ABSTRACT
Four species of the genus Artemisia L. (Artemisia monosperma, Artemisia scoparia, Artemisia judaica and Artemisia sieberi) growing in the northern region of Saudi Arabia were investigated with respect to their volatile oil contents. The yield of oil varied between 0.30 and 0.41%, % (w/w). A. monosperma showed the highest number of compounds with 30 components representing 93.78% of oil composition. However, A. judaica showed the lowest number of compounds with only 16 components representing 87.47% of essential oil. A. scoparia and A. sieberi are both composed of 17 components, representing 97.14 and 94.2% of total oil composition. A. sieberi and A. judaica were dominated by spathulenol (30.42 and 28.41%, respectively). For A. monosperma, butanoic acid (17.87%) was a major component. However, A. scoparia was a chemotype of acenaphthene. (83.23%). Essential oil of studied species showed high antibacterial activities against common human pathogens.
Subject(s)
Anti-Bacterial Agents/pharmacology , Artemisia/chemistry , Oils, Volatile/analysis , Humans , Oils, Volatile/pharmacologyABSTRACT
Objective To select a more suitable DNA barcode to identify the species in Artemisia L. Methods ITS, ITS2, and three other major universal barcode candidates (matK, rbcL, and psbA-trnH) were evaluated in the identification efficiency using a total of 1433 sequences downloaded from GenBank representing 343 species in Artemisia L. ITS and ITS2 were evaluated in the PCR and sequencing rate, sequencing peak quality (Q value), and misread rate. One hundred and twelve A. annua samples were collected from 11 populations across over China, which were amplified with universal primers on the ITS and ITS2 regions. Results ITS and ITS2 shared a higher identification efficiency and exhibited 71.43% and 64.11% detectability at the species level, respectively. The Q values of ITS and ITS2 showed that the direct PCR sequencing data were reliable for the ITS2 region and ITS exhibited poor sequencing trace quality. In certain sites, the ITS sequences exhibited reading ambiguities and errors, indicating that the misread and deletion sites in the ITS region would incorrectly inflate the identification ratio. Conclusion ITS2 is a suitable barcode for identification of species in Artemisia L., which enlarges the optimal range of divergence levels for taxonomic inferences using ITS2 sequences.
ABSTRACT
Plant volatiles have been repeatedly shown to provide valuable insight into the evolutionary relationships among plant taxa on various taxonomical levels. The number of variables available from GC-MS analyses of these plant metabolites usually represents a large data set. The comparison of such data sets requires the use of multivariate statistical analyses (MSA) but with several serious shortcomings. In order to make multivariate statistical comparison of essential oils more applicable, reliable and faster, this work was set to explore the suitability of a complementary use of relative abundances of m/z values of the average mass scan of the total GC chromatograms instead of the traditionally used variables-percentages (peak areas) of individual oil constituents. To achieve this, essential oils extracted from 12 different Artemisia species were analyzed using GC-FID and GC-MS. Almost 500 different constituents were successfully identified. Average mass scans of the total GC chromatograms (AMS) and chemical compositions (relative percentages) of the analyzed oils were separately compared using two MSA methods: agglomerative hierarchical cluster analysis and principal component analysis. This approach was applied to an additional set of essential oil compositional data (representatives of a number of different genera/families; data from the literature) using both types of variables. The obtained results strongly suggest that MSA of complex volatile mixtures, using the corresponding directly obtainable AMS, could be considered as a promising time saving tool for easy and reliable comparison purposes. The AMS approach gives comparable or even better results than the traditional method - it reflected the natural relationships between observations within both studied groups of oils.
