1
|
|
2
|
Osawa T, Sawamura M, Wada F, Yamamoto T, Obika S, Hari Y. Synthesis, duplex-forming ability, enzymatic stability, and in vitro antisense potency of oligonucleotides including 2'-C,4'-C-ethyleneoxy-bridged thymidine derivatives. Org Biomol Chem 2018; 15:3955-3963. [PMID: 28440828 DOI: 10.1039/c7ob00698e] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
We synthesized thymidine derivatives of 2'-C,4'-C-ethyleneoxy-bridged 2'-deoxyribonucleic acids with an 8'-methyl group ((R)-Me-EoDNA and (S)-Me-EoDNA) and without any substituent (EoDNA). Oligonucleotides including these EoDNAs showed high hybridization abilities with complementary RNA and excellent enzymatic stabilities compared with natural DNA. Moreover, the in vitro antisense potency of oligonucleotides with these EoDNAs and our recently reported methylene-EoDNAs was investigated and compared with that of LNA, which is a practical chemical modification for oligonucleotide-therapeutic agents. The results showed that EoDNAs and methylene-EoDNAs could be promising candidates for antisense technology.
Collapse
Affiliation(s)
- Takashi Osawa
- Faculty of Pharmaceutical Sciences, Tokushima Bunri University, Nishihama, Yamashiro-cho, Tokushima 770-8514, Japan.
| | | | | | | | | | | |
Collapse
|
3
|
Plashkevych O, Li Q, Chattopadhyaya J. How RNase HI (Escherichia coli) promoted site-selective hydrolysis works on RNA in duplex with carba-LNA and LNA substituted antisense strands in an antisense strategy context? MOLECULAR BIOSYSTEMS 2018; 13:921-938. [PMID: 28352859 DOI: 10.1039/c6mb00762g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A detailed kinetic study of 36 single modified AON-RNA heteroduplexes shows that substitution of a single native nucleotide in the antisense strand (AON) by locked nucleic acid (LNA) or by diastereomerically pure carba-LNA results in site-dependent modulation of RNase H promoted cleavage of complementary mRNA strands by 2 to 5 fold at 5'-GpN-3' cleavage sites, giving up to 70% of the RNA cleavage products. The experiments have been performed using RNase HI of Escherichia coli. The 2nd best cleavage site, being the 5'-ApN-3' sites, cleaves up to 23%, depending upon the substitution site in 36 isosequential complementary AONs. A comparison of the modified AON promoted RNA cleavage rates with that of the native AON shows that sequence-specificity is considerably enhanced as a result of modification. Clearly, relatively weaker 5'-purine (Pu)-pyrimidine (Py)-3' stacking in the complementary RNA strand is preferred (giving ∼90% of total cleavage products), which plays an important role in RNase H promoted RNA cleavage. A plausible mechanism of RNase H mediated cleavage of the RNA has been proposed to be two-fold, dictated by the balancing effect of the aromatic character of the purine aglycone: first, the locally formed 9-guanylate ion (pKa 9.3, ∼18-20% N1 ionized at pH 8) alters the adjoining sugar-phosphate backbone around the scissile phosphate, transforming its sugar N/S conformational equilibrium, to preferential S-type, causing preferential cleavage at 5'-GpN-3' sites around the center of 20 mer complementary mRNA. Second, the weaker nearest-neighbor strength of 5'-Pu-p-Py-3' stacking promotes preferential 5'-GpN-3' and 5'-ApN-3' cleavage, providing ∼90% of the total products, compared to ∼50% in that of the native one, because of the cLNA/LNA substituent effect on the neighboring 5'-Pu-p-Py-3' sites, providing both local steric flexibility and additional hydration. This facilitates both the water and water/Mg2+ ion availability at the cleavage site causing sequence-specific hydrolysis of the phosphodiester bond of scissile phosphate. The enhancement of the total rate of cleavage of the complementary mRNA strand by up to 25%, presented in this work, provides opportunities to engineer a single modification site in appropriately substituted AONs to design an effective antisense strategy based on the nucleolytic stability of the AON strand versus RNase H capability to cleave the complementary RNA strand.
Collapse
Affiliation(s)
- Oleksandr Plashkevych
- Chemical Biology Program, Department of Cell and Molecular Biology, Biomedical Center, Uppsala University, Box 581, SE-751 23 Uppsala, Sweden.
| | | | | |
Collapse
|
4
|
Plashkevych O, Upadhayaya RS, Chattopadhyaya J. Carbocyclic C-C Bond Formation: Intramolecular Radical Ring Closure to Yield Diastereomerically Pure (7'S-Me- or 7'R-Me-) Carba-LNA Nucleotide Analogs. ACTA ACUST UNITED AC 2017. [PMID: 28628208 DOI: 10.1002/cpnc.29] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
In light of the impressive gene-silencing properties of carba-LNA modified oligo DNA and RNA, both in antisense RNA and siRNA approaches, which have been confirmed as proof-of-concept for biochemical applications in post-transcriptional gene silencing, we envision the true potential of carba-LNA modifications to be revealed soon. Herein we provide detailed protocols for synthesis of carba-LNA-A, -G, -5-Me C, and -T nucleosides on a medium/large scale (gram scale), as well as important guidelines for incorporation of these modified carba-LNAs into DNA or RNA oligonucleotides. Creation of a stereoselective C-C bond during the 5-exo radical intramolecular cyclization involves trapping of a C2' radical intermediate intramolecularly by the vicinal double bond of a C4'-tethered ─CH2 -CH═CH2 group. All diastereomers of substituted carba-LNAs are now available in pure form. The present procedure allows carba-LNA to be commercialized for medicinal or biotechnological purposes. © 2017 by John Wiley & Sons, Inc.
Collapse
Affiliation(s)
| | - Ram Shankar Upadhayaya
- Department of Cell and Molecular Biology, Uppsala University, Uppsala, Sweden.,Bioimics AB, Uppsala, Sweden
| | | |
Collapse
|
5
|
Abstract
Oligonucleotide-based therapeutics have made rapid progress in the clinic for treatment of a variety of disease indications. Unmodified oligonucleotides are polyanionic macromolecules with poor drug-like properties. Over the past two decades, medicinal chemists have identified a number of chemical modification and conjugation strategies which can improve the nuclease stability, RNA-binding affinity, and pharmacokinetic properties of oligonucleotides for therapeutic applications. In this perspective, we present a summary of the most commonly used nucleobase, sugar and backbone modification, and conjugation strategies used in oligonucleotide medicinal chemistry.
Collapse
Affiliation(s)
- W Brad Wan
- Department of Medicinal Chemistry, Ionis Pharmaceuticals , 2855 Gazelle Court, Carlsbad, California 92010, United States
| | - Punit P Seth
- Department of Medicinal Chemistry, Ionis Pharmaceuticals , 2855 Gazelle Court, Carlsbad, California 92010, United States
| |
Collapse
|
6
|
Seth PP, Swayze EE. Unnatural Nucleoside Analogs for Antisense Therapy. METHODS AND PRINCIPLES IN MEDICINAL CHEMISTRY 2014. [DOI: 10.1002/9783527676545.ch12] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
|
7
|
|
8
|
|
9
|
Madsen CS, Nielsen LJ, Pedersen NS, Lauritsen A, Nielsen P. Double-headed nucleotides in DNA-zipper structures; base–base interactions and UV-induced cross-coupling in the minor groove. RSC Adv 2013. [DOI: 10.1039/c3ra40857d] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
|
10
|
Seth PP, Pallan PS, Swayze EE, Egli M. Synthesis, duplex stabilization and structural properties of a fluorinated carbocyclic LNA analogue. Chembiochem 2012. [PMID: 23193103 DOI: 10.1002/cbic.201200669] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
DNA oligonucleotides modified with nucleoside monomers which have an electron withdrawing group (EWG) at the 2'-position of the furanose ring form more stable duplexes with complementary RNA as compared to unmodified DNA. Here we show that an anti-periplanar orientation of the nucleobase and the 2'-EWG is important for optimal duplex stabilization even for nucleic acid analogues with conformationally locked furanose rings.
Collapse
Affiliation(s)
- Punit P Seth
- Department of Medicinal Chemistry, Isis Pharmaceuticals, 2855 Gazelle Court, Carlsbad, CA 92010, USA.
| | | | | | | |
Collapse
|
11
|
Hanessian S, Schroeder BR, Giacometti RD, Merner BL, Ostergaard M, Swayze EE, Seth PP. Structure-based design of a highly constrained nucleic acid analogue: improved duplex stabilization by restricting sugar pucker and torsion angle γ. Angew Chem Int Ed Engl 2012; 51:11242-5. [PMID: 22915274 DOI: 10.1002/anie.201203680] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2012] [Revised: 07/06/2012] [Indexed: 12/22/2022]
Abstract
Dual conformational restriction: a new, highly constrained modification of the α-L-locked nucleic acid (α-L-LNA) scaffold that locks the sugar furanose ring in an N-type configuration and also restricts rotation around torsion angle γ was synthesized. This new modification increases the thermostability of an oligonucleotide duplex compared to using a single mode of constraint alone.
Collapse
|
12
|
Hanessian S, Schroeder BR, Giacometti RD, Merner BL, Østergaard M, Swayze EE, Seth PP. Structure-Based Design of a Highly Constrained Nucleic Acid Analogue: Improved Duplex Stabilization by Restricting Sugar Pucker and Torsion Angleγ. Angew Chem Int Ed Engl 2012. [DOI: 10.1002/ange.201203680] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
|
13
|
Sau SP, Kumar P, Sharma PK, Hrdlicka PJ. Fluorescent intercalator displacement replacement (FIDR) assay: determination of relative thermodynamic and kinetic parameters in triplex formation--a case study using triplex-forming LNAs. Nucleic Acids Res 2012; 40:e162. [PMID: 22855561 PMCID: PMC3505983 DOI: 10.1093/nar/gks729] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Triplex forming oligonucleotides (TFOs) are the most commonly used approach for site-specific targeting of double stranded DNA (dsDNA). Important parameters describing triplex formation include equilibrium binding constants (K(eq)) and association/dissociation rate constants (k(on) and k(off)). The 'fluorescent intercalator displacement replacement' (FIDR) assay is introduced herein as an operationally simple approach toward determination of these parameters for triplexes involving TC-motif TFOs. Briefly described, relative rate constants are determined from fluorescence intensity changes upon: (i) TFO-mediated displacement of pre-intercalated and fluorescent ethidium from dsDNA targets (triplex association) and (ii) Watson-Crick complement-mediated displacement of the TFO and replacement with ethidium (triplex dissociation). The assay is used to characterize triplexes between purine-rich dsDNA targets and TC-motif TFOs modified with six different locked nucleic acid (LNA) monomers, i.e. conventional and C5-alkynyl-functionalized LNA and α-L-LNA pyrimidine monomers. All of the studied monomers increase triplex stability by decreasing the triplex dissociation rate. LNA-modified TFOs form more stable triplexes than α-L-LNA-modified counterparts owing to slower triplex dissociation. Triplexes modified with C5-(3-aminopropyn-1-yl)-LNA-U monomer Z are particularly stable. The study demonstrates that three affinity-enhancing features can be combined into one high-affinity TFO monomer: conformational restriction of the sugar ring, expansion of the pyrimidine π-stacking surface and introduction of an exocyclic amine.
Collapse
Affiliation(s)
- Sujay P Sau
- Department of Chemistry, University of Idaho, PO Box 442343, Moscow, ID 83844-2343, USA
| | | | | | | |
Collapse
|
14
|
Zhou C, Chattopadhyaya J. Intramolecular free-radical cyclization reactions on pentose sugars for the synthesis of carba-LNA and carba-ENA and the application of their modified oligonucleotides as potential RNA targeted therapeutics. Chem Rev 2012; 112:3808-32. [PMID: 22530946 DOI: 10.1021/cr100306q] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Affiliation(s)
- Chuanzheng Zhou
- Chemical Biology Program, Department of Cell and Molecular Biology, Biomedical Center, Uppsala University, Sweden
| | | |
Collapse
|
15
|
Abstract
Numerous chemically modified oligonucleotides have been developed so far and show their own unique chemical properties and pharmacodynamic/pharmacokinetic characteristics. Among all non-natural nucleotides, to the best of our knowledge, only five chemistries are currently being tested in clinical trials: phosphorothioate, 2´-O-methyl RNA, 2´-O-methoxyethyl RNA, 2´,4´-bridged nucleic acid/locked nucleic acid and the phosphorodiamidate morpholino oligomer. Since phosphorothioate modification can improve the pharmacokinetics of oligonucleotides, this modification is currently used in combination with all other modifications except phosphorodiamidate morpholino oligomer. For the treatment of metabolic, cardiovascular, cancer and other systemic diseases, the phosphorothioate class of drugs is obviously helpful, while superior efficacies can be observed in phosphorodiamidate morpholino oligomer compared to other classes of oligonucleotides for the treatment of Duchenne muscular dystrophy. Which properties of antisense molecules are actually essential for clinical applications? In this article, we provide an overview of the medicinal chemistry of existing non-natural antisense molecules, as well as their clinical applications, to discuss which properties of antisense oligonuculeotides affect therapeutic potency.
Collapse
|
16
|
Prakash TP. An Overview of Sugar-Modified Oligonucleotides for Antisense Therapeutics. Chem Biodivers 2011; 8:1616-41. [DOI: 10.1002/cbdv.201100081] [Citation(s) in RCA: 147] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
|
17
|
Upadhayaya R, Deshpande SG, Li Q, Kardile RA, Sayyed AY, Kshirsagar EK, Salunke RV, Dixit SS, Zhou C, Földesi A, Chattopadhyaya J. Carba-LNA-5MeC/A/G/T modified oligos show nucleobase-specific modulation of 3'-exonuclease activity, thermodynamic stability, RNA selectivity, and RNase H elicitation: synthesis and biochemistry. J Org Chem 2011; 76:4408-31. [PMID: 21500818 DOI: 10.1021/jo200073q] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Using the intramolecular 5-exo-5-hexenyl radical as a key cyclization step, we previously reported an unambiguous synthesis of carba-LNA thymine (cLNA-T), which we subsequently incorporated in antisense oligonucleotides (AON) and investigated their biochemical properties [J. Am. Chem. Soc.2007, 129 (26), 8362-8379]. These cLNA-T incorporated oligos showed specific RNA affinity of +3.5-5 °C/modification for AON:RNA heteroduplexes, which is comparable to what is found for those of LNAs (Locked Nucleic Acids). These modified oligos however showed significantly enhanced nuclease stability (ca. 100 times more) in the blood serum compared to those of the LNA modified counterparts without compromising any RNase H recruitment capability. We herein report the synthesis of 5-methylcytosine-1-yl ((Me)C), 9-adeninyl (A), and 9-guaninyl (G) derivatives of cLNA and their oligonucleotides and report their biochemical properties as potential RNA-directed inhibitors. In a series of isosequential carba-LNA modified AONs, we herein show that all the cLNA modified AONs are found to be RNA-selective, but the magnitude of RNA-selectivity of 7'-R-Me-cLNA-G (cLNA-G) (ΔT(m) = 2.9 °C/modification) and intractable isomeric mixtures of 7'-(S/R)-Me-cLNA-T (cLNA-T, ΔT(m) = 2.2 °C/modification) was found to be better than diastereomeric mixtures of 7'-(S/R)-Me-cLNA-(Me)C with trace of cENA-(Me)C (cLNA-(Me)C, ΔT(m) = 1.8 °C/modification) and 7'-R-Me-cLNA-A (cLNA-A, ΔT(m) = 0.9 °C/modification). cLNA-(Me)C modified AONs however exhibited the best nuclease stability, which is 4-, 7-, and 20-fold better, respectively, than cLNA-T, cLNA-A, and cLNA-G modified counterparts, which in turn was more than 100 times stable than that of the native. When the modification sites are appropriately chosen in the AONs, the cLNA-A, -G, and -(Me)C modified sites in the AON:RNA hybrids can be easily recognized by RNase H, and the RNA strand of the hybrid is degraded in a specific manner, which is important for the design of oligos for therapeutic purposes. The cLNA-(Me)C modified AON/RNA, however, has been found to be degraded 4 times faster than cLNA-A and G modified counterparts. By appropriately choosing the carba-LNA modification sites in AON strands, the digestion of AON:RNA can be either totally repressed or be limited to cleavage at specific sites or at a single site only (similar to that of catalytic RNAzyme or DNAzyme). Considering all physico- and biochemical aspects of cLNA modified oligos, the work suggests that the cLNA modified antisense oligos have the potential of being a promising therapeutic candidate due to their (i) higher nucleobase-specific RNA affinity and RNA selectivity, (ii) greatly improved nuclease stability, and (iii) efficient RNase H recruitment capability, which can induce target RNA cleavage in a very specific manner at multiple or at a single site, in a designed manner.
Collapse
Affiliation(s)
- RamShankar Upadhayaya
- Institute of Molecular Medicine, International Biotech Park, Tal Mulshi, Hinjewadi, Pune, India
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
18
|
Seth PP, Prakash TP. Synthesis of 2',4'-bridged nucleosides using a new orthogonally protected sugar synthon: 5-O-(tert-butyldiphenylsilyl)-4-C-hydroxymethyl-1,2-O-isopropylidene-3-O-napthyl-α-D-allofuranose. CURRENT PROTOCOLS IN NUCLEIC ACID CHEMISTRY 2011; Chapter 1:Unit 1.24. [PMID: 21400702 DOI: 10.1002/0471142700.nc0124s44] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
2',4'-Bridged nucleic acids (BNA) provide unprecedented increases in the thermal stability of oligonucleotide duplexes. Locked nucleic acids (LNA), a representative member of the BNA class, have shown promise in antisense applications and as a diagnostic tool. While a number of BNA analogs have been reported in the literature, their evaluation in vivo has been stymied by difficulties in securing enough amidite to support extensive animal experiments. A bottleneck has been the ability to prepare a key mono-protected allofuranose synthon that is the common starting material for all BNA analogs. This unit presents the synthesis of a novel orthogonally protected sugar synthon, 5-O-(tert-butyldimethylsilyl)-4-C-hydroxymethyl-1,2-O-isopropylidene-3-O-(2-methylnaphthlene)-α-D-allofuranose, which can be prepared in 100-gram quantities without any chromatographic purification of intermediates or the final product. The utility of this new synthon is exemplified by the synthesis of BNA analogs containing uracil nucleobases, substituted 2',4'-bridges, and oxyamino functionalities that are otherwise more difficult to prepare using the 3'-O-benzyl protecting group strategy most commonly used in the literature.
Collapse
|
19
|
Liu Y, Xu J, Karimiahmadabadi M, Zhou C, Chattopadhyaya J. Synthesis of 2',4'-propylene-bridged (carba-ENA) thymidine and its analogues: the engineering of electrostatic and steric effects at the bottom of the minor groove for nuclease and thermodynamic stabilities and elicitation of RNase H. J Org Chem 2011; 75:7112-28. [PMID: 20929200 DOI: 10.1021/jo101207d] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
2',4'-Propylene-bridged thymidine (carba-ENA-T) and five 8'-Me/NH(2)/OH modified carba-ENA-T analogues have been prepared through intramolecular radical addition to C═N of the tethered oxime-ether. These carba-ENA nucleosides have been subsequently incorporated into 15mer oligodeoxynucleotides (AON), and their affinity toward cDNA and RNA, nuclease resistance, and RNase H recruitment capability have been investigated in comparison with those of the native and ENA counterparts. These carba-ENAs modified AONs are highly RNA-selective since all of them led to slight thermal stabilization effect for the AON:RNA duplex, but quite large destabilization effect for the AON:DNA duplex. It was found that different C8' substituents (at the bottom of the minor groove) on carba-ENA-T only led to rather small variation of thermal stability of the AON:RNA duplexes. We, however, observed that the parent carba-ENA-T modified AONs exhibited higher nucleolytic stability than those of the ENA-T modified counterparts. The nucleolytic stability of carba-ENA-T modified AONs can be further modulated by C8' substituent to variable extents depending on not only the chemical nature but also the stereochemical orientation of the C8' substituents: Thus, (1) 8'S-Me on carba-ENA increases the nucleolytic stability but 8'R-Me leads to a decreased effect; (2) 8'R-OH on carba-ENA had little, if any, effect on nuclease resistance but 8'S-OH resulted in significantly decreased nucleolytic stability; and (3) 8'-NH(2) substituted carba-ENA leads to obvious loss in the nuclease resistance. The RNA strand in all of the carba-ENA derivatives modified AON:RNA hybrid duplexes can be digested by RNase H1 with high efficiency, even at twice the rate of those of the native and ENA modified counterpart.
Collapse
Affiliation(s)
- Yi Liu
- Bioorganic Chemistry Program, Department of Cell and Molecular Biology, Box 581, Biomedical Center, Uppsala University, SE-751 23 Uppsala, Sweden
| | | | | | | | | |
Collapse
|
20
|
López JC, Plumet J. Metathesis Reactions of Carbohydrates: Recent Highlights in Alkyne Metathesis. European J Org Chem 2011. [DOI: 10.1002/ejoc.201001518] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- J. Cristóbal López
- Instituto de Química Orgánica General, CSIC, Juan de la Cierva 3, 28006 Madrid, Spain
| | - Joaquín Plumet
- Universidad Complutense, Facultad de Química, Departamento de Química Orgánica, Ciudad Universitaria s/n, 28040 Madrid, Spain, Fax: +34‐91‐394‐4103
| |
Collapse
|
21
|
Herndon JW. The chemistry of the carbon–transition metal double and triple bond: Annual survey covering the year 2009. Coord Chem Rev 2011. [DOI: 10.1016/j.ccr.2010.07.003] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
|
22
|
Seth PP, Allerson CR, Berdeja A, Siwkowski A, Pallan PS, Gaus H, Prakash TP, Watt AT, Egli M, Swayze EE. An exocyclic methylene group acts as a bioisostere of the 2'-oxygen atom in LNA. J Am Chem Soc 2010; 132:14942-50. [PMID: 20886816 PMCID: PMC2993159 DOI: 10.1021/ja105875e] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
We show for the first time that it is possible to obtain LNA-like (Locked Nucleic Acid 1) binding affinity and biological activity with carbocyclic LNA (cLNA) analogs by replacing the 2'-oxygen atom in LNA with an exocyclic methylene group. Synthesis of the methylene-cLNA nucleoside was accomplished by an intramolecular cyclization reaction between a radical at the 2'-position and a propynyl group at the C-4' position. Only methylene-cLNA modified oligonucleotides showed similar thermal stability and mismatch discrimination properties for complementary nucleic acids as LNA. In contrast, the close structurally related methyl-cLNA analogs showed diminished hybridization properties. Analysis of crystal structures of cLNA modified self-complementary DNA decamer duplexes revealed that the methylene group participates in a tight interaction with a 2'-deoxyribose residue of the 5'-terminal G of a neighboring duplex, resulting in the formation of a CH...O type hydrogen bond. This indicates that the methylene group retains a negative polarization at the edge of the minor groove in the absence of a hydrophilic 2'-substituent and provides a rationale for the superior thermal stability of this modification. In animal experiments, methylene-cLNA antisense oligonucleotides (ASOs) showed similar in vivo activity but reduced toxicity as compared to LNA ASOs. Our work highlights the interchangeable role of oxygen and unsaturated moieties in nucleic acid structure and emphasizes greater use of this bioisostere to improve the properties of nucleic acids for therapeutic and diagnostic applications.
Collapse
Affiliation(s)
- Punit P Seth
- Department of Medicinal Chemistry, Isis Pharmaceuticals, Inc., 1891 Rutherford Road, Carlsbad, California 92008, USA.
| | | | | | | | | | | | | | | | | | | |
Collapse
|
23
|
Seth PP, Allerson CR, Berdeja A, Swayze EE. Replacing the 2'-oxygen with an exocyclic methylene group reverses the stabilization effects of α-L-LNA. Bioorg Med Chem Lett 2010; 21:588-91. [PMID: 21075634 DOI: 10.1016/j.bmcl.2010.10.025] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2010] [Revised: 10/04/2010] [Accepted: 10/05/2010] [Indexed: 01/22/2023]
Abstract
The synthesis and hybridization properties of an α-L-LNA analog where the 2'-oxygen atom is replaced with an exocyclic methylene group is reported. Contrary to the β-D series where the exocyclic methylene group is extremely well tolerated, this group was very poorly tolerated in the α-L-series and lead to duplex destabilization. Modeling studies showed that the exocyclic methylene group results in a steric clash with the nucleobase 3' to the modified residue. Based on this structural model one can anticipate that replacing the 2'-oxygen atom of α-L-LNA with larger groups is likely to be detrimental to duplex stability. The model also provides insights into what type of 2',4'-bridges are most likely to be tolerated in α-L-LNA modified oligonucleotide duplexes.
Collapse
Affiliation(s)
- Punit P Seth
- Department of Medicinal Chemistry, Isis Pharmaceuticals, Inc, 1891 Rutherford Road, Carlsbad, CA 92008, United States.
| | | | | | | |
Collapse
|
24
|
Nishida M, Baba T, Kodama T, Yahara A, Imanishi T, Obika S. Synthesis, RNA selective hybridization and high nuclease resistance of an oligonucleotide containing novel bridged nucleic acid with cyclic urea structure. Chem Commun (Camb) 2010; 46:5283-5. [PMID: 20567794 DOI: 10.1039/c0cc00154f] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
A novel bridged nucleic acid bearing cyclic urea structure was successfully synthesized and introduced into oligonucleotide, displaying attractive characteristics of highly RNA selective hybridization ability and excellent resistance towards nuclease degradation.
Collapse
Affiliation(s)
- Masaru Nishida
- Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka, 565-0871, Japan
| | | | | | | | | | | |
Collapse
|
25
|
Seth PP, Vasquez G, Allerson CA, Berdeja A, Gaus H, Kinberger GA, Prakash TP, Migawa MT, Bhat B, Swayze EE. Synthesis and biophysical evaluation of 2',4'-constrained 2'O-methoxyethyl and 2',4'-constrained 2'O-ethyl nucleic acid analogues. J Org Chem 2010; 75:1569-81. [PMID: 20136157 DOI: 10.1021/jo902560f] [Citation(s) in RCA: 162] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
We have recently shown that combining the structural elements of 2'O-methoxyethyl (MOE) and locked nucleic acid (LNA) nucleosides yielded a series of nucleoside modifications (cMOE, 2',4'-constrained MOE; cEt, 2',4'-constrained ethyl) that display improved potency over MOE and an improved therapeutic index relative to that of LNA antisense oligonucleotides. In this report we present details regarding the synthesis of the cMOE and cEt nucleoside phosphoramidites and the biophysical evaluation of oligonucleotides containing these nucleoside modifications. The synthesis of the cMOE and cEt nucleoside phosphoramidites was efficiently accomplished starting from inexpensive commercially available diacetone allofuranose. The synthesis features the use of a seldom used 2-naphthylmethyl protecting group that provides crystalline intermediates during the synthesis and can be cleanly deprotected under mild conditions. The synthesis was greatly facilitated by the crystallinity of a key mono-TBDPS-protected diol intermediate. In the case of the cEt nucleosides, the introduction of the methyl group in either configuration was accomplished in a stereoselective manner. Ring closure of the 2'-hydroxyl group onto a secondary mesylate leaving group with clean inversion of stereochemistry was achieved under surprisingly mild conditions. For the S-cEt modification, the synthesis of all four (thymine, 5-methylcytosine, adenine, and guanine) nucleobase-modified phosphoramidites was accomplished on a multigram scale. Biophysical evaluation of the cMOE- and cEt-containing oligonucleotides revealed that they possess hybridization and mismatch discrimination attributes similar to those of LNA but greatly improved resistance to exonuclease digestion.
Collapse
Affiliation(s)
- Punit P Seth
- Department of Medicinal Chemistry, Isis Pharmaceuticals, 1896 Rutherford Road, Carlsbad, California 92008, USA.
| | | | | | | | | | | | | | | | | | | |
Collapse
|
26
|
Lebreton J, Escudier JM, Arzel L, Len C. Synthesis of Bicyclonucleosides Having a C−C Bridge. Chem Rev 2010; 110:3371-418. [DOI: 10.1021/cr800465j] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Affiliation(s)
- Jacques Lebreton
- Université de Nantes, CNRS, Laboratoire CEISAM-UMR-CNRS 6230, Faculté des Sciences et des Techniques, 2 rue de la Houssinière, BP 92208, 44322 Nantes Cedex 3, France, Université Paul Sabatier Laboratoire de Synthèse et Physicochimie des Molécules d’Intérêt Biologique - UMR-CNRS 5068, 31062 Toulouse Cedex, France, and Université de Technologie de Compiègne, Ecole Supérieure de Chimie Organique Minérale, EA 4297, Transformations Intégrées de la Matière Renouvelable, 1 allée du Réseau Jean-Marie Buckmaster,
| | - Jean-Marc Escudier
- Université de Nantes, CNRS, Laboratoire CEISAM-UMR-CNRS 6230, Faculté des Sciences et des Techniques, 2 rue de la Houssinière, BP 92208, 44322 Nantes Cedex 3, France, Université Paul Sabatier Laboratoire de Synthèse et Physicochimie des Molécules d’Intérêt Biologique - UMR-CNRS 5068, 31062 Toulouse Cedex, France, and Université de Technologie de Compiègne, Ecole Supérieure de Chimie Organique Minérale, EA 4297, Transformations Intégrées de la Matière Renouvelable, 1 allée du Réseau Jean-Marie Buckmaster,
| | - Laurence Arzel
- Université de Nantes, CNRS, Laboratoire CEISAM-UMR-CNRS 6230, Faculté des Sciences et des Techniques, 2 rue de la Houssinière, BP 92208, 44322 Nantes Cedex 3, France, Université Paul Sabatier Laboratoire de Synthèse et Physicochimie des Molécules d’Intérêt Biologique - UMR-CNRS 5068, 31062 Toulouse Cedex, France, and Université de Technologie de Compiègne, Ecole Supérieure de Chimie Organique Minérale, EA 4297, Transformations Intégrées de la Matière Renouvelable, 1 allée du Réseau Jean-Marie Buckmaster,
| | - Christophe Len
- Université de Nantes, CNRS, Laboratoire CEISAM-UMR-CNRS 6230, Faculté des Sciences et des Techniques, 2 rue de la Houssinière, BP 92208, 44322 Nantes Cedex 3, France, Université Paul Sabatier Laboratoire de Synthèse et Physicochimie des Molécules d’Intérêt Biologique - UMR-CNRS 5068, 31062 Toulouse Cedex, France, and Université de Technologie de Compiègne, Ecole Supérieure de Chimie Organique Minérale, EA 4297, Transformations Intégrées de la Matière Renouvelable, 1 allée du Réseau Jean-Marie Buckmaster,
| |
Collapse
|
27
|
Ghosh R, Maity JK, Achari B, Mandal SB. Locked Nucleosides Based on Oxabicyclo[3.2.1]octane and Oxabicyclo[2.2.1]heptane Skeletons. J Org Chem 2010; 75:2419-22. [DOI: 10.1021/jo100194z] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Ramprasad Ghosh
- Department of Chemistry, Indian Institute of Chemical Biology (a unit of CSIR), 4, Raja S. C. Mullick Road, Jadavpur, Kolkata 700 032, India
| | - Joy Krishna Maity
- Department of Chemistry, Indian Institute of Chemical Biology (a unit of CSIR), 4, Raja S. C. Mullick Road, Jadavpur, Kolkata 700 032, India
| | - Basudeb Achari
- Department of Chemistry, Indian Institute of Chemical Biology (a unit of CSIR), 4, Raja S. C. Mullick Road, Jadavpur, Kolkata 700 032, India
| | - Sukhendu B Mandal
- Department of Chemistry, Indian Institute of Chemical Biology (a unit of CSIR), 4, Raja S. C. Mullick Road, Jadavpur, Kolkata 700 032, India
| |
Collapse
|