Semi-preparative Isolation Research Articles

Semi-preparative isolation of crepenynic acid, a potential inhibitor of essential fatty acid metabolism

Semi-preparative isolation of crepenynic acid, a potential inhibitor of essential fatty acid metabolism

Ion-exchange, gel-filtration and reversed-phase high-performance liquid chromatography in the isolation of neurotensin-degrading enzymes from rat brain

Brain and pituitary peptidases involved in the metabolism of neurotensin were identified by ion-exchange (TSK-545 DEAE) and gel-filtration (TSK-G4000 SW) high-performance liquid chromatography (HPLC). Reversed-phase HPLC on radial compression cartridges was used in a rapid assay of neurotensin-hydrolysing activity in column fractions and at the same time the bond specificity of the activity was determined. Semipreparative isolation of the major enzyme which cleaves neurotensin at Arg 8–Arg 9 was carried out and some of its characteristics were determined.

Analysis and separation of natural and synthetic mixtures of uroporphyrins by high-pressure liquid chromatography.

A new method for the quantitative analysis of mixtures of the methyl esters of uroporphyrins I and III was developed; this can be applied both to the analysis of naturally occurring uroporphyrins and also to their semi-preparative isolation.

Antioxidative properties of phenyl‐substituted phenols. III. Model studies of synergistic actions between primary and secondary antioxidants

AbstractProducts originating from the action of primary and secondary antioxidants can account, after interaction, for the synergistic effects observed in some polymers, e.g., polypropylene. Marked synergistic actions were observed between 4‐alkoxy‐2,6‐diphenylphenols and β,β′‐disubstituted diethyl sulfides. Using the corresponding phenoxyl radicals and sulfoxides as the model compounds, several products arise and disappear.In the case of 4‐methoxy‐2,6‐diphenylphenoxyl and β,β′‐diphenyldiethyl sulfoxide, 4‐methoxy‐2,6‐diphenylphenol (the primary antioxidant) and the formation of a variety of sulfur compounds, capable of acting as peroxide decomposers, were detected, isolated, and identified using high‐pressure liquid chromatography (HPLC) as a separation technique followed by semipreparative isolation.