ABSTRACT
This study focuses on the microbial quality control of the Chinese herbal decoction pieces. In view of the shortcomings of traditional culture methods such as slow detection speed and inability to detect unculturable microorganisms, a new method based on ATP bioluminescence technology combined with statistical analysis methods was established to rapidly predict and quantitatively detect the total aerobic microbial count (TAMC) and total yeast and mold count (TYMC) contaminated Bupleurum chinense DC. decoction pieces. Based on the optimized ATP bioluminesence detection system, accurate detection of pure bacterial solution of Escherichia coli, Bacillus subtilis and Staphylococcus aureus can be achieved, with detection limits of 47.86, 89.13 and 1 862.09 CFU·mL-1, respectively. The detection time was 6.5 h, and the detection cost was as low as 2 yuan/time. The upper and lower warning limits of TAMC were determined by the misjudgment rates of 10% and 20%, respectively. And the warning limit of TYMC was determined by the misjudgment rate of 20%. The proposed crossing method could quickly predict the amount of microbial contamination in Bupleurum chinense DC. decoction pieces. The constructed partial least squares regression (PLSR) model could accurately quantify the quantity of microbial contamination in Bupleurum chinense DC. decoction pieces. The optimal PLSR prediction model for TAMC had a correction coefficient (R2) of 0.826, a root mean square error of correction set (RMSEE) of 0.468 and a root mean square error of cross-validation set (RMSECV) of 0.465. The R2, RMSEE and RMSECV in the prediction model of TYMC were 0.778, 0.543 and 0.541, respectively. The aim of this study is to establish a kind of rapid detection method and prediction models for the microbial limit of traditional Chinese medicine and Chinese herbal decoction pieces, and to provide a more convenient and sensitive detection technology for the microbial quality process control of traditional Chinese medicine products.
ABSTRACT
italic>Bupleurum L. (Apiaceae) is an economically important genus, in which many species are of medicinal value. In this study, the complete plastid genomes (plastomes) of B. chinense DC. and B. boissieuanum H. Wolff were sequenced and their characteristics were investigated. Comparative and phylogenetic analyses were conducted with other published Bupleurum plastomes. The complete plastomes of B. chinense and B. boissieuanum were 155 458 and 155 800 bp in length, and both exhibited the typical quadripartite circular structure consisting of a large single copy region (LSC, 85 343 and 85 804 bp), a small single copy region (SSC, 17 495 and 17 410 bp), and a pair of inverted repeat regions (IRa/b, 26 310 and 26 293 bp), respectively. A total of 129 genes, including 84 protein-coding genes, 37 transfer RNA (tRNA) genes, and eight ribosomal RNA (rRNA) genes were identified from each of the two plastomes. Repeat sequences detected were similar in types and distribution patterns, but the numbers were slightly different. Comparative analyses revealed that the Bupleurum plastomes were highly conserved in length, structure, the guanine and cytosine (GC) content, and gene content and order, both intraspecifically and interspecifically, and no obvious expansion or contraction of the inverted repeat regions occurred. Sequence variation was lower within the same species than among different species, noncoding sequences (including intergenic regions and introns) showed a higher divergence than the protein-coding sequences, and sequences in the LSC and SSC regions were more divergent than those in the IR regions. In addition, 11 sequences with higher nucleotide diversity among species were detected in the LSC and SSC regions. All studied Bupleurum species were inferred forming a monophyletic group with a 100% bootstrap value. Bupleurum chinense and B. boissieuanum were phylogenetically closest to B. commelynoideum and B. falcatum, separately, with all three B. chinense accessions clustered into a distinct clade. These results provide genetic information for further species identification, phylogenetic resolution, and will assist in exploration and utilization of medicinal Bupleurum species.
ABSTRACT
Characterization of the polysaccharides and monosaccharides of Bupleurum chinense was undertaken to identify differences in the Bupleurum chinense's sugar profiles, so as to provide a basis for the identification of different varieties. High performance liquid chromatography (HPLC) was used to generate chromatograms of the total polysaccharides of Bupleurum using an Evaporation Light Detector (ELSD), and a monosaccharide chromatogram was generated using a UV-detector (UV) following polysaccharide derivatization. The data were analyzed using SIMCA software and SPSS software to distinguish different varieties of Bupleurum. The results show that the yield of polysaccharides from Bupleurum falcatum is the highest, while the yield of polysaccharides from Bupleurum chinense is the lowest. The polysaccharide spectrum shows that the molecular weights of the polysaccharides in different Bupleurum differ, and their percentages of the total peak area are also different. The four Bupleurum polysaccharides are composed of mannose, glucuronic acid, rhamnose, galacturonic acid, glucose, galactose, and arabinose, but differ in length. The ratio of glucose to arabinose in Bupleurum chinense, Bupleurum scorzonerifolium, Bupleurum falcatum and Bupleurum marginatum var. stenophyllum is: 3.0-4.0, 5.5-7.0, 12.0-17.0, 9.0-12.0. In this study, a sugar profile technique was developed to provide a new method for the identification of different varieties of Bupleurum.