Verhuellia is a segregate lineage in Piperaceae: more evidence from flower, fruit and pollen morphology, anatomy and development

Background and Aims The perianthless Piperales, i.e. Saururaceae and Piperaceae, have simple reduced flowers strikingly different from the other families of the order (e.g. Aristolochiaceae). Recent molecular phylogenies proved Verhuellia to be the first branch in Piperaceae, making it a promising object to study the detailed structure and development of the flowers. Based on recently collected material, the first detailed study since 1872 was conducted with respect to morphology, anatomy and development of the inflorescence, pollen ultrastructure and fruit anatomy. Methods Original Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM) and Light Microscopy (LM) observations on Verhuellia lunaria were compared with Piperaceae, Saururaceae and fossils. Key results The inflorescence is an indeterminate spike with sessile flowers, each in the axil of a bract, developing in acropetal, helical succession. Flowers consist of two (occasionally three) stamens with basifixed tetrasporangiate anthers and latrorse dehiscence by a longitudinal slit. The gynoecium lacks a style but has three to four stigma branches and a single, basal orthotropous, and unitegmic ovule. The fruit is a drupe with large multicellular epidermal protuberances. The pollen is very small, inaperturate, and areolate with hemispherical microechinate exine elements. Conclusions Despite the superficial similarities with different genera of Piperaceae and Saururaceae, the segregate position of Verhuellia revealed by molecular phylogenetics is supported by morphological, developmental and anatomical data presented here. Unitegmic ovules and inaperturate pollen, which are synapomorphies for the genus Peperomia, are also present in Verhuellia

Direct metalation of heteroaromatic esters and nitriles using a mixed lithium-cadmium base. Subsequent conversion to dipyridopyrimidinones.

International audienceAll pyridine nitriles and esters were metalated at the position next to the directing group using (TMP)(3)CdLi in tetrahydrofuran at room temperature. The 2-, 3-, and 4-cyanopyridines were treated with 0.5 equiv of base for 2 h to afford, after subsequent trapping with iodine, the corresponding 3-iodo, 2-iodo, and 3-iodo derivatives, respectively, in yields ranging from 30 to 61%. Cyanopyrazine was similarly functionalized at the 3 position in 43% yield. Ethyl 3-iodopicolinate and -isonicotinate were synthesized from the corresponding pyridine esters in 58 and 65% yield. Less stable ethyl 4-iodonicotinate also formed under the same conditions and was directly converted to ethyl 4-(pyrazol-1-yl)nicotinate in a two-step 38% yield. All three ethyl iodopyridinecarboxylates were involved in a one-pot palladium-catalyzed cross-coupling reaction/cyclization using 2-aminopyridine to afford new dipyrido[1,2-a:3',2'-d]pyrimidin-11-one, dipyrido[1,2-a:4',3'-d]pyrimidin-11-one, and dipyrido[1,2-a:3',4'-d]pyrimidin-5-one in yields ranging from 50 to 62%. A similar cross-coupling/cyclization sequence was applied to methyl 2-chloronicotinate using 2-aminopyridine, 2-amino-5-methylpyridine, and 1-aminoisoquinoline to give the corresponding tricyclic or tetracyclic compounds in 43-79% yield. Dipyrido[1,2-a:4',3'-d]pyrimidin-11-one and dipyrido[1,2-a:3',4'-d]pyrimidin-5-one showed a good bactericidal activity against Pseudomonas aeroginosa . Dipyrido[1,2-a:2',3'-d]pyrimidin-5-one and pyrido[2',3':4,5]pyrimidino[2,1-a]isoquinolin-8-one showed a fungicidal activity against Fusarium and dipyrido[1,2-a:4',3'-d]pyrimidin-11-one against Candida albicans . Ethyl 4-(pyrazol-1-yl)nicotinate and dipyrido[1,2-a:2',3'-d]pyrimidin-5-one have promising cytotoxic activities, the former toward a liver carcinoma cell line (HEPG2) and the latter toward a human breast carcinoma cell line (MCF7

Direct metallation of thienopyrimidines using a mixed lithium-cadmium base and antitumor activity of functionalized derivatives

International audienceA series of thieno[2,3-d]- and thieno[3,2-d]pyrimidines have been easily synthesized using as key step a deproto-cadmiation-trapping sequence. Some of the compounds thus synthesized were screened for anti-cancer (cytotoxic) activities, and (S)-2-(6-iodo-2-phenylthieno[2,3-d]pyrimidin- 4-ylamino)-3-phenylpropanoic acid proved to have a significant activity towards liver, human breast and cervix carcinoma cell lines

Impaired peripheral reaching and on-line corrections in patient DF: optic ataxia with visual form agnosia

An influential model of vision suggests the presence of two visual streams within the brain: a dorsal occipito-parietal stream which mediates action and a ventral occipito-temporal stream which mediates perception. One of the cornerstones of this model is DF, a patient with visual form agnosia following bilateral ventral stream lesions. Despite her inability to identify and distinguish visual stimuli, DF can still use visual information to control her hand actions towards these stimuli. These observations have been widely interpreted as demonstrating a double dissociation from optic ataxia, a condition observed after bilateral dorsal stream damage in which patients are unable to act towards objects that they can recognize. In Experiment 1, we investigated how patient DF performed on the classical diagnostic task for optic ataxia, reaching in central and peripheral vision. We replicated recent findings that DF is remarkably inaccurate when reaching to peripheral targets, but not when reaching in free vision. In addition we present new evidence that her peripheral reaching errors follow the optic ataxia pattern increasing with target eccentricity and being biased towards fixation. In Experiments 2 and 3, for the first time we examined DF’s on-line control of reaching using a double-step paradigm in fixation-controlled and free-vision versions of the task. DF was impaired when performing fast on-line corrections on all conditions tested, similarly to optic ataxia patients. Our findings question the long-standing assumption that DF’s dorsal visual stream is functionally intact and that her on-line visuomotor control is spared. In contrast, in addition to visual form agnosia, DF also has visuomotor symptoms of optic ataxia which are most likely explained by bilateral damage to the superior parietal occipital cortex. We thus conclude that patient DF can no longer be considered as an appropriate single-case model for testing the neural basis of perception and action dissociations

Utilisation des systèmes 1,3-dicarbonyles (et de leurs équivalents) dans les réactions de couplage catalysées par la palladium : Application à la synthèse de systèmes polycycliques

Not availableDu fait de leur faible réactivité, les composés chlorés sont moins utilisés dans les réactions de couplage que leurs homologues bromés ou iodés. Cependant, les [beta]-chloroacroléines, dérivés chlorés vinyliques activés par la présence du groupement aldéhydique, se sont montrées suffisamment réactives pour être couplées. Nous avons aussi étudié leur réactivité dans les couplages de Suzuki en milieu aqueux ainsi que dans les réactions de Sonogashira. Nous nous sommes également intéressés à la réactivité des triflates et phosphates vinyliques (synthétisés à partir de [beta]-cétoesters) dans ces mêmes réactions de couplage palladocatalysées. Les produits issus de ces couplages nous ont permis d'accéder à divers systèmes polycycliques contenant des noyaux hétérocycliques tels que coumarine, pyridine ou isoquinoléine

Utilisation des systèmes 1,3-dicarbonyles (et de leurs équivalents) dans les réactions de couplage catalysées par la palladium (Application à la synthèse de systèmes polycycliques)

METZ-SCD (574632105) / SudocSudocFranceF

Controlling charge-transfer properties through a microwave-assisted mono- or bis-annulation of dialkynyl-N-(het)arylpyrroles

International audienceA selective microwave-assisted mono and bis-annulation of dialkynyl-N-(het)arylpyrrole derivatives is described. These polycyclic aromatic hydrocarbons (PAHs) have been photophysical and computationally characterized. The mono-annulated systems display interesting charge-transfer properties. By contrast, these properties vanish within the more conjugated bis-annulated compounds

Synthesis and antiproliferative studies of 5-aryl-2-(3-thienylamino)-1,3,4- thiadiazoles

A series of 5-aryl-2-(3-thienylamino)-1,3,4-thiadiazoles 3a-m were synthesized in good yields in two steps starting from thiophen-3- isothiocyanates. Those compounds as well as the thiosemicarbazide intermediates 2a-m were screened for their antiproliferative activity against a panel of six cancer cell lines. Among them, two 5-aryl-2-(3-thienylamino)-1,3,4-thiadiazoles (3f and 3i) have shown very interesting results with IC50 <10 μM on three cell lines. © 2014 Elsevier Ltd. All rights reserved.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Synthesis and biological evaluation of novel 2-heteroarylimino-1,3-thiazolidin-4-ones as potential anti-tumor agents

International audienceA series of 35 heteroarylimino-1,3-thiazolidinones with three sites of functionalization were synthesized and their antiproliferative properties were studied. The in vitro screening by MTT assay was performed against five cancer cell lines (human colon cancer cell lines HT29, HCT116 and SW620 and breast cancer cell lines MCF7 and MDA-MB-231). It was observed that N3-substituted thiazolidinones had moderate activities whereas 5-benzylidene thiazolidinones showed promising activities. To investigate the mechanism of action, detailed biological studies of six selected compounds (those presenting the lower mitotic index) were carried out on the human colon cancer HT29 cell line. Cell cycle assay revealed that those compounds induced cell accumulation in G2/M and in subG0/G1 phases of cell cycle. Moreover, dissipation of mitochondria membrane potential was observed as well as redox changes in treated cells

Synthesis and properties of new multiple TCNE-adducts from dialkynyl-N-(het)arylpyrroles.

International audienc