The Calabar Bean and its Alkaloids, 1st ed. 2018
From Magic, via Miracle, to Memory
Author: Robinson BrianLanguage: Anglais
Subjects for The Calabar Bean and its Alkaloids:
In Print (Delivery period: 15 days).Add to cart the livre of Robinson Brian
218 p. · 15.5x23.5 cm · Hardback
Investigations into Calabar beans (the dried ripe seeds of Physostigma venenosum) and their alkaloidal components compose a classical scientific journey throughout some one-and-a-half centuries and not only represent a fascinating aspect of the history of medicine but which is, moreover, still ongoing at the forefront of chemical and medical discovery. Those in particular involving its major such component, l-physostigmine, have led to an understanding of some of the fundamental mechanisms occurring in physiology, pharmacology and biochemistry and, either actually or potentially (by providing a template and thereby acting as a ?lead compound?) have provided a useful treatment for a variety of neurological disorders associated with irregularities in cholinergic transmission in which augmentation of cholinergic activity has proved to be beneficial.
Physostigma venenosum is distributed throughout equatorial West Africa and having a colourful history ? by virtue of their former use as an ordeal poison in trials for witchcraft in the Efik society of Old Calabar ? are its dried ripe seeds (Calabar beans). The major toxic compound isolated from these, l-physostigmine, which is also known as eserine and is the only alkaloid as yet also to be isolated from a microbial source (along with l-N(8)-norphysostigmine) and is the first alkaloid found to contain a 1,2,3,3a,8,8a-hexahydropyrrolo[2,3-b]indole ring system, and the first natural product found to contain a carbamyl group. It also became one of the first examples whereby the mechanism of action of a drug could be defined at the molecular level relatively simply, played a crucial role in the Nobel Prize ? winning discovery of the mechanism of neurohumoral transmission, and has led to products for the treatment of a wide range of disorders associated with deficiencies in cholinergic transmission. Several other alkaloids have also been isolated from the Calabar bean. For some of these, structures have been established, syntheses effected and pharmacology investigated.
One of the most exciting and interesting aspects of the study of natural products is the “field work” involving ethnological and ethnobotanical studies and which, where apposite, have been alluded to in the present treatise
Many texts on alkaloids are limited to chemical aspects, whereas the somewhat unique and therapeutically significant biological activities of the Calabar bean’s alkaloids (particularly l-physostigmine) has led to a detailed and through presentation of these facets in the present treatise
Throughout this present study, along with a detailed account of what has been done, investigations of what remains to be done have been high-lighted and approaches to effecting this are suggested, including the interpretations of already – published data