Complete assignments of 1H and 13C NMR spectroscopic data for two new triterpenoid saponins from Ilex hainanensis

Two novel unsaturated E-ring pentacyclic triterpenoid saponins, ilexhainanoside A and ilexhainanoside B, were isolated from the leaves of Ilex hainanensis. Their chemical structures were determined by MS, NMR spectroscopy and chemical analysis. Complete assignments of the 1H and 13C NMR spectroscopic data were achieved by 1D and 2D NMR experiments (HSQC, HMBC, ROESY and 1H-1H COSY).     

Preparation and properties of diuridine 3'''',5''''-boranophosphate

Diuridine 3', 5'-boianophosphate has been synthesized. Its diastereomers were separated and their configurations were tentatively assigned based on the selective snake venom phosphodiesterase (SVPDE) hydrolysis. It is found that, compared to the unmodified parent compound diuridine phosphate, the nucleophilicity and the stability of the modified compounds to SVPDE are significantly enhanced.     

Complete assignments of (1)H and (13)C NMR spectroscopic data for two new triterpenoid saponins from Ilex pernyi

Ilexpernoside A and ilexpernoside B, two new pentacyclic C(4)-nortriterpenoid saponins, were isolated from the leaves of Ilex pernyi Franch. Their chemical structures were determined by MS, NMR spectroscopy and chemical analysis. Complete assignments of the (1)H and (13)C NMR spectroscopic data were achieved by 1D and 2D NMR experiments (HSQC, HMBC, (1)H-(1)H COSY and NOESY).     

Complete assignments of 1H and 13C NMR spectroscopic data for three new stigmastane glycosides from Vernonia cumingiana

Three new steroidal saponins, Vernoniosides S1 ( 1 ), Vernoniosides S2 ( 2 ) and Vernoniosides S3 ( 3 ) were isolated from the stem of Vernonia cumingian. Their chemical structures were elucidated on the basis of MS, NMR spectroscopic and chemical analysis. Complete assignment of ¹H and ¹³C NMR spectroscopic data were achieved by 1D and 2D NMR experiments (HMQC, HMBC, ROESY). Copyright © 2008 John Wiley & Sons, Ltd.     

Synthesis and spectroscopic studies of some new metal carbonyl derivatives of 1-(2-pyridylazo)-2-naphthol

Interaction of 1-(2-pyridylazo)-2-naphthol (PAN) with [Mo(CO)₆] in air resulted in formation of the tricarbonyl oxo-complex [Mo(O)(CO)₃(PAN)], 1. The dicarbonyl complex [Ru(CO)₂(PAN)], 3, was obtained from the reaction of [Ru₃(CO)₁₂] with PAN. In presence of triphenyl phosphine (PPh₃), the reaction of PAN with either Mo(CO)₆ or Ru₃(CO)₁₂ gave [Mo(CO)₃(PAN)(PPh₃)], 2, and [Ru(CO)₂(PAN)(PPh₃)], 4. All the complexes were characterized by elemental analysis, mass spectrometry, IR, and NMR spectroscopy. The thermal properties of the complexes were also investigated by thermogravimetry.     

Synthesis,spectroscopic properties,and antimicrobial activity of some new 5-phenylazo-6-aminouracil-vanadyl complexes

Six complexes, [VO(L¹-H)₂]?·?5H₂O (1), [VO(OH)(L^2,3?H)(H₂O)]?·?H₂O (2,3), [VO(OH)(L^4,5?H)(H₂O)]?·?H₂O (4,5), [VO(OH)(L⁶?H)(H₂O)]?·?H₂O (6), were prepared by reacting different derivatives of 5-phenylazo-6-aminouracil ligands with VOSO₄?·?5H₂O. The infrared and ¹H NMR spectra of the complexes have been assigned. Thermogravimetric analyses (TG, DTG) were also carried out. The data agree quite well with the proposed structures and show that the complexes were finally decomposed to the corresponding divanadium pentoxide. The ligands and their vanadyl complexes were screened for antimicrobial activities by the agar-well diffusion technique using DMSO as solvent. The minimum inhibitory concentration (MIC) values for 1–4 and 6 were calculated at 30°C for 24–48?h. The activity data show that the complexes are more potent antimicrobials than the parent ligands.     

1H and 13C NMR studies of 2-functionalized 5-(methylsulfonyl)-1-phenyl-1H-indoles

The 1H and 13C NMR resonances of thirty 2-functionalized 5-(methylsulfonyl)-1-phenyl-1H-indoles were assigned completely and unequivocally using the concerted application of one- and two-dimensional experiments (DEPT, gs-HMQC and gs-HMBC). Finally, the influence of the 2-substituent of 5-(methylsufonyl)-1-phenyl-1H-indoles on the carbon atoms of the indole moiety was estimated.     

Synthesis,crystal structures and spectroscopic properties of dichloroethylphenyltin(IV) and its phenanthroline adduct

The reaction of dichloroethylphenyltin(IV), Ph(Et)SnCl₂, with phenanthroline monohydrate (phen·H₂O) in chloroform, in 1:1 mole ratio, afforded [Ph(Et)SnCl₂(phen)]. The crystal structures of dichloroethylphenyltin(IV) and its phenanthroline adduct were studied by X‐ray diffraction. In Ph(Et)SnCl₂ the tin atom is in a distorted tetrahedral environment, the distortion probably being imposed by weak intermolecular Sn· · ·Cl interactions. In [Ph(Et)SnCl₂(phen)] the tin atom is in an octahedral trans‐C₂, cis‐Cl₂, N₂ environment and weak intermolecular C–H· · ·Cl interactions connect the molecules throughout the lattice. Spectroscopic studies in solution (¹H, ¹³C and ¹¹⁹Sn NMR) were also carried out; the ¹H and ¹³C NMR data in dimethylsulfoxide suggest that [Ph(Et)SnCl₂(phen)] remains at least partially undissociated in this solvent. Copyright © 2003 John Wiley & Sons, Ltd.     

Synthesis and spectroscopic study of hexadecaalkyl-substituted rare-earth diphthalocyanines

New hexadecaalkyl-substituted diphthalocyanine complexes of lanthanides ^RPc₂Ln (R = Et, or Bu; Ln = Lu, Dy, or Eu) were synthesized by three methods: in solution in the presence of 1,8-diazabicyclo[5.4.0]undec-7-ene, in a melt of a mixture of the reagents, and under microwave irradiation. The first of the above-mentioned procedures has an advantage for the preparation of Dy and Eu diphthalocyanines, whereas the melt synthesis is a method of choice for the preparation of Lu complexes. The reaction time decreases in going from the first to the third method. The structures of the complexes were confirmed by mass spectrometry, NMR spectroscopy, and electronic absorption spectroscopy.     

1H, 13C and 15N NMR assignments for N6‐isopentenyladenosine/inosine analogues

The complete ¹H, ¹³C and ¹⁵N NMR signals assignments of some new isopentenyladenosine analogues were achieved using one‐ and two‐dimensional experiments (gs‐NOESY, gs‐HMQC and gs‐HMBC). Copyright © 2010 John Wiley & Sons, Ltd.     

Hydrogen bonding in 2-hydroxybenzoyl and 2-hydroxythiobenzoyl compounds: Spectroscopic characterization and spectroscopic bond strength sequences

Summary A survey of IR and NMR spectroscopic data is given for 30 2-hydroxybenzoyl and 2-hydroxy-thiobenzoyl compounds, which are representative for various kinds of (thio)carbonyl groups. The data shall provide a basis for a comparison between corresponding intramolecular O-H··O and O-H··S hydrogen bonds and for the evaluation of systematic dependencies. Correlations between v_OH frequencies, which are considered as the main characteristic of hydrogen bond strengths, and several other spectroscopic quantities are shown. For O-H··O type associations the bond strength sequence is acid chloridesOH-Frequenzen, die als wesentliches Kriterium zur Charakterisierung der Bindungsstärken herangezogen werden, und verschiedenen anderen spektroskopischen Daten werden gezeigt. Bei den Wasserstoffbrückenbindungen des Typs O-H··O nehmen die Bindungsstärken in der Reihenfolge SäurechlorideCO-Frequenzen. Die auffällige Sonderstellung der tertiären Amide ist auf sterische Effekte zurückzuführen. Die v_OH-Frequenzen der O-H··S Wasserstoffbrückenbindungen sind denen der entsprechenden O-H··O Bindungen sehr ähnlich, ausgenommen Thiosäuren und Thioester, für die wesentlich niedrigere Frequenzen gefunden wurden.     

Hydrogen bonding in 2-hydroxybenzoic, 2-hydroxythiobenzoic,and 2-hydroxydithiobenzoic acid. A structural and spectroscopic study

Summary X-ray structural data are reported for 2-hydroxythiobenzoic acid (T=200 K;P2₁/a;a=14.903(5) Å,b=5.203(3) Å,c=9.114(6) Å, =92.40(4)°;Z=4;R=0.049) and 2-hydroxydithiobenzoic acid (T=297 K;P2₁/a;a=14.416(3) Å,b=13.447(3) Å,c=3.947(1) Å, =90.96(2)°;Z=4;R=0.047). In 2-hydroxythiobenzoic acid, each two molecules form cyclic dimersvia S-H...O=C hydrogen bonds, analogous to the association pattern of 2-hydroxybenzoic acid. In 2-hydroxydithiobenzoic acid, the molecules are linked to chains by S-H...O(H)-C hydrogen bonds. Solid state IR, and solution IR and NMR spectroscopic data of 2-hydroxybenzoic acid, 2-hydroxythiobenzoic acid, and 2-hydroxydithiobenzoic acid are summarized. The main characteristics of the intramolecularly associated phenolic O-H groups of the three title compounds are for the solids, for solutions (CCl₄), and _OH=10.21, 10.53, 12.20 ppm for solutions (CCl₄:CDCl₃=5:1).Dedicated to Prof.O. Olaj on the occasion of his 60^th birthday     

Structural determination of atricins A and B, new triterpenes from Perovskia atriplicifolia, by 1D and 2D NMR spectroscopy

Atricins A (1) and B (2), two new oleanane-type triterpenes have been isolated from the chloroform-soluble fractions of Perovskia atriplicifolia and their structures assigned from (1)H and (13)C-NMR spectra, Distortion Enhancement by Polarization Trasfer (DEPT) and by 2D-COSY, HMQC, Nuclear Overhauser Enhancement Spectroscopy (NOESY) and Hetronuclear mutiple-bond correlation (HMBC) experiments.     

Magnesium Hexafluoridozirconates MgZrF6·5H2O,MgZrF6·2H2O,and MgZrF6: Structures,Phase Transitions,and Internal Mobility of Water Molecules

The MgZrF₆ · n H₂O (n = 5, 2 and 0) compounds were studied by the methods of X‐ray diffraction and ¹⁹F, MAS ¹⁹F, and ¹H NMR spectroscopy. At room temperature, the compound MgZrF₆ · 5H₂O has a monoclinic C‐centered unit cell and is composed of isolated chains of edge‐sharing ZrF₈ dodecahedra reinforced with MgF₂(H₂O)₄ octahedra and uncoordinated H₂O molecules and characterized by a disordered system of hydrogen bonds. In the temperature range 259 to 255 K, a reversible monoclinic ? two‐domain triclinic phase transition is observed. The phase transition is accompanied with ordering of hydrogen atoms positions and the system of hydrogen bonds. The structure of MgZrF₆ · 2H₂O comprises a three‐dimensional framework consisting of chains of edge‐sharing ZrF₈ dodecahedra linked to each other through MgF₄(H₂O)₂ octahedra. The compound MgZrF₆ belongs to the NaSbF₆ type and is built from regular ZrF₆ and MgF₆ octahedra linked into a three‐dimensional framework through linear Zr–F–Mg bridges. The peaks in ¹⁹F MAS spectra were attributed to the fluorine structural positions. The motions of structural water molecules were studied by variable‐temperature ¹H NMR spectroscopy.     

One‐step synthesis of 6‐acetamido‐3‐(N‐(2‐(dimethylamino) ethyl) sulfamoyl) naphthalene‐1‐yl 7‐acetamido‐4‐hydroxynaphthalene‐2‐sulfonate and its characterization with 1D and 2D NMR techniques

A one‐step method was reported for the synthesis of 6‐acetamido‐3‐(N‐(2‐(dimethylamino) ethyl) sulfamoyl) naphthalene‐1‐yl 7‐acetamido‐4‐hydroxynaphthalene‐2‐sulfonate by treating 7‐acetamido‐4‐hydroxy‐2‐naphthalenesulfonyl chloride with equal moles of N, N‐dimethylethylenediamine in acetonitrile in the presence of K₂CO₃. The chemical structure of the obtained compounds was characterized by MS, FTIR, ¹H NMR, ¹³C NMR, gCOSY, TOCSY, gHSQC, and gHMBC. The chemical shift differences of ¹H and ¹³C being δ 0.04 and 0.2, respectively, were unambiguously differentiated. Copyright © 2013 John Wiley & Sons, Ltd.     

NMR spectroscopic characterization of new 2,3‐dihydro‐1,3,4‐thiadiazole derivatives

The ¹H and ¹³C NMR resonances of twenty‐seven 2,2‐dimethyl‐5‐(2‐nitrophenyl‐5‐substituted)‐2,3‐dihydro‐1,3,4‐thiadiazoles, and twenty‐seven 3‐acyl‐5‐(2‐amino‐5‐substituted)‐2,2‐dimethyl‐2,3‐dihydro‐1,3,4‐thiadiazoles were assigned completely using the concerted application of one‐dimensional and two‐dimensional experiments (DEPT, HMQC and HMBC). NOESY experiments, X‐ray crystallography and conformational analysis confirm the preferred conformation of these compounds. Copyright © 2012 John Wiley & Sons, Ltd.     

1H and 13C NMR spectral assignments of 2′‐hydroxychalcones

Chalcones are of interest to medicinal chemists because their structures can be easily modified with various functional groups. The syntheses and biological activities of chalcones from natural sources are well known. In this study, 24 2′‐hydroxychalcones bearing methoxy substituents were synthesized, among which five are new. The NMR data for all synthesized chalcones are described for the first time. The complete assignments of the ¹H and ¹³C NMR data can be used for the identification of newly discovered and widely isolated, synthesized chalcones. Copyright © 2013 John Wiley & Sons, Ltd.     

Selective synthesis and spectroscopic properties of alkyl-substituted lanthanide(<Emphasis Type="SmallCaps">III</Emphasis>) mono-, di-, and triphthalocyanines

Methods for the selective synthesis of mono-(^RPcLnOAc), di-(^RPc₂Ln), and triphthalocyanines (^RPc₃Ln₂) of rare-earth metals (Ln = Lu, Er, Eu) from symmetrically substituted 2,3,9,10,16,17,23,24-octaalkylphthalocyanines ^RPcH₂ (R = Et, Bu) were developed. The synthesized complexes were characterized by NMR spectroscopy, mass spectrometry, and electronic absorption spectra. The conditions for ¹H NMR spectra recording were optimized. Regularities in changing the spectral properties of the synthesized compounds, depending on the lanthanide nature and the planarity of metal phthalocyanine complexes, were found. tom@org.chem.msu.su Dedicated to Academician A. L. Buchachenko on the occasion of his 70th birthday. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 2024–2030, September, 2005.     

Structural determination of aspericins A?C,new furan and pyran derivates from the marine‐derived fungus Rhizopus sp. 2‐PDA‐61, by 1D and 2D NMR spectroscopy

Three new furan and pyran derivatives named aspericins A? C (1–3), as well as a known asperic acid (4), have been isolated from the marine‐derived fungus Rhizopus sp. 2‐PDA‐61. The complete ¹H and ¹³C NMR assignments for the new compounds were carried out using ¹H, ¹³C, DEPT, COSY, HMQC, HMBC, and NOESY NMR experiments. Compounds 1–3 were evaluated for their cytotoxic activities on P388, A549, HL‐60, and BEL‐7420 cell lines by the MTT and SRB methods. Copyright © 2009 John Wiley & Sons, Ltd.     

Synthesis, structures and spectroscopic properties of platinum complexes containing orthometalated 2-phenylpyridine

The synthesis, structure and spectroscopy of a series of luminescent orthometalated square planar platinum(II) complexes are reported. Reaction of K₂PtCl₄ with one mole equivalent of 2-phenylpyridine (ppyH) in 2-ethoxyethanol and water (1:1 ratio) resulted in the formation of chloro-bridged dimeric precursor [Pt₂(μ-Cl)₂(ppy)₂], which on further reactions with various anionic one-, two- and three-atom ancillary ligands, having O/N/S donors, yielded mono- and bi-nuclear platinum(II) complexes. Platinum(III) complexes of composition [Pt₂Cl₂(μ-Epy)₂(ppy)₂] have been isolated with pyE⁻ (E = O or S) ligands. These complexes have been characterized by elemental analysis, NMR (¹H, ³¹P, ¹⁹⁵Pt) and absorption spectroscopy. The complexes [Pt₂(μ-N^∩N)₂(ppy)₂] (N^∩N = pyrazole and 3,5-dimethylpyrazole); [Pt(S^∩S)(ppy)] (S^∩S = ethylxanthate and diisopropyldithiophosphate); [Pt₂Cl₂(μ-Epy)₂(ppy)₂] (Epy = 2-pyridinol {Opy} and 2-mercaptopyridine {Spy}) and [PtCl(ppy)(PhNC(Me)NHPh)] have been structurally characterized by X-ray crystallography.