Antibacterial activity exerted by some diazabicyclo-steroid derivatives against staphylococcus aureus and streptococcus pneumoniae. Theoretical analysis of its interaction with the DNA-gyrase

The aim of this study was to synthesize three diazabicyclo-steroid derivatives to evaluate its antibacterial activity. This process involved a series of reactions such as; i) cycloaddition [2 + 2] of 5-hexyn-1-ol to OTBS-testosterone (1) or progesterone (2) or OTBS-pregnenolone (3) to form cyclobutene-ol-steroid derivatives (4 or 5 or 6); ii) the compounds 4 or 5 or 6 were reacted with ethylenediamine to form steroid-amino conjugates (7 or 8 or 9); iii) alkynylation of 7 or 8 or 9 with 5-hexyn-1-ol to form the steroid-amino-hexynol conjugates (10 or 11 or 12); iv) preparation of the cyclobuta-ynal-steroid derivatives (13 or 14 or 15) by the reaction of 10 or 11 or 12 with DMSO; v) amination of 13 or 14 or 15 with ethylenediamine to form new amino-steroid derivatives 16 or 19 or 21; vi) removal of the tert-butyldimethylsilyl from 16 or 21 with hydrofluoric acid to form hydroxyl-steroids (17 and 22); vii) preparation of 1,4-diazacycloundeca-5,11-dien-steroid derivatives by the reaction 17 or 19 or 22 with Copper(II) chloride. In order to evaluate the possibility of that compounds synthesized may have biological activity; in this study its antibacterial effect on Streptococcus pneumoniae and Staphylococcus aureus bacteria was evaluated. The results indicate that compound 20 exert higher antibacterial activity against Staphylococcus aureus and Streptococcus pneumoniae compared with 18 and 23 via interaction DNA-gyrase. In conclusion, these data indicate that antibacterial activity exerted by the compounds 20 depend of their structure chemical in comparison with the other steroid derivatives involved in this study.