Outbreaks of highly pathogenic avian influenza in zoo birds caused by HA clade 2.3.4.4 H5N6 subtype viruses in Japan in 2016.

In late 2016, two zoos, one in northern Japan and the other in central Japan, experienced highly pathogenic avian influenza (HPAI) outbreaks, in which multiple zoo birds were infected with H5N6 subtype HPAI virus (HPAIV). Here, we report an overview of these HPAI outbreaks. HPAIV infections were confirmed by virus isolation in three black swans (Cygnus atratus) and three snowy owls (Bubo scandiacus) kept in the Omoriyama Zoo hospital. At Higashiyama Zoo and Botanical Gardens, following the death of a black swan at a zoo pond, nine waterfowl, including two black swans, four cackling geese (Branta hutchinsii leucopareia), two mallards (Anas platyrhynchos), and a wigeon (Anas penelope), died after HPAIV infection in isolation facilities. Based on the presence of H5-specific antibodies in their sera, two surviving black swans and a surviving mallard at Higashiyama Zoo appeared to have HPAIV infection, although the virus was not isolated. The detectable levels of antibodies (≥10 HI) were maintained for at least 5-9 months, as determined by haemagglutinin inhibition test. Isolation of two H5N6 subtype HPAIVs from an open-air pond where affected zoo birds were previously housed at Higashiyama Zoo strongly indicates that wild waterfowl associated with aquatic environments brought the virus to the zoo. The phylogenetic relationships of the 18 isolates indicated direct viral transmission among birds within each zoo. In both zoos, containment of suspected birds in isolation facilities might have allowed the virus spread among birds inside the facility. However, maintaining containment measures and strict sanitation procedures could facilitate successful physical containment and clearance of HPAIV in both zoos.

[Synthesis and optical properties of the helical oligonaphthalenes].

We have developed an efficient synthesis method for optically active oligonaphthalenes (from 2 mer to 16 mer), which are connected at their 1,4-positions, under oxidative homo coupling with a stoichiometric amount of CuCl(2) and amines. The absolute configuration of the newly formed axis bond was determined based on the CD spectra of oligonaphthalenes with 1) two pyrene rings on the central naphthalenes or 2) two tetraphenylporphyrins (TPP) on the top and bottom naphthalenes. The fluorescence quantum yields increased as the number of naphthalene units increased in methoxy derivatives 10-12, and the intramolecular energy transfer quantum yields of bispyrene derivatives 7-9 were around 20% regardless of the number of naphthalene units. Furthermore, the hexadecanaphthalene derivative 4b with two TPPs exhibited a clear exciton coupling over an interchromophore distance to ca. 66 A.

Bottom-up synthesis of optically active oligonaphthalenes: three different pathways for controlling axial chirality.

The oxidative homocoupling of optically active binaphthalenes 1a-d with a stoichiometric amount of CuCl2 and amines afforded quaternaphthalenes 2a-d in up to 93% de. The high diastereoselectivities were achieved through three different pathways (epimerization of the axis together with diastereoselective crystallization, thermodynamic, and kinetic control pathways). The type of side chains on the naphthalene influenced which pathway dominates. Three pathways were applicable to octinaphthalenes (8a-d) and hexadecanaphthalene 10a with 46-99% de. The absolute configuration of the newly formed axial bond was determined by (1) X-ray crystallographic analysis, (2) transformation to known compounds 15 and 16, (3) CD spectra of oligonaphthalenes with two pyrene rings as exciton parts, and (4) the shift values in 13C NMR spectra of 13C-enriched derivatives 29-31 toward chiral shift reagent Eu(+tfc)3.

Long-range exciton-coupled circular dichroism: application for determination of the absolute configuration of oligonaphthalenes.

Hexadecanaphthalenes (S,S,S,S,S,S,S,S,S,S,S,S,S,S,S)-4b and (S,S,S,S,S,S,S,R,S,S,S,S,S,S,S)-4b that possess two tetraphenylporphyrins (TPP) on the upper and lower naphthalene rings were synthesized. Long-range exciton-coupled CD in the Soret region of TPP (about 66 A) was observed. [structure: see text]

Synthesis of optically active oligonaphthalenes via second-order asymmetric transformation.

Synthesis of numerous optically active rod-shaped oligo(2,3-dioxyfunctionalized)naphthalenes connected at their 1,4-positions was achieved using oxidative coupling under CuCl2/alpha-methylbenzylamine conditions by second-order asymmetric transformation. We believe this method is practical and should contribute to the field of material science.