18595-16-9Relevant articles and documents
Tuning a robust system: N,O zinc guanidine catalysts for the ROP of lactide
Sch?fer, Pascal M.,McKeown, Paul,Fuchs, Martin,Rittinghaus, Ruth D.,Hermann, Alina,Henkel, Johanna,Seidel, Sebastian,Roitzheim, Christoph,Ksiazkiewicz, Agnieszka N.,Hoffmann, Alexander,Pich, Andrij,Jones, Matthew D.,Herres-Pawlis, Sonja
, p. 6071 - 6082 (2019)
Non-toxic, highly active and robust complexes are the holy grail as ideal green catalysts for the polymerisation of biorenewable and biodegradable polylactide. Four new zinc guanidine complexes [ZnCl2(TMG4NMe2asme)], [ZnCl2(TMG5Clasme)], [ZnCl2(TMG5Measme)] and [ZnCl2(TMG5NMe2asme)] with different electron-donating and electron-withdrawing groups on the ligand's aromatic backbone have been synthesised. Ligands are derived from low-cost commercially available compounds and have been converted by a three- or four-step synthesis process into the desired ligand in good yields. The compounds have been fully characterised and tested in the ROP of rac-LA under industrially relevant conditions. The complexes are based on the recently published structure [ZnCl2(TMGasme)] which has shown high activity in the polymerisation of lactide at 150 °C. Different substituents in the para-position of the guanidine moiety significantly increase the polymerisation rate whereas positioning substituents in the meta-position causes no change in the reaction rate. With molecular weights over 71000 g mol-1 being achievable, the best system produces polymers for multiple industrial applications and its polymerisation rate approaches that of Sn(Oct)2. The robust systems are able to polymerise non-purified lactide. The initiation of the polymerisation is suggested to occur due to impurities in the monomer.
Scaffold Hopping of Natural Product Evodiamine: Discovery of a Novel Antitumor Scaffold with Excellent Potency against Colon Cancer
Wang, Lei,Fang, Kun,Cheng, Junfei,Li, Yu,Huang, Yahui,Chen, Shuqiang,Dong, Guoqiang,Wu, Shanchao,Sheng, Chunquan
, p. 696 - 713 (2020/02/04)
Inspired by the natural product evodiamine, a novel antitumor indolopyrazinoquinazolinone scaffold was designed by scaffold hopping. Structure-activity relationship studies led to the discovery of compound 15j, which shows low nanomolar inhibitory activity against the HCT116 cell line. Further antitumor mechanism studies indicated that compound 15j acted by the dual inhibition of topoisomerase 1 and tubulin and induced apoptosis with G2 cell-cycle arrest. The quaternary ammonium salt of compound 15j (compound 15js) exhibited excellent in vivo antitumor activity (TGI = 66.6%) in the HCT116 xenograft model with low toxicity. Indolopyrazinoquinazolinone derivatives represent promising multitargeting antitumor leads for the development of novel antitumor agents.
Discovery of (S)-3′-hydroxyblebbistatin and (S)-3′-aminoblebbistatin: polar myosin II inhibitors with superior research tool properties
Verhasselt, Sigrid,Roman, Bart I.,De Wever, Olivier,Van Hecke, Kristof,Van Deun, Rik,Bracke, Marc E.,Stevens, Christian V.
supporting information, p. 2104 - 2118 (2017/03/11)
In search of myosin II inhibitors with superior research tool properties, a chemical optimization campaign of the blebbistatin scaffold was conducted in this paper. (S)-Blebbistatin is the best known small-molecule inhibitor of myosin II ATPase activity. Unfortunately, as a research tool this compound has several deficiencies: it is photolabile and (photo)toxic, has low water solubility, and its (fluorescent) precipitates interfere in (fluorescence) readouts. In view of obtaining tool compounds with improved properties, both enantiomers of a series of D-ring modified polar analogs were prepared. We identified (S)-3′-hydroxyblebbistatin (S)-2 and (S)-3′-aminoblebbistatin (S)-3 as two myosin II inhibitors with a 30-fold higher water solubility than (S)-blebbistatin. These molecules furthermore do not cause interference in (fluorescence) readouts. (S)-2 and (S)-3 thus are superior alternatives to (S)-blebbistatin as research tools to study myosin II.
