2026-04-03 北海道大学,海洋研究開発機構,九州大学,東北大学
小惑星ベヌーで検出された核酸塩基誕生までの宇宙における化学進化、及び地球への有機物供給に関する概念図（©NASA、国立天文台）。
＜関連情報＞
- https://www.hokudai.ac.jp/news/2026/04/post-2235.html
- https://www.hokudai.ac.jp/news/pdf/260403_pr.pdf
- https://www.nature.com/articles/s42004-026-01966-z
小惑星ベヌーサンプルに含まれる核酸塩基、その他窒素複素環化合物、及びそれらの前駆体の分 Distribution of extraterrestrial nucleobases, other N-heterocycles, and their precursors in a sample from asteroid Bennu
Yasuhiro Oba,Toshiki Koga,Yoshinori Takano,Hiroshi Naraoka,Yuta Hirakawa,Sako Sunami,Yoshihiro Furukawa,Tomoya Yamazaki,Takuto Tomaru,Jason P. Dworkin,Daniel P. Glavin,Harold C. Connolly Jr & Dante S. Lauretta
Communications Chemistry Published:02 April 2026
DOI:https://doi.org/10.1038/s42004-026-01966-z
Abstract
The recent discovery of all five canonical nucleobases in samples from Bennu provides compelling evidence that some of life’s ingredients were synthesized abiotically in the parent body of this asteroid and/or its precedent components. However, due to the sample availability and the limited method for the analysis, the detailed distribution of nucleobases in the samples remains elusive. Here we report the concentrations of a diverse suite of nitrogen (N)-heterocycles including nucleobases extracted by 2% and 20% hydrochloric acid from a homogenized Bennu sample. The detection of both canonical and non-canonical nucleobase pairs confirms that these biologically important compounds are extraterrestrial. Pyrimidines are more abundant than purines—like the Orgueil meteorite, but unlike the Murchison meteorite and asteroid Ryugu samples—suggesting preferential synthesis in ammonia-rich ices from the outer Solar System. The distribution of other N-heterocycles is consistent with extensive aqueous alteration on the parent body. High concentrations of urea underscore its role in N-heterocycle synthesis. Our findings offer important information on the prebiotic inventory of N-heterocycles in the Solar System.
