RESUMEN
The novel title macrocycles, based on methylene-bridged 1,5-naphthalene units, have been obtained by template effect in a thermodynamically controlled synthesis. In detail, the prism[5]arene 1 or the prism[6]arene 3 was selectively removed from the equilibrium mixture by using the complementary ammonium-templating agent. When only the solvent 1,2-DCE was used, the 1,4-confused derivative 2 was obtained. The prism[5]arene here described shows a deep π-electron-rich aromatic cavity that exhibits a great affinity for the quaternary ammonium guests, originating from favorable cation···π and +NC-H···π interactions. This recognition motif is the basis of the templated synthesis of the prism[n]arenes here reported.
RESUMEN
Calix[6]arenes disubstituted at the methylene bridges, which are stable in the cone or 1,2,3-alternate conformation, form pseudorotaxanes with dialkylammonium axles. The cone wheel-based pseudorotaxanes are 10-100 times more stable than those obtained with the native conformationally mobile calix[6]arene wheel, as a consequence of their higher degree of preorganization. The threading of conformationally stable 1,2,3-alternate calix[6]arenes is unprecedented in the literature. Therefore, very peculiar NMR features are here evidenced for this threading process involving the less symmetrical 1,2,3-alternate calix[6]arene conformation, which implies a peculiar rototranslation motion of the axle.
RESUMEN
This study shows that calixarene p-bromodienone derivatives can act as precursors for the formation of oxenium cations, which can be trapped with enamine C-nucleophiles. When calixarene p-bromodienones were treated with enamines, in the presence of AgClO4, the lower rim-substituted C-O-C products were obtained by an electrophilic attack of the intermediate calixarene-oxenium cation with a contemporary cone-to-partial-cone inversion of the involved aromatic ring.
RESUMEN
The synthesis of water-soluble prism[n]arenes (n = 5 and 6) bearing anionic carboxylato groups on the rims is described. The binding properties of this novel class of water-soluble hosts are studied by nuclear magnetic resonance and calorimetry. The complexation of singly and doubly charged ammonium guests with the more rigid pentamer is enthalpically driven by secondary interactions, while the thermodynamic fingerprint for the larger hexamer reveals driving forces that strongly depend on the guest charge and/or size.
RESUMEN
Methoxy-prism[5]arene PrS[5]Me is demethylated by a supramolecularly assisted reaction. In the presence of a tetramethylammonium cation, PrS[5]Me is demethylated by BBr3 in high yield, while in its absence a 55/40 mixture of PrS[5]OH/PrS[6]OH is formed. The dealkylation of prismarenes, such as PrS[6]R (R = Et, nPr) and c-PrS[5]Me, can be easily obtained in high yields in the presence of BBr3.
RESUMEN
Calix[2]naphth[2]arenes make up a new class of phenol-naphthalene hybrid macrocycles. X-ray studies show that calix[2]naphth[2]arene 1 adopts a 1,2-alternate conformation. Alkali metal cations are complexed by the calixnaphtharenes in a 1,2-alternate conformation, by cation···π interactions with the naphthalene walls, and by RO···M+ ion-dipole interactions. In the presence of Cs+, chiral complexes of calixnaphtharenes 5 and 6 were observed in which the cation is nested on one of the two faces of the macrocycle.
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BACKGROUND: WGA (Whole Genome Amplification) in forensic genetics can eliminate the technical limitations arising from low amounts of genomic DNA (gDNA). However, it has not been used to date because any amplification bias generated may complicate the interpretation of results. Our aim in this paper was to assess the applicability of MDA to forensic SNP genotyping by performing a comparative analysis of genomic and amplified DNA samples. A 26-SNPs TaqMan panel specifically designed for low copy number (LCN) and/or severely degraded genomic DNA was typed on 100 genomic as well as amplified DNA samples. RESULTS: Aliquots containing 1, 0.1 and 0.01 ng each of 100 DNA samples were typed for a 26-SNPs panel. Similar aliquots of the same DNA samples underwent multiple displacement amplification (MDA) before being typed for the same panel. Genomic DNA samples showed 0% PCR failure rate for all three dilutions, whilst the PCR failure rate of the amplified DNA samples was 0% for the 1 ng and 0.1 ng dilutions and 0.077% for the 0.01 ng dilution. The genotyping results of both the amplified and genomic DNA samples were also compared with reference genotypes of the same samples obtained by direct sequencing. The genomic DNA samples showed genotype concordance rates of 100% for all three dilutions while the concordance rates of the amplified DNA samples were 100% for the 1 ng and 0.1 ng dilutions and 99.923% for the 0.01 ng dilution. Moreover, ten artificially-degraded DNA samples, which gave no results when analyzed by current forensic methods, were also amplified by MDA and genotyped with 100% concordance. CONCLUSION: We investigated the suitability of MDA material for forensic SNP typing. Comparative analysis of amplified and genomic DNA samples showed that a large number of SNPs could be accurately typed starting from just 0.01 ng of template. We found that the MDA genotyping call and accuracy rates were only slightly lower than those for genomic DNA. Indeed, when 10 pg of input DNA was used in MDA, we obtained 99.923% concordance, indicating a genotyping error rate of 1/1299 (7.7 x 10(-4)). This is quite similar to the genotyping error rate of STRs used in current forensic analysis. Such efficiency and accuracy of SNP typing of amplified DNA suggest that MDA can also generate large amounts of genome-equivalent DNA from a minimal amount of input DNA. These results show for the first time that MDA material is suitable for SNP-based forensic protocols and in general when samples fail to give interpretable STR results.
Asunto(s)
Dermatoglifia del ADN/métodos , Genoma Humano , Técnicas de Amplificación de Ácido Nucleico , Polimorfismo de Nucleótido Simple , ADN/análisis , Genotipo , Humanos , Reacción en Cadena de la Polimerasa , Reproducibilidad de los ResultadosRESUMEN
Ancestry informative markers (AIMs) are human polymorphisms that exhibit substantially allele frequency differences among populations. These markers can be useful to provide information about ancestry of samples which may be useful in predicting a perpetrator's ethnic origin to aid criminal investigations. Variations in human pigmentation are the most obvious phenotypes to distinguish individuals. It has been recently shown that the variation of a G in an A allele of the coding single-nucleotide polymorphism (SNP) rs1426654 within SLC24A5 gene varies in frequency among several population samples according to skin pigmentation. Because of these observations, the SLC24A5 locus has been evaluated as Ancestry Informative Region (AIR) by typing rs1426654 together with two additional intragenic markers (rs2555364 and rs16960620) in 471 unrelated individuals originating from three different continents (Africa, Asia and Europe). This study further supports the role of human SLC24A5 gene in skin pigmentation suggesting that variations in SLC24A5 haplotypes can correlate with human migration and ancestry. Furthermore, our data do reveal the utility of haplotype and combined unphased genotype analysis of SLC24A5 in predicting ancestry and provide a good example of usefulness of genetic characterization of larger regions, in addition to single polymorphisms, as candidates for population-specific sweeps in the ancestral population.
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BACKGROUND: The recent advances in human genetics have recently provided new insights into phenotypic variation and genome variability. Current forensic DNA techniques involve the search for genetic similarities and differences between biological samples. Consequently the selection of ideal genomic biomarkers for human identification is crucial in order to ensure the highest stability and reproducibility of results. RESULTS: In the present study, we selected and validated 24 SNPs which are useful in human identification in 1,040 unrelated samples originating from three different populations (Italian, Benin Gulf and Mongolian). A Rigorous in silico selection of these markers provided a list of SNPs with very constant frequencies across the populations tested as demonstrated by the Fst values. Furthermore, these SNPs also showed a high specificity for the human genome (only 5 SNPs gave positive results when amplified in non-human DNA). CONCLUSION: Comparison between in silico and in vitro analysis showed that current SNPs databases can efficiently improve and facilitate the selection of markers because most of the analyses performed (Fst, r2, heterozigosity) in more than 1,000 samples confirmed available population data.
Asunto(s)
Biología Computacional/métodos , Antropología Forense/métodos , Polimorfismo de Nucleótido Simple , Análisis de Secuencia de ADN/métodos , África , Asia , Mapeo Cromosómico , Europa (Continente) , Frecuencia de los Genes , Tamización de Portadores Genéticos , HumanosRESUMEN
A simple strategy is outlined for preparation of the antinociceptive 1-beta-(p-methoxycinnamoyl)polygodial, isolated from Drymis winteri barks. The synthesized compound showed vanilloid activity.
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Analgésicos/síntesis química , Drimys , Canales Catiónicos TRPV/metabolismo , Analgésicos/aislamiento & purificación , Línea Celular , Evaluación Preclínica de Medicamentos/métodos , Humanos , Corteza de la Planta , Extractos Vegetales/síntesis química , Extractos Vegetales/aislamiento & purificación , Estereoisomerismo , Canales Catiónicos TRPV/síntesis química , Canales Catiónicos TRPV/aislamiento & purificaciónRESUMEN
[reaction: see text] Marine diatoms produce alpha,beta,gamma,delta-unsaturated aldehydes that have detrimental effects on the reproduction of their natural predators. The production of these defensive metabolites is suggested to involve enzymatic oxidation of polyunsaturated fatty acids. In this paper, feeding experiments with labeled precursor provide clear evidence in support of the origin of octadienals 1 and 2 from 6,9,12-hexadecatrienoic acid (5), thus proving the involvement of novel lipoxygenase/lyase activity for the oxidation of C(16) fatty acids.
Asunto(s)
Aldehídos/química , Aldehídos/metabolismo , Diatomeas/química , Diatomeas/metabolismo , Ácidos Grasos/química , Cromatografía de Gases y Espectrometría de Masas , Indicadores y Reactivos , Espectroscopía de Resonancia Magnética , EstereoisomerismoRESUMEN
Allele and genotype frequencies of three highly polymorphic loci (apoB, HLADQ alpha, D1S80) have been determined in an Italian sample using the polymerase chain reaction (PCR) amplification and non-radioactive detection. The allele frequencies ranged from 0.1% to 39%, with an average heterozygosity of 0.74 and a power of discrimination ranging from 0.90 to 0.98. These results are of value for forensic and genetic studies. © 1992 Wiley-Liss, Inc.
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The aim of the present study is to appraise the increase of the discrimination power of the Y-specific haplotype allowed by 20 STR markers in a sample of the Italian population. The set of Y STR markers analyzed includes the European "extended haplotype" DYS19, DYS385, DYS389I/II, DYS390, DYS391, DYS392, DYS393 and YCAII a/b and in addition the DYS437, DYS438, DYS439, DYS447, DYS448, DYS388, DYS426, DYS460 (Y-GATA-A7.1) and Y-H4 loci.
Asunto(s)
Cromosomas Humanos Y , Frecuencia de los Genes , Genética de Población , Secuencias Repetidas en Tándem , Dermatoglifia del ADN , Haplotipos , Humanos , Italia , Masculino , Reacción en Cadena de la PolimerasaRESUMEN
Recent advances in our ability to dissect the human genome and the availability of platforms for genome-wide analysis and whole-genome sequencing are expected to develop new tools for both biomedical and forensic DNA analyses. Nowadays, we can individualize single cells left at the crime scene or analyze ancient human remains. Here, we provide a general view on the past, current and likely future directions of forensic DNA analysis.
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Dermatoglifia del ADN/métodos , Medicina Legal/métodos , ADN/genética , ADN/aislamiento & purificación , Dermatoglifia del ADN/historia , Dermatoglifia del ADN/tendencias , Medicina Legal/historia , Medicina Legal/tendencias , Historia del Siglo XX , Historia del Siglo XXI , HumanosRESUMEN
Allele and genotype frequencies of 25 SNPs previously selected and validated for forensic purposes were assessed in 250 unrelated individuals originating from five different countries of Europe (Spain, Croatia, Bulgaria, Turkey and Serbia). All the SNPs generated extremely low F(st) values confirming our previous results on Italian, African (Benin) and Asian (Mongolian) populations. As a consequence of such F(st) values we observed similar values of random match probability across the populations: 2.26 x 10(-10) in the Spanish population, 2.13 x 10(-10) in the Croatian population, 4.21 x 10(-10) in the Bulgarian population, 2.52 x 10(-10) in the Serbian population and 1.46 x 10(-10) in the Turkish population.
Asunto(s)
Genética de Población , Polimorfismo de Nucleótido Simple , Secuencia de Bases , Cartilla de ADN , Genética Forense , Humanos , ProbabilidadRESUMEN
The Fosse Ardeatine massacre was a mass execution carried out in Rome on March 24, 1944 by Nazi German occupation troops during the Second World War as a reprisal for a partisan attack conducted on the previous day in central Rome. The 335 civilians were taken to the "Cave Ardeatine" and they were shot. Only 323 corpses out of 335 have been identified. The aim of this work is the genetic and anthropological analysis of the remains exhumed from grave number 329 of Fosse Ardeatine's Shrine to assess their identity. So far, such remains have been supposed to belong to MM but mitochondrial analysis excluded a biological relationship to two living maternal relatives. Our analysis indicated that remains recovered in grave number 329 do not belong to MM. This result suggests that genetic analysis of the remains should be also applied to the other 12 unknown corpses to elucidate their identity.
Asunto(s)
Dermatoglifia del ADN/métodos , ADN Mitocondrial/genética , Homicidio , Huesos/química , Regiones Determinantes de Complementariedad , Víctimas de Crimen , Exhumación , Antropología Forense , Humanos , Italia , Repeticiones de Microsatélite , Reacción en Cadena de la Polimerasa , Análisis de Secuencia de ADN , Segunda Guerra MundialRESUMEN
Allele frequencies for 16 previously described autosomal SNPs were tested in 1020 unrelated individuals originating from three different continents (Africa, Asia and Europe). The populations analyzed included Africans from Benin Gulf (180), Asians from Mongolia (160) and Europeans from Italy (680).