Approaches to the Total Synthesis of Puupehenone-Type Marine Natural Products

Puupehenones have been isolated from the marine sponge Chondrosia chucalla, which belong to a growing family of natural products with more than 100 members. These marine natural products have attracted increasing attention mainly due to their wide variety of biological activities such as antitumor, antiviral, and anti-HIV, and thus offer promising opportunities for new drug development. This chapter covers the approaches to the total synthesis of puupehenone-type marine natural products including puupehenol, puupehenone, puupehedione, and halopuupehenones. The routes begin with the construction of their basic skeletons, followed by the modification of their C- and D-rings. The contents are divided into two sections in terms of the key strategies employed to construct the basic skeleton. One is the convergent synthesis route with two synthons coupled by nucleophilic or electrophilic reaction, and the other is the linear synthesis route with polyene series cyclization as a key reaction

Heisenberg Spin Bus as a Robust Transmission Line for Perfect State Transfer

We study the protocol known as quantum state transfer for a strongly coupled antiferromagnetic spin chain or ring (acting as a spin bus), with weakly coupled external qubits. By treating the weak coupling as a perturbation, we find that perfect state transfer (PST) is possible when second order terms are included in the expansion. We also show that PST is robust against variations in the couplings along the spin bus and between the bus and the qubits. As evidence of the quantum interference which mediates PST, we show that the optimal time for PST can be smaller with larger qubit separations, for an even-size chain or ring.Comment: 6 figures,submitte

Bis[1,3-bis­(1-methyl-1H-benzimidazol-2-yl)-2-oxapropane]­cadmium dipicrate acetonitrile sesquisolvate 0.25-hydrate

In the title compound, [Cd(C18H18N4O)2](C6H2N3O7)2·1.5CH3CN·0.25H2O, the CdII ion is coordinated by four N atoms and two O atoms from two tridentate 1,3-bis­(1-methyl-1H-benzimidazol-2-yl)-2-oxopropane ligands in a distorted octa­hedral coordination environment. The lengths of the chemically equivalent Cd—O bonds [2.4850 (16) and 2.5488 (16)Å] are signiificantly different. One of the picrate anions is disordered over two sets of sites, with refined occupancies of 0.504 (15) and 0.496 (15). A 0.5-occupancy acetonitrile solvent mol­ecule is disordered over two sites with equal occupancies. The H atoms of a 0.25-occupancy solvent water mol­ecule were neither located nor included in the refinement

Bis[1,3-bis­(1-ethyl-1H-benzimidazol-2-yl)-2-oxapropane]­cadmium(II) dipicrate dimethyl­formamide disolvate

In the title compound, [Cd(C20H22N4O)2](C6H2N3O7)2·2C3H7NO, the CdII ion is coordinated by four N atoms and two O atoms from two tridentate 1,3-bis­(1-ethyl-1H-benzimid­azol-2-yl)-2-oxapropane ligands in a distorted octa­hedral environment

Bis[N,N-bis­(1-allyl-1H-benzimidazol-2-ylmethyl-κN 3)benzyl­amine-κN]cadmium dipicrate

The crystal structure of the title compound, [Cd(C29H29N5)2](C6H2N3O7)2, consists of CdII complex cations and picrate anions. In the complex cation, the CdII ion is chelated by two bis­(1-allyl­benzimidazol-2-ylmeth­yl)benzyl­amine (babb) ligands in a distorted octa­hedral geometry. Extensive C—H⋯O hydrogen bonding occurs between cations and anions in the crystal structure

EBV-positive Hodgkin lymphoma is associated with suppression of p21cip1/waf1 and a worse prognosis

<p>Abstract</p> <p>Background</p> <p>About 30-50% of Hodgkin lymphomas (HLs) harbor the Epstein-Barr virus (EBV), but the impact of EBV infection on clinical outcomes has been unclear. EBV-encoded small RNAs (<it>EBER</it>s) are presented in all EBV-infected cells, but their functions are still less understood.</p> <p>Results</p> <p><it>EBER1 </it>was transfected into two HL cell lines, KMH2 and L428, and microarrays were used to screen for <it>EBER1</it>-induced changes. We found that <it>EBER1 </it>suppressed <it>p21</it>^cip1/waf1transcription in HL cell lines. In addition, positive regulators of <it>p21</it>^cip1/waf1transcription, such as p53, EGR1, and STAT1, were decreased. Suppression of <it>p21</it>^cip1/waf1in the <it>EBER1</it>⁺HL cell lines was associated with increased resistance to histone deacetylase inhibitors or proteasome inhibitors, drugs known to cause apoptosis by increasing p21^cip1/waf1levels. On biopsy specimens, EBV⁺HLs had weaker expression of both p21^cip1/waf1and active caspase 3. Clinically, suppression of p21^cip1/waf1in EBV⁺HLs was associated with a worse 2-year disease-free survival rate (45% for EBV⁺HLs <it>vs</it>. 77% for EBV^-HLs, <it>p </it>= 0.002).</p> <p>Conclusion</p> <p>Although the underlying mechanisms are still relatively unclear, <it>EBER1 </it>inhibits <it>p21</it>^cip1/waf1transcription and prevents apoptosis through down-regulation of p53, EGR1, and STAT1. The anti-apoptotic activity of <it>EBER1 </it>may be important in the rescue of Reed-Sternberg cells from drug-induced apoptosis and in the clinical behaviors of EBV⁺HLs.</p