Graduate Student Hyuga Hirano at the National Museum of Nature and Science (United Graduate School of Agricultural Science, Tokyo University of Agriculture and Technology), Senior Curator Yoshinori Murai of the Department of Botany at the National Museum of Nature and Science, Takashi Kikuchi of Rigaku Corporation, and Technical Advisor Futa Sakakibara of Asterism G. K., have developed a trace component analysis method. Using this method, they successfully determined the structures of more than 10 types of phenolic compound glycosides from alpine plants, which are small in size and from which securing research samples in large quantities is difficult due to regulatory and ethical constraints. Specifically, they isolated and crystallized components from only 2 grams of flowers from Diapensia lapponica subsp. obovata, an alpine plant in the Diapensiaceae family, to determine the structure of each component. This is a pioneering example of research as it led to determining the structures of numerous components from a trace sample of a wild plant. This technology is applicable to exploratory research of untapped resources across a wide range of fields, including science, agriculture, and pharmacology. The results were published online in the Journal of Molecular Structure.
Provided by the National Museum of Nature and Science, Tokyo
Alpine plants in alpine and subalpine zones in Japan have adapted to severe environmental stresses, such as ultraviolet rays and low temperatures derived from alpine environments, by synthesizing and accumulating phenolic compounds. Many of these phenolic compounds are known to be potential natural resources, and research on alpine plants, where knowledge is limited compared to lowland plants, is highly anticipated.
On the other hand, alpine plants are rare because they grow in harsh environments, their plant bodies are small, and their distribution is limited to high-elevation areas. Even for academic research, human disturbance associated with collection must be kept to a minimum, limiting the number of samples available for structural analysis of components.
The research team has been developing methods for component analysis from trace samples. In this study, using a very small amount of flowers from the alpine plant D. lapponica subsp. obovata as a research sample, they developed a method to optimize the crystallization of each component after performing the conventional analytical methods: isolation and purification via high-performance liquid chromatography (HPLC) and molecular weight measurement via quadrupole time-of-flight mass spectrometry (QTOF-MS). By further utilizing other conventional analytical methods, such as single-crystal X-ray diffraction (SC-XRD) and micro-crystal electron diffraction (MicroED), which can determine structures from crystals about 1/100th the size of crystals, they succeeded in the structural analysis of trace components from an extremely small sample.
As a result, it was revealed that the flowers of the sub-species, which grow in harsh alpine environments, contain various phenolic compounds, including flavonoids such as quercetin glycosides, which have recently attracted attention as functional components that provide health benefits. Furthermore, during the process of technological development, they also succeeded in isolating and structurally analyzing numerous components from its leaves. They identified components that contribute to UV protection and antioxidant activity, and they discovered geographical differences in the accumulation of some of these components between Central Honshu and Hokkaido in the Japanese archipelago.
While D. lapponica subsp. obovata, which is relatively widely distributed among alpine plants, was used for the development of the analytical method, the researcher group is currently using this technique to analyze rarer plants, such as species endemic to Japan and endangered species. It is expected that this will clarify trace components in plants that were previously difficult to analyze and will be utilized in the search for useful natural substances.
Journal Information
Publication: Journal of Molecular Structure
Title: Sustainable micro-scale identification of phenolic glycosides in alpine flower through single-crystal structure analysis
DOI: 10.1016/j.molstruc.2026.145740
This article has been translated by JST with permission from The Science News Ltd. (https://sci-news.co.jp/). Unauthorized reproduction of the article and photographs is prohibited.