30 research outputs found
1H- and 13C-NMR spectra of thiocolchicine and derivatives: A complete analysis
No full textComplete and unambiguous assignments of the 1H- and 13C-nmr spectra of thiocolchicine [1], 3-demethylthiocolchicine [2], and the thiocolchicosides [3] and [4] were made through extensive nmr studies, inclusive of homonuclear COSY and COSYLR, BIRDREV, APT, HETCOR, nOe difference, INEPT, and JMODXH experiments
Glycosides. Part 1. New synthesis of 1.2-trans O-aryl glycosides, via tributyltin phenoxides
No full textA new method of glycosidation of phenols has been studied. The reaction of tributyltin phenoxides 2 with 1,2,3,4,6-penta-O-acetyl-D-hexopyranosides 3. 7 and 9, in the presence of tin tetrachloride is described. Glycosides 4, 8 and 10 have been isolated in good yields with high 1,2-trans selectivity. The tributyltin phenoxides 2 have been isolated in quantitative yields, starting from phenols 1 and Bu3SnOMe. This simple method starts from the stable peracetylated sugar, an intermediate of easy access
FINKELSTEIN REACTION WITH AQUEOUS HYDROGEN HALIDES EFFICIENTLY CATALYZED BY LIPOPHILIC QUARTERNARY ONIUM SALTS
No full textThe rate of halogen metathesis between halogenoalkanes RX 1-4 (X = F, Cl, Br, I) and aqueous concentrated hydrogen halides HY (Y = Cl, Br, I) is strongly accelerated under phase-transfer catalysis conditions, without solvent. The amount and nature of the nucleophilic species in the organic phase were determined
Isothiazoles. Part IV. Cycloaddition reactions of diaryl-oxazolones and munchnones to 3-diethylamino-4-(4-methoxyphenyl)-isothiazole 1,1-dioxide: A new synthesis of triarylpyrroles
No full text3-Diethylamino-4-(4-methoxyphenyl)-isothiazole 1,1-dioxide (3) readily reacts with oxazolones 2 and munchnones 7 affording with satisfactory yield 3-diethylamino-4,6-diaryl-3a,4-dihydro-3a-(4-methoxyphenyl)-6aH-pyrrol o[3,4-d]isothiazole 1,1-dioxides 4 and 3-diethylamino-4,6-diaryl-5-alkyl-3a-(4-methoxyphenyl)-pyrrolo[3,4-d]i sothiazole 1,1-dioxides 8, respectively. The behaviour of the cycloadducts towards elevated temperatures and/or basic conditions was investigated. Under these conditions the primary products lost SO2 and diethylcyanamide affording 1-alkyl-2,3,5-triarylpyrroles 9 and 1H-2,3,5-triarylpyrroles 10. These latter were found to be better obtained through thermal decompression of N-protected cycloadducts 8 and subsequent deprotecting the final pyrroles
Farmers’ participation in territorial planning: a methodological approach for the case study of Huerta de Valencia
No full textParticipation in planning has become progressively important in territory management.
As regards Territorial Planning, farmers are among the main stakeholders. In fact multifunctionality
of agriculture admits a new role to primary sector. In particular the management of open areas is
particularly strategic in peri-urban areas, where competition for resources is highest than in other
areas, especially for the land. In this context, the involvement of farmers as privileged stakeholders
to land management is even more important. This paper proposes a methodological approach for the
evaluation of peri-urban land use plans by farmers, by means of direct surveys on a sample of
Spanish farmers. In particular, it has been considered the "Territorial Action Plan of Valencia’s Huerta” (TAPVH)
α-Pyrones. Part V. Structure effects on the intramolecular cyclization of functionalized 6-pyronylacetamides: synthesis of new 2,5,7-trioxo-pyrano[3,2-c]pyridines
No full textReaction of arylisocyanates 2 with methyl 2-oxo-2H-pyran-6-acetate 1 and with ylide 4 gave two classes of pyronylacetamides 3 and 5, respectively. Phosphoranes 5 were reduced to the corresponding acetamides 6 with zinc and acetic acid. Compounds 6 were alkylated under solid-liquid PTC conditions using anhydrous potassium carbonate as a base to give the Cα-alkyl derivatives 7 in good yields. Intramolecular cyclization with different bases and solvents of acetamides 3,5-7 to give the new 2,5,7-trioxo-pyrano[3,2-c]pyridines has been studied
Susceptibility to entomopathogens and modulation of basal immunity in two insect models at different temperatures.
No full textAbstract In this work, we analysed the efficacy of different commercial bio-insecticides (Steinernema feltiae, Steinernema carpocapsae, Heterorhabditis bacteriophora and Bacillus thuringiensis) by valuating the mortality induced on two insect models, Galleria mellonella (Lepidoptera) and Sarcophaga africa (Diptera) after exposure to different temperatures (10, 20 and 30 °C). Moreover, we investigated the effects of temperature on the basal humoral immunity of the two target insects; particularly, phenoloxidase (PO) and lysozyme activity. Our results show that G. mellonella is susceptible to all bio-insecticides at all the examined temperatures, except when infected at 10 °C with S. carpocapsae and at 30 °C with S. feltiae and B. thuringiensis. S. africa is more susceptible at 30 °C to all bioinsecticides; whereas, when infected at 10 and 20 °C, H. bacteriophora is the most efficient. Temperature modulates PO activity of both G. mellonella and S. africa, otherwise variations in lysozyme activity is observed only in G. mellonella. Except for a possible correlation between the increased lysozyme activity and the delayed Bt efficacy recorded on G. mellonella at 30 °C, a different resistance to bio-insecticides at different temperatures does not seem to be associated to variations of the host basal immunity, probably due to immunoevasive and immunodepressive strategies of these entomopathogens
Histone acetylation deficits in lymphoblastoid cell lines from patients with Rubinstein-Taybi syndrome.
No full textABSTRACT
Background RubinsteineTaybi syndrome (RSTS) is
a congenital neurodevelopmental disorder defined by
postnatal growth deficiency, characteristic skeletal
abnormalities and mental retardation and caused by
mutations in the genes encoding for the transcriptional
co-activators with intrinsic lysine acetyltransferase (KAT)
activity CBP and p300. Previous studies have shown that
neuronal histone acetylation is reduced in mouse models
of RSTS.
Methods The authors identified different mutations at
the CREBBP locus and generated lymphoblastoid cell
lines derived from nine patients with RSTS carrying
distinct CREBBP mutations that illustrate different grades
of the clinical severity in the spectrum of the syndrome.
They next assessed whether histone acetylation levels
were altered in these cell lines.
Results The comparison of CREBBP-mutated RSTS cell
lines with cell lines derived from patients with an
unrelated mental retardation syndrome or healthy
controls revealed significant deficits in histone
acetylation, affecting primarily histone H2B and histone
H2A. The most severe defects were observed in the lines
carrying the whole deletion of the CREBBP gene and the
truncating mutation, both leading to a haploinsufficiency
state. Interestingly, this deficit was rescued by treatment
with an inhibitor of histone deacetylases (HDACi).
Conclusions The authors’ results extend to humans the
seminal observations in RSTS mouse models and point to
histone acetylation defects, mainly involving H2B and
H2A, as relevant molecular markers of the disease
High frequency of mosaic CREBBP deletions in RSTS patients and mapping of somatic and germline breakpoints
No full textRubinstein-Taybi syndrome (RSTS) is a rare malformation disorder caused by mutations in the CREBBP and EP300 genes accounting for up to 60% and 3% of the tested patients, respectively. About 10% of CREBBP mutations are deletions, often extending to flanking regions, with scattered breakpoints. By FISH and microsatellite analyses as first step of CREBBP mutation screening we identified in 60 Italian RSTS patients, six deletions, three of which present in a mosaic condition, a finding yet unreported. Using BAC clones and small-sized CREBBP- probes we could assess the extent of all deletions.
Only two of the twelve breakpoints were found to encompass the same region, confirming the heterogeneity in size and boundaries of CREBBP deletions. However four of our five intragenic breakpoints clustered to the 5’ end of CREBBP, around exon 2, where a peak breakpoints underlying rearrangements in RSTS patients and tumors is apparent too. The search of genomic motifs did not evidence LCRs, as expected by the lack of a recurrent RSTS. By contrast, the percentage of interspersed repetitive elements, mainly Alu and LINEs is in the smaller 5’CREBBP region around exon 2 significantly higher than that in the entire gene or the average in the genome suggesting this feature might be implicated in the vulnerability of the region to breaking. Search of EP300 microdeletions was also afforded by FISH , but no deletion carrier was identified among CREBBP-negative cases, pointing to a minor role of this second gene in the aetiology of RSTS. As to genotype phenotype correlation the clinical presentation was typical in all cases, although more severe in the three patients carrying constitutional deletions, raising.the issue of possible underdiagnosis of a subset of mild RSTS patients. No apparent correlations were observed between increase in the deletion size, from150 Kb to 2.6 Mb, and more severe phenotypic spectrum in the three patients carrying constitutional deletions
