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Biomedical subjects

R Busson

Publications and source records attributed to R Busson.

47 records · Page 3Linked to original sources
PubMed1983

Synthesis and antiviral activity of water-soluble esters of acyclovir [9-[(2-hydroxyethoxy)methyl]guanine].

Several water-soluble ester derivatives of acyclovir [9-[(2-hydroxyethoxy)methyl]guanine], i.e., the 2'-O-glycyl-, 2'-O-alpha-alanyl-, 2'-O-beta-alanyl- and 2'-O-3-carboxypropionyl esters, were synthesized and evaluated for their antiviral activity in cell culture. The compounds were all prepared directly from acyclovir by application of the usual esterification methods with the appropriate acyl precursors and isolated as their hydrochloride or sodium salts. When assayed in primary rabbit kidney cell cultures against various herpes simplex virus type 1 and type 2 strains, the four acyclovir esters proved almost as active as acyclovir itself, suggesting that they were readily hydrolyzed to release the parent compound.

Acyclovir↗
PubMed1980

(E)-5-(2-bromovinyl)-2'-Deoxyuridine in the treatment of experimental herpes simplex keratitis.

IDU (5-iodo-2'-deoxyuridine), BVDU [(E)-5-(2-bromovinyl)-2'-deoxyuridine] and placebo ointments were studied for their effects on experimental herpes simplex (type 1) keratoconjuncitivitis in rabbits. When treatment was begun 65 h after virus inoculation, both BVDU and IDU prevented development of keratitis. Both BVDU and IDU were also effective in suppressing the severity of conjunctivitis, and in this respect, BVDU proved significantly better than IDU. When treatment was started 110 h after virus inoculation, BVDU proved significantly better than IDU in promoting healing of established keratitis.

Animals↗
PubMedDate not supplied

Analysis of erythromycin estolate by liquid chromatography.

A method is described for the determination of erythromycin estolate by liquid chromatography. A C18 reversed-phase column (25 x 0.46 cm i.d.) was used with acetonitrile-tetrabutylammonium sulphate (pH 6.5, 0.2 M)-phosphate buffer (pH 6.5, 0.2 M)-water [x:5:5:(90-x), v/v/v/v] as mobile phase. The proportion of acetonitrile (x) has to be adapted to the type of stationary phase used. For RSil C18 LL 42.5% (v/v) was used. The column was heated at 35 degrees C, the flow rate was 1.5 ml min-1 and UV detection was performed at 215 nm. The main component, erythromycin A propionate, was separated from all other components which were present in commercial samples. The impurities most frequently observed were the propionate ester of erythromycin C and the amide N-propionyl-N-demethyl-erythromycin A. Erythromycin A was shown to be present in specialties.

Acetonitriles↗
PubMedDate not supplied

Investigation of the kinetics of degradation of hexopyranosylated cytosine nucleosides using liquid chromatography.

Liquid chromatography was used to follow the degradation of hexopyranosylated cytosine nucleosides in buffers of acid, neutral and alkaline pH and of constant ionic strength. The compounds were found to degrade by hydrolysis to cytosine and/or by deamination to the corresponding uracil nucleosides. Degradation in acid is influenced by the number of sugar hydroxyl groups, presence of sugar double bonds and the type of anomer. Stability of some of the compounds was compared with that of related thymine nucleosides. Temperature studies support a unimolecular mechanism of hydrolysis at pH 1.22.

Buffers↗
PubMedDate not supplied

Methylated hexitol nucleic acids, towards congeners with improved antisense potential.

In an effort to further improve the hybridisation potential of anhydro-hexitol nucleoside analogues, the 1'-methoxyl and 3'-methoxyl substituents were introduced and evaluated for their antisense potential. In view of the selectivity of pairing with RNA, especially the introduction of a 3'-O-alkyl moiety deserves further study.

Alcohols↗
PubMedDate not supplied

Determination of the composition of gentamicin sulfates by 1H and 13C nuclear magnetic spectroscopy.

The British Pharmacopoeia test controlling the composition of gentamicin sulfate is based on CW 60 MHz magnetic resonance spectroscopy. Application of this method to FT 90 MHz spectra was evaluated. Results clearly show the limitations of this technique and point out the need for more reliable assay methods. Thus a 13C nuclear magnetic resonance (NMR) procedure for quantitative analysis of gentamicin sulfate was developed. Ratios of 4 gentamicin components (C1, C2, C1a, and C2a) were obtained from peak height measurements of selected resonance signals in spectra recorded under steady-state conditions. Relative response factors were determined from spectra of a reference mixture or, alternatively, from spectra of the individual pure components. Results obtained by the 13C NMR method were in agreement with those obtained by liquid chromatography using pre-column derivatization.

Gentamicins↗