Inconclusive evidence for nonterrestrial isoleucine enantiomeric excesses in primitive meteorites

Inconclusive evidence for nonterrestrial isoleucine enantiomeric excesses in primitive meteorites.

Pizzarello et al. (1) recently described the soluble organic content of eight Antarctic Renazzo-type (CR) carbonaceous chondrites and reported large enantiomeric excesses (ee) of Lisoleucine and D-alloisoleucine. The reported values of ee decrease with inferred increases in aqueous alteration. We believe the conclusions presented in the paper are not fully justified and the data are potentially...

Large enantiomeric excesses in primitive meteorites and the diverse effects of water in cosmochemical evolution.

Carbonaceous chondrites are meteoritic fragments of asteroids that avoided the geological reprocessing of larger planets and allow laboratory probing of early solar-nebula materials. Among these, Renazzo-type (CR) chondrites found in Antarctica appear remarkably pristine and are distinguished by abundant organic materials and water-soluble molecules such as amino acids and ammonia. We present a...

Lifelike Forms in Meteorites: Are fossils present in carbonaceous meteorites? The evidence is suggestive but as yet inconclusive.

Are fossils present in carbonaceous meteorites? The evidence is suggestive but as yet inconclusive. At a meeting held 1 May 1962 at the New York Academy of Sciences, a group of papers was presented dealing with the organized elements which were observed in carbonaceous chondrites and described by Claus and Nagy and by Nagy, Claus, and Hennessy, and with the hydrocarbon compounds reported by Nag...

Recent Advances in the Measurement of Enantiomeric Excesses

The elaboration of an ever increasing number of chiral catalysts or reagents demands fast and sensitive methods to measure enantiomeric excesses of the products. This review discusses the various ways to solve these problems. Mass spectrometry, chromatographic or chiroptical methodologies, fluorescence, liquid crystals, enzymatic methods, and immunoassays, are some of the technologies which may...

Inconclusive evidence for patrilocality in Neandertals.