Renin-angiotensin system: biochemistry and mechanisms of action.

Much research has been conducted in an attempt to fit the so-called plant secondary substances into the general framework of plant metabolism. Though some success has been achieved in this area, e.g., chlorogenic acid as a regulator of plant metabolic systems under stress21, most such studies have met with a conspicuous lack of success. Possible metabolic roles for the plant alkaloids as intermediate metabolites have probably received the greatest such attention and it was concluded at an early stage44 that, since a definitive metabolic role could not be assigned to alkaloids, they best be considered as plant waste products. More recent workers in the field of alkaloid biochemistry have concurred with this evaluation44,83 and the “waste product hypothesis” has been expanded, principally by Muller (1969, 1970), to include plant secondary substances in general.

Toward a general theory of plant. antiherbivore chemistry

,8-IMINAZOLYLETHYLAMINE is the amine which is produced when carbon dioxide is split off from histidine. It was first prepared synthetically by Windaus and Vogt'. Recently Ackermann2 obtained a large yield of the base by submitting histidine to the action of putrefactive organisms. It has been shown that several of the amines thus related to amino-acids possess marked physiological activity. The activity of j8-iminazolylethylamine was discovered in the course of the investigation of ergot and its extracts by G. Barger and one of us3, who attributed this structure to a base which they obtained, and which in minute doses produced tonic contraction of the uterus. The synthetic substance, and the base produced by splitting off carbon dioxide from histidine by bacterial action or by chemical means, were found to have an identical action. Meanwhile Kutscher4 had simultaneously and independently described the isolation from ergot of a base having this action and presumably identical with that obtained by Barger and Dale. By its chemical properties this first ergot base of Kutscher was not distinguishable from 8-iminazolylethylamine; but certain apparent differences in the physiological action of the two bases, observed by Ackermann and Kutscber-5, led them to the conclusion that the ergot base, though closely related to 8-iminazolylethylamine, is not identical with it. The alleged difference in action, on the existence and cause of which our experiments throw light, was as follows: the

The physiological action of β-iminazolylethylamine

Preparation of adsorbents for biospecific affinity chromatography. Attachment of group-containing ligands to insoluble polymers by means of bifuctional oxiranes.

Estimation of Molecular Size and Molecular Weights of Biological Compounds by Gel Filtration

Natural proteinase inhibitors

Isolierung und Charakterisierung eines Proteaseninhibitors aus menschlichem Bronchialsekret

Several procedures for the isolation of histamine from tissues and body fluids were examined For the fluorometric assay of histamine concentrations higher than 1 μg/g tissue or ml blood the extraction into n-butanol as well as the cation-exchange chromatography on Dowex 50W-X8 proved suitable The determination of histamine in whole blood of dogs gave valid results only after chromatography on Dowex 50, in human plasma and gastric juice only after the combined application of both purification methods Histamine was identified by thin-layer chromatography on cellulose, by inactivation in the presence of purified diamine oxidase from pig kidney and purified histamine methyltransferase from guinea-pig brain, by the biological activities and by the fluorescence spectra of the condensation product between histamine and o-phthaldialdehyde Histamine concentrations in tissues and body fluids of man and some laboratory animals are reported

Eugen Werle

Papers

Natural proteinase inhibitors

Isolierung und Charakterisierung eines Proteaseninhibitors aus menschlichem Bronchialsekret

Fluorometric assay of histamine in tissues and body fluids: Choice of the purification procedure and identification in the nanogram range

Isolation and structure of kallidine

Über Proteaseinhibitoren, I. Isolierung und Charakterisierung des Trypsininhibitors aus Pankreasgewebe und Pankreassekret vom Hund