茶花粉萃取液之酚類化合物組成分析及抗氧化活性探討   全文下載

Preliminary Analyses of Phenolic Compounds and Antioxidant Activities in Tea Pollen Extracts

台灣的蜂花粉商品主要來源是茶花（Camellia sinensis, tea pollen）。本研究分析茶花粉經酒精與水萃取得4種花粉萃取液(50% EE 、95% EE 、 CWE及HWE）中之酚類化合物（包含總多酚、類黃酮、游離類黃酮糖?配基與酚酸化合物）的種類與含量，進一步比較分析其總抗氧化效果、清除過氧化氫及鐵離子螯合能力。研究中直接以高效液相層析儀定量出茶花粉中9種酚類物質，包含gallic acid 、catechin 、methyl gallate 、caffeic acid 、 p-coumaric acid 、ferrulic acid 、rutin 、myricetin及chlorogenic acid。在4種萃取液中均以gallic acid（0.69 ± 0.01 ~ 2.55 ± 0.05 mg/g）含量最多。此外，亦有豐富的 caffeic acid 、P-coumaric acid及ferulic acid；Methyl gallate 、 rutin 及myricetin則僅存在花粉酒精（50%及95%）萃取液中，在花粉水（冷水及熱水）萃液中並無發現。結果顯示酒精萃取液中酚類化合物（游離類黃酮糖?配基及酚酸）的種類多於水萃取液。以ABTS（2, 2'-azino-bis-(3- ethylbenzthiazoline-6-sulfonic acid）法進行抗氧化實驗發現花粉酒精萃取液高於花粉水萃取液；花粉冷水萃取液（CWE）之過氧化氫清除力最佳；50%酒精萃取液（50% EE）則呈現較好的金屬螯合能力。本研究應是第一篇探討分析茶花粉游離類黃酮糖?配基及酚酸種類與含量的報告。研究結果顯示茶花粉含豐富多酚物質，是一項提供抗氧化物質來源的良好補充品。"

Tea (Camellia sinensis) pollen is one of the main bee-collected pollen staples in Taiwan. We analyzed the contents of the phenolic compounds (total phenols, flavonoids, free aglycones of flavonoid and phenolic acids) in tea pollen, obtained by aqueous extraction (cold and hot water) or ethanolic extraction (50% EE and 95% EE). The antioxidant activity, capacity of scavenging H2O2, and chelating ability were measured. Nine phenolic compounds, including gallic acid, catechin, methyl gallate, caffeic acid, p-coumaric acid, ferulic acid, rutin, myricetin, and chlorogenic acid, were identified and quantified, while gallic acid (0.69 ± 0.01 to 2.55 ± 0.05 mg/g) was the most abundant. In the four tea pollen extracts, caffeic acid, P-coumaric acid, and ferulic acid presented high concentrations. Methyl gallate, rutin and myricetin were detected only in the ethanolic extracts (50% and 95% ethanolic extracts). Ethanolic extracts contained more phenolic compounds than in aqueous extracts. The total antioxidant activity, as measured by the ABTS (2, 2′-azino-bis-(3-ethylbenzthi-azoline- 6-sulfonic acid) method, indicated that the ethanolic extracts had greater antioxidant activities than the aqueous extracts and the 50% ethanolic extract effectively chelated ferrous ions. The cold water extract had the greatest hydrogen peroxide scavenging ability. We believe this is the first report on the content of phenolic compounds, especially free flavonoid aglycones, and phenolic acids from tea pollen. Our findings indicated that tea pollen could be a good nutraceutical and dietary antioxidant supplement.