Walter A. Tabaczynski

Standard operating procedure for metabonomics studies of blood serum and plasma samples using a 1H-NMR micro-flow probe†

A standard operating procedure (SOP) is presented for high‐throughput metabonomics studies using a 600 MHz NMR spectrometer equipped with a micro‐flow probe that is connected to an auto‐sampler. The procedure is designed to minimize random and systematic variation of NMR data collection. In addition, a protocol is described to assess the quality of the data acquired by a given NMR spectroscopist to ensure that (i) all researchers involved in the NMR data acquisition of a metabonomics research program perform equally and (ii) operator‐associated variation of NMR data collection is statistically not relevant for the interpretation of results obtained from multivariate data analyses. Copyright

First total synthesis of sialylated and sulfated Lewisx mucin Core 2 structures as potential tumor associated antigens

Abstract Two branched Core 2 structures, (3-O-SO3Na)Galβ1→4(Fucα1→3)GlcNAcβ1→6(NeuAcα2→3Galβ1→3)GalNAcαOMe (1) and its positional isomer NeuAcα2→3Galβ1→4(Fucα1→3)GlcNAcβ1→6(3-OSO3Na-Galβ1→3)GalNAcαOMe (2), were chemically synthesized for the first time as potential tumor associated antigens.

A5–4 PYRIMIDINE‐PYRIMIDONE PHOTOPRODUCT PRODUCED FROM MIXTURES OF THYMINE AND 4‐THIOURIDINE IRRADIATED WITH 334 nm LIGHT

The nucleoside 4‐thiouridine, present in some bacterial tRNA species, is known to be a chromophore and a target for near‐UV light‐induced growth delay and also mediates both photoprotection and near‐UV cell killing in various bacterial strains. To investigate the photoreaction of 4‐thiouridine with DNA or its precursors, we irradiated aqueous mixtures of thymine and 4‐thiouridine with 334 nm light and then separated photoproducts using two or more stages of reversed‐phase high performance liquid chromatography. The two equally abundant major photoproducts were analyzed by UV absorbance spectrophotometry, fast‐atom bombardment and electron‐impact mass spectrometry, and 1H‐ and 13C‐NMR spectroscopy, and have been identified as two diastereomers of 6‐hydroxy‐5‐[1‐(β‐D‐erythro‐pentofuranosyl)‐4′‐pyrimidin‐2′‐one]dihydrothymine (o6hThy[5‐4]Pdo), of molecular weight = 370.32. These two diastereomers, although stable at room temperature or below, are interconvertible by heating (90d̀C for 5 min) in aqueous solution. The possible biological significance of this photoproduct is discussed, and an application as a crosslinker for oligonucleotides to selectively block replication is suggested.

Synthesis of oligosaccharides containing β-d-Gal-(1→3)-O-(6-O-sulfo-β-d-GlcNAc) as a terminal unit

The chemical synthesis of beta-D-Gal-(1-->3)-6-O-SO3Na-beta-D-GlcNAc-(1-->6)-alpha-D-Man-O-+ ++C6H4NO2 (1) and beta-D-Gal-(1-->3)-6-O-SO3Na-beta-D-GlcNAc-(1-->2)-alpha-D-Man-OMe (2) is reported using a key glycosyl donor, phenyl O-(2,3,4,6-tetra-O-acetyl-beta-D-galactopyranosyl)-(1-->3)-4,6-di-O- chloroacetyl-2-deoxy-2-phthalimido-1-thio-beta-D-glucopyranoside (3).

A novel synthetic route to fused propenochlorin and benzochlorin photodynamic therapy probes

Reaction of meso-(2-formylvinyl)octaethylporphyrin with (CH3)3SiCN-Cu(OTf)2 produced unexpected 10(3)-trimethylsiloxyl and 10(3)-hydroxyl fused propenochlorins which, in H2SO4, underwent subsequent migration of the 8-ethyl group to the 10(3)-position of the exocyclic benzene ring to form a novel benzochlorin.