Amino acid abundances and compositions in iron and stony‐iron meteorites

Abstract

The organic compositions of carbonaceous chondrite meteorites have been extensively studied; however, there have been fewer reports of other meteorite classes, and almost none from iron meteorites, which contain much less carbon than carbonaceous chondrites but make up~4% of observed meteorite falls. Here, we report the bulk amino acid content of three iron meteorites (Campo del Cielo, IAB; Canyon Diablo, IAB; and Cape York, IIIAB) and both the metal and silicate portions of a pallasite (Imilac). We developed a novel method to prepare the samples for analysis, followed by hot water extraction and analysis via liquid chromatography-mass spectrometry. Free amino acid abundances ranging from 301 to 1216 pmol g À1 were observed in the meteorites, with the highest abundance in the silicate portion of the pallasite. Although some of the amino acid content could be attributed to terrestrial contamination, evidence suggests that some compounds are indigenous. A suite of C 5 amino acids was observed with a distinct distribution favoring a straight chain (n-pentanoic acid) structure; this straight chain dominance is suggestive of that observed in thermally altered stony meteorites. Amino acids were also observed in terrestrial iron granules that were milled and analyzed in the same way as the meteorites, although the distribution of detected amino acids was different. It is possible that similar formation mechanisms existed in both the meteorites and the terrestrial iron, or that observed amino acids resulted from reactions of precursors during sample preparation. This work suggests that iron meteorites should not be overlooked for contributions of amino acids and likely other soluble organic molecules to the early Earth. Future studies of iron-nickel meteorites and asteroids, such as Psyche, may provide further insights into their potential organic inventory.

Geoelectrochemistry-driven alteration of amino acids to derivative organics in carbonaceous chondrite parent bodies

“…Here we examine the alteration of amino acids under simulated electrochemical conditions within icy planetesimals. Three proteinogenic amino acids (glycine (Gly), alanine (Ala), and valine (Val)) that were commonly discovered in CCs 48 – 50 were tested. We demonstrate that the electrolysis of these amino acids simultaneously generates monoamines, α-hydroxy acids, and monocarboxylic acids under a wide range of redox conditions at ambient temperature (25 °C).…”

Solid-State Single-Molecule Sensing with the Electronic Life-detection Instrument for Enceladus/Europa (ELIE)

“…We generated a literature-based database of reported abundances of meteoritic α-amino acids and amino acids extracted from diverse environmental samples (Elsila et al . 2021; Glavin et al .…”

On the Evolutionary History of the Twenty Encoded Amino Acids

“…Summary on four major experimental set-ups or protometabolic approaches, their chemical conditions, and listing of amino acids formed in these scenarios as well as amino acids found on carbonaceous meteorites. [13,14] [a] Status 2018 according to Ref. [13c]; [b] these amino acids are decomposed by ultraviolet radiation, which prevailed in space and on the early Earth; [c] Powner and co-workers reported a cysteine synthesis based on a thio-Michael addition of H 2 S to an acrylonitrile derivative (ref.…”