497834-53-4Relevant academic research and scientific papers
Cooperative Intramolecular Hydrogen Bonding Strongly Enforces cis-Peptoid Folding
Wijaya, Andrew W.,Nguyen, Andy I.,Roe, Leah T.,Butterfoss, Glenn L.,Spencer, Ryan K.,Li, Nan K.,Zuckermann, Ronald N.
, p. 19436 - 19447 (2019)
Sequence-defined peptoids, or N-substituted glycines, are an attractive class of bioispired polymer due to their biostability and efficient synthesis. However, the de novo design of folded peptoids with precise three-dimensional structures has been hindered by limited means to deterministically control backbone conformation. Peptoid folds are generally destabilized by the cis/trans backbone-amide isomerization, and few side-chains are capable of enforcing a specific amide conformation. Here, we show that a novel class of cationic alkyl ammonium ethyl side-chains demonstrates significant enforcement of the cis-amide backbone (Kcis/trans up to 70) using an unexpected ensemble of weak intramolecular CH-O and/or NH-O hydrogen bonds between the side-chain and the backbone carbonyl moieties. These interactions are evidenced by X-ray crystallography, variable-temperature NMR spectroscopy, and DFT calculations. Moreover, these side-chains are inexpensive, structurally diverse, hydrophilic, and can be integrated into longer peptoid sequences via solid-phase synthesis. Notably, we extended these concepts to synthesize a water-soluble peptoid 10-mer that adopts one predominant fold in solution, as determined by multidimensional NMR spectroscopy. This decamer, to the best of our knowledge, is the longest linear peptoid sequence atomically characterized to retain a well-folded structure. These findings fill a critical gap in peptoid folding and should propel the development of peptoid applications in a broad range of contexts, from pharmaceutical to material sciences.
Cationic lipid-conjugated dexamethasone as a selective antitumor agent
Sau, Samaresh,Banerjee, Rajkumar
, p. 433 - 447 (2014/07/21)
Dexamethasone (Dex) is one of the highly potent synthetic glucocorticoids. It exhibits prominent anti-inflammatory but moderate anti-proliferative activities. It is widely used along side chemotherapy to alleviate toxic side effects. Additionally, Dex is also a potent inducer of gluconeogenesis. However, its overuse critically desensitizes cells against chemotherapy. Herein, we report on the development of a new class of cationic lipid-Dex conjugates in which the C-8 carbon chain analogue (DX8) exhibited glucocorticoid receptor (GR)-mediated, caspase-3-assisted, cancer cell-selective anti-proliferative activity. Melanoma tumors in DX8-treated mice exhibited significantly reduced tumor aggressiveness with respect to tumors in Dex-treated mice. Tumor lysates prepared from DX8-treated group showed elevated levels of p53. DX8-treated cancer cells showed clear degradation of kinase JAK3/STAT3 protein levels. Additionally, DX8-treatment decreased the level of VEGFR2 in tumor-endothelial cells implying DX8's anti-proliferative roles in both tumor cells and tumor neovascular cells. Collectively, our results demonstrate potent anti-angiogenic, and selective JAK3/STAT3 down-regulating anticancer characteristics of DX8, a new dexamethasone-based antitumor molecule.
Microwave assisted mild, rapid, solvent-less, and catalyst-free chemoselective N-tert-butyloxycarbonylation of amines
Dighe, Satish N.,Jadhav, Hemant R.
, p. 5803 - 5806 (2012/10/29)
Microwave assisted simple, rapid, solventless, and catalyst-free chemoselective method for the protection of amino group in aromatic, aliphatic, heterocyclic, aralkyl amines, phenyl hydrazine, and amino acid esters in good to excellent isolated yield (83-98%) in short reaction time (2-12 min) has been reported.
