The Experts below are selected from a list of 9 Experts worldwide ranked by ideXlab platform
Kristin Bowmanjames - One of the best experts on this subject based on the ideXlab platform.
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sulfur oxygen and nitrogen mustards stability and reactivity
Organic and Biomolecular Chemistry, 2012Co-Authors: Qiqiang Wang, Rowshan Ara Begum, Victor W Day, Kristin BowmanjamesAbstract:Mustard gas, bis(β-chloroethyl) sulfide (HD), is highly toxic and harmful to humans and the environment. It comprises one class of chemical warfare agents (CWAs) that was used in both World Wars I and II. The three basic analogues or surrogates are: the monochloro derivative, known as the half mustard, 2-chloroethyl ethyl sulfide (CEES); an oxygen analogue, bis(β-chloroethyl) ether (BCEE); and several nitrogen analogues based on the 2,2′-Dichlorodiethylamine framework (e.g., HN1, HN2, and HN3). The origin of their toxicity is considered to be from the formation of three-membered heterocyclic ions, a reaction that is especially accelerated in aqueous solution. The reaction of these cyclic ion intermediates with a number of important biological species such as DNA, RNA and proteins causes cell toxicity and is responsible for the deleterious effects of the mustards. While a number of studies have been performed over the last century to determine the chemistry of these compounds, early studies suffered from a lack of more sophisticated NMR and X-ray techniques. It is now well-established that the sulfur and nitrogen mustards are highly reactive in water, while the oxygen analog is much more stable. In this study, we review and summarize results from previous studies, and add results of our own studies of the reactivity of these mustards toward various nonaqueous solvents and nucleophiles. In this manner a more comprehensive evaluation of the stability and reactivity of these related mustard compounds is achieved.
Qiqiang Wang - One of the best experts on this subject based on the ideXlab platform.
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sulfur oxygen and nitrogen mustards stability and reactivity
Organic and Biomolecular Chemistry, 2012Co-Authors: Qiqiang Wang, Rowshan Ara Begum, Victor W Day, Kristin BowmanjamesAbstract:Mustard gas, bis(β-chloroethyl) sulfide (HD), is highly toxic and harmful to humans and the environment. It comprises one class of chemical warfare agents (CWAs) that was used in both World Wars I and II. The three basic analogues or surrogates are: the monochloro derivative, known as the half mustard, 2-chloroethyl ethyl sulfide (CEES); an oxygen analogue, bis(β-chloroethyl) ether (BCEE); and several nitrogen analogues based on the 2,2′-Dichlorodiethylamine framework (e.g., HN1, HN2, and HN3). The origin of their toxicity is considered to be from the formation of three-membered heterocyclic ions, a reaction that is especially accelerated in aqueous solution. The reaction of these cyclic ion intermediates with a number of important biological species such as DNA, RNA and proteins causes cell toxicity and is responsible for the deleterious effects of the mustards. While a number of studies have been performed over the last century to determine the chemistry of these compounds, early studies suffered from a lack of more sophisticated NMR and X-ray techniques. It is now well-established that the sulfur and nitrogen mustards are highly reactive in water, while the oxygen analog is much more stable. In this study, we review and summarize results from previous studies, and add results of our own studies of the reactivity of these mustards toward various nonaqueous solvents and nucleophiles. In this manner a more comprehensive evaluation of the stability and reactivity of these related mustard compounds is achieved.
Victor W Day - One of the best experts on this subject based on the ideXlab platform.
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sulfur oxygen and nitrogen mustards stability and reactivity
Organic and Biomolecular Chemistry, 2012Co-Authors: Qiqiang Wang, Rowshan Ara Begum, Victor W Day, Kristin BowmanjamesAbstract:Mustard gas, bis(β-chloroethyl) sulfide (HD), is highly toxic and harmful to humans and the environment. It comprises one class of chemical warfare agents (CWAs) that was used in both World Wars I and II. The three basic analogues or surrogates are: the monochloro derivative, known as the half mustard, 2-chloroethyl ethyl sulfide (CEES); an oxygen analogue, bis(β-chloroethyl) ether (BCEE); and several nitrogen analogues based on the 2,2′-Dichlorodiethylamine framework (e.g., HN1, HN2, and HN3). The origin of their toxicity is considered to be from the formation of three-membered heterocyclic ions, a reaction that is especially accelerated in aqueous solution. The reaction of these cyclic ion intermediates with a number of important biological species such as DNA, RNA and proteins causes cell toxicity and is responsible for the deleterious effects of the mustards. While a number of studies have been performed over the last century to determine the chemistry of these compounds, early studies suffered from a lack of more sophisticated NMR and X-ray techniques. It is now well-established that the sulfur and nitrogen mustards are highly reactive in water, while the oxygen analog is much more stable. In this study, we review and summarize results from previous studies, and add results of our own studies of the reactivity of these mustards toward various nonaqueous solvents and nucleophiles. In this manner a more comprehensive evaluation of the stability and reactivity of these related mustard compounds is achieved.
Rowshan Ara Begum - One of the best experts on this subject based on the ideXlab platform.
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sulfur oxygen and nitrogen mustards stability and reactivity
Organic and Biomolecular Chemistry, 2012Co-Authors: Qiqiang Wang, Rowshan Ara Begum, Victor W Day, Kristin BowmanjamesAbstract:Mustard gas, bis(β-chloroethyl) sulfide (HD), is highly toxic and harmful to humans and the environment. It comprises one class of chemical warfare agents (CWAs) that was used in both World Wars I and II. The three basic analogues or surrogates are: the monochloro derivative, known as the half mustard, 2-chloroethyl ethyl sulfide (CEES); an oxygen analogue, bis(β-chloroethyl) ether (BCEE); and several nitrogen analogues based on the 2,2′-Dichlorodiethylamine framework (e.g., HN1, HN2, and HN3). The origin of their toxicity is considered to be from the formation of three-membered heterocyclic ions, a reaction that is especially accelerated in aqueous solution. The reaction of these cyclic ion intermediates with a number of important biological species such as DNA, RNA and proteins causes cell toxicity and is responsible for the deleterious effects of the mustards. While a number of studies have been performed over the last century to determine the chemistry of these compounds, early studies suffered from a lack of more sophisticated NMR and X-ray techniques. It is now well-established that the sulfur and nitrogen mustards are highly reactive in water, while the oxygen analog is much more stable. In this study, we review and summarize results from previous studies, and add results of our own studies of the reactivity of these mustards toward various nonaqueous solvents and nucleophiles. In this manner a more comprehensive evaluation of the stability and reactivity of these related mustard compounds is achieved.
Brennie E Hackley - One of the best experts on this subject based on the ideXlab platform.
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histopathologic and immunohistochemical features in human skin after exposure to nitrogen and sulfur mustard
American Journal of Dermatopathology, 1998Co-Authors: Kathleen J Smith, William J Smith, Tracey A Hamilton, Henry G Skelton, John S Graham, Carlin V Okerberg, Robert B Moeller, Brennie E HackleyAbstract:N-methyl-2,2'-Dichlorodiethylamine (HN2)is a topical chemotherapeutic agent used as therapy for cutaneous T-cell lymphomas (CTCL). Di(2-chloroethyl)sulfide (SM), and less often HN2, have been used as chemical weapons, with the skin being a principle target. The mechanisms by which these chemicals produce their therapeutic and toxic effects in skin, however, are not clearly defined. We exposed human skin explants to two doses of HN2 and SM. At 18 hours after exposure, histopathologic features were compared. In addition, immunohistochemical markers to basement membrane proteins were used to evaluate the effects of both chemicals on the basement membrane zone. Gross vesication was not seen. Pyknotic nuclei with or without dyskeratotic changes within epidermal keratinocytes were present at both doses. These changes varied more between skin specimens than they did between doses. Ballooning degeneration was more marked after SM exposures. Diffuse dermal-epidermal separation was present only at high-dose exposures and did not appear to correlate with the degree of changes locally in the overlying epidermis. Antibodies to laminin-5 showed decreased immunoreactivity after exposure to HN2 and SM. Immunoreactivity for laminin- was decreased to a lesser extent, and immunoreactivity for collagen IV and VII was unchanged. HN2 and SM produce similar histopathologic and immunohistochemical features after cutaneous exposure. These features suggest that part of mechanism of action of HN2 and SM is a direct effect on the basement membrane zone. Understanding the effects of HN2 and SM separate from their effect on DNA may be important in designing therapies and in advancing our understanding of the pathophysiologic changes induced by these chemicals when delivered topically.