Rauwolfia vomitoria alkaloids

The isolation of a new reserpine-type alkaloid from Rauwolfia vomitoria Afz. named neonorreserpine has recently been reported however, the stereochemistry of its substituents attached to ring E has not yet been established (86). 

The enzyme responsible for the stereospecific condensation of trypt-amine and secologanin 34) was called strictosidine synthase, and its presence was demonstrated by Treimer and Zenk 194) in a number of indole alkaloid-producing plants, including Amsonia salicifolia, Catharanthus roseus, Ochrosia elliptica, Rauwolfia vomitoria, Rhazya orientalis, Stem-madenia tomentosa. Vinca minor, and Voacanga africana. Enzyme activity as high as 1698 pkat/mg protein was observed for O. elliptica. No... 

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). 

It has been pointed out that the C n.m.r. data reported for ajmalinol, a new alkaloid of Rauwolfia vomitoria, are inconsistent with the proposed 11-hydroxyajmaline structure. Some of the data are very close to those reported for ajmaline itself, others are consistent neither with an ajmaline nor an 11-hydroxyajmaline structure. Hence the structure of ajmalinol is at present obscure. 

Ajtnalicine is found in plants belonging to Apocynaceae, namely, Catharanthus roseus, Rauwolfia serpentina, and Rauwolfia vomitoria. Ajmalicine was first isolated from yohimbe bark and is one of the principal alkaloids of Catharanthus roseus and widely used to treat circulatory disorders [6] (Fig. 20.3). Ajmalicine is... 

The alkaloid reserpine is obtained naturally from the rhizome and roots of Rauwol-fia spp. Rauwolfia serpentina is a small shrub belonging to Apocynaceae family and found in India, Burma, Java, and Thailand. Rauwolfia vomitoria is widely grown in Congo, Africa, and contains more than twice quantity of reserpine. Ninety percent of reserpine is present in the roots and only 10 % in the stem and leaves [107] (Fig. 20.7a). 

The alkaloidal constituents of the stem bark of Nigerian Rauwolfia vomitoria have been isolated and characterized, some of which are described in Table 5.2.3 (129). 

Table 5.2.3. Principal alkaloid obtained from 1.5 kg stem bark of Rauwolfia vomitoria...

Sabri N N, Court W E 1978 Stem alkaloids of Rauwolfia vomitoria. Phytochemistry 17 2023-2026... 

Rauwolfia serpentina Benth, which derives its name from Leonhart Rauwolf, a 16th century botanist, and its serpentine root (Figure 56.1), has long been used in India for a variety of ailments. The discovery of its tranquilizing action, particularly in lowering the blood pressure, led to its introduction into Western medicine. The Rauwolfia alkaloids are derived from a family of tropical and semitropical plants related to oleander and periwinkle. They vary from small shrubs to tall trees. The important species from which the alkaloids are derived include Rauwolfia serpentina (Ophioxylon serpentinum or Indian snakeroot), R. micrantha, R. vomitoria, and R. hirsuta (Canescens heterophylla). 

The occurrence of reserpine has been reported from all Rauwolfia species, with the exception of about half a dozen in which it is probably present in minute amounts. Renoxidine, the A-oxide of reserpine, has been isolated from R. vomitoria, R. serpentina, and R. canescens, and it may not be a natural product, since it could have been derived by autoxi-dation of the tertiary base which is abundant in these plants. If it was an artifact, the occurrence of other analogous A-oxides should have been noted, but so far the only other recognized case is raujemidine A-oxide, which is found along with the parent alkaloid, raujemidine (a minor base of R. canescens). In contrast to reserpine, deserpidine and rescinnamine are of restricted distribution, each being recognized so far in about ten species only. 

An alkaloid obtained from the roots of certain species of Rauwolfia (Apocynaceae), mainly R. serpentina and R. vomitoria, or by synthesis. 

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