Gambier

These two substances, composed of the evaporated and dried aqueous extracts of certain plants, may be included among the colouring matters and also among the tanning materials, with reference to either their composition or their uses. 

Catechu forms brittle, reddish-brown masses, with a shining or opaque fracture and an astringent bitter and then sweetish taste. 

Of similar appearance to these products is kino, which is the condensed juice flowing from certain trees and forms brittle, shining, deep-red lumps it has a very astringent taste and, unlike catechu and gambier, dyes the saliva red. 

Catechu and gambier have catechu-tannic acid and catechin for their essential components. They may be adulterated with mineral matter (earth, ochre, clay, sand), starch, dextrin, extraneous tanning materials and dried blood. 

Their examination comprises especially certain qualitative tests for the identification of the product and for the detection of adulteration, and a dyeing test sometimes certain quantitative determinations are required. The analytical methods followed are indicated below. 

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Silyl ethers serve as preeursors of nucleophiles and liberate a nucleophilic alkoxide by desilylation with a chloride anion generated from CCI4 under the reaction conditions described before[124]. Rapid intramolecular stereoselective reaction of an alcohol with a vinyloxirane has been observed in dichloro-methane when an alkoxide is generated by desilylation of the silyl ether 340 with TBAF. The cis- and tru/u-pyranopyran systems 341 and 342 can be prepared selectively from the trans- and c/.y-epoxides 340, respectively. The reaction is applicable to the preparation of 1,2-diol systems[209]. The method is useful for the enantioselective synthesis of the AB ring fragment of gambier-toxin[210]. Similarly, tributyltin alkoxides as nucleophiles are used for the preparation of allyl alkyl ethers[211]. 

Gambir, n. gambier, yellow catechu. Gambo nf, m. gambo hemp, ambary hemp (Hibiscus cannabinus). 

Scaritoxin. During a survey of ciguatera intoxication in the Gambier Islands, Bagnis et al. observed that patients poisoned by parrotfish (Scaridae) suffered a longer period than conventional ciguatera symptoms, and postulated the presence of a... 

Gambier Resin exuded by Uncatia gambir shrubs... 

The contribution of Rubiaceae to Western pharmaceuticals and medicine is substantial because it is the source for Uncaria gambier (Hunt.) Roxb. (Catechu, British Pharmaceutical Codex, 1963), Cephaelis ipecacuanha (Brot.) A. Rich. (uragoga ipecacuanha, Brazilian ipecacuanha), or Cephaelis acuminata Karsten (Cartagena ipecacuanha) (Ipecacuanha, British Pharmacopeia, 1963), Cinchona calisaya (yellow... 

Microalgae produce many potent natural products in the form of complex polycyclic polyethers, a type of polyketide. The ladder-like polyether brevetoxin B (Fig. 1.8a) (Lin et al. 1981) is representative of a host of such toxins, which include cigua-toxin (Scheuer et al. 1967), yessotoxin (Murata et al. 1987), maitotoxin (Murata et al. 1993), gambieric acids (Murata et al. 1992), and azaspiracid (Satake et al. 1998). Brevetoxin B, one of the causitive agents of red tide poisoning, can be isolated from... 

The following cheap procedure serves for the preparation of large amounts of methylamine hydrochloride (Brochet and Gambier, Bull. Soc. chim., 1895 [iii.], 13, 533). Heat together in a distilling flask attached to a downward condenser 250 g. of ammonium chloride and 570 c.c. of 35 per cent formaldehyde solution. With the thermometer in the liquid, slowly raise the temperature to 104° and maintain at this point until distillation ceases (about 4-5 hours from the start). By then 100-120 g. of water and methyl alcohol will have collected in the receiver. Cool the flask, remove the ammonium chloride which separates by filtration at the pump, and evaporate the filtrate to half its volume on the water bath. Again remove ammonium chloride by filtration and concentrate the filtrate until a film of crystals forms on the surface. Cool and separate the methylamine hydrochloride by Ultra-... 

Scragg RK, Dorsch MM, McMichael AJ, Baghurst PA (1982) Birth defects and household water supply epidemiological studies in the Mount Gambier region of South Australia. Med J Australia 2 577-579... 

Several natural products and pharmaceuticals have been made in which a TRAP-catalysed oxidation of a primary alcohol to aldehyde step occnrs, and these are listed in 2.1.3 abscisic acid, altohyrtin A, (+)-arisngacin A, 14-[2H]-arteether (Fig. 2.4), astrogorgin, avermectin-Bla (Fig. 2.6), (H-)-batzelladine A (Fig. 1.13), brevetoxin B, (+)-catharanthin, ( )-epibatidine, 2-epibotcinolide, (-)-7-epicylin-drospermopsin, ( )-epimaritidine, epothilone C, irisqninone (Fig. 2.3), gambieric... 

Gambir or Gambier(Pale Catechu). An odorless brown powder prepd by drying an extract from a decoction of the leaves and twigs of an Indian shrub, Ourouparia or Uncaria gambir. It is insol in w and sol in ale. Used as an astringent and tanning material... 

Gambier. Deep-green colora- Do. No reaction J darkens Ppte. redissolves to olive-green... 

Where, as with gambier, it is not possible, either by grinding or by other mechanical means, thoroughly to mix the whole sample, it is allowable to dissolve all the sample or a large part of it in a small amount of water, to remix well and to weigh for analysis part of the concentrated solution. 

The following paragraphs deal especially with the tests and determinations to be made on the principal natural and artificial organic dyes, and among the former are considered certain tanning materials (q.v.) which also serve as colouring matters, namely, catechu and gambier. 

Gambier dissolves in hot water and is largely reprecipitated on cooling its dilute solution is coloured green by ferric chloride. 

To distinguish catechu from gambier, the substance is treated with 30% acetic acid or with 10% soda solution and the insoluble residue examined under the microscope if this consists of fragments of woody fibre the product is catechu, whereas if it is formed of parenchymatous cells and hairs with curved and dotted base, i.e., of leaf elements, the product is gambier. 

C.I. Natural Brown 3, 75250 (catechu) has the basic structure of catechin (2) and is a condensed tannin, e.g., gambier from leaves and twigs of the Uncaria gambler bush. Many of these tanning agents are based on a catechin flavanoid. 

Love, A.J., Hreczeg, A.L., Armstrong, D., Stadter, F., and Mazor, E. (1993) Ground-water flow regime within the Gambier Embayment of the Otway Basin, Australia evidence from hydraulics and hydrochemistry. J. of Hydrology 143, 297-338. 

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