Two labelled arginines, DL-[2,3,3,-²H₃]arginine, 8,
and DL-[ ¹³C, 2-¹⁵N]arginine, 9, were synthesized. These
were fed to cultures of Streptomyces griseochromogenes in
order to probe the mechanism of the apparent arginine-2,3-
aminomutase reaction occurring in biosynthesis of blasticidin
S, 1. In previous studies of the enzymes lysine-2,3-
aminomutase and tyrosine-2,3-aminomutase different...
At liquid nitrogen temperature the spectra of sublimed
films of NH₄NCS, both as phase I (the usual form stable at
room temperature) and phase II (the low temperature form),
exhibit detail usually reserved for gases at low pressures.
In both phases the symmetry of ammonium ion has degenerated
from tetrahedral...
Major and minor minerals have been separated from
three L-6 chondritic meteorites (Alfianello, Colby (Wisconsin),
and Leedey). Olivine, hypersthene, diopside, feldspar,
troilite, chromite, phosphate minerals, and metallic
minerals were analyzed for major, minor and trace elements
using instrumental neutron activation analysis and radiochemical
neutron activation analysis techniques. Concentrations
df the...
The thermolysis of trans-1 -trimethylsiloxy- 1-vinylcyclotridec-
3-ene (VI-OTMS) led to the formation of two major products: 4-vinylcyclotridecanone
(VII) and cyclopentadec-5-en-l-one (VIII) after
hydrolysis. Ketone VII is produced by a concerted [3, 3] sigmatropic
shift, while ketone VIII is formed by a [1, 3] sigmatropic shift with
a concerted or diradical...
Resonance Electron Capture Mass Spectrometry (REC-MS) is a sensitive
experimental technique for the study of gas-phase compounds with positive electron
affinity. This technique was used to study a class of compounds known as
baloetbylenes containing chlorine and bromine substitutions. Haloetbylenes are an
important class of compounds because ethylene is the...
In order to examine some possible tyrosyl interactions, poly-tyrosyl lysozyme and poly-O-methyltyrosyl lysozyme were prepared and their solubilities were compared. Both derivatives exhibited
similar pH dependent solubilities, showing a minimum solubility at
about pH 8. Their solubilities varied with temperature, having a
positive enthalpy of solution. The effect of a...
Part I describes the synthesis of bis(fac-S)((tris)2-aminoethanethiolatoiron( III))iron(III) chloride. The compound was first discovered during an attempt to prepare a ternary complex of iron, thiolate and pi-acid ligand. The compound is a reasonably air-stable iron(III)-thiolate that contains a linear tri-iron cluster with each iron bridged to the adjacent iron by...
Early studies on the biosynthesis of Sarubicin A, 1, had suggested the
intermediacy of the novel aromatic amino acid 6-hydroxyanthranilic acid,
17. To investigate the biosynthetic steps beyond 17, [¹³C-¹⁵N carboxamide]
6-hydroxyanthranilamide, 27a, was synthesized, and fed to fermentations
of Streptomyces helicus. Incorporation of 27a into 1 provided suggestive
evidence...
Polypeptidyl derivatives of bovine pancreatic ribonuclease
(RNase) containing two or three tyrosine chains
with an average of two to three residues per chain have
been prepared. The effects of various perturbants such as
neutral salts, ethanol, urea and guanidine hydrochloride
on the thermal transition of the derivatives have been
studied....
