Spectrophotometric studies op nucleic acid derivatives and related compounds as a function of pH

Shugar, David; Fox, Jack J.

doi:10.1016/0006-3002(52)90147-9

Cited by 402 publications

(110 citation statements)

References 24 publications

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“…These biochemicals assayed 99% by UV spectroscopy (5,6). Water was triply distilled and stored in a C02-free atmosphere.…”

Section: Methodsmentioning

confidence: 99%

Protonation/deprotonation energetics of uracil, thymine, and cytosine in water from e.m.f./spectrophotometric measurements

Ganguly¹,

Kundu²

1994

Can. J. Chem.

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The protonatioddeprotonation constants for uracil (U) (pK, and pK2), thymine (T) (pK1) and cytosine (C) (pK1 and pK2) in water have been determined from emf measurements of Harned-Ehler type cells comprising HZ and Ag-AgI electrodes at five equidistant temperatures ranging from 15-35°C. The pKa values were fitted in the temperature equation pK, = AT-' + B + CT by the method of least squares and the standard free energies (AGO), entropies (AS0), and enthalpies (AH0) of protonatioddeprotonation processes in water were evaluated using the values of the coefficients A, B, and C of the respective acids. The second step deprotonation constant for T was determined using precise spectrophotometric method. The results have been duly compared with the existing literature data and are also shown to derive important reflections on the sites of protonatioddeprotonation in the light of pK values of some acids and bases of comparable~functional groups and especially the entropies of protonatioddeprotonation of the key DNA-RNA base molecules.

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“…These biochemicals assayed 99% by UV spectroscopy (5,6). Water was triply distilled and stored in a C02-free atmosphere.…”

Section: Methodsmentioning

confidence: 99%

Protonation/deprotonation energetics of uracil, thymine, and cytosine in water from e.m.f./spectrophotometric measurements

Ganguly¹,

Kundu²

1994

Can. J. Chem.

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“…1), acts as a diacid in aqueous solution, with the acidic function suggested to be located on the carboxylic group (pK a1 = 2.09) and on the N1 site (pK a2 = 9.45). 24 The monobasic form, hydroorotate, H 2 L − , appears to predominantly form complexes with coordination through the carboxyl oxygen atoms. With the Cu(I) 25 and Zn(II) 26 cations, a bidentate coordination is observed whereas UO 2 (II) coordinates monodentately.…”

Section: Introductionmentioning

confidence: 99%

New cerium(III) and neodymium(III) complexes as cytotoxic agents

Kostova

Rastogi

Kiefer

et al. 2006

Appl. Organometal. Chem.

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The cerium(III) and neodymium(III) complexes of 5-aminoorotic acid were synthesized and characterized by means of spectral data (IR, Raman, 1 H NMR and 13 C NMR) and elemental analysis. Significant differences in the IR spectra of the complexes were observed as compared with the spectrum of the ligand. A comparative analysis of the Raman spectra of the complexes with that of the free 5-aminoorotic acid allowed a straightforward assignment of the vibrations of the ligand groups involved in coordination. 1 H NMR and 13 C NMR spectra confirmed the formation of the complexes. The ligand and the complexes were tested for the cytotoxic activities on the chronic myeloid leukemia-derived K-562, overexpressing the BCR-ABL fusion protein, and the non-Hodgkin lymphoma-derived DOHH-2, characterized by a rexpression of the antiapoptotic protein bcl-2 cell lines. The results obtained indicate that the tested compounds exerted a considerable cytotoxic activity upon the evaluated cell lines in a concentration-dependent manner, which enabled the construction of dose-response curves and the calculation of the corresponding IC 50 values. Cytotoxicity towards tumor cells was determined for a broad concentration range. The inorganic salts exerted a very weak cytotoxic effect on these cells that is in contrast to the lanthanide complexes, which exhibited potent cytotoxic activity towards K-562 and DOHH-2 cell lines.

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“…The bases released were determined according to Wyatt (1951), except that the chromatograms were developed in butanol+ water + ammonia (Hotchkiss, 1948), and recently published optical values were used (Johnson, 1955;Shugar & Fox, 1952) which, however, differ very little from those of Wyatt.…”

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confidence: 99%

Studies of Extracellular and Intracellular Bacterial Deoxyribonucleic Acids

Catlin

Cunningham

1958

Journal of General Microbiology

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SUMMARY : Highly polymerized bacterial deoxyribonucleic acids (DNAs) obtained from extracellular and from intracellular locations were analysed. DNAs from two strains (Staphylococcus aureus and S. epidermidis) were of the type having high adenine and thymine contents ; two others (Alcaligenes faecalis and Pseudomonas fluorescens) had a high content of guanine and cytosine. For each micro-organism the composition of extracellular DNA was essentially the same as that of the intracellular DNA. Conditions associated with the extracellular accumulation of DNA in cultures of 3 strains were investigated. S. aureus elaborated a deoxyribonuclease (DNase) which required calcium ion and high pH for activity. In a culture medium of c. pH 6 and insufficient calcium, the DNase was inactive and DNA slime accumulated. In cultures of P . jluorescens a specific ribonuclease-sensitive DNase inhibitor protected slime DNA from depolymerization by culture DNase. In cultures of A . faecalis, also, both a DNA slime and a low concentration of DNase may occur. This enzyme, detected by studying its action against solutions of calf thymus DNA prepared from dried fibres, was activated by various cations within the pH range of cultures. Unlike other DNases, however, it has little capacity to attack the slimelayer DNA, which presumably is more nearly native.

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Spectrophotometric studies op nucleic acid derivatives and related compounds as a function of pH

Cited by 402 publications

References 24 publications

Protonation/deprotonation energetics of uracil, thymine, and cytosine in water from e.m.f./spectrophotometric measurements

Protonation/deprotonation energetics of uracil, thymine, and cytosine in water from e.m.f./spectrophotometric measurements

New cerium(III) and neodymium(III) complexes as cytotoxic agents

Studies of Extracellular and Intracellular Bacterial Deoxyribonucleic Acids

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