The loss of all deuterium labels from previous feedings of [2-²H]-,
[3,3-²H₂]-, and [2,3,3-²H₃]arginines had indicated the possible intermediacy
of β-hydroxy- and β-ketoarginine (30 and 31, respectively) in the
biosynthesis of the streptolidine portion of streptothricin F (la).
In order to confirm or refute this evidence, D,L-[2,3,3,5,5-²H₅]-
arginine (32) was...
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...
The design and construction of a chemiluminescence
photometer is described. The design is based on a discrete
sample system which has a number of advantages over
the previously described flow cell system and centrifugal
analyzer. The advantages include simple and inexpensive
equipment, small sample size, versatile electronic readout
system, and...
The work presented in this thesis deals with the mechanisms by which a vibrationally excited diatomic molecule gives up its energy to a host monatomic lattice at low temperature. The vibrational lifetimes (v"=1) of the metal oxides Ba0 and A10 in their ground electronic states are studied using pulsed dual...