Triterpene glycosides ofAstragalus and their genins LVII. The structure of cyclopycnanthogenin

A new cycloartane methysteroid cyclopycnanthogenin, has been found in stems of the plantAstragalus pycnanthus Boriss. (Leguminosae). Its structure has been determined on the basis of IR, mass, and¹H and¹³C NMR spectra with the involvement of DEPT experiments and 2M¹H−¹H and¹H−¹³C chemical shift correlations [¹H−¹H COSY and¹H−¹³C (HMQC)] and also 2M NMR correlations of long-range¹H−¹³C interactions (HMBC). Cyclopycnanthogenin is 6α, 16β, 25-trihydroxy-20R, 24S-epoxycycloartane-3-one. Institute of the Chemistry of Plant Substances, Academy of Sciences of the Republic of Uzbekistan, Tashkent, fax (3712) 40 64 75. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 515–518, July–August, 1998.     

Rhaposerine and rhaserolide, new sesquiterpene lactones fromRhaponticum serratuloides

Two new crystalline guaianolides,viz., rhaposerine and rhaserolide, were isolated from an ethanolic extract of the above-ground part of the plantRhaponticum serratuloides by column chromatography along with sesquiterpene lactones,viz., centaurepensin and acroptilin, which have been found in other plants. The chemical structures of the title lactones were established by¹H and¹³C NMR spectroscopy and 2D¹H−¹H (COSY) and¹³C−¹H (COSY and COLOC) NMR spectroscopy. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 2010–2014, October, 1999.     

Low-molecular-weight metabolites of fungi. II. Refinement of the structure of stachybotrin

The structure of stachybotrin has been reconsidered in the light of¹H,¹³C,¹H−¹H COSY, HMQC, and HMBC NMR spectra, and the revised structure has been confirmed by x-ray structural analysis. 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. 5, pp. 666–669, September–October, 1998.     

Low-molecular-mass metabolites of fungi I. Stachybotrin fromStachybotrys alternans

Stachybotrys alternans produces a series of low-molecular-mass compounds. By their column chromatography we have isolated the nitrogen-containing compound stachybotrin. The structure of stachybotrin has been determined on the basis of chemical transformations together with the results of¹H and¹³C NMR spectroscopy, 2M NMR¹H–¹H and¹H–¹³C chemical shift correlation (COSY), correlation of long-range¹H–¹³C interactions (HMBC), measurements of NOEs in a rotating coordinate system (ROESY), and IR and electronimpact mass spectra.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Republic of Uzbekistan, Tashkent, fax (3712) 40 64 75. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 599–607, July–August, 1997.     

Ajanolide A, a new germacranolide fromAjania fruticulosa

A new germacranolide, ajanolide A, was isolated from aerial parts ofAjania fruticulosa by means of extraction with CHCl₃ and adsorption chromatography. This compound was identified as (1(10)E,3S,4Z,6R,7S,11R)-3-acetoxygermacra-1(10),4-dien-12,6-olide ((1S,7S,10R,13R)-7-acetoxy-4,8,13-trimethyl-11-oxabicyclo[8.3.0]trideca-4(E),8(Z)-dien-12-one) by X-ray diffraction analysis. 2D¹H−¹H (COSY) and¹³C−¹H (COSY) NMR spectroscopy was used for assigning the¹H and¹³C NMR signals in the spectra of ajanolide A. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 1, pp. 167–170, January, 1998.     

Pattern recognition of the multiplet structure of NMR spectra

A new method of analysis of high-resolution NMR spectra was suggested, and an algorithm and the PAREMUS program package for assignment of patterns of the spectral components based on pattern recognition theory were developed. High effectiveness of the method has been exemplified by determination of the values and relative signs of the interring¹H−¹H and¹³C−¹H spin-spin coupling constants in 1,2,3-trichloronaphthalene. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya. No. 3, pp. 444–451, March, 1997.     

13C and19F NMR study of α,β-difluorostyryl derivatives of transition metal carbonylates. A method of signal assignment based on the carbon—fluorine spin-spin coupling constants

The¹³C and¹⁹F NMR spectra ofZ- andE-isomers of β-X-substituted α,β-difluorostyrenes (X=F, Cl, CpFe(CO)₂, Re(CO)₅, Re₂(CO)₉Na) were studied. Direct and long-range (across 1–5 bonds) spin-spin coupling constants and the (¹³C−¹²C) isotope shifts in the¹⁹F NMR spectra were determined. The study of the¹³C satellites in the¹⁹F NMR spectra of substituted difluorostyrenes permitted assignment of the¹³C NMR signals of the vinylic carbon atoms. Similarly, the signals in¹⁹F NMR spectra were assigned based on coupling constants of fluorine withipso-carbon. These assignments were found to be in good agreement with the data available from the literature (X=F, Cl). The developed approach was applied to the elucidation of the structure ofZ−PhCF=CClFe(CO)₂Cp. Translated fromIzvestiya Akademii Nauk, Seriya Khimicheskaya. No. 8, pp. 1575–1579, August, 1998.     

Reactions of chiral phosphoramidites with complexes Pd(COD)Cl2 and Pt(COD)Cl2

Reactions of phosphoramidites based on (−)-ephedrine and [(1S)-endo]-(−)-borneol with the complexes M(COD)Cl₂ (M is Pd or Pt, and COD is cycloocta-1,5-diene) were studied. The formation ofcis andtrans complexes of the general formulas MCl₂L₂ and M₂Cl₂(μ-Cl)₂L₂ was observed. The structures of the resulting compounds were established by³¹P,¹³C, and¹⁹⁵Pt NMR and IR spectroscopy and by plasma desorption mass spectrometry. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 8, pp. 1627–1630, August, 1998.     

2-Phenyl-1-boraadamantane complexes. Synthesis and intramolecular dynamics

The reaction of triallylborane with 3-phenylprop-1-yne at 135–140 °C followed by treatment of the reaction mixture with MeOH afforded 7-benzyl-3-methoxy-3-borabicyclo[3.3.1]non-6-ene (1) in 81% yield. Hydroboration of compound1 with a solution of BH₃ in THF yielded the tetrahydrofuran complex of 2-phenyl-1-boraadamantane (2). The reactions of trimethylamine or pyridine with compound2 afforded the trimethylamine (3) or pyridine (4) complexes of 2-phenyl-1-boraadamantane. respectively. Hindered rotation about the C(2)−Ph bond in adduct3 was observed by¹H and¹³C NMR spectroscopy. The activation energy of this process is 58.6 kJ mol⁻¹ (determined by 2D¹H−¹H EXSY spectroscopy).     

Dependence of geminal1H−1H and31P−1H spin-spin coupling constants on the specific intramolecular C−H...X interaction

Participation of the proton in a specific intramolecular C−H...X (X=N, 0) interaction leads to an increase in its geminal¹H−¹H and¹H−³¹P spin-spin coupling constants (SSCC). According toab initio calculations carried out in the 6–31G^** basis set, the observed effect is mainly due to the change in the diamagnetic spin-orbital contribution to SSCC. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 306–309, February, 1997.     

Possibilities of the determination of3H,14C and131I individually and in mixtures,by the method of amplitude attenuation using liquid scintillators

Possibilities of the determination by radioactivity measurements of³H,¹⁴C and¹³¹I are described for the individual nuclides and their mixtures, with the use of liquid scintillators. The changes in the counting efficiency have been determined as a function of the parameters of the measuring equipment, and parameters are suggested which make possible the determination of³H,¹⁴C and¹³¹I individually, or in the pairs³H−¹⁴C,³H−¹³¹I,¹⁴C−¹³¹I, and finally, in the triplet³H−¹⁴C−¹³¹I.     

12-Epinapelline and its N-oxide fromAconitum baicalense

12-Epinapelline and its N-oxide have been isoated from the epigeal part ofAconitum baicalense Turcz. ex Rapaics (A. Czekanovskyi Steinb.). The structures of these compounds have been determined with the aid of two-dimensional¹H and¹³C NMR spectroscopy, and IR and mass spectrometry. Irkutsk Institute of Organic Chemistry, Siberian Branch, Russian Academy of Sciences. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 888–892. November–December, 1993.     

Triterpene glycosides fromTupidanthus calyptratus I. Structure of glycosides B1, B2, F1, and F2 from leaves of hooded tupidanthus

Chromatographically inseparable mixtures of oleanolic and ursolic 3-O-α-L-rhamnopyranosyl-(1→2)-O-α-L-arabinopyranosides (glycosides B₁ and B₂) and their 28-O-α-L-rhamnopyranosyl-(1→4)-O-β-D-glucopyranosyl-(1→6)-O-β-D-glucopyranosyl esters (glycosides F₁ and F₂) are isolated from the leaves ofTupidanthus calyptratus Hook f. (Araliaceae). The structures of the isolated glycosides are established from chemical methods and¹H and¹³C NMR spectra. Glycoside F₂ is a new triterpene glycoside. Simferopol' State University. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 627–633, September–October, 1999.     

Withasteroids of Physalis. IX. Physangulide — The first natural 22S-withasteroid

A new withasteroid — physangulide — has been isolated from the leaves ofPhysalis angulata L. It has been shown that physangulide is the first natural 22S-withanolide. Its structure has been determined as 3β,4β,20,24,25-pentahydroxy-1-oxo-5β,6β-epoxy-20R,22S,24S,25R-withanolide. Its¹H and¹³C NMR spectra, confirming this interpretation, are given. Institute of the Chemistry of Plant Substances, Uzbek SSR Academy of Sciences, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 366–371, May–June, 1990.     

Correlation NMR spectroscopy of 1,1-dichloro-2,3,4,5-tetraphenyl-1-germacyclopenta-2,4-diene

Assignment of all of the signals in the¹H and¹³C NMR spectra of 1,1-dichloro-2,3,4,5-tetraphenyl-l-germacyclopenta-2,4-diene has been carried out using two-dimensional NMR spectroscopy. Translated fromIzvestiya Akademii Nauk Seriya Khimicheskaya, No. 3, pp. 623–625, March, 1997.     

Structural characterization of gentiobiosyl diglycerides fromBacillus pumilus associated with ascidiaHalocynthia aurantium

A mixture of 1(3),2-di-O-acyl-3(1)-O-β-gentiobiosylglycerols was isolated from a sea isolate ofBacillus pumilus. The components of the mixture were structurally characterized by mass spectrometry and¹H and¹³C NMR spectroscopy data for the native compounds and their derivatives. The predominant component contains two C₁₅ acyl groups, while the second component contains C₁₅ and C₁₇ fatty acids. Six minor components differ in residues of fatty acids and/or their combinations. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 1, pp. 166–170, January, 2000.     

Structural characterization of gentiobiosyl diglycerides fromBacillus pumilus associated with ascidiaHalocynthia aurantium

A mixture of 1(3),2-di-O-acyl-3(1)-O-β-gentiobiosylglycerols was isolated from a sea isolate ofBacillus pumilus. The components of the mixture were structurally characterized by mass spectrometry and¹H and¹³C NMR spectroscopy data for the native compounds and their derivatives. The predominant component contains two C₁₅ acyl groups, while the second component contains C₁₅ and C₁₇ fatty acids. Six minor components differ in residues of fatty acids and/or their combinations. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 1, pp. 166–170, January, 2000.     

Stereochemicai study of 7-aryl-1,7,8,8a-tetrahydro-3(2H)indolizinones by1H and13C NMR

Stereochemistry of 7-aryl-1,7,8,8a-tetrahydro-3(2H)-indolizinones was studied by¹H and¹³C NMR. Complete assignment of¹H NMR signals and analysis of¹H-¹H coupling constants were performed using the iterative PANIC program. Values of³ J _6,7,³ J _7,8endo, and⁴ J _5,7 allow one to unambiguously identify the correspondingexo- andendo-stereoisomers. For stereoisomers with exo-orientation of H(7), complete assignment of¹³C NMR signals was performed on the basis of analysis of the¹³C-¹H coupling constants using two dimensional heteronuclear shift-correlating spectroscopy.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 591–593, March, 1996.     

Structure,Spectral Properties,and Complexing Ability of 1-Phenyl-3-methylpyrazol-5-one Ferrocenoyl Hydrazone

A potentially tridentate coordinating chelating ligand system, 1-phenyl-3-methylpyrazol-5-one ferrocenoylhydrazone, has been synthesized. Structure of the obtained ligand and its equilibrium forms in the solution has been elucidated from the data of elemental analysis, IR, electronic absorption and NMR (1H, 13C, and 15N NMR including 1H–1H COSY, 1H–1H NOESY, 1H–13C HSQC, 1H–13C HMBC, and 1H–15N HMBC 2D correlation techniques) spectroscopy as well as quantum chemistry methods. The reactions of 1-phenyl-3-methylpyrazol-5-one ferrocenoylhydrazone with selected transition metal ions have afforded metal chelates, their composition, the mode of coordination, and type of tautomeric form of the coordinated ligand being dependent on the metal nature.     

Alkaloids ofArundo donas VII. A spectroscopic and X-ray structural investigation of arundinine—A new dimeric alkaloid from the epigeal part ofArundo donax

FromArundo donax L. we have isolated the new dimeric alkaloid arundinine, with the composition C₂₃H₂₈N₄O, the structure of which has been established on the basis of its physicochemical characteristics and¹H and¹³C NMR spectroscopy, including 1D and 2D experiments in both homo- and heteronuclear regimes. The proposed structure—3a-(3′-dimethylaminoethylindol-5′-yloxy)-1-methylpyrrolidino[1a,3a-b]indoline — has been confirmed by x-ray structural analysis (XSA). 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. 6, pp. 790–795, November–December, 1998.