Tryptamine alkaloids from

Indole alkaloids from Tabernaemontana plants are all biogenetically derived from tryptophan (tryptamine) and secologanine, which constitute the indole and terpenic portions, respectively, and can be classified into nine main types depending on the structural characteristics of their skeleton (Fig. 1). 

The relationship between anemone fish, Amphiprion sp., and their sea anemone partners are regulated by alkaloids from the sea anemone. Amphiprion perideraion is attracted to the sea anemone Radianthus kuekenthali by the simple lysine-derived alkaloid amphikuemin (Fig. 12.6 Murata etal, 1986). Other simple alkaloids, aplysinopsin and dihydroaplysinopsin, also attract A. perideraion, regulate its swimming rate and induce their species-specific partnership. A related anemone fish, Amphiprion ocellaris, is attracted to the sea anemone Stoichactis kenti by tyramine (Fig. 12.6) and tryptamine induces searching by the fish (Murata etal, 1986). 

The oral activity of tryptamines that are degraded by MAO can be enhanced by chemicals called monoamine oxidase inhibitors (MAOI). This synergism serves as the basis for the Amazonian entheogenic brew, ayahuasca (which means vine of the souls ), where DMT is rendered orally active by the presence of MAOI harmala alkaloids from the plant Banisteriopsis caapi (Metzner 1999). Anoliher botanical source of the MAOI harmala alkaloids harmaline and harmine is the seed of the Syrian rue, Beganum harmala, a bush related to the creosote, native to Asia and Africa. There are anecdotal reports that the potency of psilocybin... 

While each shaman has his own secret formula for the mixture (with probably no two exactly alike), it has been established that true ayahuasca always contains both beta-carboline and tryptamine alkaloids, the former (harmine and harmaline) usually obtained from the Banisteriopsis caapi vine, and the latter (N, N-dimethyl-tryptamine, or DMT) from the leaves of the Psy-chotria viridis bush. (There may be variations among plant species, but the alkaloids are always consistent.)... 

Rearrangements of Iboga and Aspidosperma Types. It is possible to envisage the biological rearrangements of the monoterpene-tryptamine alkaloid skeleta as proceeding via a common intermediate (132), reversibly derivable, at least on paper (see below) from each of the skeletal types, providing that a structure at the correct oxidation level is chosen. Thus tabersonine (133) (aspidosperma). 

Scheme 11. Alkaloids from the marine bryozoan Flustra foliacea. Structures numbered in Arabic originate from specimens from the North Sea and those with Roman numbers are from Canadian specimens. Flustrabromine (11) and 6-bromo-/Vb-methyl-/Vb-formyl-tryptamine (10) were isolated as an intimate mixture of Z and E geometrical isomers. The formulas are not intended to depict absolute stereochemistry.

That the complex indole alkaloids contain a tryptamine unit is a requirement which is not always met at first sight. For example, some alkaloids from the Cinchona and Bemijia species (Rubiaeeae) (Volume VIII, Chapter 10 type Ij, Fig. 2) contain quinoline rings in their overall structures. Nevertheless, it has been shown that tryptophan is readily incorporated into these alkaloids and on this basis they are justly included in Table II. Furthermore, there are a number of complex alkaloids belonging to some Aspidosperma species (Apocynaceae) which seem to have lost the ethylamine side chain of a tryptamine unit (type li. Fig. 2). 

In the present review we divide the pathway leading to the Catharanthus alkaloids into five parts (Fig. 2). The first two concern the biosynthesis of tryptophan and geraniol diphosphate they are similar to (or even part of) primary metabolism and occur in all plant species. Whether these pathways in C. roseus are differently regulated, or whether even an additional pathway exists parallel to the normal primary metabolism, is a question not yet answered. The third and the fourth part coneern the steps from tryptophan to tryptamine and from geraniol to secologanin, respectively. Both pathways occur also in other plants, including plants that do not produce terpenoid indole alkaloids. The fifth part is the condensation of secologanin and tryptamine to strictosidine and the subsequent conversion into a plethora... 

The synthesis of indole alkaloids from the common precursors tryptamine and secologanin by cell cultures of C, roseus has been studied in detail (IT). Cells entrapped in agar, agarose, or carrageenan produce ajmalicine isomers at about the same rate as the freely suspended cells, while cells entrapped in alginate showed up to 160 fold increased synthesis. A major reason for this increased synthesis is believed to be the restricted growth of the entrapped cells, as has been discussed above for Capsiaum. The yield of ajmalicine is above 12 times as much product formed from added precursors as by de novo synthesis. In this case too, alginate entrapped cells were much more productive than freely suspended cells (140% increase), and were also used to synthesize the related alkaloid serpentine in a batch procedure (17). 

Leaves of mature C. roseus have been made to yield a cell-free system which catalyses the formation of vindoline (111). Radioactivity was incorporated into this alkaloid from [2- C]tryptamine and S-adenosyl[Me- C]methionine. 

Monoterpenoid Alkaloids. — Corynantheine - Heteroyohimbine - Yohimbine Group, and Related Oxindoles. Details of the AT-ray crystal structure determination of borreline (92) have now been published,and the species from which it was isolated has been identified as Borreria capitata R. et P. A second alkaloid from this species, borrecapine (93), has a similar structure but, in place of the second methyl group in borreline, borrecapine contains an isobutenyl group which completes the monoterpenoid unit of the non-tryptamine part of the molecule. 

As part of a search for naturally occurring substances acting on neurochemical transmission, a new trimeric tryptamine alkaloid, idiospermuline (177), was isolated from the seeds of Idiospermum australiense, occurring in North Queensland, Australia 113). The structure elucidation was based on spectral data and an X-ray crystallographic analysis of its trimethiodide derivative, which also provided the absolute configuration. 

Many alkaloids contain an indole nucleus as a part of their structure. Monoterpene-derived indole alkaloids see Chapter 34) are the most important of these compounds, but several other significant types of indole alkaloids exist. Ergot alkaloids formed from tryptamine and a mevalonate-derived hemiterpene unit are of medical importance. Others, such as harmane alkaloids, physostigmine and a series of structurally similar alkaloids, Calycanthus alkaloids (Calycanthaceae) and related compounds (principally from the Rubiaceae), and relatively minor types of alkaloids from the Ascelpiada-... 

Kitajima M, Mori I, Aral K, Kogure N, Takayama H (2006) Two New Tryptamine-Derived Alkaloids from Chimonanthus praecox L. concolor. Tetrahedron Lett 47 3199... 

Psychollatine is a monoterpene indole alkaloid, the major alkaloid from P. umbellata, being restricted to shoots (nearly 4% of dry weight in leaves). The alkaloid structure suggests an alternative biosynthetic pathway, STR-independent, by the condensation of tryptamine and a geniposide derivative [124],... 

Monoterpenoid indole alkaloids (MIAs) are derived from tryptophan metabolism. MIAs are one of the most structurally diverse class of compounds with over 2,000 structures. They are mostly found in the Apocynaceae, Loganiaceae, and Rubiaceae family of plants [12]. Similar to BIA biosynthesis, the committed step of MIA biosynthesis begins with the condensation of tryptamine (derived from tryptophan) and secologanin (derived from terpene biosynthesis) to form strictosidine... 

Mescaline A tryptamine alkaloid obtained from the peyote cactus. 

Yohimbine (104), also from the bark of C.johimbe K Schum. and from the roots of R. serpentina (1. ) Benth. has a folk history (unsubstantiated) of use as an aphrodisiac. Its use has been confirmed experimentally as a local anesthetic, with occasional employment for rehef ia angiaa pectoris and arteriosclerosis, but is frequently contraindicated by its undesired renal effects. Yohimbine and some of its derivatives have been reported as hahuciaogenic (70). In addition, its pattern of pharmacological activities ia a variety of animal models is so broad that its general use is avoided. All ten carbon atoms of secologanin (102) as well as the entire skeleton of tryptamine (98, R = H) are clearly seen as iatact portions of this alkaloid. 

Barger el al. took the view that the alkaloid contains two tryptamine residues, one represented in the degradation products by -methyltrypt-amine, and the other by methyl-3-carboline, and on this basis proposed formula (II). Manske and Marion, on the contrary, regard 2V-methyl-tryptamine and 3-carboline as originating from the same moiety of the molecule, the other half being represented by 4-methylquinoline, and on this conception based formula (III). 

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