Calabar bean Physostigma

Physostigmine (eserine) is a carbamate found in the calabar bean (Physostigma benenosum), which acts as an anticholinesterase. It was used in West Africa in witchcraft trials by ordeal. It has also been used in human medicine. Insecticidal carbamates are structurally related to it and also act as anticholinesterases (Ballantyne and Marrs 1992). 

The classical synaptic clearance antagonist is the cholinesterase inhibitor physostigmine, from the calabar bean, Physostigma... 

Cholingeric Calabar bean Physostigma venenosum Physostigmine in ripe seeds Cholinergic toxicity Chewing seeds releases more physostigimine... 

Calabar bean Physostigma venenosum Cholinergic toxicity... 

The prototype carbarnate-derived acetylcholinesterase inhibitor is physostigmine (247), an alkaloid isolated from the seeds of the Calabar bean, Physostigma venenosum. Physostigmine exhibits equal inhibitory activity against acetylcholinesterase and butyrylcholinester-ase (308). 

Alkaloids from the calabar bean (Physostigma venenosum) Amberboa ramosa Amberbin A Amberbin B Amberbin C Amberin Angelica gigas Decursinol Apiumgmveolens Apigenin Arborvitae Seed Areca catechu MA9701... 

A myriad of natural compounds have been tested for the past 20 years in a frenetic search for agents with potential effects against AD neuropathology. Some of these compounds include alkaloids from the calabar bean (Physostigma venenosum) huperzine A from Huperzia serrata-, galantamine from the snowdrop Galanthus woronowii cannabinoids (cannabidiol from Cannabis sativa) ... 

Physostigmin—Rserin—CisH-nNsO —is an alkaloid existing in the Calabar bean, Physostigma venenomm. It is a colorless, amori>hous solid, odorless and tasteless, alkaline and difficultly soluble in water. It neutralizes acids completely, with formation, of tasteless salts. Its salicylate—Physostigminse salicylas, TJ. S. —forms short, colorless, prismatic crystals, sparingly soluble in water. 

The bryozoon Flustra foliacea contains bromoindole alkaloids ( bryozoan alkaloids) with the physostig-mine skeleton this is also characteristic for a group of alkaloids from the calabar bean Physostigma veneno-sum) F. A, Cj.HjsBrN, Mr 389.38 F B, CjiHjsBrNj, Mr 389.38. 

Physostigmine from the Calabar bean Physostigma venenosum (Fig. 130) is an indole alkaloid of simple structure. It is derived from tryptophan via its biogenic amine, tryptamine. 

While phenyl pyrrole derivatives have not been isolated from higher plants, a number of plant alkaloids have been shown to be derived from tryptophan (Manske, 1965). Several of these plants, such as the calabar bean (Physostigma venenosum Balf.) and the family Calycanthaceae [Calycanthus L. and Chimonanthus Lindl.), yield compounds, e.g. physostigmine (VIII) and folicanthine (IX) whose biosynthesis may follow a pathway similar to that of pyrrolnitrin. 

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