Synthesis,characterization and anticancer activity of a series of curcuminoids and their half‐sandwich ruthenium(II) complexes

A series of curcuminoids (L¹–L⁷) and their corresponding (η⁶‐p ‐cymene)Ru^II(Cur)Cl complexes ( 1 – 7 ) were synthesized and characterized using ¹H NMR spectroscopy, elemental analysis and high‐resolution electrospray ionization mass spectrometry. The molecular structures of L², L⁴, 1 and 4 were determined using single‐crystal X‐ray diffraction analysis. The stability of 1 – 7 was investigated by monitoring their UV profiles. The compounds were further evaluated for their in vitro antiproliferative activities against the HepG2 human liver and HeLa human cervical cancer cell lines and HEK‐293 T noncancerous cell line.     

Synthesis,characterization, and biological screening of metal complexes of novel sulfonamide derivatives: Experimental and theoretical analysis of sulfonamide crystal

This study reports the synthesis of sulfonamide-derived Schiff bases as ligands L ¹ and L ² as well as their transition metal complexes [VO(IV), Fe(II), Co(II), Ni(II), Cu(II), and Zn(II)]. The Schiff bases (4-{E-[(2-hydroxy-3-methoxyphenyl)methylidene]amino}benzene-1-sulfonamide ( L ¹ ) and 4-{[(2-hydroxy-3-methoxyphenyl)methylidene]amino}-N-(5-methyl-1,2-oxazol-3-yl)benzene-1-sulfonamide ( L ² ) were synthesized by the condensation reaction of 4-aminobenzene-1-sulfonamide and 4-amino-N-(3-methyl-2,3-dihydro-1,2-oxazol-5-yl)benzene-1-sulfonamide with 2-hydroxy-3-methoxybenzaldehyde in an equimolar ratio. Sulfonamide core ligands behaved as bidentate ligands and coordinated with transition metals via nitrogen of azomethine and the oxygen of the hydroxyl group. Ligand L ¹ was recovered in its crystalline form and was analyzed by single-crystal X-ray diffraction technique which held monoclinic crystal system with space group (P2₁/c). The structures of the ligands L ¹ and L ² and their transition metal complexes were established by their physical (melting point, color, yields, solubility, magnetic susceptibility, and conductance measurements), spectral (UV–visible [UV–Vis], Fourier transform infrared spectroscopy, ¹H NMR, ¹³C NMR, and mass analysis), and analytical (CHN analysis) techniques. Furthermore, computational analysis (vibrational bands, frontier molecular orbitals (FMOs), and natural bonding orbitals [NBOs]) were performed for ligands through density functional theory utilizing B3LYP/6-311+G(d,p) level and UV–Vis analysis was carried out by time-dependent density functional theory. Theoretical spectroscopic data were in line with the experimental spectroscopic data. NBO analysis confirmed the extraordinary stability of the ligands in their conjugative interactions. Global reactivity parameters computed from the FMO energies indicated the ligands were bioactive by nature. These procedures ensured the charge transfer phenomenon for the ligands and reasonable relevance was established with experimental results. The synthesized compounds were screened for antimicrobial activities against bacterial (Streptococcus aureus, Bacillus subtilis, Eshcheria coli, and Klebsiella pneomoniae) species and fungal (Aspergillus niger and Aspergillus flavous) strains. A further assay was designed for screening of their antioxidant activities (2,2-diphenyl-1-picrylhydrazine radical scavenging activity, total phenolic contents, and total iron reducing power) and enzyme inhibition properties (amylase, protease, acetylcholinesterase, and butyrylcholinesterase). The substantial results of these activities proved the ligands and their transition metal complexes to be bioactive in their nature.     

Chemically bonded multiwalled carbon nanotubes as efficient material for solid phase extraction of some metal ions in food samples

Multiwalled carbon nanotubes chemically functionalized with 2-((3-silylpropylimino) methyl) phenol (SPIMP-MWCNT) and successfully applied for the solid phase extraction (SPE) of some metal ions in food samples. The influences of the analytical parameters including pH, amounts of solid phase, eluent conditions (type, volume and concentrations), sample volume and interference of some metal ions on the recoveries of ions Cu²⁺, Pb²⁺, Fe²⁺, Ni²⁺ and Zn²⁺ ion were investigated. The metal ions retained on SPIMP-MWCNT was eluted using 6?mL of 4?mol?L^?1 HNO₃ solution and their content was determined by flame atomic absorption spectrometry (FAAS) with recoveries more than 95% and relative standard deviations (n?=?5) between 2.4–3.4% for both reproducibility and repeatability. The detection limit of this metal ions was between 1.0–2.6?ng?mL^?1 (3S _b , n?=?10) and their preconcentration factor was 100, while their loading capacity was above 32.9?mg?g^?1 of SPIMP-MWCNT. The proposed method was successfully applied for the preconcentration and determination of analytes in different samples.     

Evaluation of methane negative ion chemical ionization mass spectra of polycyclic aromatic hydrocarbons and related compounds

Negative ion chemical ionization (NICI) mass spectra with methane as reagent gas and the ion abundance ratios of the negative to the positive base peak for 51 polycyclic aromatic hydrocarbons and related compounds were measured and evaluated for highly sensitive detection and isomer differentiation. Either [M ? H]^?, M^?˙ or MH^? was the base peak, except for one compound with [M ? H₂]^?˙ as its base peak. The numbers of compounds with [M ? H]^?, M^?˙ or MH^? as their base peaks were 17, 26 and 7, respectively. Many of the compounds with [M ? H]^? as the base peak had an aliphatic part in their structure. The average value of N/P (negative/positive ion abundance ratio at the base peaks) was < 1. Many of the compounds with M^?˙ as the base peak had a relatively high electron affinity. A correlation between electron affinities and ion abundances was found. In most cases, the N/P ratios were > 1, and even reached 400 in benzo [a] pyrene. Many of the compounds with MH^? as their base peaks had a phenyl group, in which cases the N/P ratios were < 1. In the case of compounds with 18 or fewer carbon atoms, in particular, it was easy to distinguish isomers by comparing their NICI mass spectra. The N/P values served as a guideline in sensitive detection. Nine compounds achieved an N/P of ≥50.     

On triazoles. V. Synthesis of 1- and 2-R1-3-R2,R3-amino-5-amino-1,2,4-triazoles

The correct isomeric and tautomeric structure of different 1- and 2-R¹-3-R²,R³-amino-5-amino-1,2,4-triazole derivatives prepared from the corresponding N-cyano-N'-R²,R³-S-methyl-isothioureas and the corresponding hydrazines was proved with the help of their ir, uv, ¹H-nmr and ¹³C-nmr spectra as well as the uv spectra of the Schiff bases of an isomeric pair.     

Spectrophotometric investigation of trace copper and silver complexes with a new chromogenic ligand,o-methylbenzenediazoaminobenzene-p-azobenzene

The synthesis of o-methylbenzenediazoaminobenzene-p-azobenzene (o-MDAP) was made. At pH 12, copper and silver formed a sensitive complex with o-MDAP. The characteristics of copper and silver complexes have been determined. The results showed that the formed complexes were Cu(o-MDAP)2 and Ag(o-MDAP), respectively. Their true molar absorptivities were equal to ε = 7.79 x 10⁴ L mol^-1 cm^-1 at 510 nm and 2.21 x 10⁴ L mol^-1 cm^-1, and their overall stability constants were K = 3.41 x 10⁹ and 1.80 x 10⁴ respectively. The precision of copper and silver determinations was 2.3% and 3.1%, respectively.     

A Pd(II) complex of a β-cyclodextrin-based polydentate ligand: an efficient catalyst for the Suzuki reaction in aqueous media

Molecular assembly has become a promising strategy for designing new polydentate ligands. But very often such ligands and their complexes are sparingly soluble in aqueous phase due to their intrinsic hydrophobic character. Pd(II) complexes are good homogeneous catalysts but their poor solubility in aqueous phase may limit their catalytic efficacy in the universal green solvent water. However, solubility related challenges especially in aqueous phase can be mitigated through the formation of inclusion complexes by exploiting the hydrophobic nature of the β-cyclodextrin (β-CD) cavity. Hence, an ionic liquid ChCD (1) was synthesized from β-CD and Choline bromide (ChBr). Next a supramolecular N, N^′, O-tridentate ligand 1?2 (3) was synthesized by the inclusion of 2,6-diaminopyridine (2) in the hydrophobic β-CD cavity of the ionic liquid ChCD (1) and was well characterized by elemental analysis, UV-visible, FTIR, ¹H NMR spectroscopy, etc. The stoichiometry of the inclusion complex 1?2 (3) was found to be 1:1 based on UV-visible spectrophotometric study. A new air stable, highly water soluble Pd²⁺-complex [κ³-N, N^′, O-Pd(1?2)H₂O]OAc (4) was then synthesized from the supramolecular ligand (3) with 1:1 stoichiometry and used as a catalyst for Suzuki cross-coupling reactions in water at ambient temperature with good to excellent yields. The catalyst can be removed and recycled. Additionally, the use of non-toxic solvent water makes the methodology green, sustainable, and economically viable.     

Photocatalytic production of hydrogen in systems based on Cd<Subscript><Emphasis Type="Italic">x</Emphasis></Subscript>Zn<Subscript>1–<Emphasis Type="Italic">x</Emphasis></Subscript>S/Ni<Superscript>0</Superscript> nanostructures

A relation was established between the composition of Cd _x Zn_1–x S nanoparticles and their ability to accumulate excess negative charge during irradiation. The rate of expenditure of the accumulated charge depends on the composition of the nanoparticles and is determined by their electric capacitance. A correlation was found between the photocatalytic activity of the Cd _x Zn_1–x S nanoparticles in the release of hydrogen from solutions of Na₂SO₃, their composition, and their capacity for photoinduced accumulation of excess charge. It was shown that Ni⁰ nanoparticles photodeposited on the surface of Cd _x Zn_1–x S are effective cocatalysts for the release of hydrogen. It was found that Zn^II additions in photocatalytic systems based on Cd _x Zn_1–x S/Ni⁰ nanostructures have a promoting action on the release of hydrogen from water–ethanol mixtures. Translated from Teoreticheskaya i éksperimental’naya Khimiya, Vol. 45, No. 1, pp. 8–16, January-February, 2009.     

Synthesis,spectroscopic characterization,thermal behaviour,in vitro antimicrobial and anticancer activities of novel ruthenium tricarbonyl complexes containing monodentate V‐shaped Schiff bases

The interaction of Ru₃(CO)₁₂ with a novel family of monodentate V‐shaped Schiff base ligands (L^1–4; L¹: (E)‐1‐(4‐((4‐bromobenzylidene)amino)phenyl)ethanone, L²: (E)‐1‐(3‐(4‐(dimethylamino)benzylideneamino)phenyl)ethanone, L³: (E)‐1‐(4‐(4‐(dimethylamino)benzylideneamino)phenyl)ethanone, L⁴: (E)‐1‐(3‐(3,4‐dimethoxybenzylideneamino)phenyl)ethanone) in air under atmospheric pressure afforded the novel complexes [Ru(CO)₃(L^1–4)₂]. The parent ligands and their complexes were characterized using elemental analyses and spectroscopic techniques. In addition, the structure of the representative ligand L¹ was determined using single‐crystal X‐ray analysis. The stereochemistry and theoretical optimization of the three‐dimensional geometry of the ligands and their complexes were justified. In vitro antimicrobial screening against bacterial stains Escherichia coli and Staphylococcus aureus and fungus Candida albicans was conducted. Cytotoxicity of the compounds as anti‐tumour agents was evaluated against liver carcinoma (HepG2), breast carcinoma (MCF7) and colon carcinoma (HCT‐116) cell lines relative to cisplatin and doxorubicin. The complexes showed variable in vitro cytotoxic activities against the three studied cell lines, with IC₅₀ values less than those of cis‐platin, and thus appear to be building blocks for promising anti‐tumour agents.     

Assignment of indirect 13C, 1H couplings in the 13C NMR spectra of some purine and pyrimidine nucleosides and their analogues by long-range selective 1H decoupling

The assignments of the long-range ¹³C, ¹H coupling constants in the ¹³C NMR spectra of the base moieties of several purine and pyrimidine nucleosides and their analogues were established by the application of long-range selective ¹H decoupling with low-power ¹H irradiation. The ³J values between the carbons and protons of the pyrimidine ring in these compounds were larger than the ²J values. The conformational preference of these nucleosides in solution was shown to be predominantly anti from the value of the vicinal ¹³C, ¹H coupling constants between H-1′ and the base carbons through the glycosidic bond.     

Cationic surfmers with benzyl groups: Synthesis and copolymerization with acrylamide

A series of cationic surfmers with benzyl groups（QARBCs）with different R groups on the benzene ring were synthesized and characterized by IR,¹H-NMR,¹³C-NMR.The aggregation of QARBCs was studied by the steady-state fluorescence technique.It turned out that QARBCs had surface activity and their critical micelle concentration（CMC）values varied in the range of 10^-2—10^-3mol/L with slight increase with temperature.The copolymerization of acrylamide（M₁）and QARBCs（M₂）was studied below and above CMC,their reactivity ratios were determined by the Finemann-Ross method.It was found that below CMC,copolymerization took place in a homogeneous system and reactivity ratios of acrylamide and QARBCs were less than 1;while above CMC,reactivity ratios of QARBCs were greater than 1.The copolymerization mechanism of QARBC was observed to be similar to that of micellar polymerization.QARBCs tended to homopolymerization,which gave rise to micro-blocky sequences in the polymer backbone.The Q and e values of QARBCs were calculated according to the Alfrey-Price equation by using r_1（AM）and r_2（qarBC）.Samples of poly（AM-co-QARBC） were prepared above and below CMC and their hydrophobic associations were studied by the steady-state fluorescence spectra and 2D NOESY spectra,and their critical associating concentrations（CAC）were estimated.The results showed that samples of poly（AM-co-QARBC）prepared above CMC had stronger hydrophobic association in aqueous solution than those prepared below CMC.     

New Cell Growth-Inhibitory Cyclohexadienone Derivatives from Hypericum calycinum L.

The crude petroleum-ether extract of the aerial parts of Hypericum calycinum L. (Guttiferae) exhibited in vitro growth-inhibitory activity against the Co-115 human colon carcinoma cell line. Bioassay-guided fractionation of this extract allowed the isolation of the cyclohexadienone derivatives 1–5 , four of which are previously undescribed compounds. The structures of the known chinesin II (1) and of 2 (hypercalin A) were established by ¹H- and ¹³C-NMR spectroscopy and were confirmed by X-ray analysis of their crystalline mixture which revealed the complete relative configuration of both compounds. The structure of 3 (hypercalin B) was elucidated by means of extensive 1D- and 2D-NMR experiments, including DQ-COSY, HETCOR and LR-HETCOR. The structure of compound 4 (hypercalin C) was established by ¹H- and ¹³C-NMR spectroscopy and confirmed by X-ray analysis to be the 3,5-dihydroxy-4-{[(1R*,2S*, 5S*)-2-hydroxy-2-methyl-5-(1-methylethenyl)cyclopentyl]methyl}-6,6-bis-(3-methylbut-2-enyl)-2-(2-methylpropanoyl)cyclohexa-2,4-dien-1-one. The structures of the higher isomeric homologues 5a/5b were deduced by comparison of their UV, ¹H-, and ¹³C-NMR spectra with those of 4 . The isolated compounds appeared to be related to chinesin I and II previously isolated from Hypericum chinense L. and were responsible for the growth-inhibitory activity of the extract against the Co-115 human carcinoma cell line. Moreover, 1/2 and 3 showed molluscicidal activity against the schistosomiasis-transmitting snail Biomphalaria glabrata.     

Studies of C. I. Acid Red 186 and Metal Complexes with Uo++2, Ce3+ and Th6+ Ions

The electronic absorption spectra of C. I. Acid Red 186 are studied in solution of different pH. The pK values of the acid-base equilibria set are determined and commented upon. The complexes of UO⁺⁺₂, Ce³⁺ and Th⁴⁺ ions are investigated by some spectroscopic techniques and potentiometric titration. The formation of 1:1, 1:2 and 1:2 complexes (M:L) with UO₂⁺⁺, Ce³⁺ and Th⁴⁺ respectively is confirmed and their conditional stability constants are determined. The solid complexes are prepared and analysed for their metal content, their ir spectra are disussed in comparison to that of the ligand to establish the bonding between the ligand and metal ions.     

Reactions of 1-bromo-1-nitro-3,3,3-trichloropropene with <Emphasis Type="Italic">O</Emphasis>- and <Emphasis Type="Italic">N</Emphasis>-nucleophiles

Reactions of 1-bromo-1-nitro-3,3,3-trichloropropene with alcohols, benzidine and o-, m-, and p-phenylenediamines was investigated and the reaction conditions were developed. The alkoxylation and amination products and an unusual nitrogen-containing bis-aziridine were obtained; their structures were characterized by the spectral (IR, ¹H, ¹³C NMR, HMQC, and HMBC) methods.     

A new lignan with hypoglycemic activity from Tadehagi triquetrum

A new lignan named tadehaginosin, together with a known compound 3,4-dihydro-4-(4′-hydroxyphenyl)-5,7-dihydroxycoumarin, was isolated from the aerial part of Tadehagi triquetrum. The new structure was determined by various spectroscopic techniques (¹H and ¹³C APT, HSQC, HMBC, ¹H–¹HCOSY, NOESY and HR-ESI-MS). The two isolates were evaluated for their hypoglycemic effects in vitro. Biological investigation showed that both of them possessed the capability to increase glucose consumption by HepG2 cells.     

Metal Complexes of 1-Allenylimidazoles

Monomeric complexes ML _n X _m , where M = Co^{2 +}, Ni^{2 +}, Zn^{2 +}, Cd^{2 +}, Cu^{2 +}, Pd^{2 +}, Sn^{4 +}; L = 1-allenylimidazole, 1-allenyl-2-methylimidazole, 1-allenylbenzimidazole; n = 2, 4; m = 1, 2, 4; X = Cl, OCOCH3, was prepared for the first time, and their structure was studied by NMR and IR spectroscopy. In the complexes, 1-allenylimidazoles act as monodentate ligands coordinating via the heteroring ^N3atom, and the CH2 = C = CH group is stabilized by coordination of the azolyl ring with the metal, which hinders elec- tron transfer from the heteroring to the allenyl fragment. The prospective use of the complexes of Zn(OCOCH3)2 with 1-allenyl imidazole derivatives as antidotes and antihypoxants was demonstrated.     

Synthesis of 2H-pyrano[2,3-b]quinolines. Part II. Preparation and 1H-nmr investigations of 4-hydroxy-2-methyl-3,4-dihydro-2H-pyrano[2,3-b]quinolines

Diastereoisomers of 4-hydroxy-2-methyl-3,4-dihydro-2H-pyrano[2,3-b]quinolines 8 and 9 were synthesized starting from the appropriate 2-chloroquinoline-3-carboxaldehydes 1. The relative configuration of the 1,3-diol intermediates 4 and 5 was determined on the basis of the ¹³C-nmr spectra of their acetonides. The relative stereochemistry of title compounds was confirmed by using homonuclear NOE and selective decoupling experiments, as well as by analysis of the coupling patterns observed in their ¹H-nmr spectra.     

Synthesis,characterization and biological studies of oxovanadium(IV) complexes with triazole‐derived Schiff bases

A series of triazole‐derived Schiff bases (L¹–L⁵) and their oxovanadium(IV) complexes have been synthesized. The chemical structures of Schiff bases were characterized by their analytical (CHN analysis) and spectral (IR, ¹H and ¹³C NMR and mass spectrometry) data, and oxovanadium(IV) complexes were elucidated by their physical (magnetic susceptibility and conductivity), analytical (CHN analysis), conductance measurements and electronic spectral data. The molar conductivity data indicate the oxovanadium(IV) complexes to be non‐electrolyte. The Schiff bases act as bidentate and coordinate with the oxovanadium(IV)‐forming stoichiometry of a complex as [M (L‐H)₂] where M = VO and L = L¹–L⁵ in a square‐pyramidal geometry. The agar well diffusion method was used for in vitro antibacterial screening against E. coli, S. flexenari, P. aeruginosa, S. typhi, S. aureus and B. subtilis and for antifungal activity against T. longifucus, C. albican, A. flavus, M. canis, F. solani and C. glaberata. The biological activity data show the oxovanadium(IV) complexes to be more antibacterial and antifungal than the parent Schiff bases against one or more bacterial and fungal strains. Copyright © 2009 John Wiley & Sons, Ltd.     

Effect of copper and manganese ions on activities of laccase and peroxidases in three Pleurotus species grown on agricultural wastes

Copper (Cu²⁺) and manganese (Mn²⁺) ions influenced laccase (Lac) and peroxidase production in Pleurotus eryngii, Pleurotus ostreatus, and Pleurotus pulmonarius. In P. eryngii, the optimum Cu²⁺ concentration for Lac production was 1 mM and for peroxidases 10mM, and Mn²⁺ concentration of 5mM led to peaks of Lac and peroxidase activity. In P. ostreatus HAI 493, the highest level of Lac activity was at Cu²⁺ concentrations of 1 and 10 mM and Mn²⁺ concentration of 1mM, respectively. The absence of Cu²⁺ and Mn²⁺ caused the highest levels of peroxidase production. In P. ostreatus HAI 494, the highest level of Lac activity was at a Cu²⁺ concentration of 5 mM and at Mn²⁺ concentration of 1 mM, respectively. High levels of peroxidase activity were found in the medium without and with 1mM Cu²⁺, and at 1 and 5 mM Mn²⁺, respectively. In P. pulmonarius, the highest Lac activity was found in the presence of 5 mM Cu²⁺ and 5 mM Mn²⁺, respectively. The absence of Cu²⁺ and Mn²⁺ as well as their presence at a concentration of 1 mM led to the peaks of peroxidase activities.     

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.