ABSTRACT
In this study, we accurately collected the embryonic parenchyma cells and endocarp stone cells of Arctii Fructus at five different growth stages by laser microdissection. Quantitative analyse of caffeic acid, arctiin and arctigenin in these cells were performed using ultra-fast liquid chromatography-tandem mass spectrometry (UFLC-MS/MS). The results showed that a large amount of arctiin was produced and accumulated in embryonic parenchyma cells from the late flowering stage to mature stage, while much lower content of arctiin was produced and accumulated in endocarp stone cells at these stages. It suggested that the biosynthetic pathways of arctiin were different in embryonic parenchyma cells from endocarp stone cells of Arctii Fructus. Arctigenin was found to be produced and accumulated in both embryonic parenchyma cells and in endocarp stone cells from the late flowering stage to mature stage, but it reached a peak in endocarp stone cells at late flowering stage, then decreased slowly. The concentration of arctigenin was far less than that of arctiin regardless of embryonic parenchyma cells or endocarp stone cells. These results have validated the new method for analysis of dynamic accumulation of arctiin in Arctii Fructus by UFLC-MS/MS with frozen sections and microdissection.
ABSTRACT
Fructus Arctii is a traditional Chinese medicine. The main counterfeit species are the seeds of Arctium tomentosum, Onopordum acanthium, Silybum marianum, Saussurea costus, Amorpha fruticosa. Traditional identification methods or molecular barcoding techniques can identify Fructus Arctii and its counterfeit species. However, the identification of the mixture of it and its spurious species is rarely reported. In this paper, we sequenced the ITS2 sequences of Fructus Arctii and 5 kinds of spurious species mix powder by high-throughput sequencing to identify the mixed powder species and providing new ideas for the identification of Fructus Arctii mix powder. The total DNA in mixed powder was extracted, and the ITS2 sequences in total DNA was amplified. Paired-end sequencing was performed on the DNA fragment of the community using the Illumina MiSeq platform. The sequence was analyzed by the software FLASH, QIIME and GraPhlAn etc. The results showed that the high quality ITS2 sequences of 39910 mix samples were obtained from the mixed samples, of which the total ITS2 sequence of the samples genus was 34 935. Phylogenetic analysis showed that the samples contained Fructus Arctii, A. tomentosum, O. acanthium, S. marianum, S. costus and A. fruticosa. Using ITS2 sequences as DNA barcodes, high-throughput sequencing technology can be used to detect the Fructus Arctii and its spurious specie in mixed powder, which can provide reference for the quality control, safe use of medicinal materials of Fructus Arctii and the identification of mixed powder of traditional Chinese medicine.