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Recent observations have suggested that nonionizing radiation in the microwave and terahertz (THz; far-infrared) regimes could have an effect on double-stranded DNA (dsDNA). These observations are of significance owing to the omnipresence of microwave emitters in our daily lives (e.g., food preparation, telecommunication, and wireless Internet) and the increasing prevalence of THz emitters for imaging (e.g., concealed weapon detection in airports, skin cancer screenings) and communication technologies. By examining multiple DNA nanostructures as well as two plasmid DNAs, microwaves were shown to promote the repair and assembly of DNA nanostructures and single-stranded regions of plasmid DNA, while intense THz pulses had the opposite effect (in particular, for short dsDNA). Both effects occurred at room temperature within minutes, showed a DNA length dependence, and did not affect the chemical integrity of the DNA. Intriguingly, the function of six proteins (enzymes and antibodies) was not affected by exposure to either form of radiation under the conditions examined. This particular detail was exploited to assemble a fully functional hybrid DNA–protein nanostructure in a bottom-up manner. This study therefore provides entirely new perspectives for the effects, on the molecular level, of nonionizing radiation on biomolecules. Moreover, the proposed structure–activity relationships could be exploited in the field of DNA nanotechnology, which paves the way for designing a new range of functional DNA nanomaterials that are currently inaccessible to state-of-the-art assembly protocols.

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Clustered disaccharide analogues of adenophostin A (2), i.e. mono-, di-, and tetravalent derivatives 6-8, respectively, were synthesized and evaluated as novel ligands for the tetrameric D-myo-inositol 1,4, 5-trisphosphate receptor (IP(3)R). The synthesis was accomplished via Sonogashira coupling of propargyl 2-O-acetyl-5-O-benzyl-3-O-(3, 4-di-O-acetyl-2, 6-di-O-benzyl-alpha-D-glucopyranosyl)-beta-D-ribofuranoside (16) with iodobenzene 18, 22, or 25, followed by deacetylation, phosphorylation, and deprotection. The abilities of the target compounds 6-8, as well as ribophostin 4, propylphostin 5, and IP(3) (1), to evoke Ca(2+) release from permeabilized hepatocytes or displacement of [(3)H]IP(3) from its receptor in hepatic membranes were compared. Although the binding affinities of 4-8 were similar, there were modest though significant differences in their potencies in Ca(2+) release assays: tetraphostin 8 > IP(3) approximately diphostin 7 > phenylphostin 6 > ribophostin 4 approximately propylphostin 5.

The synthesis of the recently discovered modified DNA base 5‐(β‐D‐glucopyranosyloxymethyl)‐2′‐deoxyuridine (β‐dJ, 1) is described. TMSOTf mediated β‐glucosylation of 5‐hydroxymethyl‐2′‐deoxyuridine (5‐HMdU) derivative 10 (obtained in 20% from 2′‐deoxyuridine) with trichloroacetimidate 12 gave dimer 13 in 47% yield. On the other hand, condensation of 12with N3‐POM‐protected derivative 20, readily available from thymidine in 48%, afforded the fully protected nucleoside 22 in 96% yield. The latter compound was converted into phosphoramidite 3 which was applied in the automated solid phase synthesis of several biological interesting β‐dJ containing DNA fragments.

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