(1R,1′R,3S,3′S)-5,5′,10,10′-Tetra­meth­oxy-1,1′,3,3′-tetra­methyl-3,3′,4,4′-tetra­hydro-1H,1′H-8,8′-bi[benzo[g]isochromene]

In the title compound, C34H38O6, the methyl groups on each pyran ring exhibit 1,3-cis stereochemistry, established during synthesis by pseudo-axial delivery of hydride during a lactol reduction step. In the crystal structure, the mol­ecule lies on a twofold rotation axis and the torsion angle about the central diaryl bond is 41.3 (1)°. The mol­ecules pack in a herringbone arrangement

Selection for Heterozygosity Gives Hope to a Wild Population of Inbred Wolves

Recent analyses have questioned the usefulness of heterozygosity estimates as measures of the inbreeding coefficient (f), a finding that may have dramatic consequences for the management of endangered populations. We confirm that f and heterozygosity is poorly correlated in a wild and highly inbred wolf population. Yet, our data show that for each level of f, it was the most heterozygous wolves that established themselves as breeders, a selection process that seems to have decelerated the loss of heterozygosity in the population despite a steady increase of f. The markers contributing to the positive relationship between heterozygosity and breeding success were found to be located on different chromosomes, but there was a substantial amount of linkage disequilibrium in the population, indicating that the markers are reflecting heterozygosity over relatively wide genomic regions. Following our results we recommend that management programs of endangered populations include estimates of both f and heterozygosity, as they may contribute with complementary information about population viability

Synthesis and incorporation into cyclic peptides of tolan amino acids and their hydrogenated congeners: construction of an array of A–B-loop mimetics of the Cε3 domain of human IgE

The disruption of the human immunolobulin E–high affinity receptor I (IgE–FcεRI) protein–protein interaction (PPI) is a validated strategy for the development of anti asthma therapeutics. Here, we describe the synthesis of an array of conformationally constrained cyclic peptides based on an epitope of the A–B loop within the Cε3 domain of IgE. The peptides contain various tolan (i.e., 1,2-biarylethyne) amino acids and their fully and partially hydrogenated congeners as conformational constraints. Modest antagonist activity (IC50 660 μM) is displayed by the peptide containing a 2,2′-tolan, which is the one predicted by molecular modeling to best mimic the conformation of the native A–B loop epitope in IgE

Synthesis and Incorporation into Cyclic Peptides of Tolan Amino Acids and Their Hydrogenated Congeners: Construction of an Array of A–B-loop Mimetics of the Cε3 Domain of Human IgE

The disruption of the human immunolobulin E–high affinity receptor I (IgE–FcεRI) protein–protein interaction (PPI) is a validated strategy for the development of anti asthma therapeutics. Here, we describe the synthesis of an array of conformationally constrained cyclic peptides based on an epitope of the A–B loop within the Cε3 domain of IgE. The peptides contain various tolan (i.e., 1,2-biarylethyne) amino acids and their fully and partially hydrogenated congeners as conformational constraints. Modest antagonist activity (IC₅₀ ∼660 μM) is displayed by the peptide containing a 2,2′-tolan, which is the one predicted by molecular modeling to best mimic the conformation of the native A–B loop epitope in IgE

Parental care and external sexual characters in the Warbling Doradito (Pseudocolopteryx flaviventris)

Biparental care is the dominant (81 %) form of parental care in birds. The degree of sexual selection and the resulting mating system and parental care type have been determined, in many cases, by inference from external characters of sexual dimorphism. The lack of information and the biological attributes of the tyrant flycatchers (e.g., low sexual dimorphism) make it difficult to determinate the parental care roles in most species. Tyrant flycatchers comprise a diverse bird family, but information on the reproductive behavior of many Tyrannid species is lacking. Our aim was to describe external sexual characters (morphology and coloration) and determine the parental care behavior at the nest in the Warbling Doradito (Pseudocolopteryx flaviventris), especially considering the potential role of sexual differences in relation to parental roles at nest. We studied the parental care behavior during two breeding seasons. Parents were captured to take morphological measurements and a blood sample for molecular sex determination. We found that parental care in the Warbling Doradito was biparental biased toward females, where the incubation was performed exclusively by females and the 74 % of activities of nestling brooding and feeding was performed by females. We also found sexual differences, slight in size and plumage, but more conspicuous in bill color. Despite the relatively slight sexual dichromatism of the Warbling Doradito, the parental care behavior in the nest was biased towards females, and the assistance of males to nestlings was highly variable and was not correlated with either clutch size or increasing nestling mass. Therefore, the evidence presented here suggest that Pseudocolopteryx genus may have an unusual social system, otherwise uncommon in tyrannids.Fil: Cardoni, Daniel Augusto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencia Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; ArgentinaFil: Pretelli, Matías Guillermo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencia Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; ArgentinaFil: Isacch, Juan Pablo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencia Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; ArgentinaFil: Madrid, Enrique Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencia Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; ArgentinaFil: Baladron Felix, Alejandro Victor. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencia Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; ArgentinaFil: Chiaradia, Nicolas Mariano. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencia Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; Argentin