| Popis: |
The diacetate and di-O-methyl derivative of polyporic acid have anomalous mass spectra. Ions are observed at m/e values equal to the molecular weight but ions 2 mass units larger than these, often of greater intensity, are also observed. The abundance of such ions depends on the temperature of the sample, the pressure in the source, and the partial pressure of water in the instrument. In addition, ions m/e 420 and 462 are found in the spectrum of the diacetate which are parents of the M + 2 ion(s). Similarly, M + 17 and M + 32 ions are observed in the spectrum of the dimethoxy compound. When deuterium oxide and the ester or the perdeuterioacetyl derivative were introduced into the source M + 4 ions were seen in the mass spectra. These unusual reactions should permit diagnosis of the 2,5-dihydroxy-1,4-benzoquinone moiety in newly isolated natural products. |
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