New solid supports are described which allow the direct synthesis of oligonucleotides bearing either cholesterol or acridine at the 3'-terminus. A stereochemically defined amino diol was prepared by reduction of N-Cbz-hydroxy-L-proline. This linker molecule was first acylated with the desired conjugate molecule, then protected as the dimethoxytrityl ether. The remaining secondary hydroxyl group was succinylated and immobilized on a controlled-pore glass support. 3'-Modified oligodeoxynucleotides (ODNs) were prepared from these supports by using standard phosphoramidite coupling and deprotection conditions. A cholesterol-modified support was prepared from cholesterol chloroformate and the amino diol linker. Two types of acridine-modified solid supports were prepared from acridine tetrafluorophenyl esters with linker arms of different length. In an alternative synthesis of 3'-derivatized ODNs, these active esters were also utilized for acylation of a 3'-amine-modified ODN. A thermal denaturation study was done to determine the effect of the different linker arms on hybridization to a complementary ODN target. Facile synthesis and purification of the 3'-modified ODNs makes these functionalized solid supports especially useful for preparation of oligonucleotides bearing these and other modifications.

Acridines↗

PubMedDate not supplied

A novel biotinylated adenylate analogue derived from pyrazolo[3,4-d]pyrimidine for labeling DNA probes.

A novel dATP analogue, 3-[5-[(N-biotinyl-6- amiocaproyl)amino]pentyl]-1-(2-deoxy-beta-D-erythro-pentofuranosyl )-1H-pyrazolo[3,4-d]pyrimidin-4-amine 5'-triphosphate (9, bio-13-dAPPTP), which is modified at the 3-position with a flexible linker arm bearing a terminal biotin moiety, has been synthesized. This nucleotide is readily incorporated into DNA probes by nick translation. These probes hybridize to complementary targets as well as probes labeled with bio-dUTP, as judged by slot blot. When incorporated into oligonucleotides, they do not cause the loss of hybridization efficiency that an N-6-substituted adenine nucleotide does when incorporated into the same sites in the oligonucleotide.

Adenosine Triphosphate↗

PubMedDate not supplied

An improved CPG support for the synthesis of 3'-amine-tailed oligonucleotides.

A new controlled-pore glass (CPG) support is described that allows for the direct synthesis of oligonucleotides bearing a 3'-aminohexyl tail. This solid support (AH-CPG) exhibits superior performance as compared to a commercially available 3'-amine CPG. The AH-CPG is prepared from 6-aminohexan-1-ol with a unique protecting group for the amine that also functions as the site of attachment to the CPG. A 3'-amine-tailed oligodeoxynucleotide (ODN) was prepared from this support using standard phosphoramidite coupling and deprotection conditions. The 3'-amine-tailed ODN was subsequently modified with an acridinylpropionic acid tetrafluorophenyl ester. Facile synthesis of the AH-CPG and the stability of the deprotected product makes this functionalized solid support especially useful for preparation of oligonucleotides bearing 3'-amine tails and other modifications.

Acridines↗

PubMedDate not supplied

Oligodeoxyribonucleotides with conjugated dihydropyrroloindole oligopeptides: preparation and hybridization properties.

Synthesis of a new class of conjugates between oligodeoxyribonucleotides (ODNs) and minor groove binders (MGBs) is described. The MGBs are analogs of the potent antibiotic CC-1065 and consist of repeating 1,2-dihydro-3H-pyrrolo[3,2-e]indole-7-carboxylate (DPI) subunits with N-3 carbamoyl or tert-butyloxycarbonyl groups (CDPI or BocDPI subunits, respectively). The ODN-MGB conjugates were obtained by postsynthetic modification of 5'- or 3'-amino-tailed ODNs with the 2,3,5,6-tetrafluorophenyl (TFP) esters of CDPI1-3 or BocDPI1-2 or by ODN synthesis using a CDPI3-modified controlled pore glass (CPG) support. The hybridization properties of MGB-tailed octathymidylates were determined; they varied with respect to the site of conjugation (3' or 5'), the nature of the linker, the length of the DPI oligopeptide, and the type of N-3 substitution. Optical melting studies showed that the linkage of CDPI1-3 residues to (dTp)8 significantly increased the stability of hybrids formed by the latter with poly(dA). The extent of stabilization increased with the length of the peptide. When CDPI3 was conjugated to either end of (dTp)8, the melting temperature (Tm) of the hybrid formed with poly(dA) was increased by 43-44 degrees C. Free CDPI3 stabilized the (dTp)8-poly(dA) hybrid by only 2 degrees C, thus demonstrating the importance of conjugation. (dTp)8-CDPI1-3 conjugates also formed stabilized duplexes with poly(rA). The extent of stabilization was half that observed with poly(dA).

Antibiotics, Antineoplastic↗