Molecular structure of the alkaloid solasodine

An x-ray structural study of the monohydrate of the alkaloid solasodine has been made. Rings A, C, and F have the chair conformation, ring B half-chair, and rings D and E envelope conformations. The linkages of rings B/C and C/D are trans and that of rings D/E cis. It has been shown that solasodine is a diastereomer of the alkaloid tomatidenol.A. N. Nesmeyanov Institute of Heteroorganic Compounds, Moscow. Institute of Organic Synthesis and Coal Chemistry of the Kazakh SSR Academy of Sciences, Karaganda. Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 86–88, January–February, 1989.     

Crystal and molecular structure of the new dilactone anabsin

A complete x-ray structureal study has been made of the dilactone anabsin. The crystals are monoclinic, a = 9.863 (4). A, b = 14.240 (6) Å,c = A,c 11.149 (6) Å, = 103.61°, z = 2, space group P2₁ (diffractometer,2035 reflections, MLS in the anisotropic approximation, R ßO.65). The conformation of the molecule and the position of attachment of the monomeric parts of anabsin have been determined unambiguously. The length of the bonds and the magnitude of the valence angles are the usual ones. The five-membered rings A, C, D, and H have the envelope conformation, and the five-membered ring F a planar conformation. The seven-member ring G has the chair conformation and B a distorted twisted chair conformation. The linkages of rings A/B and G/H are trans, and of E/F cis.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 446–453, July–August, 1981. Original article submitted February 16, 1981.     

Molecular and crystal structure of sophoridine

The three-dimensional structure of the alkaloid sophoridine C₁₅H₂₄ON₂ has been studied by x-ray structural analysis; the parameters of the elementary cell are: a=5.458, b=10.640, c=11.989 Å; =99.7°; z=2; space group P2₂. The experimental set was obtained on a Sinteks-P2₁ diffractometer, the structure being determined by the direct method with refinement by the method of least squares in the anisotropic approximation taking the hydrogen atoms into account to R=0.059. Ring A has the chair conformation, rings B and C the boat conformation, and ring D the half-chair conformation. The linkages of rings A/B, B/C, and C/D are trans, and of B/C cis. There are no shortened intermolecular contacts in the crystal structure of the compound.Institute of Bioorganic Chemistry, Academy of Sciences of the Uzbek SSR, Tashkent. Institute of Crystallography, Academy of Sciences of the USSR, Moscow. V. I. Lenin Tashkent State University. Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 355–362, May–June, 1979.     

Minor diterpenoids of Teucrium chamaedrys

Summary The structures of four new diternenoids ofTeucrium chamaedrys L.—teucrins B, E, F, and G, be-longing to the group of rearranged labdanes — has been shown. For teucrins E and F, the trans-(5, 10)-linkage of rings A/B has been shown.Institute of Chemistry, Academy of Sciences of the Moldavian SSR. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 589–598, September–October, 1974.     

Glycosides from ginseng roots IV. Isolation of new glycosides from ginseng

Summary 1. New glycosides — panaxosides C, D, E, and F — have been isolated from the root of ginseng by partition chromatography.2. The glycosides of ginseng contain genins of two groups: the first consists of the genins of panaxosides A, B, and C, and the second of those of panaxosides D, E, and F. When panaxosides D, E, and F are hydrolyzed, panaxadiol is formed as the main product of the decomposition of the genins.Khimiya Prirodnykh Soedinenii, Vol. 1, No. 2, pp. 82–86, 1965     

Triterpene glycosides ofCaltha polypetala glycosides A, B, D, E, and F

Five individual triterpene glycosides — A, B, D, E, and F — which are hederagen-in mono- and biosides, have been isolated from the roots ofCaltha polypetala (Great Marsh Marigold), familyRanunculaceae. Glycosides E and F proved to be new compounds for which, on the basis of the results of acid and alkaline hydrolyses, methylation, methanolysis, and physicochemical methods of investigation, the following structures are proposed: E — hederagenin 3-0-D-glucopyranoside, 28-O-L-rhamnopyranoside; and F — heteragenin 28-O-[O-L-rhamnopyranosyl-(1 6)-D-glucopyranoside].I. G. Kutateladze Institute of Pharmacochemistry, Academy of Sciences of the Georgian SSR, Tbilisi. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 712–716, November–December, 1986.     

The structure of ervine

Conclusions Results of a comparative study of the NMR and mass spectra of ervine and hydroxyindole-ervine have shown that ervine belongs to the heteroyohimbine alkaloids in which the C/D rings have a trans linkage and the D/E rings a cis linkage and the CH₃ group at C₁₉ has the -axial configuration.Khimiya Prirodnykh Soedinenii, Vol. 6, No. 3, pp. 346–347, 1970     

Crystal and molecular structure of the diterpene alkaloid talatisine

As a result of x-ray studies, the spatial structure and conformation of the talatisine molecule have been determined. The mean bond lengths are C-C 1.539(6) Å, N-C 1.493 (5) Å, HO-C(sp³) 1.429(5) Å. The six-membered rings A and B have the chair conformation, and rings C and D have distorted boat conformations. The five-membered rings E, F, and G have the envelope conformation.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 335–341, May–June, 1981.     

Spatial structure of diacetyldihydroungminorine

The structure of diacetyldihydroungminorine, C₂₁H₂₅NO₇ (I), has been determined by the x-ray structural method: diffractometer, CuK radiation, 1278 reflections, R=0.089. An analysis has been made of the conformation of the (I) molecule in comparison with that observed for dihydrolycorine in solution and in the crystalline form. It was shown that the conformations of rings B, C, and D of the (I) molecule in the crystal and of dihydrolycorine in solution are identical. The lack of correspondence of the crystal-solution conformations in dihydrolycorine is connected with an inversion of the unshared electron pair of the nitrogen atom on the formation of a salt — the hydrobromide.Institute of Chemistry of Plant Substances, Uzbekistan Academy of Sciences, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 105–108, January–February, 1992.     

Thermochemistry of Amines: Experimental Standard Molar Enthalpies of Formation of N-Alkylated Piperidines

The standard molar enthalpies of formation _f H _m ^° (l) at the temperature T = 298.15 K were determined using combustion calorimetry for N-methylpiperidine (A), N-ethylpiperidine (B), N-propylpiperidine (C), N-butylpiperidine (D), N-cyclopentylpiperidine (E), N-cyclohexylpiperidine (F), and N-phenylpiperidine (G). The standard molar enthalpies of vaporization _l ^g H ^{m °} of these compounds were obtained from the temperature variation of the vapor pressure measured in a flow system. From these data the following standard molar enthalpies of formation in gaseous phase _f H _m ^° (g) were derived for: A –(61.39 ± 0.88); B –(88.1 ± 1.3); C –(105.81 ± 0.66); D –(126.2 ± 1.3); E ( –88.21 ± 0.75); F –(135.21 ± 0.94); G (70.3 ± 1.4) kJ · mol^–1. They are used to determine the strain enthalpies of the cyclic amines A–G. The N-alkylated piperidine rings have been found to be about strainless.     

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.     

Glycosylation of betulin and its acetates in the presence of cadmium carbonate

The glycosylation of betulin and its acetates by -acetobromoglucose in toluene in the presence of cadmium carbonate is considered. It has been shown that the reaction is accompanied by Wagner-Meerwein rearrangements of the initial alcohols in rings A and E. This leads to the formation — in addition to acetates of betulin glycosides — of derivatives of allobetulin — A-nor-³⁽⁵⁾-allobetulin and A-nor-³⁽⁵⁾-betulin — as was shown by¹H and¹³C NMR spectroscopy.Pacific Ocean Institute of Biochemistry, Far Eastern Scientific Center, Academy of Sciences of the USSR, Vladivostok. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 182–187, March–April, 1984.     

Triterpene glycosides of Caulophyllum robustum

Conclusions Glycosides which we have called caulosides A, B, C, D, and E have been isolated from the perennial relict plantCaulophyllum robustum.The aglycone of caulosides A, C, D, and E is hederagenin. It has been found that the carbohydrate chains of caulosides D and E contain glucose, arabinose, and rhamnose; those of C, glucose and arabinose; and those of A and B, arabinose. Caulosides D and E contain carbohydrate chains attached by an O-acyl glycoside bond.Institute of Biologically Active Substances, Far Eastern Division, Siberian Branch, Academy of Sciences of the USSR. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 552–555, September–October, 1970.     

Polysaccharides of saponin-bearing plants. II. Isolation and characterization of the polysaccharides ofBiebersteinia multifida

The polysaccharides of the tuberous roots ofBiebersteinia multifida D. C. have been isolated and characterized. The neutral polysaccharide consists of a mixture of three glucans — A, B, and C — with molecular weights of 4100, 2200, and 1100, respectively, formed by D-glucopyran residues linked by bonds.Deceased.Institute of the Chemistry of Plants Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 755–757, November–December, 1985.     

Nmr investigation of the spatial structure of quinolizidine alkaloids IV. Conformation of sophoridine in solution

Summary On the basis of PMR spectra at 100 and 300 MHz, the conformation of the molecule of the alkaloid sophoridine in solution has been determined as A/B-, A/C-, and C/D-trans, B/C-cis, with the chair conformation of rings A and D and the boat conformation of rings B and C.For Communications I–III, see [1].V. I. Lenin Tashkent University. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 744–751, November–December, 1974.     

Transformed steroids. 133. Synthesis of 20-deoxysteroids with a tetrahydropyran ring E

The synthesis of 20-deoxy compounds — the precursors of the steroid pyranols and pyranones synthesized by the authors previously — has been effected from a steroid 20-ketotetrahydropyran by the hydrogenolysis of the corresponding ethylene dithioketal with Raney nickel. The¹H and¹³C NMR spectra have been studied in detail. Transformations of rings A and B via the epoxide or the 3,5-cyclosteroid have led to 3-acetoxy-16,23-epoxy-5H-21,24-dinorchol-5-en-6-one and 3-acetoxy-5-hydroxy-16,23-epoxy-21,24-dinorchol-5-en-6-one.N. D. Zelinskii Institute of Organic Chemistry, Academy of Sciences of the USSR, Moscow. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 732–735, November–December, 1983.     

13C NMR spectra and three-dimensional structures of isomeric 3,4-substituted thiophans

The chemical shifts and the direct carbon-proton spin-spin coupling constants for a number of cis and trans isomers of 4-amino-substituted 3-hydroxy(acyloxy)-thiophans, the configurations of the substituents in which and the conformational states were previously established by an independent method, were studied. It was found that in the spectra of the cis isomers the signals of the vicinal ¹³C atoms, which bear the substituents, are shifted to strong field as compared with the trans isomers ( trans-cis 1.7–4.3 ppm). Conformational effects of the substituents on the chemical shifts of the ring ¹³C atoms were noted. It is shown that a relationship exists between the direct carbon-proton spin-spin coupling constants and the spatial orientations of the acyloxy and acylamino substituents for five-membered saturated rings.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1612–1616, December, 1981.     

Molecular and crystal structures of the complex of 18-dehydroglycyrrhetic acid with dimethyl sulfoxide

The crystal structure of the complex of 18-dehydroglycyrrhetic acid (GLD) with DMSO (C₃₀H₄₁O₄·C₂H₆OS) has been determined by x-ray structural analysis. Syntex P21 diffractometer, CuK radiation, 1309 reflections, R = 0.080. A conformational analysis has been made of the GLD molecule in comparison with that of glycyrrhetic acid. The conformations of rings A and B in the GLD molecule do not differ from the conformations of the corresponding rings of glycyrrhetic acid. Differences arise in ringsC,D, andE because of the presence of the double bond between the C18 and C19 atoms.Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 362–366, May-June, 1996. Original article submitted Novemher 11, 1995.