Vinyl sulfone analogs of lysophosphatidylcholine irreversibly inhibit autotaxin and prevent angiogenesis in melanoma
摘要:
Autotaxin (ATX) is an enzyme discovered in the conditioned medium of cultured melanoma cells and identified as a protein that strongly stimulates motility. This unique ectonucleotide pyrophosphatase and phosphodiesterase facilitates the removal of a choline headgroup from lysophosphatidylcholine (LPC) to yield lysophosphatidic acid (LPA), which is a potent lipid stimulator of tumorigenesis. Thus, ATX has received renewed attention because it has a prominent role in malignant progression with significant translational potential. Specifically, we sought to develop active site-targeted irreversible inhibitors as anti-cancer agents. Herein we describe the synthesis and biological activity of an LPC-mimetic electrophilic affinity label that targets the active site of ATX, which has a critical threonine residue that acts as a nucleophile in the lysophospholipase D reaction to liberate choline. We synthesized a set of quaternary ammonium derivative-containing vinyl sulfone analogs of LPC that function as irreversible inhibitors of ATX and inactivate the enzyme. The analogs were tested in cell viability assays using multiple cancer cell lines. The IC50 values ranged from 6.74 to 0.39 mu M, consistent with a K-i of 3.50 mu M for inhibition of ATX by the C16H33 vinyl sulfone analog CVS-16 (10b). A phenyl vinyl sulfone control compound, PVS-16, lacking the choline-like quaternary ammonium mimicking head group moiety, had little effect on cell viability and did not inhibit ATX. Most importantly, CVS-16 (10b) significantly inhibited melanoma progression in an in vivo tumor model by preventing angiogenesis. Taken together, this suggests that CVS-16 (10b) is a potent and irreversible ATX inhibitor with significant biological activity both in vitro and in vivo. (C) 2015 Elsevier Ltd. All rights reserved.
Synthesis and pharmacological properties of N-(3-{3-(1-piperidinylmethyl)phenoxy}propyl)-2-(2-hydroxyethylthio)acetamide and related compounds as antiulcer agents. I.
N-Phenoxypropylacetamide derivatives were prepared and tested for antiulcer activity. These compounds exhibited both gastric acid antisecretory and cytoprotective properties. Structure-activity studies led to the identification of N-[3-(3-(1-piperidinylmethyl)phenoxy)propyl]-2-(2-hydroxyethylt hio)acetamide (8), which was selected for further development and clinical evaluation.
Visible-Light-Mediated Thiol–Ene Reactions through Organic Photoredox Catalysis
作者:Gaoyuan Zhao、Sarbjeet Kaur、Ting Wang
DOI:10.1021/acs.orglett.7b01441
日期:2017.6.16
Synthetically useful radical thiol–ene reactions can be initiated by visible-light irradiation in the presence of an organic photocatalyst, 9-mesityl-10-methylacridinum tetrafluoroborate. The key thiyl radical intermediates are generated upon quenching of the photoexcited catalyst with a variety of thiols. The success of this method requires only the use of near-stoichiometric levels of alkene coupling
作者:Sarbjeet Kaur、Gaoyuan Zhao、Evan Busch、Ting Wang
DOI:10.1039/c8ob02313a
日期:——
presence of visible light is used to initiate thiol–ene and thiol–yne reactions. Thiyl radicals are generated upon quenching the photoexcited catalyst with a range of thiols. The highlighted mild nature of the reaction conditions allows a broad substrate scope of the reactants. Relying on this efficient metal-free condition, both thiol–ene and thiol–yne reactions between carbohydrates and peptides could