Synthesis of macrosphelides with a thiazole side chain: new antitumor candidates having apoptosis-inducing property

Hybrid compounds of macrosphelides and epothilones, both of which are natural macrolides having a 16-membered skeleton, were designed and synthesized using a ring-closing metathesis (RCM) strategy. Some of these hybrids were found to exhibit notable apoptosis-inducing activity against human lymphoma cells with higher potency than parent natural macrosphelides, and to be a promising lead compound for development of a new antitumor agent.     

Beta-isocupreidine-catalyzed Baylis-Hillman reaction of chiral N-boc-alpha-amino aldehydes

[Structure: see text] Beta-isocupreidine (beta-ICD)-catalyzed Baylis-Hillman reaction of chiral N-Boc-alpha-amino aldehydes and 1,1,1,3,3,3-hexafluoroisopropyl acrylate (HFIPA) takes place without racemization and exhibits the match-mismatch relationship between the substrate and the catalyst. In the case of acyclic amino aldehydes, L-substrates show excellent syn selectivity and high reactivity in contrast to D-substrates. On the other hand, in the case of cyclic amino aldehydes, D-substrates rather than L-substrates show excellent anti selectivity and high reactivity.     

Catalytic diastereoselective polycyclization of homo(polyprenyl)arene analogues bearing terminal siloxyvinyl groups

Highly diastereoselective polycyclization of homo(polyprenyl)arene analogues bearing terminal siloxyvinyl groups was catalyzed by tin(IV) chloride (10 mol %). The cyclizations of tert-butyldiphenylsilyl and triisopropylsilyl polyenol ethers gave 4alpha(equatorial)- and 4beta(axial)-siloxypolycycles as major isomers, respectively. The strong nucleophilicity of pro-C(9), a (6E) geometry, and a bulky silyl group effectively favored the alpha-preference, whereas the weak nucleophilicity of pro-C(9), a (6Z)-geometry, and less steric hindrance of a silyl group favored the beta-preference. [reaction: see text].     

Two convergent routes to the left-wing fragment of ciguatoxin CTX3C using O,S-acetals as key intermediates

Ciguatoxins, principal causative toxins of ciguatera seafood poisoning, are large ladderlike polycyclic ethers. Here, we report two convergent routes to synthesis of the multiolefinic left half of ciguatoxins based on a newly developed acyl radical strategy. Remarkably, only 13 steps from the monocyclic E-ring were required to construct the left wing. [reaction: see text]     

Force control between quantum dots by light in polaritonic molecule states

Photomediated force between quantum dots (QDs) is theoretically studied. An attractive (repulsive) interparticle radiation force (IRF) arises by selectively exciting the lower (higher) split state of coupled polaritons in QDs. Since these states are analogous to bonding and antibonding states of a diatomic molecule, we term this system the "polaritonic molecule (PM)". IRF in PM states is controlled by the photon energy, polarization, and phase at each QD. This mechanism can be used to probe internal quantum properties of nano-objects and to manipulate collective dynamics of QDs.     

Refined holographic entanglement entropy for the AdS solitons and AdS black holes

We consider the refinement of the holographic entanglement entropy for the holographic dual theories to the AdS solitons and AdS black holes, including the corrected ones by the Gauss–Bonnet term. The refinement is obtained by extracting the UV-independent piece of the holographic entanglement entropy, the so-called renormalized entanglement entropy which is independent of the choices of UV cutoff. Our main results are: (i) the renormalized entanglement entropies of the _AdSd+1${\mathrm{AdS}}_{d+1}$ soliton for d=4,5$d=4,5$ are neither monotonically decreasing along the RG flow nor positive-definite, especially around the deconfinement/confinement phase transition; (ii) there is no topological entanglement entropy for AdS₅ soliton even with Gauss–Bonnet correction; (iii) for the AdS black holes, the renormalized entanglement entropy obeys an expected volume law at IR regime, and the transition between UV and IR regimes is a smooth crossover even with Gauss–Bonnet correction; (iv) based on AdS/MERA conjecture, we postulate that the IR fixed-point state for the non-extremal AdS soliton is a trivial product state.     

Jelly-filled optical cable

Abstract

Jelly-filled optical fiber cables have been investigated. The waterproof characteristics and transmission and mechanical properties of the fabricated jelly-filled cables, including temperature and aging characteristics, were sufficient to apply them for practical use.     

The N = 16 Spherical Shell Closure in 24O

The unbound excited states of the most neutron-rich dripline oxygen isotope, ²⁴O, have been investigated by using the ²⁴O(p,p′)²⁴O^* reaction at the beam energy of 62 MeV/nucleon in inverse kinematics. The first and second unbound excited states of ²⁴O have been observed at ${E_{\rm x}= 4.63_{-0.14}^{+0.30}}$  MeV and ${E_{\rm x}= 5.13_{-0.24}^{+0.19}}$  MeV (preliminary) along with the evidence for another higher lying state at around 7.3 MeV. The quadrupole deformation parameter ${\beta_{2^+}}$ was deduced to be ${0.15_{-0.03}^{+0.08}}$ (preliminary) for the first time. The systematics of the ${\beta_{2^+}}$ and the ${E_{\rm x}(2_1^+)}$ in the Z = 8 isotopes shows the N = 16 spherical shell closure in ²⁴O.     

Highly efficient generation of entangled photons by controlling cavity bipolariton states

We theoretically investigate entangled-photon generation via a biexciton in a planar microcavity. Owing to strong exciton-photon coupling, the biexciton in the cavity produces a bound two-cavity-polariton state (cavity bipolariton). Entangled photons are generated by the cascade decay of the cavity bipolariton. We propose a novel scheme for highly efficient entangled-photon generation by controlling the cavity bipolariton states. It is shown that highly efficient generation can be achieved when a weak cavity bipolariton, formed by a biexciton and unbound cavity polaritons, is realized.