Screening method for chromatographic analysis of diarylheptanoids in alder bark extracts

An experimentally proven novel analytical approach for chromatographic analysis of diarylheptanoids in grey alder (Alnus incana) and black alder (Alnus glutinosa) bark matrices was established. A method for qualitative and quantitative determination of oregonin (dominant diarylheptanoid) and semiquantitative analysis of related diarylheptanoids from alder bark using a photodiode array (PDA) detector coupled to a high-resolution mass spectrometer (QTOF-MS) was developed. A comparison of different liquid chromatography detectors (UV, MS and ELS) showed that only a combination of them is applicable for comprehensive analysis of multicomponent extracts. A total of sixteen different diarylheptanoids were simultaneously identified and semi-quantified in alder bark extracts. This is the first report of the method for individual and total diarylheptanoid determination in alder bark extracts, discussed in detail. The liquid chromatography complex is suggested as a tool for the reliable identification and quality control of the diarylheptanoids containing extracts isolated from the Alnus species and their dominant component - oregonin. The semiquantitative methodology established, and the dominant compound quantification provided means for assessing comparative sample complexities.

Automated summary

An experimentally proven chromatographic analysis method was established for the analysis of diarylheptanoids in grey alder and black alder bark. The combination of a photodiode array detector and a high-resolution mass spectrometer was found to be the most effective for comprehensive analysis of multicomponent extracts. Sixteen different diarylheptanoids were successfully identified and semi-quantified in the alder bark extracts. This method provides a reliable tool for the identification and quality control of diarylheptanoids in Alnus species extracts.