Water-soluble Bioisosteres of the ortho-substituted Phenyl Ring

Water-soluble analogues of the ortho-substituted phenyl ring were developed. Replacement of the phenyl ring in bioactive compounds with 2 oxabicyclo[2.1.1]hexanes in many cases improved solubility, reduced lipophilicity, enhanced metabolic stability, and most importantly – retained bioactivity

The long-term consequences of antibiotic therapy: Role of colonic short-chain fatty acids (SCFA) system and intestinal barrier integrity.

Epidemiological studies revealed that antibiotics exposure increases a risk of inflammatory bowel diseases (IBD) development. It remained largely unknown how antibiotic-induced dysbiosis confers the risk for enhanced inflammatory response. The aim of the present study was to test the hypothesis that SCFAs, their receptors and transporters mediate the antibiotic long-term effects on the functional state of colonic mucosa and susceptibility to the experimental colitis. Male Wistar rats were treated daily for 14 days with antibiotic ceftriaxone (300 mg/kg, i.m.) or vehicle; euthanized by CO2 inhalation followed by cervical dislocation in 1, 14 or 56 days after antibiotic withdrawal. We found increased cecum weight and sustained changes in microbiota composition after ceftriaxone treatment with increased number of conditionally pathogenic enterobacteria, E. coli, Clostridium, Staphylococcus spp. and hemolytic bacteria even at 56 days after antibiotic withdrawal. The concentration of SCFAs was decreased after ceftriaxone withdrawal. We found decreased immunoreactivity of the FFA2, FFA3 receptors, SMCT1 and increased MCT1 & MCT4 transporters of SCFAs in colon mucosa. These changes evoked a significant shift in colonic mucosal homeostasis: the disturbance of oxidant-antioxidant balance; activation of redox-sensitive transcription factor HIF1α and ERK1/2 MAP kinase; increased colonic epithelial permeability and bacterial translocation to blood; morphological remodeling of the colonic tissue. Ceftriaxone pretreatment significantly reinforced inflammation during experimental colitis 56 days after ceftriaxone withdrawal, which was confirmed by increased histopathology of colitis, Goblet cell dysfunction, colonic dilatation and wall thickening, and increased serum levels of inflammatory cytokines (TNF-α and IL-10). Since the recognition of the importance of microbiota metabolic activity rather than their composition in the development of inflammatory disorders, e.g. IBD, the present study is the first report on the role of the SCFA system in the long lasting side effects of antibiotic treatment and its implication in IBD development

An “Ideal” Bioisoster of the para-substituted Phenyl Ring

The phenyl ring is a basic structural element in chemistry, and we learn about it already in school. We have developed an “ideal” saturated bioisoster of the para-substituted phenyl ring, - 2 oxabicyclo[2.2.2]octane. Its incorporation into Imatinib drug led to dramatic improvement of all physicochemical properties. This study opens new horizons in science, given the commonplace of the phenyl ring everywhere