| Abstrakt: |
A group of nine dihydrogenated ergot alkaloids inhibit cyclic AMP phosphodiesterase in the grey matter of the cat brain. The degree of inhibition is of the same order as that produced by the methyl xanthines. The inhibitory properties of the ergot alkaloids with the higher molecular weight (average 600), DH-ergostine, DH-ergocristine and DH-ergoptine, are more powerful by a factor of 1.5 to 2 than that of the compounds with an average molecular weight of 540, DH-ergovaline, DH-ergonine and DH-ergosine. A significant correlation was found to obtain for each ergot alkaloid derivative between the degree of PEase inhibition and the molecular weight. Since no side group showed particularly outstanding inhibitory properties, the steric configuration of the larger derivatives was held responsible for the different degree of inhibition. The members of the group with the molecular weight of 600 were indeed found to exert greater inhibitory activity that those with a molecular weight of 540. The chromatographic method of Krishna [24], reported in the literature, was modified in combination with the incubation set-up after Williams [23] to yield an easy-to-handle micro-method. [ABSTRACT FROM AUTHOR] |
