Loganiaceae-curare

LOGANIACEAE—CURARE To prepare this type of curare, the bark of Strychnos toxifim Rob. Schomb. ex. Lindl., S. iuimmsis(AMh tt)... 

Strychnos usambarensis (Loganiaceae) [root] S. Am. Indian poison curare component Derived synthetically from morphine, a morphinan isoquinoline alkaloid from Papaver somniferum (opium poppy) (Papaveraceae) [aerial]... 

Introduction and Interrelationships.—Calabash-curare is prepared from the bark of South American Strychnos of the family Loganiaceae. From the curare and the Strychnos species, along with a large number of monomeric indole alkaloids, fifteen structurally classified bisindole alkaloids have been isolated. Their structures are all based on one CjgN skeleton. Only the N h N h fdimetho-salts exhibit high curare-activity. 

Melinonine A. 16,17- Didehydro-16-( methoxycar-bonyl)-4,16a -dimethyloxayohimbanium. [C,jHj7N203] + Calabash-curare alkaloid from Strychnos meltnoniana Bail-lon, Loganiaceae. Isoln and structure Sc blit tier, Hohl. 

As described previously, the origins of the three types of curare are the extracts of Chondodendron (Menispermaceae) and/or Strychnos (Loganiaceae) plants. Among them, the toxic components of Strychnos plants are C-curarine and C-toxiferine I, etc.These constituents are alkaloids derived from tryptophan and are described in the next (Section 2.15).The C- is the initial of calabash. On the other hand, the toxic principle of tubocu-rare is d-tubocurarine, an alkaloid derived from phenylalanine. The alkaloid was first isolated as a hydrochloride from tubocurare and is preserved in the Museum of the British Society of Pharmacy [1]. The chemical structure of d-tubocurarine was first proposed as a bisbenzylisoquinoline with two quaternary ammonium moieties. This was revised in 1970 to be the structure with one tertiary and one quaternary amine after X-ray crystallographic analysis [2]. 

On the other hand, calabash curare is an arrow poison prepared from Strychnos toxifera (Loganiaceae) and related plants of the same genus. S. tox-ifera is also contained in the pot curare mentioned above. 

Fig. 1.1). The tribes involved are mostly hunter-gatherers in the tropical rain-forest area some marginal tribes such as the Guaharibo on the Upper Orinoco and the Nambikwara and Paresi on the central Brazilian plateau are also included. Tables 1.1 and 1.2 record the species of Loganiaceae and Menispermaceae that have been documented, usually by means of herbarium specimens, as components of curare the localities where used and some of the tribes that are known to have employed the plants are also indicated. 

Strychnos is the only genus of the Loganiaceae whose species are involved in the making of curare (Table 1.1). On the other hand, representatives of several genera of Menispermaceae have been utilized—not only species of Chondrodendron and Curarea, which are known to be active, but also species of Sciadotenia, Abuta, Anomospermum, Telitoxicum, as well as Cissampelos (Table 1.2) there is a dearth of information about the activity of these latter genera. 

Tables 1.1 and 1.2 (Section 1.2.1) list the species of Loganiaceae and Meni-spermaceae, most of which are documented by annotated herbarium specimens, that are known to be, or to have been, utilized in making curare. The plants themselves are discussed briefly in the paragraphs below and, for completeness, information on those employed in the curarizing poisons of Africa and Malaysia is also included. Table 1.3 brings together a selection of the families and genera that have provided other components of curare.

The following sections deal in turn with the alkaloids of the Loganiaceae and Menispermaceae and with those isolated directly from samples of curare. 

To establish the active ingredient(s) that were essential to the activity of curare, several of the early explorers attempted to make their own poison Robert Schomburgk (151) prepared what turned out to be a weak curare from Strychnos toxifera Jobert (442) experimented with both Loganiaceae and Menispermaceae de Lacerda (443) discussed the tests that Couty and he (444, 445) had previously carried out with extracts from S. trinervis and S. gardneri Schwacke (127) noted that extracts of S. castelnaeana (castelnei) and S. hirsuta alone had the same effects as curare while de Lacerda (394) studied a product made with a species of Menispermaceae, possibly Curarea tecu-narum (see Table 1.6, footnote g). 

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