Calculations of the circular dichroism of adenosine derivatives constrained in the
            <i>syn</i>
            form

Miles, Daniel W.; Farmer, Morris; Eyring, Henry

doi:10.1073/pnas.77.6.3398

Cited by 6 publications

(2 citation statements)

References 22 publications

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“…D -78.7 [17]. Moreover, the circular dichroism (CD) spectrum of 2 shows two negative cotton effect bands at 260 and 215 nm (Figure S13), consistent with the CD spectrum from adenosine [22][23][24], which features, like most of the naturally-occurring monosaccharides, a d-configured ribose [22][23][24]. Finally, the subsequently identified biosynthetic origin of 1 and 2 strikingly suggests a d-configured ribose (see below).…”

Section: Discovery Of 2-hydroxysorangiadenosine and Sorangiadenosinesupporting

confidence: 65%

2-Hydroxysorangiadenosine: Structure and Biosynthesis of a Myxobacterial Sesquiterpene–Nucleoside

et al. 2020

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Myxobacteria represent an under-investigated source for biologically active natural products featuring intriguing structural moieties with potential applications, e.g., in the pharmaceutical industry. Sorangiadenosine and the here-discovered 2-hydroxysorangiadenosine are myxobacterial sesquiterpene–nucleosides with an unusual structural moiety, a bicyclic eudesmane-type sesquiterpene. As the biosynthesis of these rare terpene–nucleoside hybrid natural products remains elusive, we investigated secondary metabolomes and genomes of several 2-hydroxysorangiadenosine-producing myxobacteria. We report the isolation and full structure elucidation of 2-hydroxysorangiadenosine and its cytotoxic and antibiotic activities and propose a biosynthetic pathway in the myxobacterium Vitiosangium cumulatum MCy10943T.

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Section: Discovery Of 2-hydroxysorangiadenosine and Sorangiadenosinesupporting

confidence: 65%

2-Hydroxysorangiadenosine: Structure and Biosynthesis of a Myxobacterial Sesquiterpene–Nucleoside

et al. 2020

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“…Along with difficulties associated with treating the weak perturbation effects of the nonchromophoric sugar, this incomplete knowledge has hindered the development of theoretical models for calculating the rotatory parameters and extracting stereochemical information from them. In spite of these problems, CD studies of nucleosides have produced some useful rules and diagrams relating the sign of the first CD band to anomeric configuration and to conformation (10,(31)(32)(33)(34)(35)(36)(37)(38)(39)(40)(41)(52)(53)(54)(55)(56)(57)(58)(59)(60)(61).…”

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confidence: 99%

Optical activity and electronic absorption spectra of some simple nucleosides related to cytidine and uridine: all-valence-shell molecular orbital calculations.

Miles¹,

Redington²,

Miles³

et al. 1981

Proc. Natl. Acad. Sci. U.S.A.

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The circular dichroism and electronic absorption of three simple model systems for cytidine and uridine have been measured to 190 nm. The molecular spectral properties (excitation wavelengths, oscillator strengths, rotational strengths, and polarization directions) and electronic transitional patterns were investigated by using wave functions of the entire nucleoside with the goal of establishing the reliability of the theoretical method. The computed electronic absorption quantities were shown to be in satisfactory agreement with experimental data. It was found that the computed optical rotatory strengths of the B2. and El.electronic transitions and lowest observed n-ir* transition are in good agreement with experimental values. Electronic transitions were characterized by their electronic transitional patterns derived from population analysis of the transition density matrix.The theoretical rotational strengths associated with the B2. and El. transitions stabilize after the use of just a few singly excited configurations in the configuration interaction basis and, hypothetically, are more reliable as indicators of conformation in pyrimidine nucleosides related to cytidine.Spectroscopic studies of the nucleic acid bases and their derivatives have appeared continuously over the past quarter century (1-40). Many of these studies were motivated by the prospect of obtaining stereochemical information from changes in the absorption and optical rotation spectra of the nucleic acids and their models (41-51). More recently, the increasing importance of slightly modified versions of the nucleic acid monomers as potential therapeutic agents has accentuated the importance of optical studies in this area, particularly circular dichroism (CD) studies, which indirectly give one stereochemical information (10-18, 31-41, 52-61). The biological significance of the conformational aspects ofnucleosides and nucleotides has been sufficiently documented (60-63).Of the two main aspects of CD studies, stereochemical and spectroscopic, the spectroscopic problem is currently the more fundamental because incomplete knowledge of the electronic transitions that give rise to the absorption of radiation and the rotatory power has limited attempts to determine optically the chirality of nucleosides. Along with difficulties associated with treating the weak perturbation effects of the nonchromophoric sugar, this incomplete knowledge has hindered the development of theoretical models for calculating the rotatory parameters and extracting stereochemical information from them. In spite of these problems, CD studies of nucleosides have produced some useful rules and diagrams relating the sign of the first CD band to anomeric configuration and to conformation (10, 31-41, 52-61).The major goal of this study is to use the experimental data on 3-deaza-4-deoxyuridine, 3-deazauridine, and 3-deazacytidine to evaluate a new theoretical method for calculating and interpreting the optical properties of nucleosides. The method uses wave functions of...

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Conformational studies of adenosine 5′‐phosphorodiamidates in aqueous solution

et al. 1984

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SynopsisCD and nmr studies show that the conformational equilibrium of' N(P)-alkylated adenosine 5'-phosphorodiamidates 2-4 and, t o a much lesser extent, adenosine 5'-phosphorodiamidate 1 differ at two parts from that of adenosine 5'-phosphate in water. The glycosidic bond conformation is slightly shifted into the direction of the syn range, and the ribose ring Nconformer population increases. The conformational changes increase with increasing degree of N(P)-alkylation and cause a change of the sign of the long-wavelength CD hand for 2-4.The new conformation may be characterized by a stacked arrangement for the adenine ring and the 5'-substituted phosphate group of 2-4. Hydrophobic attraction between the head and the tail of the molecules, as well as the entropy effect (which promotes the clustering of apolar faces in water), may be jointly responsible for this stacked arrangement. The intramolecular attractive forces stabilizing the stacked conformation may act at the expense of the solubility decreasing intermolecular attractive forces, and may thus he responsible for the increased water solubility of 2-4, which is higher than that of 1 by more than two orders of magnitude.

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Calculations of the circular dichroism of adenosine derivatives constrained in the syn form

Cited by 6 publications

References 22 publications

2-Hydroxysorangiadenosine: Structure and Biosynthesis of a Myxobacterial Sesquiterpene–Nucleoside

2-Hydroxysorangiadenosine: Structure and Biosynthesis of a Myxobacterial Sesquiterpene–Nucleoside

Optical activity and electronic absorption spectra of some simple nucleosides related to cytidine and uridine: all-valence-shell molecular orbital calculations.

Conformational studies of adenosine 5′‐phosphorodiamidates in aqueous solution

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