Some unusual complexes of iron with 1,10-phenanthroline and 2,2'-bipyridyl

1967 ◽  
Vol 20 (7) ◽  
pp. 1375 ◽  
Author(s):  
R Driver ◽  
WR Walker
Keyword(s):  
Trans Form ◽  
First Time ◽  
Derivatives Of ◽  
Red Form

The following hydroxy-bridged iron(III) complexes have been isolated for the first time : [phen2 Fe(OH)2Fe phen2](SO4)2,7H2O, [phen2 Fe(OH)2Fe phen2]Br4,2H2O, [bipy2 Fe(OH)2Fe bipy2](SO4)2,9H2O. Attempts to prepare thiocyanate derivatives of these complexes resulted unexpectedly in the synthesis of the compounds Fe(SCN)2 phen2,H2O and [FeSCN phen2]ClO4 which were investigated in the light of the well-known complexes of the type FeX2 chelate2. The compound [Fe phen3][Fe(CN)4 phen],5H2O which, except for water, has the same stoicheiometry as Fe(CN)4 phen2, is also described for the first time. The claim by Madeja (Chemicke Zvesti, 1965, 19, 186) that the compound Fe(SCN)2 bipy2 exists both as a red trans form (μeff 3.0 B.M.) and a violet cis form (μeff 5.2 B.M.) is not justified according to this work. It seems that the red form may be a mixture of the paramagnetic bis- and the diamagnetic tris-compounds.

scholarly journals Insight into the Secondary Metabolites of Geum urbanum L. and Geum rivale L. Seeds (Rosaceae)

Plants ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1219
Author(s):  
Marek Bunse ◽  
Peter Lorenz ◽  
Florian C. Stintzing ◽  
Dietmar R. Kammerer
Keyword(s):  
Fatty Acids ◽  
Phenolic Compounds ◽  
Unsaturated Fatty Acids ◽  
Asiatic Acid ◽  
Cosmetic Products ◽  
Nutritional Properties ◽  
First Time ◽  
Derivatives Of ◽  
Geum Urbanum ◽  
Insight Into

The present study aimed at the identification and quantitation of phenolic compounds, fatty acids, and further characteristic substances in the seeds of Geum urbanum L. and Geum rivale L. For this purpose, individual components of extracts recovered with MeOH, CH2Cl2, and by cold-pressing, respectively, were characterized by HPLC-DAD/ESI-MSn and GC/MS and compared with reference compounds. For both Geum species, phenolic compounds, such as flavonoids and gallic acid derivatives, and triterpenes, such as saponins and their aglycones, were detected. Surprisingly, both Geum species revealed the presence of derivatives of the triterpenoid aglycons asiatic acid and madecassic acid, which were characterized for the first time in the genus Geum. Furthermore, the fatty acids of both species were characterized by GC–MS after derivatization. Both species showed a promising fatty-acid profile in terms of nutritional properties because of high proportions of unsaturated fatty acids. Linoleic acid and linolenic acid were most abundant, among other compounds such as palmitic acid and stearic acid. In summary, the present study demonstrates the seeds of G. urbanum and G. rivale to be a valuable source of unsaturated fatty acids and bioactive phenolics, which might be exploited for nutritional and cosmetic products and for phytotherapeutic purposes.

scholarly journals Identification of pigments in artworks by inverse tangent derivative of spectrum and a new filtering method

2020 ◽  
Vol 8 (1) ◽  
Author(s):  
F. Fazlali ◽  
S. Gorji Kandi
Keyword(s):  
Reflectance Spectrum ◽  
Practical Method ◽  
Chemical Methods ◽  
Munk Function ◽  
Absorption Of Light ◽  
Spectrophotometric Data ◽  
First Time ◽  
Non Destructive ◽  
Derivatives Of

Abstract Employing an economical and non-destructive method for identifying pigments utilized in artworks is a significant aspect for preserving their antiquity value. One of the non-destructive methods for this purpose is spectrophotometry, which is based on the selected absorption of light. Mathematical descriptive methods such as derivatives of the reflectance spectrum, the Kubelka–Munk function and logarithm have been employed for the characterization of the peak features corresponding to the spectrophotometric data. In the present study, the mentioned mathematical descriptive methods were investigated with the aim to characterize the constituents of an Iranian artwork but were not efficient for the samples. Therefore, inverse tangent derivative equation was developed on spectral data for the first time, providing considerable details in the profile of reflectance curves. In the next part, to have a simpler and more practical method it was suggested to use filters made up of pure pigments. By using these filters and placing them on the samples, imaging was done. Then, images of samples with and without filter were evaluated and pure pigments were distinguished. The mentioned methods were also used to identify pigments in a modern Iranian painting specimen. The results confirmed these methods with reliable answers indicating that physical methods (alongside chemical methods) can also be effective in determining the types of pigments.

Synthesis of Galactomannan Sulfate-Citrate

2022 ◽  
Vol 1049 ◽  
pp. 218-223
Author(s):  
Aleksandr S. Kazachenko ◽  
Yuriy N. Malyar ◽  
Anna S. Kazachenko
Keyword(s):  
Biological Activity ◽  
Ftir Spectroscopy ◽  
X Ray Diffraction ◽  
Absorption Bands ◽  
X Ray ◽  
Mixed Ester ◽  
First Time ◽  
Derivatives Of

Sulfated derivatives of polysaccharides have anticoagulant, hypolipedimic and other biological activity. In this work, a complex mixed ester of galactomannan, its sulfate-citrate, was obtained for the first time. The introduction of citrate and sulfate groups was proved by FTIR spectroscopy by the appearance of corresponding absorption bands. It was shown by X-ray diffraction that the introduction of the citrate group leads to the amorphization of the galactomannan structure.

scholarly journals Synthetic Derivatives of Natural Alkaloid Harmine

2016 ◽  
Vol 11 (3) ◽  
pp. 199
Author(s):  
N.M. Ismagulova ◽  
Zh.S. Nurmaganbetov ◽  
A.Zh. Turmukhambetov ◽  
T.S. Seitembetov ◽  
S.M. Adekenov
Keyword(s):  
Indole Alkaloid ◽  
Quaternary Ammonium Salts ◽  
Ammonium Salts ◽  
Peganum Harmala ◽  
Underground Part ◽  
X Ray ◽  
Natural Alkaloid ◽  
First Time ◽  
Synthetic Derivatives ◽  
Derivatives Of

The indole alkaloid harmine was extracted from underground part of <em>Peganum harmala L.</em> With the purpose of obtaining the new biological active derivatives on base of alkaloid harmine the chemical modification was carried out. The p-toluolsulfochlorid, p-toluolsulfoacid, hydrochloric, sulfuric, nitric acids, dioxide selenium and phthalic anhydride have been chosen as modifiers. For the first time quaternary ammonium salts, derivatives of N-oxide and N (2)-oxyharminiumphthalate harmine are synthesized. The structure of the synthesized compounds is determined by methods of the spectral analysis and X-ray analysis. Antimicrobic and phagocytosis stimulating activities of isolated alkaloids and their derivatives are investigated.

scholarly journals Trends and Exceptions in the Interaction of Hydroxamic Acid Derivatives of Common Di- and Tripeptides with Some 3d and 4d Metal Ions in Aqueous Solution

Molecules ◽  
2019 ◽  
Vol 24 (21) ◽  
pp. 3941 ◽  
Author(s):  
Ozsváth ◽  
Bíró ◽  
Nagy ◽  
Buglyó ◽  
Sanna ◽  
...  
Keyword(s):  
Metal Ions ◽  
Hydroxamic Acid ◽  
Hydroxamic Acids ◽  
17O Nmr ◽  
Equilibrium Study ◽  
Sandwich Type ◽  
Uv Visible ◽  
First Time ◽  
Derivatives Of ◽  
Half Sandwich

By using various techniques (pH-potentiometry, UV-Visible spectrophotometry, 1H and 17O-NMR, EPR, ESI-MS), first time in the literature, solution equilibrium study has been performed on complexes of dipeptide and tripeptide hydroxamic acids—AlaAlaNHOH, AlaAlaN(Me)OH, AlaGlyGlyNHOH, and AlaGlyGlyN(Me)OH—with 4d metals: the essential Mo(VI) and two half-sandwich type cations, [(η6-p-cym)Ru(H2O)3]2+ as well as [(η5-Cp*)Rh(H2O)3]2+, the latter two having potential importance in cancer therapy. The tripeptide derivatives have also been studied with some biologically important 3d metals, such as Fe(III), Ni(II), Cu(II), and Zn(II), in order to compare these new results with the corresponding previously obtained ones on dipeptide hydroxamic acids. Based on the outcomes, the effects of the type of metal ions, the coordination number, the number and types of donor atoms, and their relative positions to each other on the complexation have been evaluated in the present work. We hope that these collected results might be used when a new peptide-based hydroxamic acid molecule is planned with some purpose, e.g. to develop a potential metalloenzyme inhibitor.

scholarly journals Suppression of Methane Generation during Methanogenesis by Chemically Modified Humic Compounds

Antioxidants ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 1140
Author(s):  
Elena Efremenko ◽  
Olga Senko ◽  
Nikolay Stepanov ◽  
Nikita Mareev ◽  
Alexander Volikov ◽  
...  
Keyword(s):  
Antioxidant Properties ◽  
Nutrient Media ◽  
Potassium Humate ◽  
Methane Generation ◽  
Chemically Modified ◽  
Humic Compounds ◽  
Negative Effect ◽  
The Media ◽  
First Time ◽  
Derivatives Of

The introduction of various concentrations of chemically modified humic compounds (HC) with different redox characteristics into the media with free and immobilized anaerobic consortia accumulating landfill gases was studied as approach to their functioning management. For this purpose, quinone (hydroquinone, naphthoquinone or methylhydroquinone) derivatives of HC were synthesized, which made it possible to vary the redox and antioxidant properties of HC as terminal electron acceptors in methanogenic systems. The highest acceptor properties were obtained with potassium humate modified by naphthoquinone. To control possible negative effect of HC on the cells of natural methanogenic consortia, different bioluminescent analytical methods were used. The addition of HC derivatives, enriched with quinonones, to nutrient media at concentrations above 1 g/L decreased the energetic status of cells and the efficiency of the methanogenesis. For the first time, the significant decrease in accumulation of biogas was reached as effect of synthetic HC derivatives, whereas both notable change of biogas composition towards increase in the CO2 content and decrease in CH4 were revealed. Thus, modification with quinones makes it possible to obtain low-potential HC derivatives with strongly pronounced acceptor properties, promising for inhibition of biogas synthesis by methanogenic communities.

scholarly journals Processing and Stability of Inducibly Expressed rpsO mRNA Derivatives in Bacillus subtilis

2009 ◽  
Vol 191 (18) ◽  
pp. 5680-5689 ◽  
Author(s):  
Shiyi Yao ◽  
David H. Bechhofer
Keyword(s):  
Bacillus Subtilis ◽  
Early Step ◽  
Stem Loop ◽  
Processing Event ◽  
Shine Dalgarno Sequence ◽  
Ribosomal Protein S15 ◽  
High Level ◽  
First Time ◽  
Derivatives Of

ABSTRACT The Bacillus subtilis rpsO gene specifies a small (388-nucleotide), monocistronic mRNA that encodes ribosomal protein S15. We showed earlier that rpsO mRNA decay intermediates accumulated to a high level in a strain lacking polynucleotide phosphorylase. Here, we used inducibly expressed derivatives of rpsO, encoding smaller RNAs that had the complex 5′ region deleted, to study aspects of mRNA processing in B. subtilis. An IPTG (isopropyl-β-d-thiogalactopyranoside)-inducible rpsO transcript that contained lac sequences at the 5′ end, called lac-rpsO RNA, was shown to undergo processing to result in an RNA that was 24 nucleotides shorter than full length. Such processing was dependent on the presence of an accessible 5′ terminus; a lac-rpsO RNA that contained a strong stem-loop at the 5′ end was not processed and was extremely stable. Interestingly, this stability depended also on ribosome binding to a nearby Shine-Dalgarno sequence but was independent of downstream translation. Either RNase J1 or RNase J2 was capable of processing lac-rpsO RNA, demonstrating for the first time a particular in vivo processing event that could be catalyzed by both enzymes. Decay intermediates were detected in the pnpA strain only for a lac-rpsO RNA that was untranslated. Analysis of processing of an untranslated lac-rpsO RNA in the pnpA strain shortly after induction of transcription suggested that endonuclease cleavage at 3′-proximal sites was an early step in turnover of mRNA.

Comprehensive analysis of metabolites in Corynebacterium glutamicum by gas chromatography/mass spectrometry

2004 ◽  
Vol 385 (9) ◽  
pp. 853-861 ◽  
Author(s):  
Sergey Strelkov ◽  
Mirko von Elstermann ◽  
Dietmar Schomburg
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Corynebacterium Glutamicum ◽  
Growth Conditions ◽  
Gas Chromatography Mass Spectrometry ◽  
Fast Method ◽  
Chromatography Mass Spectrometry ◽  
High Matrix ◽  
First Time ◽  
Derivatives Of

AbstractAn analytical method based on gas chromatography/mass spectrometry was developed for metabolome investigation ofCorynebacterium glutamicum. For the first time a fast method for metabolic screening that can be automated is described for this organism. More than 1000 compounds could be detected per experiment, ca. 330 of those showed a peak area significantly above background. Out of these 164 compounds were identified so far, representing derivatives of 121 different metabolites, which were quantified in one sample. In spite of the different chemical nature of metabolites and high matrix content, a measurement reproducibility in the range of 6% error was achieved. The application of this method for the analysis of the adaptation ofC. glutamicumto different growth conditions is demonstrated.

The vibrational spectra (100–1500 cm−1) of a series of bicyclo[3.2.1]octanes assigned by means of scaled 3-21G ab initio harmonic force fields

1993 ◽  
Vol 71 (4) ◽  
pp. 578-609 ◽  
Author(s):  
Thomas Eggimann ◽  
Nan Ibrahim ◽  
R. Anthony Shaw ◽  
Hal Wieser
Keyword(s):  
Ab Initio ◽  
Vibrational Spectra ◽  
Force Fields ◽  
Basis Set ◽  
Average Error ◽  
Field Scale ◽  
Harmonic Force ◽  
First Time ◽  
Derivatives Of ◽  
Phase Spectra

The infrared absorption (vapor phase and solution) and Raman (liquid phase) spectra of bicyclo[3.2.1]octane, 8-oxabicyclo[3.2.1]octane, 6-oxabicyclo[3.2.1]octane, 6,8-dioxabicyclo[3.2.1]octane, and the 7,7-dideutero-substituted derivatives of the last two compounds are reported in the region 100–1500 cm−1 for the first time. The vibrational spectra are assigned almost completely with the guidance of ab initio 3-21G geometries and scaled force fields. A total of 14 force-field scale facors are transferred from smaller molecules, predicting the frequencies with an average error of 7.6 cm−1 (1.2%) for 196 assigned transitions. After optimizing the factors in an overlay refinement involving all six molecules, the frequencies are within 5.7 cm−1 (0.75%) of experiment. The ab initio absorption and Raman intensities are calculated with the 3-21G basis set and are demonstrated to be of such accuracy as to be useful for the spectral assignments. These intensities are calculated with uniformly and nonuniformly scaled force fields and compared to the experimental spectra. The intensities derived from the latter force fields are superior, meaning that nonuniform scaling is preferable at this level of theory for both vibrational frequencies and normal mode descriptions.

scholarly journals Synthesis of 5-arylacetylene 1,2,4-oxadiazoles and their transformations under superelectrophilic activation conditions

2021 ◽  
Author(s):  
Andrey I Puzanov ◽  
Dmitry S Ryabukhin ◽  
Anna S Zalivatskaya ◽  
Dmitriy N Zakusilo ◽  
Darya S Mikson ◽  
...  
Keyword(s):  
Double Bond ◽  
Dft Calculations ◽  
Reaction Mechanisms ◽  
Room Temperature ◽  
Triflic Acid ◽  
Activation Conditions ◽  
First Time ◽  
Vinyl Triflates ◽  
Derivatives Of ◽  
Acetylene Derivatives

Acetylene derivatives of 1,2,4-oxadiazoles, 5-(2-arylethynyl)-3-aryl-1,2,4-oxadiazoles, have been obtained, for the first time, from 5-(2-arylethenyl)-3-aryl-1,2,4-oxadiazoles by their bromination at the carbon-carbon double bond followed by di-dehydrobromination with NaNH2 in liquid NH3.  Reaction of the acetylene 1,2,4-oxadiazoles with arenes in neat triflic acid TfOH (CF3SO3H) at room temperature for 1 h result in the formation of E-/Z-5-(2,2-diarylethenyl)-3-aryl-1,2,4-oxadiazoles as products of regioselective hydroarylation of the acetylene bond. Addition of TfOH to acetylene bond of these oxadiazoles gives rise quantitatively to E-/Z-vinyl triflates. Reaction cationic intermediates have been studied by DFT calculations. The reaction mechanisms have been discussed.

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