Vignette d'image

Kissling, Jonathan

Nom
Kissling, Jonathan
Affiliation principale
Fonction
Chargé de cours
Email
jonathan.kissling@unine.ch
Identifiants
https://libra.unine.ch/handle/123456789/334
_
0000-0002-1078-4000

Résultat de la recherche

Filtres

11
11
101
Réinitialiser les filtres

Paramètres

Voici les éléments 1 - 10 sur 11
  • Publication
    Accès libre
    Phytochemical study of Alzatea verticillata, the sole species belonging to the Alzateaceae family
    (2023)
    Marcos Marçal Ferreira Queiroz
    ;
    Robin Huber
    ;
    Laurence Marcourt
    ;
    Laure Guénée
    ;
    Pierre-Marie Allard
    ;
    Adriano Rutz
    ;
    Louis-Félix Nothias
    ;
    Concetta Carlotta De Ruvo
    ;
    Kissling, Jonathan 
    ;
    Mahabir Prashad Gupta
    ;
    Emerson Ferreira Queiroz
    ;
    Jean-Luc Wolfender
    Alzatea verticillata Ruiz & Pav. (Alzateaceae) is a tropical tree from Central and South America. It is the only living species of Alzatea genus and the Alzateaceae family, all others being extinct. With the aim to investigate the possibility to find unusual natural products, the chemical content of the dichloromethane and methanolic extracts (stems and leaves) of A. verticillata have been investigated. Apolar and polar extracts were purified by semi-preparative HPLC using appropriate stationary phase columns allowing the isolation of 12 compounds: walterolactone B (2) walterolactone A/B β-D-pyranoglucoside (3), gallic acid (4), caffeic acid 4-O-β-D-glucopyranoside (6), walterolactone A/B 6-O-gallate-β-D-glucopyranoside (8), caffeic acid (9), 8-desmethylsideroxylin (11), sideroxylin (12) and 7,7′-bis(3,4-dihydroxyphenyl)-8,8′-cyclobutanedicarboxylic acid (7). Three isolated compounds are natural products described here for the first time: dimethyl-anemonin (1) and two β-truxinic acid derivatives (rel-(7S, 8R, 7′R, 8′S)-7,7′-bis(4-glucosyloxy-3-hydroxyphenyl)-8,8′-cyclobutane dicarboxylic acid (5) and rel-(7S, 8R, 7′R, 8′S)-7,7′-bis(4-glucosyloxy-3-hydroxyphenyl)-8,8′-cyclobutane-9-methyl dicarboxylic acid (10). The structures of the isolated compounds were elucidated by NMR and HRMS. The structure of compound 1 was confirmed by X-ray crystallography. A MS-based metabolite analysis of the A. verticillata extracts revealed additional truxinic acid derivatives that were putatively annotated with the help of feature-based molecular network. The presence of phenolic compounds such as truxinic acid derivatives could explain the traditional use of this plant as these compounds are known to possess anti-inflammatory and anti-nociceptive properties.
  • Publication
    Accès libre
    Exochaenium natalense (Gentianaceae), a reinstated taxon endemic to KwaZulu-Natal, South Africa
    (2023)
    Kissling, Jonathan 
    ;
    Kate W. Grieve
    ;
    Graham Grieve
    ;
    Benny Bytebier
    Based on morphological and ecological considerations, Belmontia natalensis (syn. Exochaenium grande var. homostylum) is reinstated as Exochaenium natalense (Gentianaceae). It only occurs in a section of the coastal region of the Eastern Cape (Pondoland) and southern KwaZulu-Natal provinces, South Africa. Exochaenium natalense differs from E. grande, the only other South African Exochaenium taxon, by having smaller flowers (corolla diameter < 2 cm vs > 3 cm) with a different colour (white vs cream-salmon or yellow). Because the type material of E. natalense consists of two sheets, a lectotype is designated.
  • Publication
    Accès libre
    Revisiting the taxonomy of Exacum courtallense (Gentianaceae) and recognizing E. courtallense var. laxiflorum at the species rank
    (2022-8-23)
    Geethakumary, M. P.
    ;
    Deepu, S.
    ;
    Kissling, Jonathan 
    ;
    Pandurangan, A. G,.
    Morphological, phenological and ecological evidences support the exclusion of Exacum courtallense var. laxiflorum Gamble (synonym: E. courtallense var. bonaccordense M. Mohanan) from E. courtallense Arn. resulting in the establishment of a new species Exacum laxiflorum (Gamble) Geethakumary, Deepu, Kissling & Pandurangan.
  • Publication
    Accès libre
    Evolutionary diversification in the hyper-diverse montane forests of the tropical Andes: radiation of Macrocarpaea (Gentianaceae) and the possible role of range expansion
    (2021-11-19)
    Kissling, Jonathan 
    ;
    Vieu, Julien 
    ;
    Hughes, Colin
    ;
    Grant, Jason 
    The humid mid-elevation montane forests (MMF) of the tropical Andes harbour high levels of plant species diversity, contributing to the exceptional overall diversity of the tropical Andean biodiversity hotspot. However, little is known about the diversification dynamics of MMF plant lineages compared to lineages in other Andean biomes. Here, we use Macrocarpaea (Gentianaceae) to investigate patterns of plant diversification in the MMF, using molecular dating with fossils and secondary calibration (from a family-wide phylogenetic analysis of Gentianaceae). We sequenced 76 of 118 recognized Macrocarpaea spp. for six markers to reconstruct a time-calibrated phylogenetic tree and infer the historical biogeography of Macrocarpaea using maximum-likelihood methods implemented in BioGeoBEARS, estimating diversification rates through time and among lineages with BAMM. We document a rapid radiation of Macrocarpaea in Andean MMF coinciding with rapid colonization and range expansion across the entire distribution of the genus in the Andes starting 7.2 Mya. Our results support allopatric founder-event speciation as the dominant process contributing to geographical phylogenetic structure across the genus. We propose that establishment of the MMF in the late Miocene, when the Andes attained critical elevation to modify regional climates, provided large new areas of suitable habitat for Macrocarpaea to quickly colonize and expand through repeated founder-events. We suggest that this wave of colonization and range expansion triggered rapid diversification, and, as the MMF became progressively occupied, the diversification rate slowed. Our study also supports the idea that MMF plant radiations are older and more slowly evolving than the quickly evolving lineages in the recent Andean high-elevation grasslands.
  • Publication
    Accès libre
    Back to Gondwanaland: can ancient vicariance explain (some) Indian Ocean disjunct plant distributions?
    (2015)
    Michael D. Pirie
    ;
    Glenn Litsios
    ;
    Dirk U. Bellstedt
    ;
    Nicolas Salamin
    ;
    Kissling, Jonathan 
    Oceans, or other wide expanses of inhospitable environment, interrupt present day distributions of many plant groups. Using molecular dating techniques, generally incorporating fossil evidence, we can estimate when such distributions originated. Numerous dating analyses have recently precipitated a paradigm shift in the general explanations for the phenomenon, away from older geological causes, such as continental drift, in favour of more recent, long-distance dispersal (LDD). For example, the ‘Gondwanan vicariance’ scenario has been dismissed in various studies of Indian Ocean disjunct distributions. We used the gentian tribe Exaceae to reassess this scenario using molecular dating with minimum (fossil), maximum (geological), secondary (from wider analyses) and hypothesis-driven age constraints. Our results indicate that ancient vicariance cannot be ruled out as an explanation for the early origins of Exaceae across Africa, Madagascar and the Indian subcontinent unless a strong assumption is made about the maximum age of Gentianales. However, both the Gondwanan scenario and the available evidence suggest that there were also several, more recent, intercontinental dispersals during the diversification of the group.
  • Publication
    Accès libre
    Ancestral and monophyletic presence of diplostigmaty in Sebaea (Gentianaceae) and its potential role as a morphological mixed mating strategy
    (2009)
    Kissling, Jonathan 
    ;
    Endress, Peter K.
    ;
    Bernasconi, Giorgina
    • Diplostigmaty, the presence of a primary (apical) stigma and secondary (mid-stylar) stigmas along the style, is only known from the genus Sebaea (Gentianaceae). Early work indicated that the secondary stigmas provide a mechanism of autogamy, suggesting that it might ensure reproductive assurance.
    • Here, we test the monophyly of this unique morphological trait. Using Bayesian methods, we infer a nuclear DNA phylogeny for 96 accessions, including c. 50% of the species from the genus Sebaea. With this phylogeny, we infer the distribution of ancestral states on critical nodes using parsimony and likelihood methods.
    • The inferred nrDNA phylogeny shows that the genus Sebaea is divided in two statistically well-supported clades, A and B, consistent with recent estimates. The most recent ancestor (MRCA) of clade A, except the most basal species (Sebaea pusilla), is resolved as diplostigmatic. No reversal to a single stigma is observed within this clade.
    • We suggest that diplostigmaty is evolutionarily stable through time. We also discuss why this reproductive system is not found elsewhere than in Gentianaceae and the potential advantage of diplostigmaty as a stable mixed mating strategy.
  • Publication
    Accès libre
    Cytogeography of Gentianaceae–Exaceae in Africa, with a special focus on Sebaea: the possible role of dysploidy and polyploidy in the evolution of the tribe
    (2008)
    Kissling, Jonathan 
    ;
    Zeltner, Louis
    ;
    Küpfer, Philippe 
    ;
    Mansion, Guilhem
    Unlike other tribes of Gentianaceae, Exaceae have so far received little attention regarding their karyological evolution. Indeed, only 35 chromosome number counts (19 species) have been referenced to date, representing only a negligible fraction of the tribal diversity. In this paper, we performed an intensive chromosome count on material collected in the field (South and central Africa, plus Madagascar), encompassing 155 populations and c. 60 species from four genera of Exaceae, including Exacum, Ornichia, Sebaea and Tachiadenus. Fifty nine species (14 Exacum, one Ornichia, 42 Sebaea and two Tachiadenus) were examined for the first time, revealing a broad set of chromosome numbers (2n = 18, 28, 32, 36, 42, 56) and the occurrence of polyploid systems within Exacum and Sebaea. These results allow us to postulate x = 7, 8 or 9 as possible base chromosome numbers for Exaceae and emphasize the importance of both dysploidy and polyploidy processes in the evolution of the tribe. Finally, chromosome numbers appear to be associated to some morphological or geographical traits, suggesting new systematic combinations and likely active speciation patterns in the group.