Structural Studies on Bioactive Compounds. 32. Oxidation of Tyrphostin Protein Tyrosine Kinase Inhibitors with Hypervalent Iodine Reagents
摘要:
Hydroxylated styrenes (tyrphostins) undergo oxidation by hypervalent iodine oxidants such as [(diacetoxy)iodo]benzene (DAIB) to give a range of products depending on the structure of the phenolic substrate, the solvent, the oxidant stoichiometry, and the purification strategy. Conditions have been developed to modify the phenolic component of the tyrphostin without affecting the appended substituted-vinyl moiety. Novel products include: unstable 2-acyloxy-2-methoxy-4-(substituted-vinyl)cyclohexadienones and their rearrangement products 2-acyloxy-4-hydroxy-3 -methoxy-1-(substituted-vinyl)benzenes; phenyliodoniophenolates and their rearrangement products iodophenoxytyrphostins; and 3,3'-dialkoxy-2,2'-dihydroxy-5,5'-di(substituted-vinyl)biphenyls. None of these oxidation products displayed enhanced activity in vitro in the NCI 60-cell line panel or in a panel of human breast cancer cell lines, compared to their tyrphostin precursors. The inhibitory activity of three representative tyrphostins (3e,n, 28) was not modulated by aerobic/anaerobic conditions in MCF-7 and MDA 468 cells and was independent of EGFR status in clones of ZR75B cells transfected with this receptor. Basal growth of MCF-7 cells was unaffected by co-administration of the growth factors EGF, TGF-alpha, IGF-I, and IGF-II, and the new agents did not inhibit EGFR and c-erbB2 autaphosphorylation in cell lysates from MDA 468 or SkBr3 cells, respectively, suggesting that receptor tyrosine kinases are not targets for these compounds. Growth stimulation by the tyrphostin 3n in the ER+ breast cell lines MCF-7, T47D, and ZR75-1 was abolished by 1 mu M tamoxifen, suggesting that this compound has estrogen agonist activity.
A convenient synthesis of pyrimidinone and pyrimidine containing bisheteroarenes and analogs
作者:Hardesh K. Maurya、Atul Gupta
DOI:10.1039/c4ra01689k
日期:——
The synthesis of pyrimidinone containing bisheteroarenes (3) and related analogs (9 and 10) by the reaction of active methylenes or substituted methyl acrylate with nitrogen containing precursors viz. amidines, or thiourea in water as well as other organic solvents was studied. Synthesized compounds have further been explored for the synthesis of diversified pyrimidines 4, 6–8, 11, 12 and 14 through
New photoactive polymers, their use as liquid crystal (LC) orientation layers and their use in the construction of unstructured and structured optical and electro-optical elements and multi-layer systems. The new photoactive polymers are crosslinkable polymers that can be readily cross linked over a relatively short irradiation time.