Stability and Biological Activity of Catecholamines and 5-Hydroxytryptamine Immobilized to Sepharose and Glass Beads

Abstract

[14C]Noradrenaline, [14C]adrenaline, and 5-[14C]hydroxytryptamine were complexed to several types of Sepharose derivatives through an amide or a diazo linkage. Complexes were also made with arylamine glass beads through a diazo linkage. After the reaction the complexes were extensively washed with distilled water or dilute HCl or both, plus other solvents. Radioactivity appeared in the storage solutions and the amount increased with time. When initial low levels of release were achieved by extensive washing, the addition of a different solvent produced a marked increase in release. The biological activity of these complexes was tested on isolated rabbit aortic strips and rat fundus strips. All complexes caused the tissues to contract. The biological activity, however, closely paralleled the release of the ligands from the complexes and the release of ligand was demonstrated through the use of oil immersion and dialysis sac. These data do not support the recent claims that catecholamines bound to glass beads exert their pharmacological effects as covalently bound complexes on isolated tissue. The lack of stability of these complexes indicates the need for caution in drawing conclusions as to the site or the mechanism of action of immobilized catecholamines and other drugs.

The antihypertensive and positive inotropic diterpene forskolin: effects of structural modifications on its activity

“…1-Benzoylforskolin (5). A solution of forskolin (0.1 g, 0.24 mmol), benzoyl chloride (0.5 mL, 4.3 mmol), and pyridine (0.5 mL) was left overnight at room temperature.…”

“…l-(Anilinocarbonyl)forskolin (6). A solution of forskolin (0.5 g, 1.21 mmol) and phenyl isocyanate (0.35 g, 2.94 mmol) in toluene (25 mL) was refluxed for 20 h. Hz, respectively, CH=CH2), 5.51 (1 H, d, =7 = 4 Hz, 7-H), 5.6 (1 H, m, W1/2 = 10 Hz, 1-H), 7-7.6 (5 H, m, Ar H). Properties of 6 and of 32 prepared in a similar manner are included in Table I.…”

Polymers of biogenic amines

“…7, bsttom), This increase was not seen with either the NA or the 5-HT and was considered a sign of release of the free amine (Yeng and Richardson 1975).…”

Conjugates of catecholamines. VII. Synthesis and β‐adrenergic activity of peptide catecholamine conjugates†

“…A solution Of 45 (' .39 g' 3.29 ml, 3.09 mmol) in 20 ml of dry THF was added. acid (1:l) was stirred at room temperature for were removed under reduced pressure, the removed under reduced residue redissolved in EtOAc and washed with 0.1 N HCl, 2% NaHC03 (3 x ) and saturated pressure.…”