Investigation of Chemical Composition and Biological Activities of Ajuga pyramidalis-Isolation of Iridoids and Phenylethanoid Glycosides.

Despite several studies on the Ajuga L. genus, the chemical composition of Ajuga pyramidalis, an alpine endemic species, is still largely unknown. The purpose of this study was to therefore deeper describe it, particularly from the phytochemistry and bioactivity perspectives. In that respect, A. pyramidalis was investigated and 95% of the extracted mass of the plant was characterized by chromatography and mass spectrometry. Apart from the already determined chemical compounds, namely, harpagide and 8-O-acetylharpagide, two iridoids, and neoajugapyrin A, a neo-clerodane diterpene, and three polyphenols (echinacoside, verbascoside and teupoloside) were identified for the first time in A. pyramidalis. Incidentally, the first RX structure of a harpagoside derivative is also described in this paper. The extracts and isolated compounds were then evaluated for various biochemical or biological activities; notably a targeted action on the renewal of the epidermis was highlighted with potential applications in the cosmetic field for anti-aging.

A flat petal as ancestral state for Ranunculaceae.

Ranunculaceae comprise ca. 2,500 species (ca. 55 genera) that display a broad range of floral diversity, particularly at the level of the perianth. Petals, when present, are often referred to as "elaborate" because they have a complex morphology. In addition, the petals usually produce and store nectar, which gives them a crucial functional role in the interaction with pollinators. Its morphological diversity and species richness make this family a particularly suitable model group for studying the evolution of complex morphologies. Our aims are (1) to reconstruct the ancestral form of the petal and evolutionary stages at the scale of Ranunculaceae, (2) to test the hypothesis that there are morphogenetic regions on the petal that are common to all species and that interspecific morphological diversity may be due to differences in the relative proportions of these regions during development. We scored and analyzed traits (descriptors) that characterize in detail the complexity of mature petal morphology in 32 genera. Furthermore, we described petal development using high resolution X-Ray computed tomography (HRX-CT) in six species with contrasting petal forms (Ficaria verna, Helleborus orientalis, Staphisagria picta, Aconitum napellus, Nigella damascena, Aquilegia vulgaris). Ancestral state reconstruction was performed using a robust and dated phylogeny of the family, allowing us to produce new hypotheses for petal evolution in Ranunculaceae. Our results suggest a flat ancestral petal with a short claw for the entire family and for the ancestors of all tribes except Adonideae. The elaborate petals that are present in different lineages have evolved independently, and similar morphologies are the result of convergent evolution.

Tempo and drivers of plant diversification in the European mountain system.

There is still limited consensus on the evolutionary history of species-rich temperate alpine floras due to a lack of comparable and high-quality phylogenetic data covering multiple plant lineages. Here we reconstructed when and how European alpine plant lineages diversified, i.e., the tempo and drivers of speciation events. We performed full-plastome phylogenomics and used multi-clade comparative models applied to six representative angiosperm lineages that have diversified in European mountains (212 sampled species, 251 ingroup species total). Diversification rates remained surprisingly steady for most clades, even during the Pleistocene, with speciation events being mostly driven by geographic divergence and bedrock shifts. Interestingly, we inferred asymmetrical historical migration rates from siliceous to calcareous bedrocks, and from higher to lower elevations, likely due to repeated shrinkage and expansion of high elevation habitats during the Pleistocene. This may have buffered climate-related extinctions, but prevented speciation along elevation gradients as often documented for tropical alpine floras.

Resurrection of Passifloraacuminata DC. and synonymization of P.tolimana Harms, P.gleasonii Killip, P.metae M. Bonilla, C. Aguirre & Caetano (Passifloraceae) following a study of their morphology and ecogeography.

Within the very uniform series Laurifoliae, Passifloraacuminata (treated as a synonym of P.laurifolia in the Flora of China), P.tolimana, P.gleasonii and P.metae appear particularly similar. A review of their descriptions and the associated specimens confirms their lack of morphological differentiation and leads us to formally resurrect P.acuminata and place the three other taxa under its synonymy. This taxonomic move is also supported by a revision of 72 additional geolocalized specimens (for a grand total of 78) and an analysis of their distribution and habitats. In fact, the bioclimatic space corresponding to the specimens previously assigned to P.acuminata encompasses that of all specimens previously assigned to the three other taxa under study. The species range covers a wide region, comprising the lower Amazon and the north of its basin, mostly below 200 m, and, to the west, in the upper Amazon, the Orinoco basin, and along the Andean foothills and valleys, from Venezuela to Peru, at elevations between 100 and 2200 m. In the lowlands, the species appears associated with white sand savannas and water courses. A more complete description is proposed for the species, including its unusual fusiform and slightly ribbed fruit. Another rare trait in the series Laurifoliae is that the outer corona filaments tend to be longer than the corolla.

Development of an innovative maceration technique to optimize extraction and phase partition of natural products.

The active component extraction from plants is the first crucial step in natural product research. For non-targeted extraction with an objective to isolate and characterize as many compounds as possible, the most classical technique, and the simplest to implement, is the Soxhlet extraction; however, it does not allow retrieving all the compounds from the plant (when it does not additionally cause artifacts during long heating process). The second most used technique is the extraction by successive macerations using solvents of increasing polarity. While this method is frequently used, few studies are available to rationalize and optimize it. Furthermore, this extraction technique requires some enhancement mainly for efficiency, environmental and time constraint reasons. Here, we present an innovative method of successive macerations using a mixture of solvents with the aim of simultaneously improving the yield, the partition of the compounds between the different phases and reducing the volume of extraction solvents. Triphasic systems were prepared by mixing five solvents (n-heptane, ethyl acetate, acetonitrile, butan-1-ol, water) in various proportions. To validate this method, the most efficient triphasic system was subsequently used to perform three successive macerations with a polarity gradient on a model plant before being extended to several alpine plants. Our results showed an overall good yield compared to conventional maceration techniques, while improving phase partition and reducing extraction time and volume of solvents.

Phytochemical and Biological Investigation of Helianthemum nummularium, a High-Altitude Growing Alpine Plant Overrepresented in Ungulates Diets.

Helianthemum nummularium is a European shrub growing at high altitude where it copes with a high level of stress. It was found to be overexpressed in ungulates diets compared to more abundant surrounding plants. These elements combined with the fact that H. nummularium from the Alps has never been investigated prompted us to study the phytochemical composition of its aerial parts. The analysis of the polar extract allowed for the isolation of eight compounds: p-hydroxybenzoic acid, tiliroside, kaempferol, astragalin, quercetin, plantainoside B, quercetin-3-O-glucoside, and quercetin-3-O-glucuronide. We investigated the effect of the polar extract and isolated compounds on nuclear factor erythroid 2-related factor 2 transcription factor, which regulates the expression of a wide variety of cytoprotective genes. We found that the ethanolic extract activates the expression of nuclear factor erythroid 2-related factor 2 in a dose-dependent manner, whereas the pure compounds were much less active. The activation of the nuclear factor erythroid 2-related factor 2 pathway by the plant extract could pave the way for studies to promote healthy aging through protection of cells against oxidative stress. Moreover, the isolated compounds could be investigated alone or in combination in the perspective of making the link between the ungulate's preference for this plant and possible use of it for self-medication.

Imprecise descriptions of Passiflorariparia Martius ex Masters led to redundant descriptions as P.emiliae Sacco, P.crenata Feuillet & Cremers, P.pergrandis Holm-Nielsen & Lawesson and P.fernandezii Escobar.

Passiflorariparia was incompletely described by Masters, who cited specimens of Martius and Spruce. While Spruce 2191, the unique syntype with an observable corona, exhibits a reduced outermost series of filaments, the accompanying iconography represents two equal outer series. Later descriptions have neither added significant information nor corrected the inconsistency in the corona description, so that four closely related species have been distinguished on the basis of traits not properly documented for P.riparia: P.emiliae (unequal outer series of filaments), P.crenata (bract color), P.pergrandis (flower size and sepal awn length), and P.fernandezii (hypanthium pubescence and shape). The present study compares (i) the descriptions of the above-mentioned taxa and (ii) 43 associated vouchers, as well as live specimens from two associated P.crenata populations. These and other specimens were georeferenced for a comparison of their distribution and habitat. Of the five P.riparia descriptions found in floras, only that of the Flora of Ecuador appears clearly divergent, corresponding in fact to P.tolimana. Those of the four other taxa only differ by unequal corona filaments (except for P.crenata) and the pubescence of floral parts. However, 22 vouchers associated with all these descriptions (including 16 for P.riparia), as well as the live specimens, share both these traits; the other 21 vouchers were uninformative and/or could not be assigned to any of the five species. The wider sample of 62 specimens indicates no significant differences in either geographic or in climatic distribution (lowlands of the Amazon basin), and a marked preference for riparian habitats. Thus, their very close morphology and ecology justify the placement of P.emiliae, P.crenata, P.pergrandis and P.fernandezii as synonyms of P.riparia, designating Spruce 2191 as epitype. The most similar species, P.ambigua (20 specimens mapped), differs in corolla and bract color, as well as a distribution centered along the tropical Andes of South America and in Central America, in more diverse habitats.

A new lectotype for Passiflora laurifolia L.

From the "Description des plantes d'Amérique" by Plumier, in 1693, to the "Species Plantarum" by Linnaeus in 1753, several dubious synonymies of Passiflora laurifolia L. were proposed, generating a persisting confusion. A revision of the process, which led to the Linnaean description of this species, shows that the type finally chosen by Cusset does not match the original description. A new lectotype for the species and a more complete description are proposed from field observations, herbarium and bibliographic data.

Traditional uses, phytochemistry and pharmacological properties of African Nauclea species: A review.

ETHNOPHARMACOALOGICAL RELEVANCE: The genus Nauclea in Africa comprises seven species. Among them, N. latifolia, N. diderrichii and N. pobeguinii are widely used by the local population in traditional remedies. Preparation from various parts of plants (e.g. roots, bark, leaves) are indicated by traditional healers for a wide range of diseases including malaria, pain, digestive ailments or metabolic diseases. MATERIALS AND METHODS: A literature search was conducted on African species of the genus Nauclea using scientific databases such as Google Scholar, Pubmed or SciFinder. Every document of ethnopharmacological, phytochemical or pharmacological relevance and written in English or French were analyzed. RESULTS AND DISCUSSION: The Nauclea genus is used as ethnomedicine all along sub-Saharan Africa. Several local populations consider Nauclea species as a major source of remedies for malaria. In this regard, two improved traditional medicines are currently under development using extracts from N. latifolia and N. pobeguinii. Concerning the chemical composition of the Nauclea genus, indoloquinolizidines alkaloids could be considered as the major class of compounds as they are reported in every analyzed Nauclea species, with numerous structures identified. Based on traditional indications a considerable amount of pharmacological studies were conducted to ensure activity and attempt to link them to the presence of particular compounds in plant extracts. CONCLUSION: Many experimental studies using plant extracts of the African species of the genus Nauclea validate traditional indications (e.g. malaria and pain). However, bioactive compounds are rarely identified and therefore, there is a clear need for further evaluations as well as for toxicity experiments. The sustainability of these plants, especially of N. diderrichii, a threatened species, should be kept in mind to adapt local uses and preparation modes of traditional remedies.