02227nas a2200205   4500008004100000245013300041210006900174260000800243300001400251490000600265520145700271100002301728700002501751700002201776700002001798700002401818700001901842700002801861856013201889       2018                        eng d00aDesign and synthesis of 2-amino-thiophene-tethered ureidopenicillin analogs with potentantibacterial and antitubercular activity0 aDesign and synthesis of 2aminothiophenetethered ureidopenicillin  cMAR  a3122-31260 v33 aUreidopenicillins are a class of penicillins which are antibiotics active against gram-negative bacteria. Herein, we report the synthesis of 2-aminothiophene-tethered ureidopenicillin analogues and their in vitro antibacterial and antitubercular activity. Intriguingly, unlike the reported ureidopenicillins which are active against gram-negative bacteria, the synthesised 2-aminothiophene-tethered ureidopenicillins were significantly active against Gram-positive bacterial strains and showed moderate inhibition towards gram-negative bacterial strains. Among all the analogs, compound 1b containing 2-aminothiophene moiety with minimum inhibitory concentration (MIC): 0.29, 0.32, > 10, > 10 mg/ml for Staphylococcus aureus, Bacillus subtilis, Escherichia coli and Pseudomonas aeruginosa, respectively, showed better anti-bacterial profile as compared to cephalexin and equipotent to ampicillin and amoxicillin on gram-positive bacterial strains. All the derivatives were also screened for anti-TB activity against mycobacterium tuberculosis H37Ra. Among the series, cycloocta-thiophene-tethered cephalexin analog 3c displayed excellent antitubercular activity with MIC values 0.78 mg/ml. Low cytotoxicity and high selectivity index indicate the efficacy of 3c against mycobacterial infections. The results from present study offer a novel approach to modify the existing drug class of ureidopenicillins to yield antimicrobials with promising utility.1 aWagh, Mahendra, A.1 aBaravkar, Sachin, B.1 aJedhe, Ganesh, S.1 aBorkute, Rachna1 aChoudhari, Amit, S.1 aSarkar, Dhiman1 aSanjayan, Gangadhar, J.  uhttps://library.ncl.res.in/content/design-and-synthesis-2-amino-thiophene-tethered-ureidopenicillin-analogs-potentantibacterial