Objective To investigate the spatiotemporal distribution characteristics of kaempferol-3-O-rutinoside and ellagic acid, the medicinal marker components of Rubus chingii, and optimize the processing technology to improve their contents based on the findings. Methods Matrix-assisted laser desorption/ionization time-of-flight imaging mass spectrometry (MALDI-TOF IMS) was used for imaging analysis of R. chingii fruits, and high-performance liquid chromatography (HPLC) was employed for quantitative determination of the marker components in fresh fruits and medicinal materials processed by different technologies. Results Kaempferol-3-O-rutinoside was mainly distributed in the outer layer of the fruit, while ellagic acid and its precursors were enriched in the receptacle. Both components exhibited the highest content in green fruits and gradually decreased with fruit ripening. Compared with oven-drying, the sun-drying process significantly increased ellagic acid content by 68.71% but reduced kaempferol-3-O-rutinoside content by 41.30%. Drying after steam moistening at 120 ℃ for 30 min followed by drying effectively improved ellagic acid content without significant negative impacts on kaempferol-3-O-rutinoside content or the appearance of medicinal materials. Conclusion The tissue-specific distribution of the marker components in R. chingii is a key factor affecting their content changes during processing. Timely harvesting of green fruits and optimization of processing technology (short-time steam moistening) can synergistically improve the quality of medicinal materials.

Rubus chingii Hu  /  kaempferol-3-O-rutinoside  /  ellagic acid  /  processing technology  /  mass spectrometry imaging