Alangium lamarckii alkaloids

Alangine, 771 Alangium lamarckii, 771 Alginine, 732, 734 Alkaloidal amines, 630 Alkaloids of undetermined constitution, 716... 

The one genus, Alangium, of the tropics and scmilropics of the Old World, is rich in alkaloids, not all of which have had structural assignments. Considerable synonymy exists in the family. The chemistry of Alangium lamarckii has been studied in some detail and positive tests lor alkaloids were obtained from the single sample of Indian origin included in this study. 

Details of Kametani s synthesis66" of (i)-tubulosine and ( )-deoxytubulosine have now been published.666 An exactly analogous route has been used in the synthesis of ( )-0-methyltubulosine.66c A conventional synthesis67" of ( )-9-desmethyltubulosine (87) has revealed that it is not identical with the alkaloid, supposedly of this structure, which has been isolated from Alangium lamarckii this alkaloid, previously obtained by Popelak et al.,67b must therefore be the isomeric 10-desmethyltubulosine (88). 

Three new alkaloids that can be regarded as 10-aza-berberines have been isolated from Alangium lamarckii, namely alangimarine (71 R = H=CH2), alangimaridine (72), and alamarine 171 R = CH(OH)Mel. Their structures were deduced from... 

Deoxytubulosine has been extracted from the seeds of Alangium lamarckii.41 In connection with structure elucidation in this area, the compilations of rH n.m.r. data for geissoschizine, ajmalicine, 19-ep/-ajmalicine, tetrahydroalstonine, and rauniticine480 and of 13C n.m.r. data for diploceline19c should prove useful. The effect of stereoisomerism on the mass-spectrometric behaviour of some corynantheine and yohimbine alkaloids has also been studied.486... 

Alangium lamarckii is a medicinal plant that accumulates tetrahydroisoquinoline monoterpene alkaloids for the production of compounds such as emetine, a constituent of ipecacuantha emetic mixture that is used to for the treatment of drug overdose. Historically, this mixture has also been used to treat amoebic dysentery by South American Indians. 

The structure of the monoterpenoid alkaloid alangiside (115 R = H) has been confirmed by synthesis of the O-methyl ether (115 R = Me) from secologanin and 3-hydroxy-4-methoxyphenethylamine 202 the isolation of loganic acid from the same plant (Alangium lamarckii) is consistent with biosynthetic theory. 

Scheme 2. Biosynthesis of ipecac, Alangium, and indole alkaloids nitrogenous portion. Pathway (a) in Cephaelis ipecacuanha pathway (b) in Alangium lamarckii.

Alamarine. Pakrashi et al. (115) isolated several new types of alkaloids alamarine, alangimarine, alangimaridine, and isoalamarine from the Indian medicinal herb, Alangium lamarckii Thw. (Alangiaceae). Ninomiya et al. (73) reported the first total synthesis of alamarine (33) via the route involving enamide cyclization under both thermal and photochemical conditions. 

Benzoquinolizidine alkaloids from Alangium lamarckii, structure and... 

For formulas 1-71 Ipecac alkaloids, t A. lamarckii alkaloids, alkaloids from other species of Alangium, new structure, revised or established structure, 5 known but newly isolated structure. 

Most of the activity in the field of Ipecacuanha alkaloids has been of the synthetic nature. One new alkaloid, alangamide (7), from Alangium lamarckii Thw., has been identified and several analytical methods for separation and quantitative determination have been reported. Unexceptional routes to tubulosine and its relatives have been developed. Details and extensions of synthetic work related to emetine have been reported and should be of general interest (these investigations are discussed in greater detail in the following chapter). N-Chain extension of emetine with amino-acid residues has been reported. ... 

Aside from the known alkaloids psychotrine and tubulosine, a new alkaloid demethylcephaeline (279 R1 = Me, R2 = H or R1 = H, R2 = Me) has been isolated from Alangium lamarckii.253... 

Emetine and Related Alkaloids.—A review on the ipecac alkaloids has ap-peared. (— )-Alangiside (208) is a terpenoidal lactam recently isolated from Alangium lamarckii Thw. (Alangiaceae). The structure was proven by chemical correlation with desacetylipecoside (209) (Scheme 13). ... 

Ipecac Alkaloids.— The stereochemistry of ipecoside (71) is known by X-ray analysis, and this has been confirmed. Feeding experiments in Cephaelis ipecacuanha have given results which demonstrate that it is not desacetylipecoside (72), as previously supposed cf. ref. 2), but desacetylisoipecoside (73), with the same stereochemistry at C-1 (= C-llb) as cephaeline (76) and emetine (75), which is the true precursor for these alkaloids. Similar results were obtained for cephaeline (76) in Alangium lamarckii On the other hand, desacetylipecoside (72), and not (73), is the precursor for ipecoside (71) (in C. ipecacu-... 

These alkaloids also have been found in the Alangiaceae Alangium lamarckii) and Araliaceae (Hedera helix) (Fujii and Ohba, 1983). The last report should be confirmed, as it is from a most unusual source. 

Dasgupta B 1965 Chemical investigations of Alangium lamarckii. I. Isolation of a new alkaloid ankorine from the leaves. J Pharm Sci 54 481-483... 

Ipecac alkaloids are derived from the amino acid tyrosine and the monoterpene secologanin and are therefore termed terpenoid-isoquinoline alkaloids. They occur in the eudicot families Alangiaceae and Rubiaceae. Two species, Psychotria ipecacuanha (Rubiaceae) and Alangium lamarckii (Alangiaceae), have been investigated in detail with respect to their metabolites and biosynthesis of their alkaloids (Fujii and Ohba, 1998). Roots and rhizomes of P. ipecacuanha are the source of cephaeline and emetine (Fig. 9), two compounds with emetic, expectorant, and amebicidal properties. 

---