|Budget Amount *help
¥2,200,000 (Direct Cost : ¥2,200,000)
Fiscal Year 1991 : ¥200,000 (Direct Cost : ¥200,000)
Fiscal Year 1990 : ¥300,000 (Direct Cost : ¥300,000)
Fiscal Year 1989 : ¥1,700,000 (Direct Cost : ¥1,700,000)
For the purpose of development of utilization methods on plant resources, the investigator attended to Japanese conifer leaves which had not been used for the human life. Together with carbohydrates such as cellulose and polyphenols such as lignin, the leaf contains a large amount of cutin constituent. Cutin is a mixture of oligo-esters, estoride, composing from aliphatic acids and alcohols. The study was undertaken in order to establish the direct and indirect utilization methods of leaf estorides.
At first, total estoride contents were estimated on 23 species of conifer leaves. Extract-free leaf powders respectively were analyzed by Klason and acetyl bromide methods which were common to quantitative analysis of lignin. Then, it was evaluated that the content difference between two values meant a real estoride content. The values among samples were covered a limit of 10-20 % for the dried leaf powder weight.
Nextly, alkaline hydrolyses of 42 samples were undergone, and their total acid
and alcohol contents were obtained respectively. The former values ranged from 1 % to 6 %, and the latter comprised from trace to 14 % against the corresponding acid content. Also, the identification arid quantitative analysis of acids and alcohols were carried out. Nine acids containing 12-hydroxylauric acid, 10, 16-dihydroxyhexadecanoic acid, hexadecane-1, 16-dioic acid, etc. were identified and their qualitative and quantitative relations were proved. The presence pattern among samples was characteristic in the plant species. Similarly, six alcohols such as 1, 12-dodecandiol, 1, 14-tetrade-canediol, 1, 16-hexadecanediol were isolated and measured. The presence tendency among samples was similar to that of the acids.
As there was a large gap between the estoride content and the calculated content based on the hydrolized acid and alcohol amounts, Various pretreatment procedures were attempted for the effective possession of estoride and its degradative products. Accordingly, steam-explosion, chlorine and enzyme treatments were effective for this purpose. Furthermore, the changes due to leaf age and season were examined on estoride and its composing monomer contents. It was indicated there were not remarkable qualitative and quantitative differences among samples.
Consequently, for the most effective possession of some objective estoride and/or monomer, one suitable sample and pretreatment method can be presented. Then, it can be judged that these knowledges is available for developing utilization methods of leaf estoride. Less