Perthamides C and D, two new potent anti-inflammatory cyclopeptides from a Solomon Lithistid sponge Theonella swinhoei

Two new metabolites, perthamides C and D, have been isolated from the marine sponge Theonella swinhoei. Their structures were determined by interpretation of NMR and ESIMS data. All compounds exhibited in vivo potent anti-inflammatory activity. Biological activity and structural elucidation are reported.     

Cycloruthenated Complexes from Imine‐Based Heterocycles: Synthesis,Characterization, and Reactivity toward Alkynes

Novel cycloruthenated complexes 2 a – c , 4 a – c , and 6 a, b based on heteroaromatic cores have been synthesized by reaction of a series of heterocycle‐based imines with [{RuCl(η⁶‐p‐cymene)}₂(μ? Cl)₂] and Cu(OAc)₂. This approach has proved efficient for the cyclometalation of thiophene, benzothiophene, furan, benzofuran, pyrrole, and indole derivatives. In addition, even a double cyclometalation process over the same heterocyclic ring is possible, yielding unprecedented bimetallic complexes. These ruthenacycles react with 3‐hexyne through an unexpected pathway, which involves the coupling of the original imino heterocycle and acetylene followed by dearomatization to afford fused hetero‐hydropyridyl ligands bonded to the {Ru(p‐cymene)} organometallic moiety (i.e., 7 a – c and 8 a – c ). These complexes represent, as far as we know, the first examples of this type of compound within the context of cyclometalation, and an exhaustive analysis of their structure was carried out in solution and solid state. Furthermore, these unique species react with CuCl₂, which promotes the rearomatization and the release of highly valuable aromatic fused bis‐heterocycles (i.e., 9 a – c , 10 a – c, 11 a , and 12 a/12 a′ ), providing a novel and appealing synthetic route to this extraordinary family of molecules.     

Synthesis and characterization of 4-hydroxy-3-phenylprolines

4-Hydroxy-3-phenylprolines were synthesized via 1-acetyl-2,2-diethoxycarbonyl-2,3-dihydro-3-phenyl-1H-pyrrole. Reversed phase hplc resulted in the isolation of the products which were characterized by ¹H and ¹³C nmr spectroscopy.     

Formamidines and triazenes as precursors for the preparation of rhenium imido-complexes

Summary The rhenium(V) imido-complexes [Re(NR)Cl₃(PPh₃)₂] have been obtained by heating the rhenium(V) derivative [ReOCl₃(PPh₃)₂] with RNHCHNR R = Ph (1a), p-MeC₆H₄ (1b), p-ClC₆H₄ (1c) andp-FC₆H₄ (1d) in THF under reflux. [Re(NR)Cl₃(PPh₃)₂] (R =p-MeQ₆H₄) has also been obtained by heating the rhenium(III)-triazenido complex [ReCl₂(RN N NR)(PPh₃)₂] in CCl₄ under reflux.     

H2O−D2O solvent isotope effect in the volume behavior of some high-charge high-size electrolytes

The apparent molar volumes V of KCl, BaCl₂, K₂SO₄, LaCl₃, Co(en)₃Cl₃ [Tris(ethylenediamine)cobalt(III) chloride], K₃Co(CN)₆, K₃Fe(CN)₆, K₄Fe(CN)₆, and Ba₃[Co(CN)₆]₂ have been determined at 25°C in both light and heavy water. The V values in D₂O are systematically lower and increase more rapidly with salt concentration than the V in H₂O. The volume of transfer from H₂O to D₂O as well as the partial molar volume at infinite dilution in both solvents have also been calculated. These results together with literature values for other electrolytes were used to estimate both of these quantities for D₂O solutions of individual ions. The predictions of ion hydration models and ion-ion interactions are compared with experimental observations.     

The synthesis and application of polyamino polycarboxylic bifunctional chelating agents

Bifunctional chelating agents (BFCAs) are molecules which contain two different moieties: a strong metal chelating unit and a reactive functional group. The latter is directed to react with amines, thiols, alcohols or other reactive molecules to form stable covalent bonds while the chelating moiety is able to strongly coordinate a metal ion. In this way, it is possible to label a molecule of interest (e.g. an antibody or a peptide) with a metal or a radioactive metal ion. Of all the ligands reported so far, those based on a polyamino polycarboxylic structure are most efficient and are widely employed for the chelation of metal ions. The resulting metal complexes have found a broad range of applications in chemistry, biology and medicine. Diagnostic imaging (MRI, SPECT, PET), molecular imaging, tumour therapy and luminescent materials are only a few examples. The present critical review gives an overview of the syntheses and most important applications of polyamino polycarboxylic BFCAs (334 references).     

On the antibacterial activity of roots of Capparis spinosa L

A decoction of Capparis spinosa L. roots, widely used in the traditional folk medicine of southern Italy, was prepared and submitted to antibacterial activity tests, which showed an interesting bacteriostatic activity on the growth of Deinococcus radiophilus. Heterocyclic compounds were also recovered from the chloroformic extract of the roots.     

Liquid–Liquid Phase Equilibrium and Ion-Exchange Exploration for Aqueous Two-Phase Systems of ([C4mim]Cl + K2CO3 or K3C6H5O7 + water) at Different Temperatures

Journal of Solution Chemistry - Liquid–liquid equilibrium (LLE) data and phase diagrams for new aqueous two-phase systems (ATPSs) containing 1-butyl-3-methylimidazolium chloride...     

Synthesis of new fluorous modular chiral ligand derivatives from amino alcohols and application in enantioselective carbon–carbon bond-forming alkylation reactions

N-Trifluoracyl β-chalcogeno amides and N-perfluoracyl β-thio amide ligands were prepared by a simple and efficient reaction sequence. These new ligands were evaluated in palladium-catalyzed alkylation of rac-(E)-1,3-diphenyl-2-propenyl acetate in the presence of dimethyl malonate and an enantioselectivity of up to 99% was obtained. After catalysis, the fluorous ligand can be easily recovered by liquid–liquid extraction and reused without loss in the activity.