POLY 257 |
| Many microorganisms produce poly(hydroxyalkanoate)s, PHAs as Carbon and energy storage. Due to their natural origin, PHAs are considered biocompatible. Pseudomonas oleovorans, a gram-negative microorganism, produces medium chain-length PHAs, mclPHAs, from alkanes and alkane derivatives. Fermentations of P. oleovorans on 11-bromoundecanoic acid or 10-undecenoic acid using co-feeding techniques yield functionalized mclPHAs, fmclPHAs, with reactive pendant bromo- or vinyl side groups: (poly(hydroxynonanoate-co-hydroxy-11-bromo-undecanoate)), PHNBr, (poly(hydroxyoctanoate-co-hydroxy-10-undecenoate)), PHOU; MW ~ 100,000. The degree of functionalization can be controlled by the ratio of functionalized substrate to co-substrate. Pending vinyl-side groups were transformed into epoxy groups by m-chlorobenzoic acid and subsequently aminated with diethanol amine yielding PHA-polyelectrolytes that are readily water-soluble. This is the first report on amino-containing PHA, a bacterial polyester not accessible by direct conventional fermentation approaches. These novel PHA-polyelectrolytes can interact with DNA. Both fmclPHAs were also investigated for polymer-analogous reactions with alpha-methoxy-omega-amino and alpha-methoxy-omega-thiol poly(ethylene glycol), leading to small fractions of water-soluble mclPHA-g-PEG. |
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Polymers from Renewable Resources
8:20 AM-11:45 AM, Monday, August 20, 2007 Westin Boston Waterfront -- Douglas, Oral
Division of Polymer Chemistry |