トウガラシにおける新規カプサイシン類似物質・カプシコニノイドの含量

　In the course of analyses of nonpungent capsaicinoid analogs named capsinoids, two unknown compounds were discovered in pepper fruits. These compounds were isolated from the fruit of ‘CCB’(Capsicum baccatum var. praetermissum). Their structures were determined to be coniferyl (E)‒8‒methyl‒6‒nonenoate and coniferyl 8‒methylnonanoate. These novel capsaicin analogs were named capsiconiate and dihydrocapsiconiate, respectively, and the coniferyl ester group was named capsiconinoid. Capsiconinoids have agonist activity for transient receptor potential vanilloid type 1, and their pungency is very low, as similar to that of capsinoids. Cultivars containing high levels of capsiconinoid are considered to be important for vegetable or dietary supplement. HPLC analysis was conducted to determine capsiconinoid content in fruits of 54 Capsicum cultivars : 28 cultivars of C. annuum, 9 of C. baccatum, 12 of C. chinense, 4 of C. frutescens, and 1 of C. pubescens. Twelve cultivars contained capsiconinoids. ‘CCB’ showed the highest capsiconinoid content level (3314 μg・g‒1 DW) and ‘Charapita’ (C. chinense) had the second highest (2694 μg・g‒1 DW). The other 10 cultivars contained much lower capsiconinoid than these two cultivars (<300 μg・g‒1 DW). Time-course analysis during fruit development clarified that capsiconinoid content increased and reached maximum level in green mature fruit. Capsaicinoid contents also increased, correspondingly. As fruits matured, capsiconinoid contents decreased rapidly, while capsaicinoid content either did not change or decreased slightly.

研究紹介 (Research Report)