30954-98-4Relevant academic research and scientific papers
Competitive homolytic and heterolytic decomposition pathways of gas-phase negative ions generated from aminobenzoate esters
Xia, Hanxue,Zhang, Yong,Pavlov, Julius,Jariwala, Freneil B.,Attygalle, Athula B.
, p. 245 - 253 (2016/03/15)
An alkyl-radical loss and an alkene loss are two competitive fragmentation pathways that deprotonated aminobenzoate esters undergo upon activation under mass spectrometric conditions. For the meta and para isomers, the alkyl-radical loss by a homolytic cleavage of the alkyl-oxygen bond of the ester moiety is the predominant fragmentation pathway, while the contribution from the alkene elimination by a heterolytic pathway is less significant. In contrast, owing to a pronounced charge-mediated ortho effect, the alkene loss becomes the predominant pathway for the ortho isomers of ethyl and higher esters. Results from isotope-labeled compounds confirmed that the alkene loss proceeds by a specific γ-hydrogen transfer mechanism that resembles the McLafferty rearrangement for radical cations. Even for the para compounds, if the alkoxide moiety bears structural motifs required for the elimination of a more stable alkene molecule, the heterolytic pathway becomes the predominant pathway. For example, in the spectrum of deprotonated 2-phenylethyl 4-aminobenzoate, m/z 136 peak is the base peak because the alkene eliminated is styrene. Owing to the fact that all deprotonated aminobenzoate esters, irrespective of the size of the alkoxy group, upon activation fragment to form an m/z 135 ion, aminobenzoate esters in mixtures can be quantified by precursor ion discovery mass spectrometric experiments.
Anthranilic acid-based inhibitors of phosphodiesterase: Design, synthesis, and bioactive evaluation
Cheng, Yih-Dih,Hwang, Tsong-Long,Wang, Han-Hsiang,Pan, Tai-Long,Wu, Chin-Chung,Chang, Wen-Yi,Liu, Yi-Ting,Chu, Tzu-Chi,Hsieh, Pei-Wen
experimental part, p. 7113 - 7125 (2011/11/04)
Our previous studies identified two 2-benzoylaminobenzoate derivatives 1, which potently inhibited superoxide (O2-) generation induced by formyl-l-methionyl-l-leucyl-l-phenylalanine (FMLP) in human neutrophils. In an attempt to improve their activities, a series of anthranilic acid derivatives were synthesized and their anti-inflammatory effects and underlying mechanisms were investigated in human neutrophils. Of these, compounds 17, 18, 46, 49, and 50 showed the most potent inhibitory effect on FMLP-induced release of O2- in human neutrophils with IC50 values of 0.20, 0.16, 0.15, 0.06, and 0.29 μM, respectively. SAR analysis showed that the activities of most compounds were dependent on the ester chain length in the A ring. Conversely, a change in the linker between the A and B ring from amide to sulfonamide or N-methyl amide, as well as exchanges in the benzene rings (A or B rings) by isosteric replacements were unfavorable. Further studies indicated that inhibition of O2- production in human neutrophils by these anthranilic acids was associated with an elevation in cellular cAMP levels through the selective inhibition of phosphodiesterase 4. Compound 49 could be approved as a lead for the development of new drugs in the treatment of neutrophilic inflammatory diseases.
Process for preparing anthranilic acid esters
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, (2008/06/13)
Anthranilic esters are obtained in good yield and high purity by transesterification when using potassium carbonate as transesterification catalyst.
