scholarly journals A natural product inspired fragment-based approach towards the development of novel anti-bacterial agents

MedChemComm ◽  
2016 ◽  
Vol 7 (7) ◽  
pp. 1387-1391 ◽  
Author(s):  
Michael J. Austin ◽  
Stephen J. Hearnshaw ◽  
Lesley A. Mitchenall ◽  
Paul J. McDermott ◽  
Lesley A. Howell ◽  
...  

Simocyclinone D8 served as a natural product inspiration for the synthesis of a new DNA gyrase inhibitor.

2013 ◽  
Vol 23 (21) ◽  
pp. 5874-5877 ◽  
Author(s):  
Jenson Verghese ◽  
Thuy Nguyen ◽  
Lisa M. Oppegard ◽  
Lauren M. Seivert ◽  
Hiroshi Hiasa ◽  
...  

2014 ◽  
Vol 23 (8) ◽  
pp. 3632-3643 ◽  
Author(s):  
Lauren M. Gaskell ◽  
Thuy Nguyen ◽  
Keith C. Ellis
Keyword(s):  

2015 ◽  
Vol 59 (11) ◽  
pp. 6689-6695 ◽  
Author(s):  
George A. Jacoby ◽  
Marian A. Corcoran ◽  
David C. Hooper

ABSTRACTQnr is a plasmid-encoded and chromosomally determined protein that protects DNA gyrase and topoisomerase IV from inhibition by quinolones. Despite its prevalence worldwide and existence prior to the discovery of quinolones, its native function is not known. Other synthetic compounds and natural products also target bacterial topoisomerases. A number were studied as molecular probes to gain insight into how Qnr acts. Qnr blocked inhibition by synthetic compounds with somewhat quinolone-like structure that target the GyrA subunit, such as the 2-pyridone ABT-719, the quinazoline-2,4-dione PD 0305970, and the spiropyrimidinetrione pyrazinyl-alkynyl-tetrahydroquinoline (PAT), indicating that Qnr is not strictly quinolone specific, but Qnr did not protect against GyrA-targeting simocyclinone D8 despite evidence that both simocyclinone D8 and Qnr affect DNA binding to gyrase. Qnr did not affect the activity of tricyclic pyrimidoindole or pyrazolopyridones, synthetic inhibitors of the GyrB subunit, or nonsynthetic GyrB inhibitors, such as coumermycin A1, novobiocin, gyramide A, or microcin B17.Thus, in this set of compounds the protective activity of Qnr was confined to those that, like quinolones, trap gyrase on DNA in cleaved complexes.


2009 ◽  
Vol 54 (1) ◽  
pp. 213-220 ◽  
Author(s):  
C. Sissi ◽  
E. Vazquez ◽  
A. Chemello ◽  
L. A. Mitchenall ◽  
A. Maxwell ◽  
...  

ABSTRACT Simocyclinone D8, a coumarin derivative isolated from Streptomyces antibioticus Tü 6040, represents an interesting new antiproliferative agent. It was originally suggested that this drug recognizes the GyrA subunit and interferes with the gyrase catalytic cycle by preventing its binding to DNA. To further characterize the mode of action of this antibiotic, we investigated its binding to the reconstituted DNA gyrase (A2B2) as well as to its GyrA and GyrB subunits and the individual domains of these proteins, by performing protein melting and proteolytic digestion studies as well as inhibition assays. Two binding sites were identified, one (anticipated) in the N-terminal domain of GyrA (GyrA59) and the other (unexpected) at the C-terminal domain of GyrB (GyrB47). Stabilization of the A subunit appears to be considerably more effective than stabilization of the B subunit. Our data suggest that these two distinct sites could cooperate in the reconstituted enzyme.


2005 ◽  
Vol 49 (3) ◽  
pp. 1093-1100 ◽  
Author(s):  
Ruth H. Flatman ◽  
Alison J. Howells ◽  
Lutz Heide ◽  
Hans-Peter Fiedler ◽  
Anthony Maxwell

ABSTRACT We have characterized the interaction of a new class of antibiotics, simocyclinones, with bacterial DNA gyrase. Even though their structures include an aminocoumarin moiety, a key feature of novobiocin, coumermycin A1, and clorobiocin, which also target gyrase, simocyclinones behave strikingly differently from these compounds. Simocyclinone D8 is a potent inhibitor of gyrase supercoiling, with a 50% inhibitory concentration lower than that of novobiocin. However, it does not competitively inhibit the DNA-independent ATPase reaction of GyrB, which is characteristic of other aminocoumarins. Simocyclinone D8 also inhibits DNA relaxation by gyrase but does not stimulate cleavage complex formation, unlike quinolones, the other major class of gyrase inhibitors; instead, it abrogates both Ca2+- and quinolone-induced cleavage complex formation. Binding studies suggest that simocyclinone D8 interacts with the N-terminal domain of GyrA. Taken together, our results demonstrate that simocyclinones inhibit an early step of the gyrase catalytic cycle by preventing binding of the enzyme to DNA. This is a novel mechanism for a gyrase inhibitor and presents new possibilities for antibacterial drug development.


2014 ◽  
Vol 426 (10) ◽  
pp. 2023-2033 ◽  
Author(s):  
Stephen J. Hearnshaw ◽  
Marcus J. Edwards ◽  
Clare E. Stevenson ◽  
David M. Lawson ◽  
Anthony Maxwell

Science ◽  
2009 ◽  
Vol 326 (5958) ◽  
pp. 1415-1418 ◽  
Author(s):  
M. J. Edwards ◽  
R. H. Flatman ◽  
L. A. Mitchenall ◽  
C. E.M. Stevenson ◽  
T. B.K. Le ◽  
...  

Author(s):  
Ardalan A. Nabi ◽  
Lydia M. Scott ◽  
Daniel P. Furkert ◽  
Jonathan Sperry

The rare benzoxazepine ring in the alkaloid inducamide C is unstable and prone to rearrangement, indicating that structural revision of the natural product may be necessary.


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