Jorge R. Barrio

Fluorescent adenosine and cytidine derivatives.

Summary The reaction of chloroacetaldehyde with adenosine and cytidine produces a fluorescent product in each case. These products are easily distinguishable spectroscopically by their fluorescence emission maxima. Since the reaction is carried out in aqueous media under mild conditions of pH and temperature, it should prove extremely useful in nucleic acid chemistry. For example, reaction occurs between chloroacetaldehyde and E. coli tRNA, and the reaction can be followed by monitoring the increase in the fluorescence emission. Fluorescence lifetimes observed for the adenosine and cytidine products are close to 20 and 7 nsec, respectively.

A Fluorescent Modification of Adenosine Triphosphate with Activity in Enzyme Systems: 1,N6-Ethenoadenosine Triphosphate

A new, highly fluorescent adenosine triphophate (ATP) analog, 1,N6 ethenoadenosine triphosphate, has been synthesized. Its fluorescence properties, including the long fluorescence lifetime and the possibility of detection at very low concentrations, in conjunction with its activity in the representative enzyme systems here reported, make it a valuable probe of enzymic mechanism and structure.

Attachment of a fluorescent label to 4-thiouracil and 4-thiouridine

Abstract The conversion of 4-thiouracil and 4-thiouridine into fluorescent derivatives has been carried out using 4-bromomethyl-7-methoxy-2-oxo-2H-benzopyran. Adsorption of the water-insoluble reagent onto Celite allowed the reaction to be applied to completely aqueous media. The conditions employed for the reaction, pH 8.3–8.4 and 37°, are such as to allow ready extension to a tRNA. The blue-white fluorescence of the product ( λ max = 400 nm) is visible down to concentrations on the order of 10 −7 M .

Interactions of fluorescent analogs of adenine nucleotides with pyruvate kinase

In view of the central role played by adenine nucleotides in metabolism, fluorescent analogs of ADP and ATP represent potentially valuable probes of enzymic mechanism and structure [ 1, 21. Since the fluorescence properties of 1, Are-ethenoadenosine diand triphosphate (eADP and eATP)* are particularly favorable for a variety of physical studies, we elected to study the kinetic and fluorescence behavior of these analogs in detail with the enzyme pyruvate kinase. We have now shown that EADP and EATP substitute very well for ADP and ATP in terms of reaction rates. Moreover, the binding of EADP and EATP to the enzyme can be observed by fluorescence polarization techniques.

Iodomethylethers from 1,3-dioxolane and 1,3-oxathiolane: preparation of acyclic nucleoside analogs

Abstract Purine and pyrimidine anions were alkylated using the iodomethyl ether and thioether generated in situ by the reaction of 1,3-dioxolane and 1,3-oxathiolane with trimethylsilyl iodide.

A spray reagent for adenine-containing residues: Detection by fluorescence

Abstract Adenine-containing residues on thin-layer or paper chromatograms, when treated with chloroacetaldehyde at 70–80°C, produce highly fluorescent products which are readily visible at the 0.5-μg level under an ultraviolet lamp. In neutral aqueous solution, they can be detected at concentrations in the range of 10−8 M.