Aspidosperma bark

Carbocyclic variants related to ajmalicine such as yohimbine are likely to arise from dehy-drogeissoschizine by the mechanism indicated in Figure 6.77. Yohimbine is found in Yohimbe bark (Pausinystalia yohimbe, Rubiaceae) and Aspidosperma bark (Aspidosperma species Apocy-naceae) and has been used in folk medicine as an aphrodisiac. It does have some pharmacological activity and is known to dilate blood vessels. More important examples containing the same carbocyclic ring system are the alkaloids found in species of Rauwolfla, especially R. serpentina (Apocynaceae). Reserpine and deserpi-dine (Figure 6.78) are trimethoxybenzoyl esters of yohimbine-like alkaloids, whilst rescinnamine is... 

Aspidosperma bark Aspido.sperma quebracho-blanco SCHLECHT Apocynaceae... 

Floriani has recently examined bark from Aspidosperma quebracho bianco Schlecht f. pendulas Speg, in which he found the known alkaloids, quebrachine (yohimbine) and aspidospermine, as well as Hesse s aspidosamine, C2gH2g02N2, and a new base, aspidospermicine, Ci Hj ON, l-SHjO (1938). Hartmann and Schlittler have shown that the alkaloid vallesine from Vallesia glabra (Apocynaceae) is aspidospermine, and this has been confirmed by Deulofeu et aJ. who have also found it in V. dichotoma. Later Schlittler and Rottenberg by chromatographic analysis of the mother liquors of aspidospermine isolated a second alkaloid for which they used the old name Vallesine (1948). ... 

N-Oxygenated C=N functionalities also occur in plants. Thus, harman N-oxide (har-manine, 9) is the main alkaloid in all parts of Calligonium minimum14. The trunk bark of Aspidosperma nigricans contains the unstable olivacine N-oxide (10)74. Orellanine (11) has been isolated from the toadstool Cortinarius orellanus15. The substance is heat-stable and exerts considerable nephrotoxicity. 

This "psychedelic stimulant" is derived primarily from the bark of a West African tree called Pausinystalia or Corynantheyohimbe, although it is also present in other species of Corynanthe and in Aspidosperma quebran-choblanco and Mitragyna stipulosa. When this alkaloid is brewed as a tea and then drunk, its effects come on within forty-five minutes to an hour. The action is reportedly swifter if taken with 500 mg. vitamin C... 

From the leaves of Pleiocarpa tubicina, in addition to bases described in Sections III, G, and VI, C, there has been isolated an alkaloid, tubotaiwine, of structure CCXXIV (119). The same substance also occurs in the root bark of Aspidosperma limae (120). 

The bark of Aspidosperma compactinervium, contains an alkaloid, compactinervine, whose high negative rotation, UV- (A 237, 297, 331) and IR-spectra (conjugated C02Me, 6.04 p conjugated double bond,... 

A wide variety of alkaloids has been encountered in the bark of Aspidosperma quebrachoblanco (see Table I). An investigation of the leaf alkaloids yielded a new base, quebrachidine (CCCXXXVIII-D, 179b), whose UV- (A 242, 290) and NMR-spectra were indicative of a dihydroindole unsubstituted in the benzene ring, while the IR-spectrum showed the presence also of the groupings NH, OH, and CO2R. The NMR-spectrum further indicated that the ester was a carbomethoxyl group... 

The typical fragmentations pattern of the alkaloid type (199) was very useful for the structural elucidation of some minor alkaloids occurring in the bark of Aspidosperma oblongum A. DC. They were shown to be methoxyl and dehydro derivatives of the parent molecule.95, 96... 

Aspidospermine one indole alkaloid was isolated from bark of Aspidosperma quebracho-bianco, displaying antimalaiial activity on Plasmodium falciparum (29). 

Since oxidized derivatives of secodine appear to be involved as late intermediates in the biosynthesis of the aspidospermidine and pseudoas-pidospermidine alkaloids, it is logical to begin with those secodine derivatives that have been found to occur naturally. Tetrahydrosecodine (1) occurs in the root bark of Aspidosperma marcgravianum Woodson (5) and has been detected in cell-suspension cultures of Rhazya stricta Decaisne (6) its demethoxycarbonyl derivative (2) also occurs in A. marcgravianum (5), and in Haplophyton crooksii L. Benson (7,8) and the roots of R. stricta (9). The two isomeric carbonyl derivatives, 2-ethyl-3-[2-(3-acetyl-V-piperidino)ethyl]indole (3) and crooksidine (4), occur, respectively, in A. marcgravianum (5) and H. crooksii (7,8). 

Finally, IS-demethoxypyrifoline (205) has been shown to be a constituent of the root bark and leaves of Aspidosperma pyrifoHum (< S). This alkaloid appears to be the only representative of the enantiomeric series in this subgroup encountered in recent years from natural sources. 

From the bark of Aspidosperma quebracho bianco. Six alkaloids identified quebra-chine, aspidospermine, aspidospermatine, as-pidosamine, hypoquebrachine. Quebrachine is said to be poisonous with effects like those of strychnine. 

Investigating alkaloids of the Aspidosperma species, Arndt has identified carapanaubine in the bark of A. rigidum Rusby (31). Cara-panaubine and isocarapanaubine have been found to accompany rauvoxine and rauvoxinine (C23H28N20e), an isomeric pair of oxindole alkaloids first isolated from the leaves of Rauwolfia vomitoria Afz. (32, 33). 

Picraline (6) Aspidosperma rigidum Rusby bark = A. laxiflorum Kuhlm.) 18... 

Aspidosperma. Quebracho. Dried bark of Aspidosperma quebracho-bianco Schlecbt., Apocynaceae. Habit. Argentina. Constit. 0.3 -1.4% alkaloids—aspidospermine, aspidospermatine, aspidosamine, quebrachinc. quebrach-amine. hypoquebrachine. quebrachol. qucbrachit tannin. 

From the root bark of Aspidosperma fendleri Woods. Medina and coworkers (41) isolated a new crystalline alkaloid, fendlispermine. The UV spectrum indicated the dihydroindole moiety, and the mass spectrum, which showed a molecular ion at m/e 298, suggested a molecular formula of C19H26N20. Reduction of fendlispermine with lithium aluminum hydride gave quebrachamine (82). 

The aerial bark of the Venezuelan shrub Aspidosperma cuspa Blake ex Pittier afforded the alkaloid de-O-methylaspidocarpine (84) (42), previously obtained as a degradation product (43). 

From the bark of Aspidosperma quebracho-blancho Tunmann and Wolf (97) have isolated a new hydroxyindolenine, rhazidigenine JV-oxide (200). 

In previous work the stem bark of Aspidosperma album (Vahl) R. Bent, was examined, and ten alkaloids were isolated attention has now been diverted to the seeds, from which no fewer than twenty-five alkaloids were obtained. Of these,... 

C19H26N2, Mr 282.43, mp. 147-149 °C soluble in acetone, chloroform, dilute acids. A monoterpenoid indole alkaloid of the Aspidosperma type, Q. occurs in both enantiomeric forms the (+)-form, (aJu +98° (CHCI3), in leaves and root bark of Pleiocarpa species as well as the bark of Stemmadenia species the (-)-form, [aJi, -100° (CHCI3), in Aspidosperma quebra-cho-blanco and other Aspidosperma species as well as Gonioma, Hunteria, and Rhazya species. 

Quebracho (cortex). The bark of the quebracho tree, Aspidosperma quebracho-bianco (Apocynaceae), a large tree (up to 20 m high), indigenous to the west of South America. The bark contains ca. 1% monoter-penoid indole alkaloids such as yohimbine, aspido-spermine, quebrachamine. The Aspidosperma alkaloids are structurally related to the Catharanthus alkaloid vindoline. Quebracho bark contains over 25 different alkaloids of widely differing types. ... 

Mitaine A-C, Weniger B, Sauvain M, Lucumi E, Aragon R, Zeches- Hanrot M. Indole alkaloids from the trunk bark of Aspidosperma megalocarpon. Planta Med 1998 64 487. 

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