In 1959 Kitagawa discovered and isolated the amino acid,
canavanine. Since its discovery much interest has been centered on
this amino acid because of its biological aspects; e.g. canavanine has
been shown to inhibit the growth of bacteria, viruses, protozoa, and
cancer cells.
The occurrence of canavanine is widespread in...
An intramolecular variant of the modified-Julia olefination was demonstrated by the synthesis of α,β-unsaturated lactones in a mild and (Z)-selective fashion. The lynchpin reagent (benzothiazol-2-sulfonyl) acetic acid was synthesized in a straightforward fashion in 86% overall yield from commercially available 2-mercaptobenzothiazole via conversion to ethyl (benzothiazol-2-ylthio)acetate by base mediated alkylation...
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...
The DNA-binding domains of E. coli uracil-DNA glycosylase (Ung) and human replication protein A (hRPA) were studied using a general protocol developed in our laboratory for probing protein-DNA interactions. The procedure involves purification and mass spectrometric analysis of the nucleopeptide-products of a tryptically digested UV-crosslinked protein-nucleic acid complex. In the...
Current studies suggest that perfluorinated organic compounds, such as fluorotelomer alcohols (FtOHs) in the troposphere, may be precursors of perfluorocarboxylic acids and perfluorosulfonates in remote regions. Fluorinated organic compounds were investigated in archived extracts collected from remote locations in Okinawa, Japan (HSO) and Mount Bachelor, Oregon (MBO) during the springs...
Humanities have been craving more freedom and conveniences in whatever form. Carriages evolved to cars and ultimately to aircraft so that one can reach any place in the globe within a day. The mobile phone has enabled people to make a phone call without a need to find a phone...
The concentration of chlorophyll in natural bodies of water is
commonly determined as a means to rapidly estimate the phytoplankton
biomass. The literature gives numerous warnings, however, as to the
problems involved with accurately determining chlorophyll
concentrations. The author's work at Crater Lake, Oregon enticed him
to explore critically the...