221632-26-4

(2E)-OBAA is a potent phospholipase A2 (PLA2) inhibitor, with an IC50 of 70 nM. (2E)-OBAA induces apoptosis of HUVEC cells. (2E)-OBAA blocks Melittin-induced Ca2+ influx in Trypanosoma brucei, with an IC50 of 0.4 μM[1][2][3][4].

ChEBI: 4-(4-octadecylphenyl)-4-oxo-2-butenoic acid is a carbonyl compound.

This potent PLA inhibitor (FW = 428.65 g/mol; CAS 221632-26-4; Soluble to 10 mM in DMSO with gentle warming), also named 4-(4- octadecylphenyl)-4-oxobutenoic acid, targets phospholipase A2 (IC50 = 70 nM). OBAA is a mechanism-based inhibitor, showing a typical timedependence as well as a molar inactivation ratio of twenty OBAA hydrolyzed per molecule of irreversibly inactivated enzyme. Doublereciprocal replots of the apparent inactivation constants versus OBAA concentration gave a (pseudo) first-order rate constant of inactivation of 2.3 min–1 and a dissociation constant of 6 x 10–6 M–1 for the enzyme-inhibitor intermediate. OBAA reduces bronchospasm in guinea pigs in vivo.

PLA2: 70 nM (IC₅₀)

[1] J Y Miao, et al. Inhibitors of phospholipase promote apoptosis of human endothelial cells. J Biochem. 1997 Mar;121(3):612-8. DOI:10.1093/oxfordjournals.jbchem.a021629
[2] J Eintracht, et al. Calcium entry in Trypanosoma brucei is regulated by phospholipase A2 and arachidonic acid. Biochem J. 1998 Dec 15;336 ( Pt 3)(Pt 3):659-66. DOI:10.1042/bj3360659
[3] T K?hler, et al. Phospholipase A2 inhibition by alkylbenzoylacrylic acids. Biochem Pharmacol. 1992 Aug 18;44(4):805-13. DOI:10.1016/0006-2952(92)90419-j
[4] Kethineedi VR, et al. Quantum dot-NBD-liposome luminescent probes for monitoring phospholipase A2 activity. Anal Bioanal Chem. 2013 Dec;405(30):9729-37. DOI:10.1007/s00216-013-7422-z