Preparation of tetramethylcyclopropanecarboxylic-14C acid and insecticidal terallethrin-14C from it.

Preparation of tetramethylcyclopropanecarboxylic-14C acid and insecticidal terallethrin-14C from it.

Esters of tetramethylcyclopropanecarboxylic acid (I) with (•})-allethrolonel1), (•}) -pyrethrolone2) and some others3) have activity comparable to that of corresponding esters of natural (+)-transchrysanthemic acid against some insect species. However, these esters show differences in toxicity to mammals which are probably resulted from differences in rates or pathways of metabolism. Therefore,...

Incorporation of L-methionine-methyl-14C into gentamicins. II. Large-scale preparation of methyl-14C-gentamicins.

Methyl-14C-gentamicins were prepared from incubation of Micromonospora purpurea in the presence of added methyl-'4C-L-methionine, and products with high specific radioactivity were isolated in satisfactory yields. In the previous paper1), we have shown in shake flask fermentation a high and selective incorporation of radioactivity from methyl-14C-L-methionine into gentamicins. Consequently, we ...

Preparation of 14C-labeled tuberculin purified protein derivative.

(14)C-labeled tuberculin purified protein derivative ((14)C-tuberculin PPD) has been prepared from culture filtrates of Mycobacterium tuberculosis var. hominis grown in a culture medium containing uniformly labeled (14)C-amino acids. With a mixture of (14)C-amino acids (an acid hydrolysate of (14)C-Chlorella protein) in the medium, the recoveries of (14)C in the final product were higher than w...

Reactions of 14C-ADP and 14C-ATP with washed platelets from rabbits.

Preferential Accumulation of 14C-N-Glycolylneuraminic Acid over 14C-N-Acetylneuraminic Acid in the Rat Brain after Tail Vein Injection

The two main molecular species of sialic acid existing in nature are N-acetylneuraminic acid (Neu5Ac) and N-glycolylneuraminic acid (Neu5Gc). Neu5Ac is abundant in mammalian brains and plays crucial roles in many neural functions. In contrast, Neu5Gc is present only at a trace level in vertebrate brains. The brain-specific suppression of Neu5Gc synthesis, which is a common feature in mammals, s...