Feeding of [3-¹³C, 2-¹⁵N]arginine, 38a, unequivocally established that the β-
arginine moiety of blasticidin S, 1, was formed from α-arginine by an intramolecular
migration of the α-amino group to the β- position. Further feedings using chirally
deuteriated arginines 38e and 38f revealed that the aminomutase process occurred with
inversion of...
Public attention and concern about per- and polyfluoroalkyl substances (PFASs) are increasing due to detection of PFASs in drinking water supplies, the environment, including remote locations, and wildlife and to the lowering of the federal health advisory levels of perfluorooctane sulfonate (PFOS) and perfluorooctanoate (PFOA) in drinking water. Aqueous film-forming...
The presence of per- and polyfluoroalkyl substances (PFAS), organic contaminants first synthesized in the 1940s, has been reported worldwide in a variety of environmental matrices and ultimately in biological systems including humans. Ongoing research into PFAS has included identifying novel PFAS, assessing their fate and transport in the environment, and...
Aqueous film forming foams (AFFFs) are proprietary mixtures containing hydrocarbon surfactants and per-and polyfluoroalkyl substances (PFASs) that are used to extinguish hydrocarbon-based fuel fires. There is limited information on hydrocarbon surfactants in AFFFs and AFFF-contaminated groundwater even though they are more abundant (5-10% w/w) than PFASs (0.9-1.5% w /w) in...
Per- and polyfluoroalkyl substances (PFAS) are a group of anthropogenic compounds that are used ubiquitously in different industrial fields. However, concerns regarding the potential health impacts of PFAS, including perfluoroalkyl carboxylic acids
(PFCAs) and perfluoroalkyl sulfonates (PFSAs), has raised stakeholder interest regarding continued use of PFAS. Analytical methods for PFAS...
Per- and polyfluoroalkyl substances (PFAS) are a group of anthropogenic compounds gaining notoriety as contaminants of emerging concern. With the frequent detection of PFAS in the environment, drinking water, and consumer products, awareness and concern from the public regarding PFAS is increasing. The two most notorious PFAS are perfluorooctanoate (PFOA)...
The photolysis of the aqueous thymine system has been investigated
at 214 nm, 229 nm and 254 nm at room temperature. Products
of photolysis have been identified as hydrogen peroxide, 6-hydroxy-5-
hydroperoxy thymine and tentatively 5-hydroxy-6-hydroperoxy thymine.
These together with thymine loss, were determined quantitatively
under a variety of conditions....
Research and public concern of poly and perfluoroalkyl substances (PFASs) as environmental contaminants has increased significantly due to the increasing number of reports of their detection in humans and wildlife. PFASs have a number of commercial applications including surfactants, coatings, polymers, and levelers, which are used on consumer products like...
Polycyclic aromatic hydrocarbons (PAHs) are a group of environmental contaminants consisting of fused benzene rings. Parent-PAHs, methylated-PAHs (MPAHs), and PAHs with molecular weight of 302 a.m.u (MW302-PAHs) are considered as unsubstituted-PAHs. These unsubstituted-PAHs undergo transformation reactions resulting in the formation of PAH-transformation products (PAH-TPs), or substituted-PAHs, including nitrated-, oxygenated-, and...
A facile route to bicyclo(2.1.1)hexanes was developed involving
the intramolecular photocyclization of 1, 5-hexadien-3-one to
bicyclo(2.1.1)hexan-2-one. A study of the chemistry of bicyclo-(2.1.1)hexan-2-one was undertaken. Deuterium exchange and borohydride
reduction demonstrated the strain present in the ketone.
Further evidence was obtained from the failure to introduce substituents
alpha to the...