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Biomedical subjects

P Walsmann

Publications and source records attributed to P Walsmann.

At least 55 records · Page 3Linked to original sources
PubMed1979

[Synthetic inhibitors of serine proteinases. Part 21: Studies on the structure-activity relationships in bisamidines (author's transl)].

The antitrypsin, antiplasmin and antithrombin activities of bis(amidinobenzylidene)- and bis(amidinobenzyl)cycloalkanones are not markedly affected if the amidino group is substituted by an uncharged residue (H, OCH3, Cl, Br, NO2). In contrast, mono(amidinobenzylidene)cycloalkanones exhibit considerably lower inhibitory activities than the compounds of the abovementioned classes of substances. From the results obtained it is concluded that the second aromatic residue and not the second basic amidino group is decisive of the potent inhibitory action of the bisamidino derivatives.

Amidines↗
PubMed1977

Inhibition of serine proteinases by benzamidine derivatives.

Derivatives of benzamidine inhibit competitively the activity of the serine proteinases trypsin, plasmin, thrombin, and of the clotting factor Xa. The inhibitor activities (Ki-values) of various benzamidine derivatives against the several enzymes were compared. Besides parallels, deviations in the corresponding structure-activity relationships were found. From these results it is concluded that the similar enzymes exhibit certain differences in the structure of the primary and secondary binding sites.

Amidines↗
PubMed1976

[Synthetic inhibitors of serine proteinases. 13. Quantitative structure-activity relationship for inhibition of trypsin and thrombin by 4-amidinophenyl compounds with a ketone structure].

To establish quantitative structure-activity relationships for the inhibition of trypsin, plasmin and thrombin by 4-amidinophenyl compounds with a keto group, attempts have been made to detect correlations between data on inhibition and substituent constants. The inhibitor activity of the derivatives is described by lipophilic or steric substituent constants using linear free energy relationships. To describe the action of beta-ketones, an additional sigma I term is necessary. The lipophilic or steric term stands for binding of the inhibitor side chain to a second hydrophobic binding site of the enzyme. The electronic term describing inductive influences on the keto group suggests the contribution of the beta-keto group to the enzyme inhibitor binding via a tetrahedral conformation of the carbonyl carbon.

Binding Sites↗