The aim of this work was to synthesize zeolitic imidazolate framework-8 (ZIF-8) by an alternative method and then modify the surface properties for enhancing the CO2 adsorption performance. The ZIF-8 was synthesized by a water based synthesis method using 2-methyl imidazole (2-MeIM) as a hydrogen bond donor and quaternary ammonium salts (QAS) as a hydrogen bond acceptor. The optimal synthesis conditions were investigated by varying (i) the order of precursor mixing during the synthesis process (ii) different QAS (tetrabutyl ammonium bromide (TBAB), tetraethyl ammonium bromide (TEAB) and trimethyl phenyl ammonium bromide (TMPAB)) and (iii) the ratio between 2-MeIM and QAS. The results show that the optimal synthesis condition was using TMPAB as the hydrogen bond acceptor with the ratio between 2-MeIM and TMPAB of 8:2 and in the order of first mixing both hydrogen bond donor and acceptor before adding Zn(NO3)2⋅6H2O solution. TMPAB can provide uniform size distribution with the smallest particle sizes of ZIF-8. This can be explained by the higher hydrogen bond strength between hydrogen bond donor (2-MeIM) and hydrogen bond acceptor (TMPAB) when compared with that of the rest of two QAS. The synthesized ZIF-8 was modified by solvent-assisted ligand exchange methods. The organic linker of ZIF-8 (2-MeIM) was exchanged by 2-aminobenzimidazole (2-NH2bZIM) and 2-phenylimidazole (2-PhIM). The CO2 uptake of modified ZIF-8 was enhanced upon exchanging with 2-NH2bZIM. The increase in CO2 uptake was due to an additional interaction between CO2 and exchanged imidazole linker and an increase in surface properties (higher surface area, pore size and pore volume).

The ongoing search for anticancer agents from microorganisms led to the isolation of four new compounds including 6-ethyl-8-hydroxy-4H-chromen-4-one (1), 6-ethyl-7,8dihydroxy-4H-chromen-4-one (2), (3S)-3,4-dihydro-8-hydroxy -7-methoxy-3-methylisocoumarin (3) and (3S)-3,4-dihydro-5,7,8-trihydroxy-3-methylisocoumarin (4), together with eleven known compounds (5-15) from Xylaria sp. SWUF09-62 fungus. The chemical structures were deduced from IR, 1D and 2D NMR, and MS data. The absolute configurations of 3 and 4 were determined by ECD experiment. Compounds 2 and 4 indicated possible chemoprevention and chemotherapeutic properties, exhibited anti-inflammatory properties by reducing nitric oxide production in LPS-stimulated RAW264.7 cells (IC 50 = 1.57 ± 0.25 and 3.02 ± 0.27 g/mL) and cytotoxicity against HT29 cells (IC 50 = 16.46 ± 0.48 and 97.78 ± 7.14 g/mL).

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Azo dyes are used for silk textile manufacture, where their decolorization and detoxication are necessary after initial dying in the craft industry. The bio-decolorization efficiency of Streptomyces coelicoflavus CS-29 toward commercial azo blue and red dyes was investigated, analyzing the degradation and adsorption of dye molecules. S. coelicoflavus CS-29 showed reductions of 70% and 51% in red and blue dyes, respectively, after seven days. Morphological observation by light microscopy showed that dye molecules were adsorbed onto S. coelicoflavus CS-29 cell surface to form a dense cell pellet. Moreover, peroxidase and laccase activity were detected as extracellular enzymes, but no azo-reductase was detected. From the enzymatic activity, changes of dye profiles in HPLC showed differences between control dyes (untreated dyes) and metabolized products of dyes treated with S. coelicoflavus CS-29. The presence of main functional azo groups (-N=N-) in both blue and red silk dyes was indicated by FTIR analysis, in the untreated azo dyes. The azo bonds seemed to disappear in metabolites after S. coelicoflavus CS-29 treatment and other functional groups were changed compared to the control dyes. The treated dyes showed no significant effect on seed germination, root length, and shoot length of mung beans during phytotoxicity analysis. The red dyes showed a more negative effect on shoot lengths than the blue dyes. The overall results showed that S. coelicoflavus CS-29 is an effective and promising tool for the treatment of dye contaminated wastewater and the permanent elimination of recalcitrant commercial azo dye pollutants.