Comparative analysis of chloroplast genomes of three medicinal Carpesium species: Genome structures and phylogenetic relationships.

Carpesium (Asteraceae) is a genus that contains many plant species with important medicinal values. However, the lack of chloroplast genome research of this genus has greatly hindered the study of its molecular evolution and phylogenetic relationship. This study used the Illumina sequencing platform to sequence three medicinal plants of the Carpesium genus: Carpesium abrotanoides, Carpesium cernuum, and Carpesium faberi, obtaining three complete chloroplast genome sequences after assembly and annotation. It was revealed that the three chloroplast genomes were typical quadripartite structures with lengths of 151,389 bp (C. abrotanoides), 151,278 bp (C. cernuum), and 151,250 bp (C. faberi), respectively. A total of 114 different genes were annotated, including 80 protein-coding genes, 30 tRNA genes, and 4 rRNA genes. Abundant SSR loci were detected in all three chloroplast genomes, with most composed of A/T. The expansion and contraction of the IR region indicate that the boundary regions of IR/SC are relatively conserved for the three species. Using C. abrotanoides as a reference, most of the non-coding regions of the chloroplast genomes were significantly different among the three species. Five different mutation hot spots (trnC-GCA-petN, psaI, petA-psbJ, ndhF, ycf1) with high nucleotide variability (Pi) can serve as potential DNA barcodes of Carpesium species. Additionally, phylogenetic evolution analysis of the three species suggests that C. cernuum has a closer genetic relationship to C. faberi than C. abrotanoides. Simultaneously, Carpesium is a monophyletic group closely related to the genus Inula. Complete chloroplast genomes of Carpesium species can help study the evolutionary and phylogenetic relationships and are expected to provide genetic marker assistance to identify Carpesium species.

[Determination of quercetin and kaempferol in Dysosma plants by RP-HPLC].

OBJECTIVE: To determine quercetin and kaempferol in the plant of genus Dysosma that come from different species, different plant parts or different growing areas, which provide the basis of rational utilization of Dysosma plants. METHOD: The analysis was performed on a Diamonsil C18 column (4.6 mm x 150 mm, 5 microm) eluted with the mobile phase of methanol-water containing 0.1% phosphoric acid (60:40). The flow rate was 1 mL x min(-1), the detection wavelength was 360 nm; and the column temperature was set at 25 degrees C. RESULT: The linear ranges of quercetin and kaempferol are 0.22-1.1 microg and 0.42-2.1 microg. The average recoveries of quercetin and kaempferol are 97.1% (RSD 1.4%) and 99.6% (RSD 2.4%); respectively. CONCLUSION: The contents of flavones in different species of Dysosma are significantly different.