The synthesis and characterization of arsenocholine and related compounds
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| Other Authors: | , , |
| Format: | Thesis Book |
| Language: | English |
| Published: |
1982.
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| Subjects: | |
| Online Access: | Link to ProQuest Copy Link to OAKTrust copy ProQuest, Abstract |
| Abstract: | It has been known for 80 years, that arsenic is present in marine organisms in form of organic compounds. Only recently have some of these compounds been identified. Arsenobetaine, arsenocarbohydrates and dimethyl(2-hydroxyethyl)arsine oxide were isolated from marine organisms. There is some evidence that arsenocholine, 2-carboxyarsenocholine and arsenolipids are also present in nature. Many of these compounds are arsenic analogues of biologically important nitrogen derivatives. To have available model compounds to study the chromatographic, chemical and physical properties of several biologically important arsenic compounds, arsenocholine, arsenobetaine, acetylarsenocholine, arsenobetaine aldehyde diethylacetal, phosphorylarsenocholine, and 1,3-dipalmitoylglycero-2-phosphoryl arsenocholine were synthesized. The compounds {(CH(,3))(,3)AsCH(,2)R} ('+)X('-) {R=CH(,2)OH, COOH, CH(,2)O(,2)CCH(,3), CH(OC(,2)H(,5))(,2)} were prepared in good yields from trimethylarsine and RCH(,2)Br. Anion exchange reactions produced other salts. Arsenocholine and phosphoric acid yielded phosphorylarsenocholine, which was isolated as {(CH(,3))(,3)AsCH(,2)CH(,2)PO(,3)Ca} ('+)Br('-). The reaction of arsenocholine tosylate with 1,3-dipalmitoylglyceryl dichlorophosphate produced 1,3-dipalmitoylgycero-2-phosphorylarsenocholine in low yield. These compounds were characterized by ('1)H- and ('13)C-NMR spectroscopy, UV-VIS spectroscopy and mass spectrometry. NMR and mass spectroscopy can be used to differentiate between analogous arsenic and nitrogen compounds. The investigation of the chemical behavior of arsenocholine proved that it remains chemically unaltered on boiling in 2M HCl, 2M NaOH or 40% NaOH. In basic D(,2)O solutions the methyl and AsCH(,2) protons are exchanged for deuterons. Phosphorylarsenocholine is hydrolyzed slowly by acid but rapidly by base to arsenocholine. Arsenobetaine is stable in acidic solution. In base trimethylarsine oxide and acetate are slowly formed. Only the AsCH(,2) group becomes deuterated in basic D(,2)O solutions at 22(DEGREES) and acidic D(,2)O solutions of arsenobetaine at 100(DEGREES). Arsenobetaine aldehyde diethylacetal is hydrolyzed in acid to the trimeric aldehyde. The AsCH(,2) protons can be exchanged for deuterons.... |
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| Item Description: | "Major subject: Chemistry." Typescript (photocopy). Vita. |
| Physical Description: | xxi, 193 leaves : illustrations ; 29 cm |
| Bibliography: | Includes bibliographical references (leaves 184-192). |