Alkaloid naming

Derivatives of the alkaloids named may also be represent by the formulae with the following changes —... 

As found in commerce, the cinchona alkaloids are not necessarily pure quinidine, for example, may contain up to 30 per cent, of dihydroquinidine. Working with carefully pmdfied specimens of the four chief cinchona alkaloids and their dihydro-derivatives, Buttle, Henry and Trevan found the results recorded in the table (p. 471) in tests with malaria in canaries. The figures in brackets represent the dose of quinine necessary to produce the same degree of protection as unit dose of the alkaloid named. To the results are also added the data found later by the same authors, with Solomon and Gibbs, for some of the transformation products (p. 449) of quinine and quinidine. The Roman numeral at the head of each column refers to the type formula on p. 470. 

In recent years much interest has been displayed in the Indian species and other alkaloids, named in the following list, have been isolated from it, though it should be noted that doubts have been expressed by several authors as to the individuality of some of these substances. 

The validity of the oxauracil strategy for a stereoselective construction of the azabicyclic core has been proven for the syntheses of biologically important polyguanidinium alkaloids, namely, batzelladine A and D [58]. Reaction (7.48) shows that treatment of 41 under the standard free-radical conditions furnished the desired azabicycle in a 77 % yield, in a high diastereoisomeric ratio. Here it can be seen the effect of H donation from the more accessible face of the molecule. 

Instead of the originally given alkaloid names vincaleukoblastine and leurocristine we adopt the more commonly used names vinblastine (VLB) and vincristine (VCR) for alkaloids 1 and 2, respectively. 

It was recently observed that a iplant, Adhatoda vasica, long used in Indian herbal medicine (the source of many therapeutic leads) for the relief of cough and respiratory tract congestion, did appear to reduce the quantity and viscosity of sputum. The plant was studied and its active alkaloid named vasicine. The tricyclic quinazoline structure (XXVIII) was then reduced to fragments and a series of derivatives prepared [350]. From these bromhexine (XXIX, Na 274, Bisolvon)... 

An anti-snake venom principle has recently been reported as a glycosidal quaternary chromone alkaloid named schumanniofoside 36 (14). Extracts of the stem bark were tested against the venom of the black cobra, Naja melanoleuca, in mice. The methanolic extract showed the greatest activity. This was fractionated and monitored to yield 36 as the active component. 

Not surprisingly, therefore, 2,3 -bipyridine is an ingredient of tobacco smoke and is a constituent of tobacco liquors. " An alkaloid named iso-nicoteine, which was isolated from Turkish tobacco liquors and was thought to be a pyridylpyrrole derivative, was subsequently shown to be identical to 2,3 -bipyridine. 5-Methyl-2,3 -bipyridine, 2,2 -bipyridine, and 4,4 -bipyridine are also found in tobacco smoke. The range of bipyridines found in tobacco smoke condensate has been considerably extended with the identification of several alkyl substituted 2,2 -, 2,3 -, and 3,3 -bipyri-... 

It is regrettable that Australian chemists failed to discover another local alkaloid, namely castanospermine 3. It was left to an overseas group to collect and extract the seeds from a Queensland legume to yield this valuable alkaloid [6]. Castanospermine seems to display a broad biological activity which surpasses even that of swainsonine, being a particularly powerful competitive inhibitor of both a- and -o-glucosidases [7]. The alkaloid is plentiful enough in the... 

The alkaloids namely atropine, hyoscyamine and scopolamine are obtained from Atropa belladonna. Atropine is dl-hyoscyamine, and, 1-isomer is more potent than d-form both peripherally and centrally. Atropine blocks the muscarinic effects of acetylcholine, the antagonism between acetylcholine and atropine is of competitive... 

The known alkaloids senecionine, senkirkine, and retrorsine have been isolated from Senecio vernalis Wald, et Kit. by Roder et al.26 A new alkaloid, named senecivernine (59), was also present. The mass spectrum of (59) showed a molecular ion at m/z 335, and fragment ions at m/z 291, 248, and 220, characteristic for a macrocyclic diester of retronecine, arising from cleavage of the allylic ester.17 Basic hydrolysis of senecivernine gave a new necic acid which had spectroscopic data in accord with the proposed structure. Retronecine was not isolated. The necic acid from senecivernine is a Ci0 acid of an unusual structural type (cf. Vol. 8, p. 55). 

The total chemo-enzymatic synthesis of three of the (-l-)-montanine alkaloids, namely (+)-brunsvigine [138], (-l-)-nangustine [139] and (-l-)-montabuphine [140], has been reported in the last 3 years. These non-natural enantiomers have been prepared from monochiral 3-halo-m-1,2-dihydrocatechols precursors. A total of over 17-20 reaction steps are needed for their syntheses (Fig. 22). 

Unique /3-lactam indole alkaloids, namely, chartellines A (77) (87), B (78), and C (79), methoxydechlorochartelline A (80) (88), and chartella-mides A (81) and B (82) (89), were isolated from a marine bryozoan (Chartella papyracea) collected in North Britanny waters. The structure of chartelline A (77) was confirmed by X-ray analysis, and the absolute... 

The Mediterranean sponge Reniera sarai is a rich source of new macro-cyclic alkaloids, named sarains, which may be biogenetically related to petrosin (246) or araguspongins (236-243). The structures of sarains 1-3 (247-249) (2/0) and isosarain 1 (250) (211) were clarified on the basis of extensive spectroscopic analyses. The position of the double bond in 249 remains to be determined. The more polar fraction of this sponge contained three UV-absorbing alkaloids, named sarains A-C. The structure of the diacetylated derivative of sarain A (251) was established by X-ray analyis (2/2). 

Alkaloid name Molecular formula Melting point (solvent) (reference) UV, nm (solvent) (reference)... 

New extractions of the leaves of S. icaja, also from Zaire, have resulted in the isolation of seven known alkaloids, together with novacine (184), also known, but not hitherto reported to occur in this species.106 A ninth alkaloid is new, and appears to be 19,20-a-epoxy-12,15-dihydro-l 1-methoxy-Nb-methyl sec.-pseudostrychnine (185). The leaves of a specimen of this same plant from Cameroun contained four known alkaloids, plus a new one, 19,20-a -epoxy-11,12-dimethoxy-iVb-methyl see.-pseudostrychnine (186). The fruits of a Gabonese sample, which had reputedly been exhibited at the Paris Colonial Exhibition of 1889, contained eight alkaloids, namely icajine, vomicine, 19,20-a-epoxynovacine, 19,20-a-epoxy-12,1 5-dihydroxy-Nb-methyl sec.-pseudostrychnine (187), and the related bases (185) and (188)—(190), of which (190) was the major constituent.106... 

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