Synthesis and in vitro anti-HIV evaluation of disulfide linked derivatives of 1,2-dithiol-3-ylidene ketones containing a 2,3-dichloro-4-phenoxy acetic acid moiety
Synthesis of Dithiolethiones and Identification of Potential Neuroprotective Agents via Activation of Nrf2-Driven Antioxidant Enzymes
摘要:
Oxidative stress is implicated in the pathogenesis of a wide variety of neurodegenerative disorders, and accordingly, dietary supplement of exogenous antioxidants or/and upregulation of the endogenous antioxidant defense system are promising for therapeutic intervention or chemoprevention of neurodegenerative diseases. Nrf2, a master regulator of the cellular antioxidant machinery, cardinally participates in the transcription of cytoprotective genes against oxidative/electrophilic stresses. Herein, we report the synthesis of 59 structurally diverse dithiolethiones and evaluation of their neuroprotection against 6-hydroxydopamine- or H2O2 -induced oxidative damages in PC12 cells, a neuron-like rat pheochromocytoma cell line. Initial screening identified compounds 10 and 11 having low cytotoxicity but conferring remarkable protection on PC12 cells from oxidative-mediated damages. Further studies demonstrated that both compounds upregulated a battery of antioxidant genes as well as corresponding genes' products. Significantly, silence of Nrf2 expression abolishes cytoprotection of 10 and 11, indicating targeting Nrf2 activation is pivotal for their cellular functions. Taken together, the two lead compounds discovered here with potent neuroprotective functions against oxidative stress via Nrf2 activation merit further development as therapeutic or chemopreventive candidates for neurodegenerative disorders.
Copper-Catalyzed Tandem Sulfuration/Annulation of Propargylamines with Sulfur via C–N Bond Cleavage
作者:Hong-Hui Xu、Xiao-Hong Zhang、Xing-Guo Zhang
DOI:10.1021/acs.joc.9b00685
日期:2019.6.21
oxidative sulfuration and annulation of propargylamines with elemental sulfur is described. The tandem reaction involves C–N bond cleavage and the formation of multiple C–S bonds, affording 1,2-dithiole-3-thiones in good to excellent yields with good functional group tolerance.
A simple and practical strategy for the preparation of 1,2‐dithiole‐3‐thiones via copper‐catalyzed defluorinative thioannulation of trifluoropropynes has been developed using elemental sulfur as the sole sulfur source. This reaction displays a wide substrate scope and high functional group tolerance to afford the corresponding S‐heterocycles in moderate to good yields and features efficient construction
An operationally simple cascade protocol has been developed for the construction of 1,2- and 1,3-dithiole derivatives from alpha-enolic dithio esters. 1,2-Dithioles are achieved by the reaction of dithioesters with elemental sulfur in the presence of InCl3 under solvent-free conditions. 1,3-Dithioles have been constructed via DABCO mediated self coupling of dithioesters in open air enabling the formation of two new C-S bonds and one ring in a single operation in contiguous fashion. The reactions proceeded smoothly affording the desired sulfur-rich heterocycles in good to excellent yields, exhibiting gram-scale ability and broad functional group tolerance utilizing easy to handle cheap and easily available reagents. The probable mechanisms for the formation of suggested. 1,2- and 1,3-dithioles from alpha-enolic dithioesters have been suggested.