An efficient protocol was adopted to efficiently prepare three new series of bis(pyrazolo[1,5‐a]pyrimidines) linked to different spacers. The new bis(pyrazolo[1,5‐a]pyrimidines) were prepared in 80–90 % yields by reacting the respective bis(enaminones) and 4‐(4‐substituted benzyl)‐1H‐pyrazole‐3,5‐diamines in pyridine at reflux temperature for 5–7 h. The new products showed a wide spectrum of antibacterial activity against six different bacterial strains. In general, propane‐ and butane‐linked bis(pyrazolo[1,5‐a]pyrimidines), which are attached to 3‐(4‐methyl‐ or 4‐methoxybenzyl) units, had the best antibacterial activity with minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values up to 2.5 and 5.1 μM, respectively. Additionally, the previous products demonstrated promising MurB inhibitory activity with IC50 values up to 7.2 μM.
Objective: The present study aimed to investigate the extent of stability of corticosteroid hormones against the bacterial actions and their enzymatic activities that are naturally occurring in faeces. Materials and Methods: Faecal samples were freshly collected from each of 10 cattle and 10 sheep. Each sample was immediately incubated in a water bath at 38°C with either 1 μg of cortisol or corticosterone. The incubations were then run at time interval of 4, 8 and 24 h (in cattle) and at 1, 2, 4, 8 and 24 h (in sheep). The samples were extracted with methanol and the aliquots were taken after centrifugation from their supernatants and analyzed for measurement of cortisol and corticosterone by Enzyme Immunoassays (EIAs). Results: A dramatically decline in the concentrations of the added cortisol and corticosterone was observed in cattle faeces. Only about 20% of the starting levels of both hormones after 4 h in contrast to almost no cortisol with about 10% of corticosterone after 8 h and about 5% of corticosterone after 24 h was detected. Prolonged incubation of faecal samples of sheep decreased the immunoreactive substances measured by the 3-hydroxy, 11-oxoandrogens EIA (11-oxo-A-EIA), whereas with the 11, 17 dioxoandrostanes EIA (11, 17 DOA-EIA), the values were increased. Conclusion: Cortisol was heavily metabolized by faecal flora being quicker in its metabolism than corticosterone in the faeces of ruminants. In addition, the present study provides a powerful evidence to the absence of native cortisol in the faeces of ruminants.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.