Synthesis and Evaluation of Novel 7- and 8-Aminophenoxazinones for the Detection of β-Alanine Aminopeptidase Activity and the Reliable Identification of Pseudomonas aeruginosa in Clinical Samples.
A series of novel 8-aminophenoxazin-3-one and 7-aminophenoxazin-3-one chromogens and their corresponding β-alanine derivatives were synthesized and evaluated for their ability to detect β-alanyl aminopeptidase activity in bacteria known to hydrolyze β-alanine derivatized substrates. The results provided insight into the structural requirements for effective visualization of enzymatic activity and the mechanism of formation of phenoxazinon-3-ones. 8-Aminophenoxazin-3-one substrates 23c, 23d, and 23e were prepared in good to high overall yield and were selective for β-alanyl aminopeptidase activity in bacteria, producing a lighter agar background coloration facilitating visualization of colored colonies, with variable localization to the colonies, but had lower sensitivities for the detection of Pseudomonas aeruginosa in comparison to the analogous 7-aminophenoxazin-3-one substrates. The synthetic methodology employed here allows the preparation of a range of substrates for evaluation and the establishment of structure-activity relationships. For example, the 2-pentyl substituted aminophenoxazin-3-one 22b performed with analogous sensitivity to the corresponding 1-pentyl-7-aminophenoxazin-3-one substrate 1 used commercially, highlighting that the position of the pentyl substituent can be varied while maintaining detection sensitivity.
Sunderland Pharmacy School, University of Sunderland , Sunderland SR1 3SD, U.K.
Alexandre F
AF
Bedernjak
Department of Microbiology, bioMérieux , 38390 La Balme-les-Grottes, France.
Andrey V
AV
Zaytsev
Department of Microbiology, bioMérieux , 38390 La Balme-les-Grottes, France.
Michèle
M
Babolat
Department of Microbiology, bioMérieux , 38390 La Balme-les-Grottes, France.
Marie
M
Cellier
School of Life Sciences, Northumbria University , Newcastle upon Tyne, NE1 8ST, U.K.
Arthur L
AL
James
Department of Microbiology, bioMérieux , 38390 La Balme-les-Grottes, France.
Sylvain
S
Orenga
Department of Microbiology, Freeman Hospital , Newcastle upon Tyne NE7 7DN, U.K.
John D
JD
Perry
Sunderland Pharmacy School, University of Sunderland , Sunderland SR1 3SD, U.K.
Paul W
PW
Groundwater
Sunderland Pharmacy School, University of Sunderland , Sunderland SR1 3SD, U.K.
Rosaleen J
RJ
Anderson
D000900:Anti-Bacterial Agents / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*; D018826:CD13 Antigens / Q000037:antagonists & inhibitors* / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D004791:Enzyme Inhibitors / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*; D008826:Microbial Sensitivity Tests; D015394:Molecular Structure; D010078:Oxazines / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*; D011550:Pseudomonas aeruginosa / Q000187:drug effects* / Q000201:enzymology / Q000302:isolation & purification; D013329:Structure-Activity Relationship
D000900:Anti-Bacterial Agents; D004791:Enzyme Inhibitors; D010078:Oxazines; D018826:CD13 Antigens