Fluorescent indicators based on β-keto-acid bidentate coordination motifs display superior metal selectivity profiles compared to current o-aminophenol-N,N,O-triacetic acid (APTRA) based chelators for the study of biological magnesium. These low denticity chelators, however, may allow for the formation of ternary complexes with Mg(2+) and common ligands present in the cellular milieu. In this w...

Condensation reactions of carboxylic acids and anilines in the presence of polyphosphoric acid trimethylsilyl ester (PPSE) afforded a range of sterically demanding N,N'-bis(aryl)amidines, RN{C(R')}N(H)R [R = Mes (Mes = 2,4,6-trimethylphenyl), R' = Cy (Cy = cyclohexyl) L¹H; R = Dipp (Dipp = 2,6-diisopropylphenyl), R' = Cy L²H; R = Mes, R' = Ph L³H; R = Dipp, R' = Ph L⁴H; R = Mes, R' = Dmp (Dmp =...

Protoporphyrin IX is the last common intermediate between the heme and chlorophyll biosynthesis pathways. The addition of magnesium directs this molecule toward chlorophyll biosynthesis. The first step downstream from the branchpoint is catalyzed by the magnesium chelatase and is a highly regulated process. The corresponding product, magnesium protoporphyrin IX, has been proposed to play an imp...

Magnesium abnormalities are common in patients with congestive heart failure but the clinical and prognostic significance of an abnormal serum magnesium concentration in this disorder has not been investigated. Therefore, the relation between serum magnesium concentration and the clinical characteristics and long-term outcome of 199 patients with chronic heart failure was evaluated. The serum m...

The first sodium-magnesium and sodium-zinc ketimido complexes display contrasting inverse crown ring and pseudo-cubane structures respectively, while a sodium-zinc heterotrianionic alkide-alkoxide-amide adopts a third type of structure with a stepped ladder motif.

Widespread fluoroquinolone resistance has drawn attention to quinazolinediones (diones), fluoroquinolone-like topoisomerase poisons that are unaffected by common quinolone-resistance mutations. To better understand differences between quinolones and diones, we examined their impact on the formation of cleaved complexes (drug-topoisomerase-DNA complexes in which the DNA moiety is broken) with gy...

Remarkably volatile magnesium complexes have been prepared with the modified borohydride ligand N,N-dimethylaminodiboranate, H(3)BNMe(2)BH(3)(-). The homoleptic complex Mg(H(3)BNMe(2)BH(3))(2), its monoadducts with tetrahydrofuran and 1,2-dimethoxyethane, and the mixed ligand complex (C(5)Me(5))Mg(H(3)BNMe(2)BH(3))(thf) have been prepared. The homoleptic complex Mg(H(3)BNMe(2)BH(3))(2) has a va...

The metal-binding preferences of most metalloproteins do not match their metalrequirements. Thus, metallation of an estimated 30% of metalloenzymes is aided by metaldelivery systems, with ~25% acquiring preassembled metal-cofactors. The remaining ~70% are presumed to compete for metals from buffered metal-pools. Metallation is further aided by maintaining the relative concentrations of these po...