幾丁質酸水解過程中所產生N-乙醯幾丁寡醣之HPLC分析   全文下載

HPLC Analysis of N-acetyl-chito-oligosaccharides during the Acid Hydrolysis of Chitin

本研究係針對幾丁寡醣的HPLC 分析方法加以探討。幾丁質（乙醯度93%）經過鹽酸水解之後，產物多半為聚合度2 至6 之N-乙醯幾丁寡醣。幾丁寡醣在層析管柱中之滯留時間隨著流動相中水含量的增加而縮短。採用乙與水之體積比在60 分鐘之內由80:20 線性降低至60:40 之梯度沖提，可於40 分鐘內得到低聚合度N-乙醯幾丁寡醣最佳的解析與鑑定效果。N-乙醯幾丁寡醣在HPLC 中之滯留時間之自然對數值與其聚合度呈現線性關係。幾丁質之酸水解過程遵循串聯──並聯反應機制。高濃度鹽酸溶液配合較短反應時間可以產生較多較高聚合度的N-乙醯幾丁寡醣，而較高的反應溫度則有助於產生較低聚合度的N-乙醯幾丁寡醣。

The hydrolysis of chitin (93% N-acetylation) by hydrochloric acid produced N-acetylchito- oligosaccharides (NACOs) with low degrees of polymerization (DP) from 2 to 6. The HPLC retention time of NACOs decreased with increased water content in the mobile phase. A gradient elution procedure, using acetonitrile to water (v/v) ratio lowered linearly from 80/20 to 60/40 within 60 min, provided optimal resolution and characterization for the NACOs. The natural logarithm of the retention time of NACOs correlated linearly with the DP values. Hydrolysis of chitin followed a series-parallel reaction mechanism. At the same time the NACOs with higher DP’s were generated from chitin, and were degraded by hydrochloric acid to form products with lower DP’s. More NACOs with higher DP’s were produced under conditions with higher concentrations of hydrochloric acid and a shorter reaction period. Higher temperatures facilitated the generation of NACOs with lower DP’s. 本研究係針對幾丁寡醣的HPLC 分析方法加以探討。幾丁質（乙醯度93%）經過鹽酸水解之後，產物多半為聚合度2 至6 之N-乙醯幾丁寡醣。幾丁寡醣在層析管柱中之滯留時間隨著流動相中水含量的增加而縮短。採用乙與水之體積比在60 分鐘之內由80:20 線性降低至60:40 之梯度沖提，可於40 分鐘內得到低聚合度N-乙醯幾丁寡醣最佳的解析與鑑定效果。N-乙醯幾丁寡醣在HPLC 中之滯留時間之自然對數值與其聚合度呈現線性關係。幾丁質之酸水解過程遵循串聯──並聯反應機制。高濃度鹽酸溶液配合較短反應時間可以產生較多較高聚合度的N-乙醯幾丁寡醣，而較高的反應溫度則有助於產生較低聚合度的N-乙醯幾丁寡醣。