2 ハマナス(Rosa rugosa)葉の主抗菌性セスキテルペンパーオキシド、rugosal Aの生合成、局在化およびその機能について(口頭発表の部)

抄録

From Rosa rugosa leaves, three major carotane sesquiterpenes were isolated and their structures elucidated. Rugosal A (1) isolated as the major antifungal substance of the leaf extracts together with its corresponding acid rugosic acid A (2) and its precursor carota-1,4-dienaldehyde (3) constitute the highest propotion of the leaf extracts. Compound (3) was converted into (1) through autoxidation reaction process with two O_2 molecules. As a result of quantitative analyses carried out, dynamic changes in their concentration was observed at different growth period and also variations when the plant was subjected to various stresses. Young leaves were found to contain high concentration of (3), while (1) and (2) were pooled in the mature leaves. When leaves were placed in the dark or when leaves were detached, the concentration of (3) was drastically reduced. Compound (1) and (2) were found only in the exudates of mushroom-shaped trichomes, while (3) was involved chloroplast grains, suggesting these compounds function as defensive agents. Although neither soybean-lipoxygenase nor crude protein fractions of the leaves exhibited peroxidation activity, (1) is considered to be converted biochemically because unregulated radical reaction around chloroplast bodies may be lethal. The study of the physiological functions of these compounds warrant further investigation.