Reproductive isolation is mediated by pollen incompatibility in sympatric populations of two Arnebia species.[Pubmed: 26811758]

To explore uncertain aspects of the processes that maintain species boundaries, we evaluated contributions of pre- and postpollination reproductive isolation mechanisms in sympatric populations of Arnebia guttata and A. szechenyi. For this, we investigated their phylogenetic relationships, traits, microenvironments, pollinator visits, action of natural selection on floral traits, and the outcome of hand pollination between the two species. Phylogenetic analysis indicates that A. szechenyi is a derived species that could be closely related to A. guttata, and both could be diploid species. Arnebia guttata flowers have larger parts than A. szechenyi flowers, but smaller nectar guides. Soil supporting A. szechenyi had higher water contents than soil supporting neighboring populations of A. guttata (in accordance with their geographical distributions). The pollinators shared by the two species preferred A. szechenyi flowers, but interspecific visitations were frequent. We found evidence of conflicting selection pressures on floral tube length, flower diameter and nectar guide size mediated via male fitness, and on flower diameter and floral tube diameter via female fitness. Hand-pollination experiments indicate complete pollen incompatibility between the two species. Our results suggest that postpollination prezygotic mechanisms are largely responsible for reproductive isolation of sympatric populations of the two Arnebia species.

Systematic identification of shikonins and shikonofurans in medicinal Zicao species using ultra-high performance liquid chromatography quadrupole time of flight tandem mass spectrometry combined with a data mining strategy.[Pubmed: 26610615]

Shikonin, shikonofuran and their derivatives are the main bioactive components of Zicao, a traditional Chinese herbal medicine prepared with the dried roots of Lithospermum erythrorhizon, Arnebia euchroma or Arnebia guttata. However, approaches on the systematic discovery and identification of shikonins and shikonofurans, especially unknown ones, are still not available. To address this issue, the gas-phase CID-fragmentation routes for the shikonins and shikonofurans were established by using ESI-QTOF-MS in the negative ion mode and low-energy collision induced dissociation tandem mass spectrometry (CID-MS/MS) in this study using seventeen standards. As a result, diagnostic product ions for rapid discovery and classification of shikonins and shikonofurans were determined. In addition, various mobile phase compositions and UHPLC elution programs were evaluated to achieve optimal separation efficiency and detection response of these types of analytes. Based on these findings, an integral approach using UHPLC-ESI-QTOF-MS and CID-MS/MS analyses together with a novel two steps data mining strategy was developed for systematic analysis of shikonins and shikonofurans in complex samples. Consequently, 58 compounds including 32 novel ones were efficiently discovered and identified from the crude extract of Zicao. Moreover, comparative analyses of the 58 chemical components in three Zicao species including Lithospermum erythrorhizon, Arnebia euchroma and Arnebia guttata samples were conducted using the established analytical method, which can be instructive for future utilization of Zicao and its related medicinal products.

Antibacterial and COX-1 Inhibitory Effect of Medicinal Plants from the Pamir Mountains, Afghanistan.[Pubmed: 27137641]

Plants used to treat inflammatory ailments, pain, fever and infections in the Pamir Mountains in northeastern Afghanistan, were tested for antibacterial and COX-1 inhibitory activity. Water and ethanol extracts of 20 species were tested for antibacterial activity against two gram positive and two gram negative bacteria. The ethanol extract of Arnebia guttata inhibited Staphylococcus aureus with a MIC of 6 µg/mL. Water and ethanol extracts of Ephedra intermedia and the ethanol extracts of Lagochilus cabulicus and Peganum harmala inhibited Staphylococcus aureus at 0.5 mg/mL, and the P. harmala extract further inhibited the growth of Bacillus subtilis and E. coli, also with MICs of 0.5 mg/mL. Ethanol extracts of Artemisia persica (IC50: 0.5 µg/mL), Dragocephalum paulsenii (IC50: 0.5 µg/mL), Ephedra intermedia (IC50: 3.8 µg/mL), Hyoscyamus pusillus, Nepeta parmiriensis (IC50: 0.7 µg/mL) and Rumex patientia subsp. pamiricus (IC50: 3.5 µg/mL) exhibited COX-1 inhibitory activity. The observed in vitro activities support the use of some of the plant species in the traditional medicine systems of the Pamir Mountains.