The determination of the pKa's of several organic acids and bases
using chromatography was investigated. Normal-phase buffer-impregnated
paper chromatography was found to be unsuitable. TLC plates impregnated
with mineral oil were examined as a possible reversed-phase method,
with poor results. The use of XAD-2 copolymer as the stationary phase
in...
In a two part thesis, studies were made of two
different types of structure-activity relationships.
The first part consists of the synthesis and biological
evaluation of a number of 4-substituted pyrazoles and
isoxazoles as inhibitors of liver alcohol dehydrogenase.
In an effort to better define the steric and electronic
effects...
A set of 30 chemicals whose octanol-water partition
coefficients (log P) are known were injected on a XAD-2
column and a commercially available octadecylsilane
column. Two types of mobile phase were used on the XAD-2
column: buffered and unbuffered acetonitrile in water and
buffered and unbuffered octanol-saturated water passing
over...
Nalidixic acid and its derivatives act through inhibition of
bacterial DNA gyrase activity. Recently there have been a series of
papers reporting the antibacterial activity against three different
types of bacteria (S. aureus, E. coli and P. aeruginosa) by a series
of 1,4-dihydro-4-oxoquinoline (or 1,8-naphthyridine) 3-carboxylic
acids. Consistent biological data...
Molecular connectivity is a topological descriptor of
a molecule. It has been used as an independent variable
to describe biological activities, physicochemical
parameters (melting points, boiling points, partition
coefficients) and chromatographic retention indices. There
are inherent problems in using molecular connectivity. A
zero connectivity term has two opposing meanings: 1)...
Magmatic-hydrothermal ore deposits are giant geochemical anomalies in the earth’s crust most often generated by normal magmatic terrestrial processes. They are often associated with oxidized and hydrous intermediate to highly evolved magmas that have concentrated metals and have the necessary components to efficiently extract and transport them as ascending magmatic-hydrothermal...
Near-surface advanced argillic hydrothermal alteration zones, also referred to as lithocaps, are characterized by quartz, alunite, clays (pyrophyllite and kaolinite group minerals), and minor F-bearing aluminosilicates (i.e., topaz, zunyite, diaspore, and APS) that form where water-, SO2-, and HF-rich gas condenses into shallow groundwater, acidifies, and reacts with rocks. The...
Porphyry Cu-(Au-Mo) deposits are critical sources of several economically important metals. The processes governing the total metal endowment and relative proportions of ore metals at these large magmatic-hydrothermal deposits remain uncertain. The Sulphurets porphyry district, in northwestern British Columbia, Canada, contains four porphyry Au-Cu-Mo deposits that each feature distinct Cu/Au...
The Inmaculada Mine is located in the Miocene belt of epithermal deposits that extends from southern Peru to northern Chile and Bolivia. This belt is known for its silver-rich epithermal veins that have been worked since colonial times. The Inmaculada Mine belongs to a mining district that includes, from north...