Features of the splitting out of a methyl radical from lycoctonine alkaloids under electron impact
The mass spectra of 53 alkaloids and their derivatives are considered. It is known that the presence of a C6(OCH3)-C7(OH)-C8 (OH) grouping in C19-diterpene alkaloids leads to a high intensity of the (M - 15)+ ions at the expense of the C6(OCH3) group and considerably suppresses the competing processes of forming the [M - OH (OCH3)]+ ions in the alkaloids and the (M - 56)+ ions in the anhydroxy bases. When the above-mentioned grouping is absent, the (M - 15)+ ions are formed mainly by the splitting out of a ĊH3 from a N-ethyl group.
Two new diterpene alkaloids from delphinium cardiopetalum DC
Chemical, spectral and X ray data are given for cardiopetaline and cardiopetalidine, two new C-19 diterpene alkaloids from the genus Delphinium.
Dating of Historical Manuscripts Using Spectrometric Methods: A Mini-Review
An overview is provided of spectrometric methods useful for age estimation of historical manuscripts (medieval ones in particular), in order to confirm their authenticity. Individual methods (infrared and Raman spectroscopy, mass spectrometry, atomic emission spectroscopy, X-ray spectroscopy, and electron scanning microscopy) are discussed and examples of their application described. The following general strategy can be recommended for dating and/or authenticating of historical manuscripts. First of all, the pigment analysis should be carried out using Raman spectroscopy (distinguishing the period and modern pigments), followed by PIXE ink analysis (solving the question of ink homogeneity). Finally, the radiocarbon dating of the writing support, potentially supplemented by the ink dating using scanning Auger microscopy should be performed.