琵琶湖湖底堆積物におけるクロロフィルaの初期続成的変化

抄録

Chlorophyll a degradation products were extracted from various samples of the 200 m core sample collected from Lake Biwa and separated into 6 components by high performance liquid chromatography. Pheophytin a, pyropheophytin a, pheophorbide a and pyropheophorbide a were identified, however the structures of rest of two components were tentatively determined as compounds which propyl residue of pyropheophytin a was reduced to aldehyde or alcohol and alkyl residue. Sedimentary samples showed markedly change in the percentage composition of these degradation products of chlorophyll a with depth. From such a vertical change, it can be concluded that removal of methoxycarbonyl residue at C_6d of pheophytin a took place first after the burial of pheophytin a, followed by hydrolysis of phytyl ester and reduction of propyl residue at C_7b of pheophytin a.