Carboline-Containing Alkaloids

The sulfur-containing P-carboline marine alkaloids isolated from tunicates belong to three main chemical families the eudistomins, the eudistomidins, and the didemnolines. 

Other Sulfur-containing fi-Carboline Marine Alkaloids... 

Alkaloids, including ft-carbolines, are found in the three genera of the family. In the present survey, they were detected in Eleagnus latifolia, previously known to contain alkaloids, as well as in E. macrophylla, E. multiflora, and E. pungens (1/6), while E. um-bellata, E. wilsonii, and Shepherdia arguta were negative. 

Carboline-containing Manzamine Alkaloids 8.2.1.1 Manzamine A Type... 

S-Carboline alkaloids possess the tricyclic ring system shown in the formula below. Often the 6-membered nitrogen-containing ring is hydrogenated (1,2,3,4-tetrahydro-j -carbolines). Most alkaloids carry substituents in position 3. Additional rings may be present (cf. the formulas of the iridoid carbolines in Fig. 259). 

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). 

An intramolecular Mannich reaction of carboline derivative 352 afforded a complex bridged system containing an indolo[2,3-tf]quinolizidine moiety, as a mixture of two diastereomers. One of them, 353, was transformed into the alkaloid tacamonine 15 (Scheme 79) <2002T4969>. 

Psychotria viridis and P. carthagenensis Psychotria species contain DMT, A/-methyltryptamine, and N-methyltetrahydro-jS-carboline. However, a more recent study of P. carthagenensis showed the plant to be devoid of psychoactive alkaloids (Leal and Elisabetsky 1996). 

Manzamine alkaloids can be isolated from marine sponges. They often contain /3-carboline. This group has a diverse range of bioactivities. It also has its own way of establishing its structures. An intramolecular Diels-Adler reaction for manzamines has been proposed. The a is bisdihydropyridine (derived probably from amonia), and the (3 is intramolecular cycloaddition in a pentacyclic... 

The sulfur-containing (3-carboline alkaloid, 1-ethyl-4-methyl-sulfone-P-carboline (2) was isolated from the New Zealand bryozoan Cribricellina cribraria, along with several other (3-carboline alkaloids. l-Ethyl-4-methyl-sulfone-P-carboline (2) exhibited only modest antimicrobial activity, especially compared to some of the other alkaloids isolated, which were both cytotoxic and antimicrobial [27]. 

A Didemnum sp. from Rota in the northern Mariana Islands contained four new (3-carboline alkaloids, didemnolines A-D (95-98), together with known metabolites [119]. The didemnolines are characterised by substitution at N9 as opposed to Cl. A straightforward synthesis of the didemnolines was reported [120],... 

Root bark of P. callicarpoides contains, beside harman, two main alkaloids in which a 3-carboline group is linked to a pyridine ring, namely, pauridianthine (7) and its pentacyclic isomer pauridianthinine (8) (75). These two compounds are absent in P. Lyallii, in the root and stem bark of which occurs a reduced analog, pauridianthinol (9) (78). The chemotaxonomic relationship between P. callicarpoides, a plant found in the Congo, and P. Lyallii, growing exclusively in Madagascar, is thus established. 

Marine bryozoans and hydroids also contain /3-carboline alkaloids. (5)-l-(l -hydroxyethyl)- -carboline (176) was obtained from the Tas-... 

The main additives are Psychotria carthaginensis, P. viridis, Tetrapterys methystica and Banisteriopsis rusbyana. Leaves and stems of the last, known as oco-yagi or chagrapanga, don t contain the /3-carboline alkaloids produced by B. caapi and inebrians instead, they have a large amount of N,N-DMT, 5-methoxy-N,N-DMT, 5-hydroxy-N,N-DMT andN-/3 -methyltetrahydro-/3 -carboline. The other added species contain DMT-type compounds, rendered orally active by the harmala compounds in ayahuasca. 

Villalba reported in 1925 that he saw natives use about 20 cm. of the stem, which Hoffer and Osmond estimated as containing about 0.5 gm. of /3-carboline alkaloids. "Under its influence, they wrote, "they jumped, screamed, and ran about wildly but continued to take it for days to maintain the state of excitation. They add that Villalba tried the concentrated liquid and had no reaction,... 

The root bark of Ailanthus altissima Swingle contains the known alkaloids canthin-6-one (22), l-methoxycanthin-6-one, canthin-6-one A-oxide, and 1-acetyl-4-methoxy-/ -carboline, together with three new alkaloids, identified as 1-methoxy-canthin-6-one A-oxide, l-(2-hydroxyethyl)-4-methoxy-/ -carboline, and 1(1,2-dihydroxyethyl)-4-methoxy-/ -carboline.21... 

The so-called harmala alkaloids, which are derivatives of carboline, were first found in Peganum harmala, and it was in a study of these that the nuclear structure in which an indole nucleus is fused with a pyridine nucleus was first recognized. Many of the polynuclear indole alkaloids contain the carboline (harman) nucleus, but it is often concealed in such a manner that it may be difficult to recognize. The following discussion will be limited to the derivatives of carboline in which no further nuclei occur. 

The quinazolinocarboline alkaloids, as the name indicates, contain both carboline and quinazoline nuclei. The first known representatives were rutaecarpine and evodiamine, and two more representatives have been encountered more recently. Rhetsinine, which was at one time regarded as belonging here, is included in this chapter because of its affinity with rhetsine, though it does not contain the quinazoline ring system. This chapter is a summary and an extension of that dealing with these alkaloids in Volume II, p. 402. 

The isolation of /3-carboline derivatives and alstyrine from the degradation of alstonine suggests that the alkaloid contains the ring system IV to this must be added the chromophores, the ester group, and the third, unidentified, oxygen atom. Since the UV-spectrum of alstonine is very... 

A third alkaloid contained sulfur (a rare feature in higher plant nitrogen heterocycles) and was shown to be 4-methylthiocanthin-6-one (XIV) (9). Hydrolysis with amyl alcoholic alkali gave methyl mercaptan and the phenol XV which, upon permanganate oxidation, furnished /3-carboline-l-carboxylic acid. The phenol did not form a quinoxaline with o-phenylenediamine, and its acetate in moist ethereal diazomethane... 

The indole alkaloids so far discussed all have a tetrahydro-/ -carboline system. The main fragments of these alkaloids contain the indole part of the molecules. This situation is changed in alkaloids which have a larger ring C or an indoline system, permitting the production of fragments characteristic of both the indole and piperidine moieties. 

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