• Bulletin of the Korean Chemical Society
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• v.26 no.6
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• pp.998-1000
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• 2005

• Bulletin of the Korean Chemical Society
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• v.23 no.9
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• pp.1291-1294
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• 2002

Various racemic N-protected ${\alpha}-amino$ acids such as N-t-BOC-(tert-butoxycarbonyl), N-CBZ-(benzyloxycarbonyl) and N-FMOC-(9-fluorenylmethyloxycarbonyl) ${\alpha}-amino$ acids were resolved as their anilide and 3,5-dimethylanilde derivatives on an HPLC chira l stationary phase (CSP) developed by modifying a commercial (S)-leucine CSP. The chromatographic resolution results were compared to those on the commercial (S)-leucine CSP. The resolutions were greater on the modified CSP than those on the commercial CSP with only one exception, the resolution of N-t-BOC-phenylglycine anilide. In addition, the chromatographic resolution behaviors were quite consistent except for the resolution of N-protected phenylglycine derivatives, the (S)-enantiomers being retained longer. Based on the chromatographic resolution behaviors and with the aid of CPK molecular model studies, we proposed a chiral recognition mechanism for the resolution of N-protected ${\alpha}-amino$ acid derivatives. However, for the resolution of N-protected phenylglycine derivatives, a second chiral recognition mechanism, which competes in the opposite sense with the first chiral recognition mechanism, was proposed. The two competing chiral recognition mechanisms were successfully used in the rationalization of the chromatographic behaviors for the resolution of N-protected phenylglycine derivatives.

• Bulletin of the Korean Chemical Society
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• v.27 no.8
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• pp.1222-1224
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• 2006

• Journal of the Society of Cosmetic Scientists of Korea
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• v.30 no.3 s.47
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• pp.399-404
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• 2004

Novel GHK-conjugated chitosan was prepared by the solid-phase method using $N^{\alpha}-Fmoc$ amino acids/BOP coupling reagent. For this purpose, the chitosan microbeads which had a mean diameter of 70 um were prepared by the W/O emulsion-phase separation method. The GHK was successfully coupled to the chitosan microbeads by stepwise solid-phase method. The result of amino aid analysis was in good agreement with the theoretical values; $Gly_{1.02}\;of\;His_{1.13}\;Lys_{0.96).$. The cell proliferation effect of the GHK-bound chitosan microbeads was measured by MTT assay. We concluded that GHK-bound chitosan microbeads gave higher cell Proliferation effect than chitosan microbeads.