The double-peak phenomenon of talinolol is likely caused by a presystemic storage compartment, which represents the complex interplay of heterogeneous uptake and kick-back transport processes along the intestinal-hepatic absorption pathway.

Knowledge about transit of solid dosage forms (SDF) in the gastrointestinal tract is incomplete. Detection of magnetically marked capsules (MMC) via superconducting quantum interference device (SQUID) allows monitoring of oesophageal transport of SDF with high tempospatial resolution. The aim of the study was to investigate the influence of body position, volume at swallowing, and oesophageal motility on orogastric transport of SDF. In 360 measurements we determined tempospatial characteristics of orogastric transit of SDFs by a SQUID device in six volunteers. They swallowed MMCs with various amounts of water in upright and supine position with and without simultaneous oesophageal manometry. Orogastric transit time, oesophageal transport velocity and rate of oesophageal retention of SDF depend on swallowing volume and body position at all experimental conditions. At 50 mL water bolus and in upright position, the retention rate depends on the pharyngeal propulsion velocity, and the transport velocity of MMCs in the oesophageal body are faster than the propulsive oesophageal contractions. Body position, swallowing volume and pharyngeal propulsion velocity markedly influence the oesophageal transport of SDF. They should be taken in upright body position with at least 50 mL of water to minimize entrapment in the oesophagus.

The synthesis of the natural siderophore myxochelin B (1S) and its enantiomer 1R is described. 1S and 1R served as precursors for the synthesis of new hexadentate siderophores, the myxochelins C (7S) and CR (7R), D (14S) and DR (14R), E (19S) and (RS)‐F (26R, S), with 2,3‐dihydroxybenzoate (DHB) ligands and the simple backbones of asymmetric 1,2,n‐triamino‐n‐alkanes. For the myxochelins C, D, E and F n is 6 (from lysine), 5 (from ornithin), 4 (from asparagine amide) and 7 [from (±)‐2‐aminopimelic acid], respectively. The additional amino functions in the starting compounds were provided by dehydration of the corresponding primary amides, and subsequent reduction of the nitriles by cobalt boride in methanol. All new siderophores supply bacteria with ferric ions with an efficiency which depends on their chain length and stereochemistry. They show significant activity against the cytomegalo virus.

No abstract

No abstract