Distribution of Rutin and Protodioscin in Different Tissue Parts of Asparagus (Asparagus officinalis L.)

Abstract

<jats:p>Asparagus is a popular vegetable rich in healthy functional components. Asparagus spears are known to contain a large amount of rutin, which has been found to possess anti-inflammatory, antitumor, and antibacterial/viral properties, and protodioscin, which is an antitumor substance and present in the bottom parts (8 cm from the cut end). However, the process of its production leaves fern in the aboveground parts and roots in the underground parts as significant amounts of nonusable parts, and this issue should be solved. This study was conducted to examine the distributions of rutin and protodioscin, representative functional components in different parts of asparagus. The results suggested that large amounts of rutin were noted in the cladophylls and storage roots (brown and epidermis), and the protodioscin content was high in the buds, the soil-covered section of the spear, and the rhizome. A significant amount of rutin was detected in the aboveground parts, which is consistent with the results of previous studies, but it was also found in the storage roots. The largest amount of protodioscin was found in the buds, as well as in young fruits and seeds of the aboveground parts. Injury by continuously cropping asparagus may be associated with high rutin content in the storage roots of asparagus.</jats:p>

Distribution of Growth-inhibitory Activity, Mineral Contents, and Functional Components in Different Tissue Parts of Asparagus (Asparagus officinalis L.) and Availability of Unusable Parts

“…However, spears that have not been harvested at the optimum time also contain a large amount of rutin and may be useful components or resources of rutin (Motoki et al, 2012a). In addition, although a significant amount of rutin was detected in the aboveground parts, which is consistent with the results of previous studies (Motoki et al, 2012b), it was also found in the storage roots (Motoki et al, 2019). The largest amount of protodioscin was found in the buds as well as in young fruit and seeds among the aboveground parts (Motoki et al, 2019).…”

“…In addition, although a significant amount of rutin was detected in the aboveground parts, which is consistent with the results of previous studies (Motoki et al, 2012b), it was also found in the storage roots (Motoki et al, 2019). The largest amount of protodioscin was found in the buds as well as in young fruit and seeds among the aboveground parts (Motoki et al, 2019). However, the influences of the cultivation method and environmental conditions on the levels of rutin and protodioscin have not been clarified.…”

“…However, its production process leaves ferns from the aboveground parts and roots from the underground parts as large amounts of unusable parts, and this is an issue to be resolved. In our previous study, large amounts of rutin were noted in the cladophylls and storage roots (brown and epidermis), whereas the protodioscin content was high in buds, in the soil-covered section of spears, and in the rhizome (Motoki et al, 2019).…”

“…Although only a small portion of the cladophylls of asparagus harvested in the autumn are used as cladophylls powder, most of the rest is put back into the soil or disposed of. The amount is estimated to be %130,000 t annually in Japan (Motoki et al, 2019). If the unusable parts of asparagus can be retained as useful resources for soil improvement and fertilization, the cultivation cost of asparagus can be reduced.…”

“…Rutin, a functional component of buckwheat, was identified as a growth-inhibitory substance (Golisz et al, 2007). Rutin is also abundant in asparagus, suggesting that it may be a growth-inhibitory substance of asparagus (Motoki et al, 2019). However, the relationship between rutin and protodioscin as representative functional components of asparagus, and growth-inhibitory activity, are unknown.…”