Quinacrine and 9-Amino Acridine Inhibit B-Z and B-HL Form DNA Conformational Transitions

Modulation of DNA structure formation using small molecules

Genome integrity is essential for proper cell function such that genetic instability can result in cellular dysfunction and disease. Mutations in the human genome are not random, and occur more frequently at "hotspot" regions that often co-localize with sequences that have the capacity to adopt alternative (i.e. non-B) DNA structures. Non-B DNA-forming sequences are mutagenic, can stimulate the formation of DNA double-strand breaks, and are highly enriched at mutation hotspots in human cancer genomes. Thus, small molecules that can modulate the conformations of these structure-forming sequences may prove beneficial in the prevention and/or treatment of genetic diseases. Further, the development of molecular probes to interrogate the roles of non-B DNA structures in modulating DNA function, such as genetic instability in cancer etiology are warranted. Here, we discuss reported non-B DNA stabilizers, destabilizers, and probes, recent assays to identify ligands, and the potential biological applications of these DNA structure-modulating molecules.

Antimalarial Drugs as Immune Modulators: New Mechanisms for Old Drugs

The best known of the naturally occurring antimalarial compounds are quinine, extracted from cinchona bark, and artemisinin (qinghao), extracted from Artemisia annua in China. These and other derivatives are now chemically synthesized and remain the mainstay of therapy to treat malaria. The beneficial effects of several of the antimalarial drugs (AMDs) on clinical features of autoimmune disorders were discovered by chance during World War II. In this review, we discuss the chemistry of AMDs and their mechanisms of action, emphasizing how they may impact multiple pathways of innate immunity. These pathways include Toll-like receptors and the recently described cGAS-STING pathway. Finally, we discuss the current and future impact of AMDs on systemic lupus erythematosus, rheumatoid arthritis, and devastating monogenic disorders (interferonopathies) characterized by expression of type I interferon in the brain.

Exploring the mode of binding of the bioflavonoid kaempferol with B and protonated forms of DNA using spectroscopic and molecular docking studies

Mode of binding of kaempferol with B and protonated form of calf thymus DNA.

(2E)-2-Benzyl-idene-9-phenyl-3,4-di-hydro-acridin-1(2H)-one

In the title compound, C₂₆H₁₉NO, the plane of the aromatic heterocycle makes a dihedral angle of 75.22 (4)° with that of the attached phenyl ring. In the crystal, mol­ecules are connected by C—H⋯O inter­actions, generating R₂²(12) dimers. These dimers are further connected by C—H⋯π inter­actions, linking the mol­ecules into chains running along the a-axis direction.

Dimethyl 2-[(acridin-9-yl)methyl-idene]malonate

In the title compound, C₁₉H₁₅NO₄, the acridine system is essentially planar (r.m.s. deviation = 0.015 Å). The crystal packing exhibits π–π inter­actions between pairs of centrosymmetric mol­ecules, one of them between the central heterocyclic rings and others between the outer benzene rings of the acridine systems, with centroid–centroid distances of 3.692 (1) and 3.754 (1) Å, respectively. These pairs are further linked by additional π–π inter­actions along the a-axis direction through one of the two outer benzene ring of neighboring mol­ecules, with a centroid–centroid distance of 3.642 (2) Å.