4412-16-2Relevant articles and documents
Modulation of antibiotic sensitivity and biofilm formation in Pseudomonas aeruginosa by interspecies signal analogues
An, Shi-qi,Murtagh, Julie,Twomey, Kate B.,Gupta, Manoj K.,O’Sullivan, Timothy P.,Ingram, Rebecca,Valvano, Miguel A.,Tang, Ji-liang
, (2019/06/05)
Pseudomonas aeruginosa, a significant opportunistic pathogen, can participate in inter-species communication through signaling by cis-2-unsaturated fatty acids of the diffusible signal factor (DSF) family. Sensing these signals leads to altered biofilm formation and increased tolerance to various antibiotics, and requires the histidine kinase PA1396. Here, we show that the membrane-associated sensory input domain of PA1396 has five transmembrane helices, two of which are required for DSF sensing. DSF binding is associated with enhanced auto-phosphorylation of PA1396 incorporated into liposomes. Further, we examined the ability of synthetic DSF analogues to modulate or inhibit PA1396 activity. Several of these analogues block the ability of DSF to trigger auto-phosphorylation and gene expression, whereas others act as inverse agonists reducing biofilm formation and antibiotic tolerance, both in vitro and in murine infection models. These analogues may thus represent lead compounds to develop novel adjuvants improving the efficacy of existing antibiotics.
Unexpected AChE inhibitory activity of (2E)α,β-unsaturated fatty acids
Loesche, Anne,Wiemann, Jana,Al Halabi, Zayan,Karasch, Julia,Sippl, Wolfgang,Csuk, René
, p. 3315 - 3319 (2018/09/17)
A small library of (E) α,β-unsaturated fatty acids was prepared, and 20 different saturated and mono-unsaturated fatty acids differing in chain length were subjected to Ellman's assays to determine their ability to act as inhibitors for AChE or BChE. While the compounds were only very weak inhibitors of BChE, seven molecules were inhibitors of AChE holding IC50 = 4.3–12.8 M with three of them as significant inhibitors of this enzyme. The results have shown trans 2-mono-unsaturated fatty acids are better inhibitors for AChE than their saturated analogs. Furthermore, the screening results indicate that the chain length is crucial for obtaining an inhibitory efficacy. The best results were obtained for (2E) eicosenoic acid (14) showing inhibition constants Ki = 1.51 ± 0.09 M and Ki′ = 7.15 ± 0.55 M. All tested compounds were mixed-type inhibitors with a dominating competitive part. Molecular modelling calculations indicate a different binding mode of active/inactive compounds for the enzymes AChE and BChE.
Cobalt-Catalyzed Allylic C(sp3)-H Carboxylation with CO2
Michigami, Kenichi,Mita, Tsuyoshi,Sato, Yoshihiro
, p. 6094 - 6097 (2017/05/08)
Catalytic carboxylation of the allylic C(sp3)-H bond of terminal alkenes with CO2 was developed with the aid of a Co/Xantphos complex. A wide range of allylarenes and 1,4-dienes were successfully transformed into the linear styrylacetic acid and hexa-3,5-dienoic acid derivatives in moderate to high yields, with excellent regioselectivity. The carboxylation showed remarkable functional group tolerability, so that selective addition to CO2 occurred in the presence of other carbonyl groups such as amide, ester, and ketone. Since styrylacetic acid derivatives can be readily converted into optically active γ-butyrolactones through Sharpless asymmetric dihydroxylation, this allylic C(sp3)-H carboxylation showcases a facile synthesis of γ-butyrolactones from simple allylarenes via short steps.
