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.
Integrating qualitative and quantitative assessments of Yougui pill, an effective traditional Chinese medicine, by HPLC-LTQ-Orbitrap-MSn and UPLC-QqQ-MS/MS
Yougui pill (YGP) is a well-known Chinese medicine formula with definite clinical effects on kidney-yang deficiencies such as infertility. However, Aconitum carmichaeli var. carmichaeli, one of the herbs contained in YGP, shows several side effects. Therefore, it is important to carry out strict and systematic quality evaluation on YGP to ensure its effects and safety. In the present study, qualitative and quantitative analyses were performed on YGP. First, an HPLC-LTQ-Orbitrap-MSn method was applied to validate the chemical profile of YGP. Eighty-three compounds were identified, including iridoids, flavones and alkaloids. Second, an UPLC-QqQ-MS/MS method was used for the simultaneous quantitation of 16 targeted compounds in YGP. The method showed a good linear correlation (R > 0.995) over a wide range and a high sensitivity, as established by LOD (0.04–0.40 ng mL−1) and LOQ (0.10–1.00 ng mL−1). The RSD values of intra- and inter-day precisions were less than 10%. The RSD values of repeatability and stability were less than 5%, and recovery assays were between 85.8% and 96.2%. The cluster analysis indicated that the qualities of YGP from two manufacturers were very different. The present integrated qualitative and quantitative assessment of YGP provides a good example of quality evaluation strategy to assess Chinese medicine formulas.
SOME OXIDATION REACTIONS OF DELCOSINE
The alkaloid delcosine was oxidized by chromic acid in acetic acid, and also by the Oppenauer reaction, to dehydrodelcosine in which the carbonyl was shown by infrared absorption to be in a pentatomic ring. Oxidation of the alkaloid with silver oxide gave two products: (a) N-desethyldelcosine, which could be N-acetylated or converted back to the original base by ethylation, thus proving the presence of an N-ethyl group; (b) a compound, C24H37O7N, the properties of which agreed best with those of an internal ether, i.e., anhydrohydroxydelcosine. The action of N-bromosuccinimide on the alkaloid produced the same two compounds as silver oxide, plus a derivative, C22H33O7N, that proved to be N-desethyl-anhydrohydroxydelcosine. Potassium permanganate oxidized delcosine to a product, C22H31O7N, that had lost the N-ethyl group, contained the internal ether, and also a carbonyl in a five-membered ring. This same product was obtained on similar oxidation of N-desethyl-anhydrohydroxydelcosine. Oxidation of delcosin...