Pyrrole-imidazole alkaloids are widely distributed in marine sponges of the orders Halichondrida and Agelasida. Chemical investigation of the Caribbean sponge Stylissa caribica has led to the isolation of the first brominated pyrrole-imidazole alkaloid containing an oxidized pyrrole moiety. The isolation and structure elucidation of oxocyclostylidol (1) are discussed in detail.

X-ray absorption spectroscopy (XAS), including extended X-ray absorption fine structure (EXAFS) and X-ray absorption near-edge structure (XANES) analysis, has been carried out at the Zn K edge of the N-terminal part of the integrase protein of the human immunodeficiency virus, type 2 (HIV-2), and of some zinc coordination compounds. In the presence of excess beta-mercaptoethanol, which was pres...

Notomastus lobatus chloroperoxidase (NCPO) and Amphitrite ornata dehaloperoxidase (DHP) catalyze the halogenation of phenols and dehalogenation of halophenols, respectively. Both enzymes require peroxide for activity and have recently been shown to contain histidine (His) as their proximal heme iron ligand. DHP is the only heme enzyme known to catalyze peroxide-dependent defluorination reaction...

Imidazole compounds are important constituents of atmospheric brown carbon. The imidazole components aqueous secondary organic aerosol (aqSOA) that generated from the evaporation droplets containing pyruvaldehyde and inorganic ammonium on-line characterized by an laser time-of-flight mass spectrometer (ALTOFMS) off-line detected optical spectrometry in this study. results demonstrated desorptio...

Thermodynamic data for the proton and metal ion complexation equilibria of imidazole ( 1,3 diazole, glyoxaline ) and histamine ( 4-imidoazolethylamine, 4 ( 2’ aminoethyl ) imidazole ) have been collected and critically evaluated. The literature search has been performed by using IUPAC’s “Stability Constants Database” and covers the literature until 1992. Important criteria for acceptance compri...

In the title compound, [Mn(C(5)H(6)N(3)O)(2)(C(3)H(7)NO)]ClO(4), the Mn(III) atom lies on the inversion centre of the centrosymmetric complex cation and has a distorted octa-hedral coordination geometry, formed by two N atoms and two O atoms from two 1-methyl-imidazole-2-carbaldehyde oximate ligands and two O atoms from two dimethyl-formamide ligands. Perchlorate acts as a counterion to balance...

In the title compound, [Zn(C(10)H(14)O(4))(C(4)H(6)N(2))](n), each Zn(II) ion is coordinated by one N atom from one 2-methyl-1H-imidazole ligand and three O atoms from two camphorate (cap) ligands in a distorted tetra-hedral geometry. In one of the cap ligands, one methyl group is disordered between positions 1 and 3 in a 0.518 (12):0.482 (12) ratio. Each cap ligand bridges three Zn(II) ions, f...

The Fe2S2 clusters in nature are generally coordinated to the peptide backbone using thiolate ligands (from cysteines). A known variation of these are the imidazole (from histidine) coordinated active sites of Riesky proteins. Recently, a few newer modifications have been observed, e.g., the arginine coordinated cluster in biotin synthases. Very recently, a cysteine persulfide coordinated clust...

Four novel monodentate 2-(3′-(4′′-sub-aryl)-1′-phenyl-1H-pyrazole-4-yl)-1H-benzo[d]imidazole ligands (La-d) have been synthesized via the cyclocondensation of o-phenelyndiamine with 1,3-disubstituted pyrazole aldehydes by adding oxidizing agent ceria ammonium nitrate as catalyst in presence of hydrogen peroxide in alcoholic media. The non chelated Cu(II) and Ni(II) complexes of newly synthesize...