All life on Earth contains amino acids and carbonaceous chondrite meteorites have been suggested as their source at the origin of life on Earth. While many meteoritic amino acids are considered indigenous, deciphering the extent of terrestrial contamination remains an issue. The Ryugu asteroid fragments (JAXA Hayabusa2 mission), represent the most uncontaminated primitive extraterrestrial material available. Here, the concentrations of amino acids from two particles from different touchdown sites (TD1 and TD2) are reported. The concentrations show that N,N-dimethylglycine (DMG) is the most abundant amino acid in the TD1 particle, but below detection limit in the other. The TD1 particle mineral components indicate it experienced more aqueous alteration. Furthermore, the relationships between the amino acids and the geochemistry suggest that DMG formed on the Ryugu progenitor body during aqueous alteration. The findings highlight the importance of aqueous chemistry for defining the ultimate concentrations of amino acids in primitive extraterrestrial samples.

地球上的所有生命都含有氨基酸，碳质球粒陨石被认为是地球生命起源的来源。虽然许多陨石氨基酸被认为是本土的，但破译陆地污染的程度仍然是一个问题。Ryugu 小行星碎片（JAXA Hayabusa2 任务）代表了可用的最未受污染的原始地外物质。此处报告了来自不同着陆点（TD1 和 TD2）的两个粒子的氨基酸浓度。浓度显示 N,N-二甲基甘氨酸 (DMG) 是 TD1 颗粒中最丰富的氨基酸，但在另一个颗粒中低于检测限。TD1 颗粒矿物成分表明它经历了更多的水蚀变。此外，氨基酸和地球化学之间的关系表明，在水蚀变过程中，DMG 在 Ryugu 祖体上形成。这些发现强调了水化学对于确定原始地外样本中氨基酸最终浓度的重要性。