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E J Behrman

Publications and source records attributed to E J Behrman.

At least 19 recordsLinked to original sources
PubMed1995

A new synthesis of sucrose 6'-phosphate.

Sucrose 6'-phosphate (3) is the key intermediate for sucrose (1) synthesis in plants [1]. It has recently become commercially available at ca. $1500/g (Sigma). The only chemical synthesis is that of Buchanan et al. [2]. This six-step procedure, while unambiguous, gives an overall yield of only ca. 6%. We describe here a simplified route (2 steps) with an unoptimized yield of ca. 15%. Our strategy was to use a phosphorylation reagent selective for primary hydroxyl groups and thus to avoid the necessity for blocking all of the secondary ones. Sowa and Ouchi [3] described a suitable system which they used very effectively for the synthesis of 5'-nucleotides from unprotected nucleosides. We applied this reagent to 2,1':4,6-di-O-isopropylidenesucrose (2) [4] in which the only unprotected primary hydroxyl group is that at the 6'-position (Scheme 1). The identity of the product was established by comparison of its rotation with the literature value and by the correspondence of its 1H and 13C NMR spectra with those of an authentic sample synthesized by Buchanan's method (Sigma) 1H assignments were made with the help of the assignments of du Penhoat et al. [5] for sucrose and the results of a one-bond H-C COSY experiment (Fig. 1). The 13C spectrum showed that all of the resonances were shifted downfield by ca. 0.5 ppm as compared with sucrose [6] except for the C-5' doublet which was shifted upfield by 0.5 ppm and the C-6' doublet which was shifted downfield by 2.2 ppm (Table 1).

Magnetic Resonance Spectroscopy↗
PubMed1991

The synthesis and characterization of uridine 5'-(beta-L-rhamnopyranosyl diphosphate) and its role in the enzymic synthesis of rutin.

Uridine 5'-(beta-L-rhamnopyranosyl diphosphate) was synthesized by the condensation of uridine 5'-diphenylpyrophosphate and beta-L-rhamnopyranosyl phosphate. That sugar 1-phosphate was made via the phosphitylation of the hemiacetal hydroxyl group of 2,3,4-tetra-O-acetyl-beta-L-rhamnopyranose. An enzyme preparation from the primary leaves of mung bean (Phaseolus aureus) was shown to catalyze the transfer of L-rhamnose from UDP-beta-L-rhamnose to the flavonol D-glucoside isoquercitrin to form rutin.

Plants↗
PubMed1982

Cleavage and cross-linking of proteins with osmium (VII) reagents.

The specific cleavage of proteins following reaction with osmium tetroxide is slowed down by tertiary amines which are known to be good ligands for osmium. Bidentate ligands are more effective than monodentate ligands. These same ligands also promote an intermolecular cross-linking reaction.

Cross-Linking Reagents↗
PubMed1981

Reaction of osmium reagents with amino acids and proteins. Reactivity of amino acid residues and peptide bond cleavage.

We report a study of the relative reactivity of the common amino acids and of their residues in lysozyme with osmium tetroxide, the osmium tetroxide-pyridine reagent, and with the oxo-osmium(VI)-pyridine reagent. With free amino acids, the osmium(VIII) reagents are most reactive with Met, Cys, His, Thr, Ser, Trp, Lys, and Pro; the osmium(VI) reagent only reacts significantly with His, Met, Cys, Thr, and Ser. In lysozyme, only Cys, Met, and Trp react extensively with the osmium(VIII) reagents; with the osmium(VI) reagent, Cys and Met are most reactive. We also note evidence both for cross-linking of proteins and for peptide bond cleavage, which appears to have considerable specificity for tryptophanyl residues.

Amino Acids↗
PubMed1979

Resolution of D- and L-galactose peracetates as their bis(ethyl L-lactate) acetals by gas-liquid chromatography.

Reaction between ethyl L-lactate and each of a pair of sugar enantiomers, the peracetylated D-galactose and L-galactose diethyldithioacetals, produced two acyclic diasterioisomers. They could be separated by conventional gas-liquid chromatography. The corresponding fucose diastereomers were also separated. This process should make it possible to develop a general analytical method by which small amounts of enantiomeric sugars can be identified and their quantities measured.

Chromatography, Gas↗
PubMed1977

Synthesis of beta-L-fucopyranosyl phosphate and L-fucofuranosyl phosphates by the MacDonald procedure.

Fusion of beta-L-fucopyranose tetraacetate with phosphoric acid for 1 min at 50 degrees gives a 9:1 anomeric mixture of the alpha- and beta-pyranosyl phosphates. Longer fusion times give the alpha-anomer exclusively. The L-fucofuranose tetraacetates were synthesized for the first time by acetolysis of methyl-2,3,5-tri-O-acetyl-beta-L-fucofuranoside. Fusion of the furanose tetraacetates with phosphoric acid gave a mixture of the fucofuranosyl phosphates in which the beta-anomer predominated (beta/alpha= 2.4). Anomeric pairs in the fucofuranose series appear to be distinguishable by the chemical shift of the C-6 methyl protons, as already shown by Sinclair and Sleeter in the pyranose series.

Fucose↗
PubMed1976

Osmium (VI) complexes of the 3', 5'-dinucleoside monophosphates, ApU and UpA.

The dinucleoside monophosphates, ApU and UpA, react with potassium osmate (VI) and 2,2'-bipyridyl to form the corresponding oxo-osmium (VI) bipyridyl sugar ester in which the osmate group is bonded to the terminal 2',3'-glycol. Osmium (VIII) tetroxide and 2,2'-bipyridyl react with the dinucleosides to form the corresponding oxo-osmium (VI) bipyridyl heterocyclic esters which result from addition of the tetroxide to the 5,6-double bond of the uracil residue. Although capable of transesterification reactions, these heterocyclic esters are exceptionally stable toward exchange reactions in solution. No apparent exchange was observed after 1 month. This reaction thus seems promising for single-site osmium labeling in polynucleotides.

Adenine Nucleotides↗
PubMed1976

The reactions of oxo-osmium ligand complexes with isopentenyl adenine and its nucleoside.

We report syntheses of oxo-osmium(VI)bis(ligand) esters of N6-(delta2-isopentenyl) adenine (6-ipAde) and its nucleoside (IPA) which result from the addition of OsO4 to the double bond of the isopentenyl group. A study of the kinetics of these reactions shows that under typical conditions the rates of reaction relative to thymidine are as follows: for OsO4-pyridine: thymidine = 1; 6-ipAde = 4600: for OsO4-2,2'-bipyridyl: thymidine = 380; 6-ipAde = 8600; IPA = 8600. We also report syntheses of osmate esters of IPA in which the osmium is bonded through the 2'-and 3'-hydroxyl groups of the ribose residue.

Adenine↗