Rauwolfia plants

The 3,4,5-trimethoxycinnamic ester of methyl reserpate is also present in Rauwolfia plants and obtainable in purified form therefrom by extraction as described in U.S, Patents 2,974,144 and 2,876,228. 

Rauwolfia plants, by extraction Deserpidine Rescinnamine Reserpine... 

Reserpine, an alkaloid from the Rauwolfia plant, abolishes the vesicular storage of biogenic amines (NE, dopamine = DA, serotonin = 5-HT) by inhibiting an ATPase required for the vesicular amine pump. The amount of NE re-Liillmann, Color Atlas of Pharmacology 2000 Thieme All rights reserved. Usage subject to terms and conditions of license. 

Antihypertensive agents, substances that lower high blood pressure, are an important subclass of cardiovascular agents. Reserpine, an indole alkaloid obtained from the Rauwolfia plant, was the first successful drug to... 

Rauwolfia (Raudixin, Rauserpa, etc.), the powdered whole root of the Rauwolfia plant, is a tan, bitter, fine amorphous powder with a slight odor, sparingly soluble in alcohol and only very slightly soluble in water. 

The biosynthetic pathways of reserpine and other alkaloids of Rauwalfia have been extensively studied by several authors. Leete (l8, 19) fed DL-[2- C]-tryptophan into Rauwolfia serpentina (3 years old plants) which led to the formation of radioactive ajmaline, serpentine and reserpine (18). Later, he found that radioactive serpentine was labeled solely at C-5 indicating that tryptophan was a direct precursor of the -carboline moiety of this alkaloid (19). Other radioactive precursors have been administered to Rauwolfia plants such as [l- C] acetate (20), [2- C] acetate (21), [2-11 C] alanine (20) and [2-l2 C] glycine (21, 22). All incorporated into ajmaline and reserpine. 

Trimethoxycinnamic acid Methyl reserpate Thionyl chloride Rauwolfia plants... 

Many alkaloids have pronounced biological properties, and a substantial number of the pharmaceutical agents used today are derived from naturally occurring amines. As a few examples, morphine, an analgesic agent, is obtained from the opium poppy Papaver somnifemm. Cocaine, both an anesthetic and a central nervous system stimulant, is obtained front the coca bush Erythroxylon coca, endemic to upland rain forest areas of Colombia, Ecuador, Peru, Bolivia, and western Brazil. Reserpine, a tranquilizer and antihypertensive, comes from powdered roots of the semitropical plant Rauwolfia serpentina. Ephedrine, a bronchodilator and decongestant, is obtained front the Chinese plant Ephedra sinica. 

In 1952 reserpine, an alkaloid extract from the Indian snakewort plant, Rauwolfia serpentina, which had been used in that country to treat madness , was first tried in schizophrenia. The beneficial impact on patients and the hospital wards was dramatic, as was that a year later of chlorpromazine, a phenothiazine derivative and haloperidol, a butyrophenone. These latter two drugs and closely related derivatives remained the mainstay of therapy for almost 40 years. 

Salutaridinol 7-0-acetyltransferase catalyzes the conversion of the phenanthrene alkaloid salutaridinol to salutaridinol-7-Oacetate, the immediate precursor of thebaine along the morphine biosynthetic pathway in P. somniferum (Fig. 10.7).26 Acetyl CoA-dependent acetyltransferases have an important role in plant alkaloid metabolism. They are involved in the synthesis of monoterpenoid indole alkaloids in medicinal plant species such as Rauwolfia serpentina. In this plant, the enzyme vinorine synthase transfers an acetyl group from acetyl CoA to 16-epi-vellosimine to form vinorine. This acetyl transfer is accompanied by a concomitant skeletal rearrangement from the sarpagan- to the ajmalan-type (reviewed in2). An acetyl CoA-dependent acetyltransferase also participates in vindoline biosynthesis in Catharanthus roseus, the source of the chemotherapeutic dimeric indole alkaloid vinblastine (reviewed in2). Acetyl CoA deacetylvindoline 4-O-acetyltransferase catalyzes the last step in vindoline biosynthesis. A cDNA encoding acetyl CoA deacetylvindoline 4-0-acetyltransferase was recently successfully isolated.27... 

Coincidental with the above developments, biomedical scientists in pharmaceutical companies were actively pursuing purified extracts and pure compounds derived from plants and animal sources (e.g., digitalis, rauwolfia alkaloids, and animal hormones) as human medicaments. Analogs and derivatives of these purified substances were also investigated... 

Other plants known to contain psychoactive compounds include hellebore, which was used for centuries in Europe to treat mania, violent temper, mental retardation and epilepsy. However, a drug of major importance in modern psychopharmacology arose from the discovery by medicinal chemists of the alkaloids of Rauwolfia serpentina, a root which had been used in the Indian subcontinent for centuries, not only for the treatment of snake bite but also for alleviating "insanity". Understandably, the mechanism of action of reserpine, the alkaloid purified from Rauwolfia serpentina, helped to lay the basis to psychopharmacology by demonstrating how the depletion of central and peripheral stores of biogenic amines was correlated with a reduction in blood pressure and tranquillization. 

Since the last major review of the biosynthesis of the monoterpenoid indole alkaloids (97), there have been several full and partial 98-104) reviews of various aspects of the work that has been conducted since 1974. Two major developments have dominated the field in this period, namely, the demonstrations that (i) strictosidine (33) is the universal precursor of the monoterpenoid indole alkaloids and (ii) selected cell-free systems of C. roseus have the ability to produce the full range of alkaloid structure types, including the bisindoles. This section traces some aspects of these developments, paying particular attention to work been carried out with C. roseus, and omitting work, important though it may be, on other monoterpenoid indole alkaloid-producing plants, e.g., Rauwolfia, Campto-theca, and Cinchona. 

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... 

Yohimbine Yohimbine is methyl ether ( )-2a-hydroxyyohimban-la-carboxylic acid (12.2.16). It is isolated from the plants Corynanthe johimbe and Rauwolfia serpentina [60,61], It is also synthesized [62-66],... 

Reserpine, an alkaloid extracted from the roots of an Indian plant, Rauwolfia serpentina, was one of the first effective drugs used on a large scale in the treatment of hypertension. At present, it is rarely used owing to its adverse effects. 

Reserpine is a raulwolfia alkaloid isolated from the roots of the plant Rauwolfia Serpentina. It is used for the treatment of mild essential hypertension or psychosis. 

Ajmalicine (see rauwolfia, page 353) is present in the roots of Catharanthus roseus at a level of about 0.4%, and this plant is used as a commercial source in addition to Rauwolfia serpentina. 

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