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Biomedical subjects

C Ponnamperuma

Publications and source records attributed to C Ponnamperuma.

At least 73 records · Page 4Linked to original sources
PubMed1971

Nonprotein amino acids in the murchison meteorite.

Twelve nonprotein amino acids appear to be present in the Murchison meteorite. The identity of eight of them has been conclusively established as N-methylglycine, beta-alanine, 2-methylalanine, alpha-amino-n-butyric acid, beta-amino-n-butyric acid, gamma-amino-n-butyric acid, isovaline, and pipecolic acid. Tentative evidence is presented for the presence of N-methylalanine, N-ethylglycine, beta-aminoisobutyric acid, and norvaline. These amino acids appear to be extraterrestrial in origin and may provide new evidence for the hypothesis of chemical evolution.

Journal Article↗
PubMed1969

Peptide formation mediated by hydrogen cyanide tetramer: a possible prebiotic process.

Chemical evolution on the primitive earth must have involved condensation of alpha-amino acids to peptides. Under aqueous conditions consistent with current conceptions of primordial waters, heating glycerine with the hydrogen cyanide tetramer, diaminomaleonitrile, yields dipeptide. If nitrogen was cycled through primordial waters as cyanide, peptide synthesis by stepwise tetramer-mediated condensation of alpha-amino acids would have been a plausible process.

Dipeptides↗