High-Performance Thin-layer chromatography (HPTLC) combined with DPPH free radical method and α-amylase bioassay was used to compare antioxidant and antidiabetic activities in ethanol and ethyl acetate extracts from 10 marine macroalgae species (3 Chlorophyta, 4 Phaeophyta and 3 Rhodophyta) from Blue Lagoon beach (Malaysia). Samples were also evaluated for their phenolic and stigmasterol content. On average, higher antioxidant activity was observed in the ethyl acetate extracts (55.1 mg/100 g gallic acid equivalents (GAE) compared to 35.0 mg/100 g GAE) while, as expected, phenolic content was higher in ethanol extracts (330.5 mg/100 g GAE compared to 289.5 mg/100 g GAE). Amounts of fucoxanthin, stigmasterol and α-amylase inhibitory activities were higher in ethyl acetate extracts. Higher enzyme inhibition is therefore related to higher concentrations of triterpenes and phytosterols (Note: these compounds are more soluble in ethyl acetate). Ethyl acetate extracts from Caulerpa racemosa and Padina minor, had the highest α-amylase inhibitory activity, and also showed moderately high antioxidant activities, stigmasterol content and polyphenolic content. Caulerpa racemose, being green algae, does not contain fucoxanthin, while Padina minor, being brown algae, contains high amounts of fucoxanthin. Therefore, it is very unlikely that fucoxanthin contributes to α-amylase inhibitory activity as previously reported.

高性能薄层色谱（HPTLC）与DPPH结合自由基法和α-淀粉酶生物测定法用于比较来自马来西亚蓝礁湖海滩的10种海洋大型藻类（3种绿藻，4种藻类和3种红藻类）的乙醇和乙酸乙酯提取物中的抗氧化剂和抗糖尿病活性。还评估了样品的酚和豆甾醇含量。平均而言，在乙酸乙酯提取物中观察到较高的抗氧化活性（55.1 mg / 100 g没食子酸当量（GAE），而在35.0 mg / 100 g GAE中则发现），正如预期的那样，乙醇提取物中的酚含量较高（330.5 mg / g 100克GAE，而289.5毫克/ 100克GAE）。乙酸乙酯提取物中岩藻黄质，豆甾醇和α-淀粉酶的抑制活性较高。因此，更高的酶抑制作用与更高浓度的三萜和植物甾醇有关（注意：这些化合物更易溶于乙酸乙酯）。乙酸乙酯提取物芸苔和Padina minor，具有最高的α-淀粉酶抑制活性，并且还表现出中等高的抗氧化活性，豆固醇含量和多酚含量。Caulerpa消旋体是绿藻，不包含岩藻黄质，而Padina minor是褐藻，其含有大量的岩藻黄质。因此，岩藻黄质极不可能像先前报道的那样对α-淀粉酶的抑制活性有贡献。