The pharmacophylogenetic relationships of two edible medicinal plants in the genus Artemisia

Complete chloroplast genomes of eight Artemisia species: Comparative analysis, molecular identification, and phylogenetic analysis

Artemisia L. is the largest genus in the Asteraceae, and well known for its high medicinal value. The morphological features of Artemisia species are similar, making taxonomic identification and evolutionary research difficult. We sequenced chloroplast genomes of eight Artemisia species, all of which are common adulterants of A. argyi. We used novel genetic data and compared these data to the published A. argyi chloroplast genome in to develop molecular markers for species identification and reconstructing phylogenetic relationships between Artemisia species. The eight chloroplast sequences were highly similar in gene order, content, and structure, encoding a total of 114 genes (82 protein-coding genes, 28 tRNAs, and four rRNAs). All species harboured similar repeat sequences and simple sequence repeats (SSRs), ranging from 47 to 49 and 38 to 40 repeats, respectively. In addition, we identified five hypervariable regions (rpl32-trnL, rps16-trnQ, petN-psbM, trnE-rpoB, and atpA-trnR) and ten variable coding genes (ycf1, psbG, rpl36, psaC, psaI, accD, psbT, ndhD, ndhE, and psbH), which can be used to develop chloroplast molecular markers. Finally, phylogenetic reconstructions based on six datasets produced similar topologies, revealing A. argyi is closely related to species often found as adulterants, as expected. Our research provides valuable new information on the evolution and phylogenetic relationships between Artemisia chloroplast genomes and identifies valuable molecular makers to distinguish it from closely related species.

Sesquiterpene Lactones and Flavonoid from the Leaves of Basin Big Sagebrush (Artemisia tridentata subsp. tridentata): Isolation, Characterization and Biological Activities

This research is an exploratory study on the sesquiterpenes and flavonoid present in the leaves of Artemisia tridentata subsp. tridentata. The leaf foliage was extracted with 100% chloroform. Thin-layer chromatography (TLC) analysis of the crude extract showed four bands. Each band was purified by column chromatography followed by recrystallization. Three sesquiterpene lactones (SLs) were isolated-leucodin, matricarin and desacetylmatricarin. Of these, desacetylmatricarin was the major component. In addition, a highly bio-active flavonoid, quercetagetin 3,6,4'-trimethyl ether (QTE), was also isolated. This is the first report on the isolation of this component from the leaves of Artemisia tridentata subsp. tridentata. All the components were identified and isolated by TLC, high-performance liquid chromatography (HPLC) and mass spectrometry (MS) techniques. Likewise, the structure and stereochemistry of the purified components were characterized by extensive spectroscopic analysis, including 1D and 2D nuclear magnetic resonance (NMR) and Fourier transform infrared spectroscopy (FTIR) studies. The antioxidant activities of crude extract were analyzed, and their radical-scavenging ability was determined by Ferric reducing antioxidant power (FRAP) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay. The crude extract showed antioxidant activity of 18.99 ± 0.51 and 11.59 ± 0.38 µmol TEg-1 FW for FRAP and DPPH assay, respectively, whereas the activities of matricarin, leucodin, desacetylmatricarin and QTE were 13.22, 13.03, 14.90 and 15.02 µmol TEg-1 FW, respectively, for the FRAP assay. The antitumor properties were probed by submitting the four isolated compounds to the National Cancer Institute (NCI) for NCI-60 cancer cell line screening. Overall, the results of the one-dose assay for each SL were unremarkable. However, the flavonoid's one-dose mean graph demonstrated significant growth inhibition and lethality, which prompted an evaluation of this compound against the 60-cell panel at a five-dose assay. Tests from two separate dates indicate a lethality of approximately 75% and 98% at the log-4 concentration when tested against the melanoma cancer line SK-Mel 5. This warrants further testing and derivatization of the bioactive components from sagebrush as a potential source for anticancer properties.