Lampteromyces Bioluminescence---production of the light emitter from riboflavin

本项目拟对月夜菇生物发光的分子机制进行研究。根据生物发光体的发光光谱在524 nm处出现最大值，且提取物具有相同的荧光光谱，确定该发光体的发色团为异四氧嘧啶。发光的菌丝体被培养成与蘑菇的鳃显示相同的光。这种发光物质被命名为灯盏花黄素。它是从酸性溶液中分离出来的，新鲜的鳃在氧气气氛下浸泡并发光过夜。溶液通过结合疏水物质的柱子。甲醇洗脱液得到单一的绿色荧光化合物灯盏花黄素，在FAB-MS光谱中显示m/z为509。灯盏花黄素很容易被酸水解成核黄素，m/x为377；质量差133表明存在戊糖。以m/z259为母离子的LF六乙酸酯串联MS/MS对该糖进行了鉴定。通过比较四种不同来源的MS/MS图谱，确定该糖为核糖。这进一步得到了核磁共振谱的支持。NOE实验揭示了核黄素5‘端α键核糖的连接。酶解产物的圆二色谱表明其为D-核糖，因此灯盏花黄素的绝对结构为5‘-D-呋喃核糖核黄素。进一步的研究将通过立体选择性地合成灯盏花黄素，为进一步研究蘑菇生物发光的分子机制提供依据。

The molecular mechanism of the bioluminescence in moon-night mushroom (TSUKIYOTAKE) is to be elucidated in this project. The chromophore of the light emitter in this luminescence was assigned to be isoalloxazine from the facts that the bioluminescence spectrum showed its maximum at 524 nm and that the extracts showed an identical fluorescence spectrum. Luminous myceria was cultivated to exhibit the same light as the gills from the mushroom. The light emitter was named as lampteroflavin. It was isolated from an acidic solution in which fresh gills were immerged and luminesced for overnight under oxygen atmosphere. The solution was passed through columns which combined the hydrophobic substances. Methanol eluate afforded a single green fluorescent compound, lampteroflavin, which showed m/z 509 in FAB-MS spectrum. Lampteroflavin was readily hydrolyzed by acid into riboflavin, m/x 377; the mass difference 133 suggested the presence of pentse. This sugar was identified by tandem MS/MS of hexaacetate of Lf at m/z 259 as parent ion. From comparison of four authentic MS/MS spectra the sugar was identified to be ribose. This was further supported from nmr spectra. NOE experiments disclosed the connection of the ribose in alpha linkage at the 5' position of riboflavin. CD spectrum of the hydrolysate concluded the D-ribose; and thus the absolute structure of lampteroflavin is 5'- -D-ribofuranosyl-riboflavin. Further studies will be followed by stereoselective synthesis of lampteroflavin to supply for the investigation of the molecular mechanism of the mushroom bioluminescence.