Levels of free D-amino acids were compared in 11 vinegars produced from different sources or through different manufacturing processes. To analyze the D- and L-amino acids, the enantiomers were initially converted into diastereomers using pre-column derivatization with o-phthaldialdehyde plus N-acethyl-L-cysteine or N-tert-butyloxycarbonyl-L-cysteine. This was followed by separation of the resu...

The physiological role of D-amino acid oxidase was investigated by using mutant ddY/DAO- mice lacking the enzyme. Free D-amino acid concentrations in the mutant mice were significantly higher than those of control ddY/DAO+ mice in kidney, liver, lung, heart, brain, erythrocytes, serum and urine. The results suggest that the enzyme is involved in the catabolism of free D-amino acids in the body,...

The question of the significance of free amino acids in soil or other cultural media has received attention in recent years in the fields of plant physiology (1, 3, 7, 13, 14, 15, 16, 17), soil microbiology (4, 5, 11, 16) and soil chemistry (9, 10,12). Although it originally appeared that free amino acids were not to be found in soils, later reports (2, 10) indicated they could be extracted wit...

For life to start on earth and elsewhere, it is critical that the building blocks—amino acids and sugars—be in predominant homochiral form. Over the past century, the origin of terrestrial prebiotic homochirality has been the subject of many speculations. In this Letter I summarize the experimental evidence for ways in which some meteoritic components could have led to the dominance of L amino ...

Tuberose (Polianthes tuberosa L.) is one of the most important cut flowers in Iran. This research was conducted to investigate the effects of spraying a mixture of amino acids on the physiological and morphological characteristics of tuberose. The experiment was carried out in two successive years (2009 and 2010) using two tuberose cultivars ‘Dezfuli’ and ‘Mahallati’. The experiment was arrange...

The ability of the water-soluble DD-carboxypeptidases of Streptomyces strains albus G, R61, Kll and R39 to perform transpeptidation was studied. The donor was diacetylL-lysyl-D-alanyl-D-alanine, and a whole range of amino acids, peptides and structurally related amino compounds were tested for acceptor function. No compound tested was an acceptor for the enzyme from strain albus G whereas the e...

chamomile (matricaria chamomilla l.) is one of the most important medicinal plants in iran. the main objective of this study was to determine the effects of organic nutrients on the yield and oil content of chamomile. the experiment was conducted in the spring of 2010. the treatment groups consisted of vermicompost (0, 5, 10, 15 and 20 tons/ha) and the aminol forte sprays (no spraying or contro...