Umashankar Das

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A number of 3,5-bis(benzylidene)-4-piperidones 1 and some N-4-(2-aminoethoxy)phenylcarbonyl analogs 3-6 display excellent in vitro antimycobacterial properties. In particular, 1c and 6d are potent antimycobacterials which are well tolerated in mice and are identified as important lead molecules. The nature of both the benzylidene aryl rings and the terminal(More)
A number of organic molecules which contain the 1,5-diaryl-3-oxo-1,4-pentadienyl group, referred to hereafter as the dienone moiety, have antineoplastic properties. Emphasis is made on the attachment of this structural moiety to several molecular scaffolds, namely piperidines, N-acylpiperidines, cycloalkanes and 3,4-dihydro-1H-napthalenes. Many of these(More)
Various classes of cytotoxic compounds which alkylate cellular thiols are described namely alpha,beta-unsaturated ketones, alpha-methylene-gamma-lactones, azines of Mannich bases, imexon, isothiocyanates, a benzoacronycine as well as activation by thiols prior to alkylation. The mechanisms of action of some of the molecules, such as the formation of(More)
N-myristoyltransferase (NMT) is an essential eukaryotic enzyme which catalyzes the transfer of the myristoyl group to the terminal glycine residue of a number of proteins including those involved in signal transduction and apoptotic pathways. Myristoylation is crucial for the cellular proliferation process and is required for the growth and development in a(More)
JAK3 is a cytoplasmic tyrosine kinase with limited tissue expression but is readily found in activated T cells. Patients lacking JAK3 are immune compromised, suggesting that JAK3 represents a therapeutic target for immunosuppression. Herein, we show that a Mannich base, NC1153, blocked IL-2-induced activation of JAK3 and its downstream substrates STAT5a/b(More)
A series of 3,5-bis(benzylidene)-4-piperidones 3 were converted into the corresponding 3,5-bis(benzylidene)-1-phosphono-4-piperidones 5 via diethyl esters 4. The analogues in series 4 and 5 displayed marked growth inhibitory properties toward human Molt 4/C8 and CEM T-lymphocytes as well as murine leukemia L1210 cells. In general, the N-phosphono compounds(More)
Hydrogen peroxide (H2O2) and persulfate are the most efficient and commonly used oxidants in in-situ chemical oxidation (ISCO) of organic contaminants. This review focuses on the principle and activation techniques used in H2O2 and persulfate based ISCO processes. It is crucial to understand the effect of activation techniques on process chemistry and free(More)
The 3,5-bis(arylidene)-4-piperidones 1 contain the 1,5-diaryl-3-oxo-1,4-pentadienyl pharmacophore which is considered to interact at a complementary binding site in susceptible neoplasms. The hypothesis was formulated that the presence of an acyl group attached to the piperidyl nitrogen atom in series 1 may interact with an additional binding site thereby(More)
A series of 2-(3-aryl-2-propenoyl)-3-methylquinoxaline-1,4-dioxides 3a-l were prepared by condensation of various aryl aldehydes with 2-acetyl-3-methylquinoxaline-1,4-dioxide 2. These compounds inhibit the growth of human Molt 4/C8 and CEM T-lymphocytes and the IC(50) values are mainly in the 5-30 microM range. The quinoxaline 1,4-dioxide 3j inhibited the(More)
Two novel series of dimeric 3,5-bis(arylidene)-4-piperidones 7 and 8 were prepared as cytotoxic agents. A specific objective of this study was the discovery of novel compounds displaying potent anti-proliferative activities against colon cancers. Most of the compounds demonstrate potent cytotoxicity against HCT116 and HT29 colon cancer cell lines in which(More)