CHEMICAL STUDY OF Hortia superba

Submitted by Liliane Ferreira ([email protected]) on 2019-01-23T11:28:48Z No. of bitstreams: 2 Artigo - Vanessa Gisele Pasqualotto Severinoa - 2015.pdf: 196382 bytes, checksum: 44b1ab2f5a52fa980c87a8d27c281730 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5)Approved for entry into archive by Luciana Ferreira ([email protected]) on 2019-01-23T12:14:39Z (GMT) No. of bitstreams: 2 Artigo - Vanessa Gisele Pasqualotto Severinoa - 2015.pdf: 196382 bytes, checksum: 44b1ab2f5a52fa980c87a8d27c281730 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5)Made available in DSpace on 2019-01-23T12:14:39Z (GMT). No. of bitstreams: 2 Artigo - Vanessa Gisele Pasqualotto Severinoa - 2015.pdf: 196382 bytes, checksum: 44b1ab2f5a52fa980c87a8d27c281730 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2015-01In this paper, the chemical study of Hortia superba and antimycobacterial potential of Hortia species were investigated. Crude extracts and limonoids, alkaloids, dihydrocinnamic acid derivatives and coumarins isolated from Hortia superba, Hortia oreadica and Hortia brasiliana were evaluated against Mycobacterium tuberculosis H37Rv, Mycobacterium kansasii and Mycobacterium avium. The results obtained demonstrated an inhibitory effect of the dichloromethane extract of leaves of H. oreadica (MIC 31.25 μg mL‑1), indolequinazoline (15.62 μg mL-1) and furoquinoline (31.25 μg mL-1) alkaloids, and dihydrocinnamic acid derivatives (62.50 μg mL‑1), on the growth of M. tuberculosis. These results are promising in relation to the search for biologically active natural products and could be useful in the development of effective new drugs against mycobacteria

A Dynamical Systems Approach to Studying Mid-Latitude Weather Extremes

International audienceExtreme weather occurrences carry enormous social and economic costs and routinely garner widespread scientific and media coverage. The ability to predict these events is therefore a topic of crucial importance. Here we propose a novel predictability pathway for extreme events, by building upon recent advances in dynamical systems theory. We show that simple dynamical systems metrics can be used to identify sets of large-scale atmospheric flow patterns with similar spatial structure and temporal evolution on timescales of several days to a week. In regions where these patterns favour extreme weather, they afford a particularly good predictability of the extremes. We specifically test this technique on the atmospheric circulation in the North Atlantic region, where it provides predictability of large-scale wintertime surface temperature extremes in Europe up to one week in advance. Significance Statement Extreme weather events carry major social and economic costs; improving their predictability is therefore of crucial importance. Forecasting the occurrence of a given extreme event can be more or less difficult depending on the state of the atmosphere from which the forecast is initialised. In this study we apply diagnostics from the field of dynamical systems analysis to identify the atmospheric states providing the best predictability and investigate their link to wintertime temperature extremes in Europe. We find that these states of " maximum predictability " correspond to significant changes in the frequency of very warm or cold spells, and are often followed by large-scale extreme temperature events. These findings can provide a useful complement to existing operational forecast tools