The effect of boromycin on the Ca2+ homeostasis

Boromycin Has Potent Anti-Toxoplasma and Anti-Cryptosporidium Activity

Toxoplasma gondii and Cryptosporidium parvum, members of the phylum Apicomplexa, are significant pathogens of both humans and animals worldwide for which new and effective therapeutics are needed. Here, we describe the activity of the antibiotic boromycin against Toxoplasma and Cryptosporidium Boromycin potently inhibited intracellular proliferation of both T. gondii and C. parvum at half-maximal effective concentrations (EC₅₀) of 2.27 nM and 4.99 nM, respectively. Treatment of extracellular T. gondii tachyzoites with 25 nM boromycin for 30 min suppressed 84% of parasite growth, but T. gondii tachyzoite invasion into host cells was not affected by boromycin. Immunofluorescence of boromycin-treated T. gondii showed loss of morphologically intact parasites with randomly distributed surface antigens inside the parasitophorous vacuoles. Boromycin exhibited a high selectivity for the parasites over their host cells. These results suggest that boromycin is a promising new drug candidate for treating toxoplasmosis and cryptosporidiosis.

Empirical Observations and Mechanistic Insights on the First Boron-Containing Chiral Selector for LC and Supercritical Fluid Chromatography

Boromycin is a macrodiolide that exists as a hydrophobic Böeseken complex formed from boric acid and a chiral polyhydroxy macrocyclic ligand. It was covalently bonded to silica gel through a urea linkage to an attached d-valine ester. When evaluated as a chiral stationary phase, it shows pronounced enantioselectivity toward primary amine-containing racemates, separating 98% of those tested. The selectivity is most pronounced in the presence of organic solvents and supercritical CO2 + methanol. The enantioselective binding site and mechanistic factors are examined. Analytes can be complexed as either the free base or their protonated analogues, with the free base being more strongly associated with the chiral selector.