Benzidine/Quinoidal‐Benzidine‐Linked,Superbenzene‐Based π‐Conjugated Chiral Macrocycles and Cyclophanes

Synthesis of fully conjugated cyclophanes containing large‐size polycyclic aromatics is challenging. Now, three benzidine‐linked, hexa‐peri‐hexabenzocoronene (superbenzene)‐based ortho‐, para‐, and meta‐cyclophanes are synthesized through intermolecular Yamamoto coupling reaction of structurally pre‐organized precursors. Subsequent oxidative dehydrogenation gave the corresponding quinoidal benzidine‐linked cyclophanes. Their geometries were confirmed by X‐ray crystallographic analysis and their electronic properties were investigated by electronic absorption, cyclic voltammetry, and DFT calculations. The quinoidal benzidine‐linked cyclophanes show thermally populated paramagnetic activity with a relatively large singlet‐triplet energy gap. Two enantiomers for the ortho‐cyclophanes ( 1‐NH and 1‐N ) were isolated and their chiral figure‐of‐eight macrocyclic structures were identified. The cage‐like cyclophanes 2‐NH and 3‐NH with concave surface can selectively encapsulate fullerene C₇₀.     

Target Design of Novel Histone Deacetylase 6 Selective Inhibitors with 2-Mercaptoquinazolinone as the Cap Moiety

Epigenetic alterations found in all human cancers are promising targets for anticancer therapy. In this sense, histone deacetylase inhibitors (HDACIs) are interesting anticancer agents that play an important role in the epigenetic regulation of cancer cells. Here, we report 15 novel hydroxamic acid-based histone deacetylase inhibitors with quinazolinone core structures. Five compounds exhibited antiproliferative activity with IC₅₀ values of 3.4–37.8 µM. Compound 8 with a 2-mercaptoquinazolinone cap moiety displayed the highest antiproliferative efficacy against MCF-7 cells. For the HDAC6 target selectivity study, compound 8 displayed an IC₅₀ value of 2.3 µM, which is 29.3 times higher than those of HDAC3, HDAC4, HDAC8, and HDAC11. Western blot assay proved that compound 8 strongly inhibited tubulin acetylation, a substrate of HDAC6. Compound 8 also displayed stronger inhibition activity against HDAC11 than the control drug Belinostat. The inhibitory mechanism of action of compound 8 on HDAC enzymes was then explored using molecular docking study. The data revealed a high binding affinity (−7.92 kcal/mol) of compound 8 toward HDAC6. In addition, dock pose analysis also proved that compound 8 might serve as a potent inhibitor of HDAC11.     

On the reduction number of some graded algebras

The main result of the paper confirms, for generic coordinates, a conjecture which states that . Here is a homogeneous polynomial ideal in and and are the reduction numbers.

     

Unbounded Components in the Solution Sets of Strictly Quasiconcave Vector Maximization Problems

Let (P) denote the vector maximization problem

Value sharing problems for differential and difference polynomials of meromorphic functions in a non-Archimedean field

In this paper we discuss the uniqueness problem for differential and difference polynomials of the form (f ^nm (z)f ^nd (qz + c))^(k) for meromorphic functions in a non-Archimedean field.     

On functional equations for meromorphic functions and applications

Donovan’s conjecture states that there exist only finitely many Morita equivalence classes of p-blocks with a given defect. This conjecture was shown by Radha Kessar to be equivalent to two other conjectures, one of which is that the basic algebras of p-blocks with a given defect can all be defined over a single finite field. We shall show that this latter conjecture is equivalent to the seemingly stronger statement that all p-blocks with a given defect can be defined over a single finite field.