Table 1.

Chemical structures and in vitro activity of SPCs

Structures of SPC and analogs with whole cell MIC activity and translation inhibitory activity against M. smegmatis ribosomes in cell-free translation assays. N-ethylene AmSPC (eAmSPC) series molecules are second-generation SPC analogues with enhanced antimicrobial properties over the parent compound, SPC. eAmSPCs improve upon the previously disclosed N-ethyl AmSPC analog, 1950. The eAmSPCs retain SPC ribosomal inhibition profiles while ameliorating whole cell antimicrobial activity. MICs, performed in triplicate for M. abs. and M. tb., were read on day 5 and day 7, respectively. Abbreviations: AmSPC, aminomethyl spectinomycins; M. abs, M. abscessus ATCC 19977; M. tb, M. tuberculosis H37Rv; M. smg ribo, purified M. smegmatis ATCC 19420 ribosomes; MIC, minimum inhibitory concentration; ND, not determined.