A Comprehensive LC-MS and Isolation Study of Cicada Slough as a Crude Drug

Abstract

Cicada slough is one of the traditional crude drugs in East Asia. A comprehensive LC-MS analysis was conducted to overview constituents in a commercially purchased cicada slough as a crude drug. It revealed that there were oligomers of N-acetyldopamine with the degree of polymerization of up to 8. High-resolution tandem mass spectrometry could enable a detailed analysis on their structures by uncovering the presumed fragmentation pathways. Additional isolation experiments disclosed the presence of four known compounds: 2,3’,4’-trihydroxyacetophenone, 2-oxo- N-acetyldopamine, protocatechuic acid, and paeonol. The quantified paeonol content for purchased cicada slough ranged from 3 to 290 μg/g dw crude drug, although wild cicada slough did not show the presence of paeonol.