Of 4-amino-5-chloro-2-methoxy-N-(1-ethyl-2-hydroxymethyl-4- pyrrolidinyl)benzamide, four optical isomers, (2S,4S)-1 (TKS159), (2S,4R)-25, (2R,4S)-26 and (2R,4R)-27, were prepared from optically active 4-amino-1-ethyl-2-hydroxymethylpyrrolidine di-p-toluenesulfonate [(2S,4S)-14, (2S,4R)-17, (2R,4S)-20 and (2R,4R)-23, respectively]. The requisites, (2S,4S)-14, (2S,4R)-17, (2R,4S)-20 and (2R,4R)-2...

Photoionization spectra of Se have been studied by step-wise resonance laser ionization. The Rydberg series 4s24p3(4S)np3P0,1,2 and 4s24p3(4S)np5P1,2,3 were measured via different excitation schemes. Using the 4s24p3(4S)np3P2 with n = 15–49, ionization potential was determined improved precision to 76,658.15(2)stat(4)sys cm?1, which resolved discrepancy in previous literatures. Autoionizing (AI...

In recent studies, an optically pumped Ar*/He laser has been demonstrated using the Ar 4p[1/2]1→4s[3/2]2 transition at 912.55 nm. Time-resolved data for this system, recorded using CW laser excitation and pulsed discharge production of Ar* 4p[3/2]2, yielded laser output pulses that were of unexpectedly short duration. It was speculated that radiative relaxation from the upper laser level to the...

Azotobacter vinelandii ferredoxin I is a small protein that contains one [4Fe-4S] cluster and one [3Fe-4S] cluster. Recently the x-ray crystal structure has been redetermined and the fdxA gene, which encodes the protein, has been cloned and sequenced. Here we report the site-directed mutation of Cys-20, which is a ligand of the [4Fe-4S] cluster in the native protein, to alanine and the characte...

Both 70S and 4S RNAs of Rous sarcoma virus (RSV) contain nucleotide sequences homologous to those in cellular DNA. Preparations of these RNAs were found to include some adventitious cellular sRNA. Nevertheless, both 70S and 4S RSV-RNAs were found by competition techniques to contain sequences distinct from those in cellular ribosomal RNA and 4S RNA. Competition experiments also reveal substanti...

The MoFe protein of nitrogenase catalyzes the six-electron reduction of dinitrogen to ammonia. It has long been believed that this protein receives the multiple electrons it requires one at a time, from the [4Fe-4S]2+/+ couple of the Fe protein. Recently an all-ferrous [4Fe-4S]0 state of the Fe protein was demonstrated suggesting instead a series of two electron steps involving the [4Fe-4S]2+/0...

The case is briefly reported of a 7-month-old boy with a disseminated neuroblastoma, whose marrow showed neuroblastoma rosettes and on direct examination on two occasions revealed a high proportion of cells with 48 chromosomes forming an abnormal cell line.

BACKGROUND Flobufen (F) is an original nonsteroidal anti-inflammatory drug with one center of chirality. 4-Dihydroflobufen (DHF), compound with two chiral centers, is the main metabolite of F in microsomes and cytosol in all standard laboratory animals. This work describes the biotransformation of F enantiomers and DHF stereoisomers in isolated male guinea pig hepatocytes. Guinea pigs were chos...

The role of the high potential [3Fe-4S]1+,0 cluster of [NiFe] hydrogenase from Desulfovibrio species located halfway between the proximal and distal low potential [4Fe-4S]2+,1+ clusters has been investigated by using site-directed mutagenesis. Proline 238 of Desulfovibrio fructosovorans [NiFe] hydrogenase, which occupies the position of a potential ligand of the lacking fourth Fe-site of the [3...