紫贻贝贝壳和脉红螺厣中色素的提取与鉴定

Extraction and identification of the pigment in the Mytilus edulis shells and Rapana venosa operculum

为了确定紫贻贝（Mytilus edulis）贝壳与脉红螺厣中的黑色物质是否为黑色素这一物质,作者实验选取紫贻贝贝壳和脉红螺（Rapana venosa）厣,清洗干净,之后分别对两份样品进行研磨粉碎、称量、盐酸浸泡、沸水浴加热、乙醚纯化等步骤后,将得到的黑色提取物质用0.01 ml/L氢氧化钠水溶液溶解,在190~500 nm的范围内测定紫外吸收光谱,发现两份样品最大吸收峰都在210~220 nm,随波长增加,其吸光值下降,与公认的黑色素紫外吸收光谱特征一致;另外将提取的两份黑色固体物质分别用溴化钾压片后进行傅里叶红外光谱扫描,其红外图谱都在3μm和6μm处分别有特征吸收峰,亦与公认的黑色素红外扫描图谱特征一致,从而首次确定紫贻贝贝壳和脉红螺厣中的黑色物质为黑色素,提示黑色素在贝类中可能是广泛存在的。

To determine if the black substance in the Mytilus edulis shells and Rapana venosa operculum is melanin, we selected the Rapana venosa operculum part and collected M. edulis shells, cleaned the two samples and then pulverized them, weighed, followed by hydrochloric acid soaking, boiling water bath for heating, as well as diethyl ether purification step, then, the dissolved black substance in 0.01 m L/L Na OH, the maximum absorption of the two pigments in the UV absorption spectrum within the range of 190–500 nm was both observed between 210–220 nm. The UV absorbance decreased with increasing wavelength which was consistent with the UV spectral absorption characteristics of melanin. In addition, Fourier transform infrared spectroscopy scanning revealed characteristic absorption peaks that emerged near 3 μm and 6 μm, which was consistent with infrared scanning features of eumelanin. Thus the black substance in the Rapana venosa operculum and M. edulis shells was confirmed to be melanin for the first time.