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Palm shell-based adsorbents prepared under five different thermochemical conditions and palm shell powder have been shown to be quite effective for removal of uranium from aqueous solutions. X-ray photoelectron spectroscopy (XPS), extended X-ray absorption fine structure (EXAFS), and Fourier transform infrared spectroscopy (FTIR) have been used to determine information about the speciation and binding of uranium on the adsorbents under study. Studies indicate that the uranium which is present as uranyl ion in aqueous solution is present in mixed valence states (U(IV), U(V), and U(VI)) when it is bound to the adsorbents. The mechanism of adsorption is likely to be adsorption-coupled reduction as well as complexation. Adsorption of uranium, cesium, and iron was found to be quantitative in binary as well as ternary mixtures.

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The adsorption of reactive dyes onto acid-treated palm shell powder (APSP) and chitosan has been investigated. The parameters affecting the rate process involved in the removal of dye like contact time, temperature, pH, adsorbent dose, and dye concentration were studied. pH 4 was suitable for the adsorption of both reactive dyes onto chitosan and was independent of pH in the range pH 2 to 9 using APSP as the adsorbent. The process of dye removal followed pseudosecond-order kinetics. The adsorption equilibria isotherms were analyzed by the Langmuir and Freundlich isotherms. The adsorption capacities were found to be 13.95 mg • g -1 and 24.86 mg • g -1 for reactive red 141 and reactive blue 21 using APSP as adsorbent. The adsorption capacities were found to be 22.48 mg • g -1 and 70.08 mg • g -1 for reactive red and reactive blue, respectively, using chitosan as the adsorbent.

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A series of novel pyrano[3,2-c]carbazole derivatives have been synthesized by a simple one-pot, three component reaction of aromatic aldehydes, malononitrile-ethyl cyanoacetate and 4-hydroxycarbazoles catalyzed by triethylamine. The antiproliferative activity of the derivatives on various cancer cell lines such as MDA-MB-231, K562, A549 and HeLa was investigated. Among 9a-p, congeners 9a, 9c, 9g and 9i showed profound antiproliferative activity with IC50 values ranging from 0.43 to 8.05 μM and induced apoptosis significantly by inhibiting tubulin polymerization. Cell-based biological assays demonstrated that treatment of cell lines with compounds 9a, 9c, 9g and 9i results in G2/M phase arrest of the cell cycle. Moreover the derivatives significantly disrupted the microtubule network, produced an elevation of cyclinB1 protein levels and induced apoptosis by increasing the caspase-3 levels. In particular, 9i strongly inhibited tubulin assembly compared to the positive control CA-4. Molecular docking studies demonstrated that all the lead compounds selectively occupy the colchicine binding site of the tubulin polymer.

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The oxadiazoles reported herein are tubulin inhibitors and cytotoxic agents. These findings will be helpful in future drug design of more potent tubulin inhibitor cytotoxic agents.