Gourd curare alkaloids

Gourd or Calabash Curare. This type, exported in small gourds, is said to be made from Strychnos toxifera Schomb., and this was confirmed by King, who isolated from botanically authenticated material collected in British Guiana, an amorphous, quaternary alkaloid indistinguishable from curarine prepared from gourd curare, and Wieland et al. have isolated from this species alkaloids which they have also found in this type of curare. Other Strychnos spp. from the same territory examined by King contained alkaloids, but not of the curarine type. 

Alkaloids of Goukd ok Calabash Curare. The toxic constituent of this form, as prepared by Boehm, was an amorphous curarine to which the formula C gHjgONj was assigned. Gourd curare has been investigated in recent years by Wieland et aZ. and by Schmid and Karrer. ... 

The material first used by Wieland et al. was gourd curare from the middle Orinoco district, near Urbana, in Bolivar State, Venezuela, but in the fomth paper (1941) results are recorded for curares from Colombia and Venezuela, for which more precise details of origin are not available and there is considerable difference in the nature and quantity of the alkaloids in the various samples used. An examination has also been made of the bark of Strychnos toxifera, and one of the alkaloids (toxiferine II) it contains has been found in some of the curares examined. In all, ten alkaloids have been obtained and characterised and, with the exception of curine, they are all of quaternary type. They are named toxiferine, dihydrotoxiferine, or calabash-curarine (shortened to C-curarine in practice) according to type, and the variants within the type are distinguished by numbers, or numbers and letters, e.g., toxiferine I, toxiferine Ilb. 

A considerable amount of information had been accumulated on curare, the South American arrow poisons, before 1900. The results of the early work were very inaccurate because of the complexity and variation of the composition of the mixtures of alkaloids involved. Boehm (7, 8) distinguished the types of curare preparations by the type of container in which they were packed. They were (a) para, tube, or bamboo curare, packed in bamboo tubes (b) pot curare, exported in small earthenware pots and (c) gourd or calabash curare, packed in small gourds. Boehm prepared active curarizing samples from these materials, tubocurarine from tube curare, protocurarine from pot curare, and curarine from gourd curare. These were impure, non-crystalline alkaloids which, for the most part, were quaternary ammonium compounds. The curarine of Boehm is the material used in much of the early experimental work.. ... 

Most curares derived from Strychnos species in South America are known as calabash curares because they are stored in a calabash or small gourd. Curares of this type are regarded as the most paralytic natural or synthetic neuromuscular blocking agents. At least seven alkaloids have been isolated that are more active than fi -tubocurarine (see Chapter 32). For example, C-toxiferine (48) is about 10 times as active, and C-alkaloid G (49) and E (50) are 100 times more active, being active at 1 fxg per kg (Cordell, 1981). 

Principal paralytic alkaloids present in an alternative form of curare, calabash curare, prepared from the bark of Strychnos toxifera. Used to be packed in calabashes or gourds, hence the C (for calabash) in the name. Used as an arrow poison. Actions similar to tubocurarine. 

Calabash curare, prepared from plants of the genus Strychnos, is packed in hollow gourds. It contains a large number of alkaloids and is extremely poisonous. The alkaloids contain an indole ring system and can be divided into 3 types the yohimbine type (e.g. mavacur-ine), the strychnine type (e.g. Wieland-Gumlich aldehyde) andthehfrindole type (e. g. calabash toxiferin-I). 

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