Characterization of Dengue Virus Type 2: New Insights on the 2010 Brazilian Epidemic

Dengue viruses (DENV) serotypes 1, 2, and 3 have been causing yearly outbreaks in Brazil. In this study, we report the reintroduction of DENV2 in the coast of Sao Paulo State. Partial envelope viral genes were sequenced from eighteen patients with dengue fever during the 2010 epidemic. Phylogenetic analysis showed this strain belongs to the American/Asian genotype and was closely related to the virus that circulated in Rio de Janeiro in 2007 and 2008. The phylogeny also showed no clustering by clinical presentation, suggesting that the disease severity could not be explained by distinct variants or genotypes. The time of the most recent common ancestor of American/Asian genotype and the Sao Paulo and Rio de Janeiro (SP/RJ) monophyletic cluster was estimated to be around 40 and 10 years, respectively. Since this virus was first identified in Brazil in 2007, we suggest that it was already circulating in the country before causing the first documented outbreak. This is the first description of the 2010 outbreak in the State of Sao Paulo, Brazil, and should contribute to efforts to control and monitor the spread of DENVs in endemic areas.

1-furfuryl-3-furoylthiourea

The title compound, C11H10N2O3S, was synthesized from furoyl isothiocyanate and furfurylamine in dry acetone. The thiourea group is in the thioamide form. The trans-cis geometry of the thiourea group is stabilized by intramolecular hydrogen bonding between the carbonyl and cis-thioamide and results in a pseudo-S(6) planar ring which makes dihedral angles of 2.5 (3) and 88.1 (2)degrees with the furoyl and furfuryl groups, respectively. There is also an intramolecular hydrogen bond between the furan O atom and the other thioamide H atom. In the crystal structure, molecules are linked by two intermolecular N-H center dot center dot center dot O hydrogen bonds, forming dimers. These dimers are stacked within the crystal structure along the [010] direction.

1-Benzyl-3-(2-furoyl)thiourea

In the title compound, C13H12N2O2S, the dihedral angle between the two aromatic ring planes is 87.52 (12)degrees. The molecule shows an intramolecular N-H center dot center dot center dot O hydrogen bond. The crystal structure is stabilized by intermolecular N-H center dot center dot center dot S and C-H center dot center dot center dot O hydrogen bonding.

Tris(N-benzoyl-N ',N ''-diphenylthioureato-kappa O-2,S)cobalt(III)

In the title compound, [Co(C20H15N2OS)(3)], the Co-III atom is coordinated by the S and O atoms of three N-benzoyl-N',N'-diphenylthiourea ligands in a slightly distorted octahedral geometry. The O and S atoms are in cis positions, while the positions between the O and S atoms are trans.

1-Furoyl-3-methyl-3-phenylthiourea

The title compound, C13H12N2O2S, crystallizes with two independent molecules in the asymmetric unit. The two molecules differ in the conformation of the thiocarbonyl and carbonyl groups, and show the typical geometric parameters of substituted thiourea derivatives. The crystal structure is mainly stabilized by intermolecular N-H center dot center dot center dot O hydrogen bonding.

1-Furoyl-3-[3-(trifluoromethyl)phenyl]thiourea

The title compound, C(13)H(9)F(3)N(2)O(2)S, crystallizes with two independent molecules in the asymmetric unit. The central thiourea core is roughly coplanar with the furan and benzene rings, showing O-C-N-C(S) torsion angles of 2.3 (4) and -11.4 (2) degrees and (S) C -N-C-C torsion angles of -2.4 (4) and -28.8 (4) degrees, respectively, in the two independent molecules. The trans-cis geometry of the thiourea fragment is stabilized by an intramolecular N-H center dot center dot center dot O hydrogen bond between the H atom of the cis thioamide and the carbonyl O atom. In the crystal structure, intermolecular N-H center dot center dot center dot S hydrogen bonds form centrosymmetric dimers extending along the b axis.

Redetermination of 1-benzyl-3-furoyl-1-phenylthiourea

The title compound, C(19)H(16)N(2)O(2)S, was synthesized from furoyl isothiocyanate and N-benzylaniline in dry acetone and the structure redetermined. The structure [Otazo-Sanchez et al. (2001). J. Chem. Soc. Perkin Trans. 2, pp. 2211-2218] has been re-determined in order to establish the intramolecular and intermolecular interactions. The thiourea group is in the thioamide form. The thiourea group makes a dihedral angle of 29.2 (6)degrees with the furoyl group. In the crystal structure, molecules are linked by intermolecular C-H center dot center dot center dot O interactions, forming one-dimensional chains along the a axis. An intramolecular N-H center dot center dot center dot O hydrogen bond is also present.

1-(o-tolyl)thiourea

In the title compound, C(8)H(10)N(2)S, the o-tolyl group and the thiourea core are planar. The mean planes of the two groups are almost perpendicular [82.19 (8)degrees]. The thiourea group is in the thioamide form, in which resonance is present. In the crystal structure, molecules are linked by intermolecular N-H center dot center dot center dot S hydrogen bonds, forming two infinite chains parallel to the (110) and (110) planes.

1-(2-Furoyl)-3-(o-tolyl)thiourea

The title compound, C13H12N2O2S, was synthesized from furoyl isothiocyanate and o-toluidine in dry acetone. The thiourea group is in the thioamide form. The central thiourea fragment makes dihedral angles of 2.6 (1) and 22.4 (1)degrees with the ketofuran group and the benzene ring, respectively. The molecular structure is stabilized by N-H...O hydrogen bonds. In the crystal structure, centrosymmetrically related molecules are linked by a pair of N-H...S hydrogen bonds to form a dimer with an R-2(2)(6) ring motif.

N-(2-furylcarbonyl)piperidine-1-carbothioamide

The title compound, C11H14N2O2S, was synthesized from furoyl isothiocyanate and piperidine in dry acetone. The thiourea group is in the thioamide form. The thiourea group makes a dihedral angle of 53.9 (1)degrees with the furan carbonyl group. In the crystal structure, molecules are linked by intermolecular N-H center dot center dot center dot O hydrogen bonds, forming one-dimensional chains along the c axis. An intramolecular N-H center dot center dot center dot O hydrogen bond is also present.

1-(3-cyanophenyl)-3-(2-furoyl)thiourea

The title compound, C13H9N3O2S, was synthesized from furoyl isothiocyanate and 3-aminobenzonitrile in dry acetone. The thiourea group is in the thioamide form. The thiourea fragment makes dihedral angles of 3.91 (16) and 37.83 (12)degrees with the ketofuran group and the benzene ring, respectively. The molecular geometry is stabilized by N-H center dot center dot center dot O hydrogen bonds. In the crystal structure, centrosymmetrically related molecules are linked by two intermolecular N-H center dot center dot center dot S hydrogen bonds to form dimers.

cis-Bis[N-(2-furoyl)-N ',N '-diphenylthioureato-kappa(2)O,S]nickel(II)

In the title compound, [Ni(C(18)H(13)N(2)O(2)S)(2)], the Ni(II) atom is coordinated by the S and O atoms of two N-furoyl-N ',N '-diphenylthioureate ligands in a slightly distorted squareplanar coordination geometry. The two O and two S atoms are cis to each other.

cis-bis(N-benzoyl-N ',N '-dibenzylthio-ureato-kappa O-2,S)nickel(II)

In the title compound, [Ni(C22H19N2OS)(2)], the Ni-II atom is coordinated by the S and O atoms of two N-benzoyl-N',N'-dibenzylthioureate ligands in a slightly distorted square-planar geometry. The two O atoms are cis, as are the two S atoms.

1-(2-furoyl)-3-(1-naphthyl)thiourea

In the title compound, C(16)H(12)N(2)O(2)S, the carbonylthiourea group forms dihedral angles of 75.4 (1) and 13.1 (2)degrees, respectively, with the naphthalene ring system and furan ring. The molecule adopts a trans-cis configuration with respect to the positions of the furoyl and naphthyl groups relative to the S atom across the thiourea C-N bonds. This geometry is stabilized by an N-H center dot center dot center dot center dot O intramolecular hydrogen bond. In the crystal structure, molecules are linked by N-H center dot center dot center dot S hydrogen bonds, forming centrosymmetric dimers which are interlinked through C-H center dot center dot center dot pi interactions.

Annual growth rings in the mangrove Laguncularia racemosa (Combretaceae)

Stem discs from trees of known age were used to determine the periodic nature of the growth rings formed in Laguncularia racemosa and to describe the anatomical features of these rings. The growth rings were scarcely distinct on microscopic examination, but they were well distinguishable macroscopically, with alternating light brown and dark brown layers. Cross-dating analysis revealed the occurrence of annual growth rings in L. racemosa. The existence of annual growth rings in L. racemosa suggests that it may have great potential for dendrochronology and should encourage age-related studies on the dynamics of mangrove forests. These studies can be important for the evaluation of climate change impact on mangrove ecosystems, as well as for the analysis of effects related to climate variability on plant communities.