Search results for "ASTER"

9‐Oxabicyclo[6.1.0]nonine

1989

Semiempirische quantenmechanische Rechnungen (MNDO) und Kraftfeldrechnungen (MM2) zeigen, das fur die drei konstitutionsisomeren cis-9-Oxabicyclo[6.1.0]nonine 1–3 jeweils zwei energiearme, zueinander diastereomere Konformere a und b existieren. Der synthetische Zugang zu den hoch gespannten Verbindungen 1–3 gelingt mit der Selenadiazolmethode oder durch Dehydrobromierung (Schemata 3, 4 und 6). Die NMR-spektroskopische Konformationsanalyse bestatigt bei 2 das vorhergesagte Konformerengleichgewicht; bei 1 gehen selbst bei –60°C die beiden Konformeren durch Umklappen des Achtrings schnell ineinander uber, und bei 3 ist praktisch nur eine Konformation populiert. 9-Oxabicyclo[6.1.0]nonynes Semie…

Stereochemistry of terpene derivatives. Part 5: Synthesis of chiral lactones fused to a carane system—insect feeding deterrents

2006

Abstract Chiral iodo- 9, bromo- 10 and hydroxylactones 12 condensed with the carane system were obtained. In each case, the synthetic pathway led to an enantiomerically pure diastereoisomer to generate two stereogenic centers. Iodo- 9 and bromolactone 10 possess a γ-lactone group while the hydroxylactone 12 possesses a δ-lactone moiety situated trans to the gem-dimethylcyclopropyl ring. The structures of the products were confirmed by X-ray crystallography. These lactones were tested for antifeedant activity against storage pest insects.

A retro Diels–Alder method for the preparation of pyrrolo[1,2-a]pyrimidinediones from diexo-aminooxanorbornenecarboxamide

2006

Abstract Through the reactions of diexo-3-amino-7-oxanorbornene-2-carboxamide 1 with the oxocarboxylic acids: 4-oxopentanoic acid, p-chlorobenzoylpropionic acid or 2-formylbenzoic acid, the pyrrolo[1,2-a]pyrimidinediones 2 and 3 or pyrimido[1,2-a]isoindoledione 4 were formed on cyclization and thermolysis, when the parent cycles decomposed via the loss of furan to give 2–4 in a retro Diels–Alder reaction. With cis-or trans-2-aroylcyclohexanecarboxylic acids as starting compounds, the 1-aroylhexahydroisoindol-3-ones (5–8) were formed; the phenyl-substituted derivatives gave diastereomeric mixtures. The structures of the new compounds were established by NMR spectroscopy and, for 3 and 6, als…

Bicyclo[6.1.0]nonine

1988

MNDO-Rechnungen zeigen, das fur die drei konstitutionsisomeren cis-Bicyclo[6.1.0]nonine (1–3) jeweils zwei energiearme, zueinander diastereomere Konformere a und b existieren. Zur experimentellen Uberprufung werden die mit der Selenadiazol-Methode oder durch Dehydrobromierung hergestellten, hoch gespannten Bicyclen mit Hilfe von 1H- und 13C-NMR-Messungen auf die Population der Konformeren und auf deren wechselseitige Umwandlung durch Inversion der Achtringe untersucht. Bicyclo[6.1.0]nonine MNDO calculations reveal that two diastereomeric conformations a and b of low energy exist for each of the three isomeric cis-bicyclo[6.1.0]nonynes (1–3). For the experimental proof, the highly strained b…

On the analysis of viability data: an example with Drosophila.

1990

Larval competition experiments involving two wild type and eight mutant strains of Drosophila melanogaster have been carried out following the substitution procedure proposed by Mather and Caligari (1981). Our main goal has been to compare the competitive abilities of two phenotypically indistinguishable strains (wild and Oregon-R) by means of their responses with eight different mutants. Prior to the analyses of viability data, we have studied the normalizing effect of several transformations in order to determine which was best suited for the analyses. The differences found among the five transformations tested and the untransformed data were not very great. The folded power transformatio…

Lethal and behavioural effects of a green insecticide against an invasive polyphagous fruit fly pest and its safety to mammals

2021

Abstract Plant essential oil-based insecticides, with special reference to those that may be obtained from largely available biomasses, represent a valuable tool for Integrated Pest Management. However, the sublethal effects and the potential effects on aggressive insect traits of these green insecticides are understudied. Herein, the lethal and sub-lethal effects of the carlina oxide, constituting more than 97% of the whole Carlina acaulis (Asteraceae) root essential oil (EO), were determined against an invasive polyphagous tephritid pest, Ceratitis capitata (medfly). The carlina oxide was formulated in a mucilaginous solution containing carboxymethylcellulose sodium salt, sucrose, and hyd…

The Dorsocross T-box transcription factors promote tissue morphogenesis in the Drosophila wing imaginal disc.

2012

The Drosophila wing imaginal disc is subdivided into notum, hinge and blade territories during the third larval instar by formation of several deep apical folds. The molecular mechanisms of these subdivisions and the subsequent initiation of morphogenic processes during metamorphosis are poorly understood. Here, we demonstrate that the Dorsocross (Doc) T-box genes promote the progression of epithelial folds that not only separate the hinge and blade regions of the wing disc but also contribute to metamorphic development by changing cell shapes and bending the wing disc. We found that Doc expression was restricted by two inhibitors, Vestigial and Homothorax, leading to two narrow Doc stripes…

Cytokines profiles in intestinal epithelial (Caco-2) cells exposed to 7-ketostigmasterol or 7-ketocholesterol

2013

Internationally adopted children: a new challenge for pediatricians.

2006

Children adopted from abroad by Italian families have increased during the last years. Since 2001 to 2004 they have been more than 10,000, mainly from Eastern Europe, and all indications suggest that they will continue to increase. Most of the internationally adopted children reside in orphanage before adoption where they may experience malnutrition, exposure to infectious diseases, environmental deprivation, neglect. Moreover, their pre-adoptive records are scarcely reliable and their immunization status is not always adequate. The most common long-term problems of internationally adopted children concern developmental and scholastic delay especially if they come from a long and severely d…

Il dovere di soccorso in mare e il diritto di obbedire al diritto (internazionale) del comandante della nave privata

2019

Shipmasters are commonly considered the addressees of an international legal duty to rescue at sea. This article describes the evolution of international law in this field, from the first maritime conventions of the 1910's to the IMO Safety Committee's resolutions of the 2010's. It then argues that behind the duty to rescue there is a hidden right of the shipmaster. This right has a moral pedigree and is functional to the full compliance of the duty itself. It can be enforced in the national legal order against any State (or private entity) that tries to obstruct the shipmaster's activities of assistance or to penalize her or him for the assistance given. National judges enforce this right …