Add time:07/15/2019 Source:sciencedirect.com
The inter-and intra-crystalline fractions of the topshell Phorcus lineatus recovered from modern specimens and shells from archaeological sites in Northern Spain covering Neolithic, Mesolithic, and Upper Magdalenian periods were examined for amino acid composition and racemisation over time. The main loss of proteins from the inter-crystalline fraction occurred within the first 6000 years after the death of the organism. In contrast, the intra-crystalline fraction isolated by bleaching—with a different protein composition to that of the inter-crystalline fraction—appeared to behave like a closed system for at least 12.6 ka, as reflected by the lack of a significant decrease in amino acid content. However, changes in the relative composition of the amino acids present in these shells occurred during this period. The concentration of aspartic acid remained almost constant with age within the intra-crystalline fraction and its contribution to the total amino acid content also remained the same. Good correspondence was obtained between Asx D/L values in unbleached and bleached samples and age, thereby allowing the dating of archaeological sites and the determination of chronometric age.
We also recommend Trading Suppliers and Manufacturers of L-GlutaMic-2-13C Acid (cas 133883-00-8). Pls Click Website Link as below: cas 133883-00-8 suppliers
About|Contact|Cas|Product Name|Molecular|Country|Encyclopedia
Message|New Cas|MSDS|Service|Advertisement|CAS DataBase|Article Data|Manufacturers | Chemical Catalog
©2008 LookChem.com,License: ICP
NO.:Zhejiang16009103
complaints:service@lookchem.com Desktop View