Leptothrix species, one of the Fe/Mn-oxidizing bacteria, oxidize Fe(II) and produce extracellular, microtubuar, Fe-encrusted sheaths. Since protein(s) involved in Fe(II) oxidation is excreted from Leptothrix cells, the oxidation from Fe(II) to Fe(III) and subsequent Fe(III) deposition to sheaths have been thought to occur in the vicinity or within the sheaths. Previously, Fe(III) particles gene...

Synthesis of triazole linked macrocycles grafted with glycospiroheterocycle was accomplished by stereo- and regioselective tandem double 1,3-dipolar cycloaddition (1,3-DC) reaction. By this method we could construct complex chiral macrocycles in good yields from the easily available starting materials and we could achieve the synthesis of two heterocyclic rings involving simultaneous formation ...

Microbial Fe(II) oxidation using [Formula: see text] as the terminal electron acceptor [nitrate-dependent Fe(II) oxidation, NDFO] has been studied for over 15 years. Although there are reports of autotrophic isolates and stable enrichments, many of the bacteria capable of NDFO are known organotrophic [Formula: see text]-reducers that require the presence of an organic, primary substrate, e.g., ...

The sorption of Fe(II) and Fe(III) by extracellular polymeric substances (EPS) of acidophilic bacteria Acidiphilium 3.2Sup(5) and Acidithiobacillus ferrooxidans, harvested from the ecosystem of the Tinto River (Huelva, Spain), was investigated. EPS from mixed cultures of both bacteria (EPS(mixed)) and pure cultures of A. 3.2Sup(5) (EPS(pure)) were extracted with ethylenediamine tetraacetic acid...

Mith (mithramycin) forms a 2:1 stoichiometry drug-metal complex through the chelation with Fe(II) ion as studied using circular dichroism spectroscopy. The binding affinity between Mith and Fe(II) is much greater than other divalent metal ions, including Mg(II), Zn(II), Co(II), Ni(II) and Mn(II). The [(Mith)2-Fe(II)] complex binds to DNA and induces a conformational change of DNA. Kinetic analy...

Macrocycles are essential building blocks for supramolecular architectures. In this Highlight Review, recent progress in our laboratory is summarized regarding the development of paraphenylene-derived figure-of-eight rigid macrocycles. These molecules derived from X-shaped cores including anthracene photodimer, tetraphenylethylene, and copper-phenanthroline complex, exhibit attractive topologic...

Microbial nitrate-dependent Fe(II) oxidation is known to contribute to iron biogeochemical cycling; however, the microorganisms responsible are virtually unknown. In an effort to elucidate this microbial metabolic process in the context of an environmental system, a 14-cm sediment core was collected from a freshwater lake and geochemically characterized concurrently with the enumeration of the ...

Natural products comprise a diverse array of molecules, many of which are biologically active. Most natural products are derived from combinations of polyketides, peptides, sugars, and fatty-acid building blocks. Peptidic macrocycles have attracted attention as potential therapeutics possessing cell permeability, stability, and easy-to-control variability. Here, we show that enzymes from the pa...

A new family of imidazoline-arylene macrocycles have been constructed through the simultaneous formation of four imidazoline rings in one step. These macrocycles can efficiently complex with fullerenes C60 and C70 through the formation of ground-state complexes.

A series of caesium manganese hexacyanoferrates is prepared; Cs(I)(1.78)Mn(II)[Fe(II)(CN)6]0.78[Fe(III)(CN)6](0.22) (1), Cs(I)(1.57)Mn(II)[Fe(II)(CN)6]0.57[Fe(III)(CN)6](0.43) (2), Cs(I)(1.51)Mn(II)[Fe(II)(CN)6]0.51[Fe(III)(CN)6](0.49) (3), and Cs(I)(0.94)Mn(II)[Fe(II)(CN)6]0.21[Fe(III)(CN)6](0.70).0.8H2O (4). 1-3 show charge-transfer phase transitions between the high-temperature (HT) and low-...