32 カエルの体色発現色素と脳ガングリオシドの構造(口頭発表の部)

抄録

The five pigments (1)-(5) and a colorless substance 6 were present in the dorsal skin of frogs of the nine selected species belonging to Rhacophoridae, Ranidae, Hylidae, and Bufonidae. These pigments were identified as pterin-6-carboxylic acid, xanthopterin, isoxanthopterin, erythro-biopterin, 6-hydroxymethylpterin, and guanine, respectively. Another pigment 7 was specifically present in the skin of genus Rhacophorus and was deduced to be a pteridine derivative composed of five molecules of pterin-6-carboxylic acid. The nine species were found to be divided into six chemotypes on the basis of their pigment composition. Three gangliosides were isolated from the brain tissues of bull frog (Rana gatesbeiana). The structures of these gangliosides were established to be disialosylgangliotetraosyl-ceramide (III^6NeuAcIV^3NeuAc-GgOse_4Cer), trisialosyl-gangliotetraosylceramide (III^6NeuAcIV^3(NeuAc)_2-GgOse_4Cer), and tetrasialosylgangliotetraosylceramide(III^6(NeuAc)_2IV^3(NeuAc)_2-GgOse_4Cer) by phisico-chemical method. Similarity in the dis-tribution of these gangliosides was seen among hemisph, diencephalon, and a mixed tissue of opticlobe, cerebellum, and medulla oblongata of the brain. The brain tissues of Rana nigromaculata and Rhacophorus arboreus also included the same gangliosides as those of bull frog.