New Class Of Reversible Inhibitors Research Articles

Discovery of 12-Thiazole Abietanes as Selective Inhibitors of the Human Metabolic Serine Hydrolase hABHD16A

Screening of an in-house library of compounds identified 12-thiazole abietanes as a new class of reversible inhibitors of the human metabolic serine hydrolase. Further optimization of the first hit compound lead to the 2-methylthiazole derivative 18, with an IC50 value of 3.4 ± 0.2 μM and promising selectivity. ABHD16A has been highlighted as a new target for inflammation-mediated pain, although selective inhibitors of hABHD16A (human ABHD16A) have not yet been reported. Our study presents abietane-type diterpenoids as an attractive starting point for the design of selective ABHD16A inhibitors, which will contribute toward understanding the significance of hABHD16A inhibition in vivo.

Pyrido-imidazodiazepinones as a new class of reversible inhibitors of human kallikrein 7

The human tissue kallikrein-7 (KLK7) is a chymotryptic serine protease member of tissue kallikrein family. KLK7 is involved in skin homeostasis and inflammation. Excess of KLK7 activity is also associated with tumor metastasis processes, especially in ovarian carcinomas, prostatic and pancreatic cancers. Development of Kallikrein 7 inhibitors is thus of great interest in oncology but also for treating skin diseases. Most of the developed synthetic inhibitors present several drawbacks such as poor selectivity and unsuitable physico-chemical properties for in vivo use. Recently, we described a practical sequence for the synthesis of imidazopyridine-fused [1,3]-diazepines. Here, we report the identification of pyrido-imidazodiazepinone core as a new potential scaffold to develop selective and competitive inhibitors of kallikrein–related peptidase 7. Structure-activity relationships (SAR), inhibition mechanisms and selectivity as well as cytotoxicity against selected cancer cell lines were investigated.

Acylideneoxoindoles: A new class of reversible inhibitors of human transglutaminase 2

Inhibitors of human transglutaminase 2 (TG2) are anticipated to be useful in the therapy of a variety of diseases including celiac sprue as well as certain CNS disorders and cancers. A class of 3-acylidene-2-oxoindoles was identified as potent reversible inhibitors of human TG2. Structure-activity relationship analysis of a lead compound led to the generation of several potent, competitive inhibitors. Analogs with significant non-competitive character were also identified, suggesting that the compounds bind at one or more allosteric regulatory sites on this multidomain enzyme. The most active compounds had K(i) values below 1.0 μM in two different kinetic assays for human TG2, and may therefore be suitable for investigations into the role of TG2 in physiology and disease in animals.

α,β-Dehydrophenylalanine choline esters, a new class of reversible inhibitors of human acetylcholinesterase and butyrylcholinesterase

Our goal was to design, synthesize, and evaluate new cholinesterase inhibitors. Fourteen dehydroamino acids esterified to choline and to its ternary analog were synthesized by a new method that gave a yield of 84–93%. The potency of the amino acid ester derivatives was tested by measuring K i values for inhibition of human red cell acetylcholinesterase and human plasma butyrylcholinesterase. The most potent compound was a choline ester of dehydrophenylalanine where the amine group of the amino acid was derivatized with a benzoyl group containing a methoxy in the 2-position, CH 3O(C 6H 4)CONHC(CHC 6H 5)COOCH 2CH 2N +(CH 3) 3. This compound was a strong inhibitor of both human acetylcholinesterase and human butyrylcholinesterase, with K i values of 10 μM and 0.08 μM, respectively. These K i values are comparable to that of Rivastigmine. Docking of the most potent compound into the active site of human butyrylcholinesterase showed that the lowest energy model had two benzene rings oriented towards Trp 82 and Tyr 332 whereas the positively charged nitrogen group was stabilized by Trp 231. This orientation placed the ester group 3.89 Å from the active site Ser 198, a distance too far for covalent bonding, explaining why the esters are inhibitors rather than substrates. This class of anticholinesterase agents has the potential for therapeutic utility in the treatment of disorders of the cholinergic system.