Objective To establish a liquid chromatography-tandem mass spectrometry(LC-MS/MS)method for the determination of ginsenoside Rh2(GRh2)in plasma of mice,so as to provide preclinical data support for the pharmacokinetic study and application of GRh2.Methods C57BL16 mice were given 7.5 mg/kg GRh2 by gavage.After administration,0.03 mL of whole blood was collected at 5 min,10 min,15 min,30 min,1 h,2 h,4 h,and 8 h.Then,the whole blood was centrifuged and the serum was treated with 0.1％formic acid acetonitrile,dried by nitrogen(40℃),and redissolved with 50.0 pL 50％methanol solution containing 100 ng/mL diclofenac sodium.After vortex mixing for 5 min at room temperature,it was put into the automatic sampler for sampling analysis.The chromatographic column was Waters BEHC18(2.1 mm × 50.0 mm,1.7 pm),the mobile phase was aqueous solution containing 0.1％formic acid and acetonitrile solution containing 0.1％formic acid at a flow rate of 0.60 mL/min,the column temperature was 40℃,and the injection volume was 1.00 pL.The electric spray ion source,positive ion mode and multiple reaction monitoring mode were performed.A standard curve was established to calculate blood drug concentration.The blood drug concentration-time curve was established according to the blood drug concentration,and the main pharmacokinetic parameters were calculated.Results The linear range of the standard curve of drug containing plasma was 100-40 000 ng/mL,and the correlation coefficient(r)was 0.996 0.After internal standard normalization,the matrix effect factors of GRh2 were 1.09,1.06,and 1.00(between 0.8 and 1.2),indicating no significant matrix effect.The precision and accuracy results showed that the average measured concentration of GRh2 samples at each concentration level was 103,333,23 800 and 35 000 ng/mL,the inter batch standard deviation was 6.47-1 120 ng/mL,the inter batch relative standard deviation was 1.5％-8.3％,and the inter batch accuracy deviation was 93.3％-111.1％.The long-term stability,short-term stability,repeated freeze-thaw property,and extraction recovery rate of GRh2 were all good.The pharmacokinetic parameters Tmax and Cmax of GRh2 in mice were(1.42±1.01)h and(1 251±495)ng/mL,respectively,indicating that the absorption and utilization rate of GRh2 in vivo was high and GRh2 had good drug performance.Conclusion The established LC-MS/MS method is accurate and reliable,and can be used to determine the concentration of GRh2 in mouse plasma and study its pharmacokinetic.

Objective Five chloroplast(cp)genomes from members of genus Polygonatum were assembled by hybrid assembly technique,and their intraspecic and interspecific differences were analyzed by comparative genomic method.Codon usage patterns and influencing factors were determined,and the cp genome data were applied to understand the phylogenomic relationships in the entire genus Polygonatum along with the available data.Methods In this study,the chloroplast genomes of 5 species of genus Polygonatum were assembled using Unicycler software.Sequence alignment,collinearity analysis,boundary analysis and other methods were used to evaluate the interspecific differences of these five species.Nucleotide polymorphism analysis was used to discover the high-variation sites of the five species and their related species,predict the distribution of different long repeat sequences and SSRs,and then analyze the use bias of Polygonatum code.Finally,phylogenetic tree was constructed with the coding sequences of other 47 genus Polygonatum and their closely related species to explore their phylogenetic relationships in this study.Results ①Chloroplast genomes of 155 408-155 623 bp were assembled from five species of Polygonatum.A total of 132-133 genes were annotated,and 369 long repeats and 1553 simple repeats were detected.②The contraction and expansion of chloroplast genomes in 8 species were not obvious at the IRs boundary,and the size and distribution of individual genes at the LSC-IRs-SSC boundary,such as ndhF gene and ycf1 gene,were slightly different.No interspecific or intraspecific rearrangement was observed in 8 species.③ The high-variation regions of the 8 chloroplast genomes are mainly located in two single-copy regions,the duplicate copy region is relatively conserved,and the coding region is more conserved than the non-coding region.High nucleotide polymorphic loci rps16-trnQ,trnS-trnG,trnTUGU-trnL,ndhF-rpl32 and rpl32-trnL are located in the single copy region and most of them are gene spacer regions.④ The codon preference results showed that the codon preference of the five species was similar and mainly affected by selection pressure,and the third base of the codon played A dominant role and mainly ended in A/U.RSCU clustering heat map shows that PK and PZ,PCB and PS have close relationship.⑤ Phylogenetic trees divided 52 species into five branches:Ⅰ,Ⅱ,Ⅲ,ⅣandⅤ.PS,PK,PCB,PCZ and PZ were divided into ⅣandⅤbranches,among which PK and PZ were most closely related,while PCZ was more distant than the other four,was divided into the Ⅴbranch alone.Conclusion This study provided a reference for the phylogenetic research and molecular marker development of the medicinal plants of the Polygonum genus.

Objective Five chloroplast(cp)genomes from members of genus Polygonatum were assembled by hybrid assembly technique,and their intraspecic and interspecific differences were analyzed by comparative genomic method.Codon usage patterns and influencing factors were determined,and the cp genome data were applied to understand the phylogenomic relationships in the entire genus Polygonatum along with the available data.Methods In this study,the chloroplast genomes of 5 species of genus Polygonatum were assembled using Unicycler software.Sequence alignment,collinearity analysis,boundary analysis and other methods were used to evaluate the interspecific differences of these five species.Nucleotide polymorphism analysis was used to discover the high-variation sites of the five species and their related species,predict the distribution of different long repeat sequences and SSRs,and then analyze the use bias of Polygonatum code.Finally,phylogenetic tree was constructed with the coding sequences of other 47 genus Polygonatum and their closely related species to explore their phylogenetic relationships in this study.Results ①Chloroplast genomes of 155 408-155 623 bp were assembled from five species of Polygonatum.A total of 132-133 genes were annotated,and 369 long repeats and 1553 simple repeats were detected.②The contraction and expansion of chloroplast genomes in 8 species were not obvious at the IRs boundary,and the size and distribution of individual genes at the LSC-IRs-SSC boundary,such as ndhF gene and ycf1 gene,were slightly different.No interspecific or intraspecific rearrangement was observed in 8 species.③ The high-variation regions of the 8 chloroplast genomes are mainly located in two single-copy regions,the duplicate copy region is relatively conserved,and the coding region is more conserved than the non-coding region.High nucleotide polymorphic loci rps16-trnQ,trnS-trnG,trnTUGU-trnL,ndhF-rpl32 and rpl32-trnL are located in the single copy region and most of them are gene spacer regions.④ The codon preference results showed that the codon preference of the five species was similar and mainly affected by selection pressure,and the third base of the codon played A dominant role and mainly ended in A/U.RSCU clustering heat map shows that PK and PZ,PCB and PS have close relationship.⑤ Phylogenetic trees divided 52 species into five branches:Ⅰ,Ⅱ,Ⅲ,ⅣandⅤ.PS,PK,PCB,PCZ and PZ were divided into ⅣandⅤbranches,among which PK and PZ were most closely related,while PCZ was more distant than the other four,was divided into the Ⅴbranch alone.Conclusion This study provided a reference for the phylogenetic research and molecular marker development of the medicinal plants of the Polygonum genus.