Synthesis and structural characterization of the heavy tricysteinylpnictines, models of protein-bound As(III), Sb(III), and Bi(III).

The heavier group 15 elements As, Sb, and Bi are more restricted in their biochemistry than the nearly ubiquitous lighter congeners N and P, but organisms do encounter compounds of these elements as environmental toxins, starting materials for secondary metabolite biosynthesis, substrates for primary metabolism, or exogenously applied medicines. Under many physiological conditions, these compounds are transformed into pnictogen(III) species, the soft Lewis acidic character of which leads them to interact strongly with biologically relevant soft Lewis bases such as small-molecule thiols or cysteine residues of proteins and peptides. The archetypal complexes As(Cys), Sb(Cys), and Bi(Cys) have been studied in the past but a lack of detailed information about their molecular structures has hampered the analysis of protein structures featuring As(III), Sb(III), and Bi(III) bound to cysteine thiolate residues.

Realgar and arsenene nanomaterials as arsenic-based anticancer agents.

Arsenic trioxide (ATO) is an approved therapy for the treatment of acute promyelocytic leukemia, but the extension of arsenic-based therapies to other types of malignancies, notably tumor-forming cancers, has been slow. Nanodelivery vehicles offer a means of effectively delivering ATO to tumors. Very recently, there has been a series of developments in the formulation of arsenic-based nanomedicines that are not simply loaded with ATO.

Encapsulation of -dodecaiodododecaborate in 2-hydroxypropyl-γ-cyclodextrin prevents hemolysis.

NaBI has many of the properties desired by an X-ray contrast agent but is lethal at the concentrations needed for medical imaging. We demonstrate here that PBS solutions with >50 mM NaBI induce hemolysis, consistent with the previously reported superchaotropic nature of the anion. The presence of <1 equiv.