroid lycotetraosides have been obtained by the SIMS method. On the use of a glycerol matrix, all the compounds of the spirostan series, including those with an additional carbohydrate substituent a C-24, formed the (M+H)⁺ ions, while a lycotetraoside of the furostan series formed the (M–H₂O+H)⁺ ion. They subsequently decomposed by the alternative successive elimination of the terminal carbohydrate units of the lycotetraose. Substituents at C-25 and C-26 were ejected in the form of glucose molecules. Fragments of the aglycon and of the lycotetraoside moieties of the molecules were recorded. When NaCl was added to the same matrix, all the compounds gave preferentially the (M+Na)⁺ and (M+2Na–H)⁺ ions.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. All-Union Scientific-Research Institute of Agricultural Biotechnology, Lenin All-Union Academy of Agricultural Sciences, Moscow. Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 53–58, January–February, 1991.     

Mass spectrometry of negative ions and the stereochemistry of organic compounds. IV. Acetates of epimeric diterpene glycols

Summary 1. It has been established that the fragmentation of the molecular negative ions of the diacetates of sclareol and of 13-episclareol takes place with the splitting out of the fragments Ac, OAc, CH₂CO, AcOH, CH₃, and CH=CH₂ without skeletal rearrangements.2. The relative yields of the negative ions formed depend on the stereochemistry of the molecules of the compounds investigated.Institute of Chemistry, Bashkir Branch of the Academy of Sciences of the USSR, Ufa. Institute of Chemistry, Academy of Sciences of the Moldavian SSR, Kishinev. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 454–457, July–August, 1978.     

Kinetics of metal ion sorption on clinoptilolite

From an investigation into the sorption kinetics of Na⁺, K⁺, and Sr²⁺ ions from standard solutions on finely dispersed clinoptilolite incorporated in a highly permeable inert polyacrylamide gel we have determined the characteristic kinetic size of clinoptilolite and the diffusion coefficients for Na⁺, K⁺, and Sr²⁺ in the clinoptilolite microcrystallites and transport pores. Diagrams have been constructed to enable a valid selection of kinetic models for sorption of the ions from any solutions on clinoptilolite.Institute of Chemistry, Far Eastern Branch of the Russian Academy of Sciences, 690022 Vladivostok. V. I. Vernadskii Institute of Geochemistry and Analytical Chemistry, Russian Academy of Sciences, 117975 Moscow. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 2, pp. 273–277, February, 1992.     

Nonempirical investigation of the influence of the outer-sphere environment on the geometric structure of [AF5] n−

Nonempirical calculations of the electronic structure of the [PF₅]^2– ion and of the clusters [M₅PF₅]³⁺ and [M₄PF₅]²⁺ (M=H⁺, Li⁺, Na⁺) have been carried out. The character of the dependence of the geometric parameters of the [PF₅]^2– ion on the properties and structure of the second coordination sphere has been discussed.Institute of Chemistry, Academy of Sciences of the USSR, Far-Eastern Branch. Translated from Zhurnal Strukturnoi Khimii, Vol. 32, No. 2, pp. 17–22, March–April, 1991.     

Template synthesiS: Geometrical and electronic structures of the Fe nitrosyl complex formed by bis(S-methylisothiosemicarbazone)-2,4-pentandione

Sodium acetylacetonate reacts with S-metliylisothiosemicarbazidium nitrate and Fe(NO₃)₃ · 9H₂O in ethanol to make [Fe(HL)NO]NO₃, in which H₃L is bis(S-methyl-isothiosemicarbazone)-2,4-puntandione. The [Fe(HL)NO]⁺ cation has a square pyramidal structure with the HL^2- arranged around the central ion in the basal plane and the nitrogen atom of the NO group in the apical position, with the iron atom diverging from the plane of the base of the pyramid by 0.477 Å. The FeN0 moiety has a linear structure (FeNO = l72.7°). XRD, IR, and Mössbauer spectroscopy have been combined with calculations on the electronic structure to demonstrate that the Fe-NO bond is covalent.Chemical Institute, Academy of Sciences of Moldavian SSR. Applied Physics Institute, Academy of Sciences of the Moldavian SSR. Kishinev. Institute of Crystallography, Academy of Sciences of the USSR. Kurnakov Institute for General and Inorganic Chemistry, Academy of Sciences of the USSR, Moscow. Translated from Teoreticheskaya i Éksperimental'naya Khimiya, Vol. 27, No, 3, pp. 376–381, May–June, 1991. Original article submitted February 18, 1991.     

Coumarins of Fraxinus mandschurica and F. potamophila

Summary The leaves ofFraxinus mandschurica Rupr. and the bark ofF. potamophila Herd. have yielded esculetin, fraxinol, and a new coumarin C₁₀H₈O₅, mp 228–230°C which we have called isofraxetin. On the basis of NMR and UV spectroscopy it has been established that isofraxetin is 5,7-dihydroxy-7-methoxycoumarin.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR. Institute of Chemistry, Academy of Sciences of the Turkmen SSR. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 493–497, July–August, 1973.     

Inhibition of transport (Na+, K+)-ATPase by cardenolides of the strophanthidin group and a study of the structure-activity relationship

Summary A comparative study of the inhibiting action on transport (Na⁺,K⁺)-ATPase of 15 derivatives of strophanthidin and four rhamnosides of other aglycones have been made on the microsomal fraction of the cells of the rat cerebral cortex.It has been shown that the method of determining the activity of cardiotonic substances by determining the lethal dose and the enzyme test give completely comparable results. Both biological methods objectively reflect the characteristic features of the chemical structure of the cardenolides.Institute of Biochemistry, Academy of Sciences of the Uzbek SSR, Tashkent. Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 188–194, March–April, 1976.     

Phytoecdysones of Serratula III. Mass spectrometric study of the acetates and acetonides of ecdysterone and viticosterone e

Summary Features of the fragmentation of the side chain of the acetates and acetonides of ecdysterone and of viticosterone E have been studied. It has been shown that the presence of an oxygen-containing function at C₂₅ in these compounds imparts to the spectra certain distinguishing features which have analytical value.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 155–158, March–April, 1975.     

Components ofHaplophyllum obtusifolium

Skimmianine, folimine, benzamide, and new alkaloid haplotusine (mp 118–119°C, C₁₁H₁₁NO₃, M⁺ 205) have been isolated from the epigeal part ofHaplophyllum obtusifolium Ledeb. growing in the environs of Kora-Koly, Turkmen SSR. By the analysis of spectral characteristics it has been established that haplotusine has the structure of 1,4-dimethoxy-2-quinolone.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 635–636, September–October, 1984.     

X-ray structural investigation of alkaloids VI. Crystal structure of the alkaloid parfumine

A complete x-ray structural investigation of the alkaloid parfumine has been performed. The lengths of the bonds and the valence angles have the usual values. Benzene rings A and D are planar, B a distorted half-chair^C(6)H_N, and rings C and E are flattened envelopes, E_C(14) and^C(19)E, respectively.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Institute of Heteroorganic Compounds, Academy of Sciences of the USSR, Moscow. Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 66–73, January–February, 1980.     

Structure and stereochemistry of the coumarins ofFerula lehmannii

Two new 7-hydroxycoumarins have been isolated from the roots ofFerula lehmannii (Lehmann's giant fennel): lehmferidin (I), C₂₄H₂₈O₄, M⁺ 380, mp 173–174°C, and lehmferin (II), C₂₄H₃₀O₄, M⁺ 382, mp 118–119°C; and badrakemin (III) has also been identified. The structures and configurations of the asymmetric centers of the new coumarins have been established on the basis of spectral characteristics and conversion into known substances.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 709–712, November–December, 1983.     

The x-ray structural investigation of alkaloids I. Molecular structure and absolute configuration of (+)-cocculine

Summary An x-ray structural investigation of the alkaloid (+)-cocculine in the form of the hydrobromide has been performed. The bond lengths and valence angles are the usual ones. The conformations of the rings are: A — envelope⁴E; B — half-chair⁹T₅; C — half-chair¹⁰H₅. The absolute configuration 3R,5S has been established.Institute of Heteroorganic Compounds, Academy of Sciences of the USSR. Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR. Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 395–400, May–June, 1975.     

Trisulfated glycosides from the holothurianCucumaria japonica

Three new triterpene glycosides have been isolated from an alcoholic extract of the Pacific Ocean commercial holothurian Cucumaria japonica: cucumariosides A _T 1 (I), A _T 2 (II), and A _T 3 (III). The structures of these glycosides have been established by chemical and physical methods.Deceased.Pacific Ocean Institute of Bioorganic Chemistry, Far Eastern Branch, Russian Academy of Sciences, Vladivostok. Institute of Chemistry of Plant Substances, Academy of Sciences of the Uzbekistan Republic, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 369–374, May–June, 1993.     

Spatial structures of the sesquiterpene germacrane lactones tanachin and tamirin

An x-ray investigation has been made of the sesquiterpene lactones tanachin and tamarin: diffractometer, CuK-radiation, 845 and 981 reflections, respectively, direct method, R factors 0.064 and 0.065. The conformations of both molecules are boat-boat with configurations of the¹D₁₄ and¹⁵D₅ types.Institute of the Chemistry of Plant Substances, Uzbek SSR Academy of Sciences, Tashkent. Institute of Bioorganic Chemistry, Uzbek SSR Academy of Sciences, Tashkent. Translated from Khimiya Prirodynkh Soedinenii, No. 2, pp. 198–204, March–April, 1989.