天然物為大自然賦予的重要資源，隨著人類越來越重視健康與養生，高品質的天然物也越受到重視。超臨界二氧化碳萃取技術，是為一綠色化學概念之技術，因其萃取產物無溶劑殘留問題，且只要適當的控制壓力與溫度，即具有良好的萃取選擇性，保留活性成份，並提高萃取產率；目前已愈來愈廣泛應用於各界。
本研究所選用的植物材為台灣特有之原生植物--月桃(Alpinia zerumbet)，為薑科(Zingiberaceae)月桃屬(Alpinia)之多年生常綠性草本植物，利用超臨界二氧化碳萃取(SC-CO2) 、水蒸氣蒸餾萃取、超音波萃取及溶劑萃取這四種不同的萃取法來進行月桃葉之萃取，比較其產率，並配合氣相層析質譜分析儀(GC-MS) 分析不同萃取法成分差異，並測試其抗菌 (大腸桿菌、金黃色葡萄球菌、綠膿桿菌)、抗發炎及抗氧化活性(清除DPPH‧)。
於抗氧化部分，超臨界流體萃取60℃，300bar之萃取物清除DPPH自由基能力清除效果最好。 抗發炎活性部分，抑制5-脂氧酶（5-Lipoxygenase）能力以超臨界流體萃取60℃，300bar之萃取物抑制能力效果最好。 抗菌活性部分，測試其最小抑菌濃度、最小殺菌濃度，發現只有水蒸氣蒸餾萃取之月桃精油對大腸桿菌、綠膿桿菌、金黃色葡萄球菌均具有抑制作用，且發現月桃精油對格蘭氏陰性菌的抑制效果優於格蘭氏陽性菌。 Natural products are an important resource of nature. Supercritical carbon dioxide extraction technology is a concept of green chemistry. There will be not residual solvent left in the extract. The properties of a supercritical carbon dioxide can be changed by controlling the pressure and temperature, which has a good extraction selectivity, retention of active ingredients, and to improved extraction yield. It has been more and more widely used in various fields.
In this study, Taiwan endemic plants Alpinia zerumbet, a perennial evergreen herb, was extracted by supercritical carbon dioxide extraction, steam distillation extraction, ultrasonic wave extraction and solvent extraction from leaves. The compositions, yield, antibacterial, anti-inflammatory and antioxidant activities of extracts were umpired. The result showed that the supercritical fluid extracts (60 ℃, 300bar) exhibited the best DPPH radical scavenging effect and inhibition of 5-Lipoxygenase activity.
In the assay of antibacterial activity, the essential oils extracted by steam distillation method had excellent antibacterial activity against Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus.
