Authoritarianism, Democracy and De/Centralization in Federations: What Connections?

What is the impact of democracy/authoritarianism regime change on de/centralization in federations? Based on annual coding of three politico-institutional aspects, 22 policy fields, and five fiscal categories, this article maps de/centralization in Argentina, Brazil, Mexico, Nigeria and Pakistan from the establishment of their respective federal orders to 2020. It shows that de/centralization varies greatly across its different dimensions as well as between systems, with centralization being the dominant long-term trend but with significant exceptions, notably Pakistan. Regime change plays a major role in de/centralization but not always in line with the usual expectation that authoritarian regimes centralize and democratic ones decentralize. Other factors that cut across the authoritarianism/democracy divide, notably ideological orientations, have substantial impacts on de/centralization. By investigating long-run patterns of de/centralization in federations that have experienced democracy/authoritarianism regime change, the article sheds light on how federalism operates beyond consolidated democracies

Anti-plasmodial polyvalent interactions in Artemisia annua L. aqueous extract – possible synergistic and resistance mechanisms

Artemisia annua hot water infusion (tea) has been used in in vitro experiments against P. falciparum malaria parasites to test potency relative to equivalent pure artemisinin. High performance liquid chromatography (HPLC) and mass spectrometric analyses were employed to determine the metabolite profile of tea including the concentrations of artemisinin (47.5±0.8 mg L-1), dihydroartemisinic acid (70.0±0.3 mg L-1), arteannuin B (1.3±0.0 mg L-1), isovitexin (105.0±7.2 mg L-1) and a range of polyphenolic acids. The tea extract, purified compounds from the extract, and the combination of artemisinin with the purified compounds were tested against chloroquine sensitive and chloroquine resistant strains of P. falciparum using the DNA-intercalative SYBR Green I assay. The results of these in vitro tests and of isobologram analyses of combination effects showed mild to strong antagonistic interactions between artemisinin and the compounds (9-epi-artemisinin and artemisitene) extracted from A. annua with significant (IC50 <1 μM) anti-plasmodial activities for the combination range evaluated. Mono-caffeoylquinic acids, tri-caffeoylquinic acid, artemisinic acid and arteannuin B showed additive interaction while rosmarinic acid showed synergistic interaction with artemisinin in the chloroquine sensitive strain at a combination ratio of 1:3 (artemisinin to purified compound). In the chloroquine resistant parasite, using the same ratio, these compounds strongly antagonised artemisinin anti-plasmodial activity with the exception of arteannuin B, which was synergistic. This result would suggest a mechanism targeting parasite resistance defenses for arteannuin B’s potentiation of artemisinin

Analysis of plant materials for molecules of pharmaceutical importance

Natural products are an important source for drug discovery. At present there is a resurgent interest in pharmacognosy as a platform for new combinations of active principles to provide highly potent and low-cost medications to treat a growing population with an increasing longevity. This product studied phytochemical interactions in Artemisia annua plant extracts using anti-plasmodium and anti-proliferation assays to identify interactions with potential therapeutic implications. To enable the study a rapid tandem quadrupole mass spectrometry (TQD) method was developed for metabolites in the plant and the validation indices showed the method to be robust, quick, sensitive and adequate for a range of applications [...

Multivariate data analysis and metabolic profiling of artemisinin and related compounds in high yielding varieties of Artemisia annua field-grown in Madagascar.

An improved liquid chromatography-tandem mass spectrometry (LC-MS/MS) protocol for rapid analysis of co-metabolites of A. annua in raw extracts was developed and extensively characterized. The new method was used to analyse metabolic profiles of 13 varieties of A. annua from an in-field growth programme in Madagascar. Several multivariate data analysis techniques consistently show the association of artemisinin with dihydroartemisinic acid. These data support the hypothesis of dihydroartemisinic acid being the late stage precursor to artemisinin in its biosynthetic pathway.The research leading to these results has received funding from Engineering and Physical Sciences Research Council project “Closed Loop Optimization for Sustainable Chemical Manufacture” [EP/L003309/1].This is the final version of the article. It first appeared from Elsevier via http://dx.doi.org/10.1016/j.jpba.2015.10.00

Development of efficient miniprep transformation methods for Artemisia annua using Agrobacterium tumefaciens and Agrobacterium rhizogenes

Extensive studies have been carried out for the optimization of regeneration and transformation conditions for both Agrobacterium tumefaciens- and Agrobacterium rhizogenes-mediated transformation of the highly medicinal plant Artemisia annua. Most protocols describe laborious transformation procedures requiring no less than 3 mo to obtain transgenic plants. This study reports rapid and efficient protocols for A. tumefaciens- and A. rhizogenes-mediated transformation of A. annua, which were equally effective for transformation of Artemisia dubia. In both transformation procedures, stem explants responded best for maximal production of transformed plants and hairy roots. In the case of A. tumefaciens-mediated transformation, stem explants were pre-cultured for 2 d followed by infection with A. tumefaciens strain LBA4404 for 48 h. A. annua explants showed maximal transformation rate (43.5%) on half-strength Murashige and Skoog medium containing 40 mg/L kanamycin in only 20 d. The same method was tested using a related species A. dubia and resulted in a transformation rate of 41.3%, demonstrating that this protocol is efficient and genotype-independent. In the case of A. rhizogenes-mediated transformation for the production of hairy root cultures, in vitro-grown stem explants were infected with a single colony of A. rhizogenes strain LBA9402 by creating incisions at different places of the stem explants, which resulted in production of hairy roots in only 7 d. The method was tested in both A. annua and A. dubia, which resulted in transformation rates of 90 and 87.5%, respectively. Integration of the transgene and copy number was confirmed by PCR and Southern blot analyses, respectively. The miniprep transformation protocols developed for both A. tumefaciens- and A. rhizogenes-mediated transformation are simple, efficient, and potentially applicable to other species of Artemisia for transfer of pharmaceutically important genes

A rapid method for the determination of artemisinin and its biosynthetic precursors in Artemisia annua L. crude extracts

A rapid high-pressure liquid chromatography (HPLC) tandem mass spectrometry (TQD) method for the determination of artemisinin, 9-epi-artemisinin, artemisitene, dihydroartemisinic acid, artemisinic acid and arteannuin B in Artemisia annua extracts is described. Detection and quantification of 9-epi-artemisinin in crude extracts are reported for the first time. In this method all six metabolites are resolved and eluted within 6 min with minimal sample preparation. A recovery of between 96.25% and 103.59% was obtained for all metabolites analysed and the standard curves were linear (r2 > 0.99) over the concentration range of 0.15–10 μg mL−1 for artemisinin, 9-epi-artemisinin, artemisitene and arteannuin B, and the range of 3.75–120 μg mL−1 for dihydroartemisinic acid and artemisinic acid. All validation indices were satisfactory, showing the method to be robust, quick, sensitive and adequate for a range of applications including high throughput (HTP) analysis

The effect of O-methylated flavonoids and other co-metabolites on the crystallization and purification of artemisinin

Methoxylated flavonoids casticin, artemetin and retusin were identified as putative causative factors for low crystallization yields of artemisinin from extracts. Comparative profiling of biomass grown in different countries found elevated levels (∼60% higher) of artemetin in the East African biomass, which also demonstrates poor crystallization yields. The single compound and the combined doping experiments at 0, 25 and 50 μg mL−1 doping levels showed that artemetin (at 50 μg mL−1) caused a reduction in the amount of artemisinin crystallized by ca. 60%. A combination of the three flavonoids at 50 μg mL−1 almost completely inhibited crystallization, reducing the yield by 98%. Treatment of extracts by adsorbents efficiently resolves the problem of low crystallization yield