• Journal of Microbiology and Biotechnology
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• v.16 no.4
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• pp.637-638
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• 2006

Bioassay-guided fractionation of an organic extract of the culture broth from an unidentified marine-derived fungus led to the isolation of a new metabolite, N-[2-(4-hydroxyphenyl) acetyl]formamide (1), along with four known polyketides, 4-hydroxyphenyl acetamide (2), 4-hydroxyphenyl acetic acid (3), 3,4-dihydroxyphenyl acetic acid (4), and N-[2-(4-hydroxyphenyl)ethenyl]formamide (5). The structures of 1-5 were elucidated by spectral data analyses. Among them, compounds 1, 4, and 5 exhibited significant radical scavenging activity against 1, 1-diphenyl-2-picrylhydrazyl (DPPH) with $IC_{50}$ values of 8.4, 11.9, and $0.2{\mu}M$, respectively.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.02a
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• pp.529-529
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• 2012

Dispersion of carbon nanotubes in biocompatible media are of particular interest for diverse biomedical and nanomedicine applications. Various biomolecules and biopolymers such as DNA, proteins, poly L-lysine, starch, gelatin, steroid biosurfactants, and chitosan have shown capability for the effective dispersion of carbon nanotubes in water. Chitosan has demonstrated capacity for effective dispersion of single-walled carbon nanotubes (SWCNTs) in acidic medium and it also showed tendency to preferentially disperse smaller diameter nanotubes. Chemical functionalizations of chitosan enable its solubility in neutral pH water by reducing the intra and inter molecular hydrogen bonding. Herein, we present a neutral pH water soluble chitosan derivative, chitosan-hydroxyphenyl acetamide (CHPA), obtained by functionalizing the amino groups of chitosan with 4-hydroxyphenyl acetic acid, as an efficient biocompatible dispersant for debundling and solubilization of SWNTs in neutral aqueous solutions. Various process conditions for individual dispersion of SWCNTs are analyzed based on optical absorption and Raman spectroscopy.