Alkaloids of Rauvolfia salicifolia GRISEB species

Abstract

Dedicated to Professor Holger Erdtman on the occasion 0/ his 80th birthday.From the endemic Cuban species Rauuol/ia salicl/olia GRISEB nine alkaloids were isolated of which the following seven had been already described: ( + )-ajmalidine (I), ( -)-reserpiline (11), ( -)-iso-The structure of ( -)-raucubaine (VI11) had been previously determined by X-ray diffraction and the structure of the alkaloid (-)-raucubainine (IX) was suggested on the basis of its conversion to ( -)-raucubaine (V Ill). The absol ute configuration of ( -)-raucubaine and (-)-raucubainine was elucidated by CD spectroscopy.Rau volfia salicifolia GRISEB represents one of the three endemic Cuban species of the Rauvolfia genus. This species was phytochemically studied in 1957 by Korzun and coworkers! who proved the presence of deserpidine, reserpiline, rescinamine and reserpine in the extract. The alkaloids were characterized only by paper chromatographic comparison with the authentic compounds.In this study we describe the isolation of nine alkaloids: From the root bark we isolated (+ )-ajmalidine (I), (-)-reserpiline (II), (-)-isoreserpiline (III) and ( -)-isocarapanaubine (IV). The principal alkaloid present in the plant is reserpiline. Isocarapanaubine was isolated from the Rauvolfia genus for the second time, the first isolation being from Rauvolfia vo mitoria 2 • From the tree bark we obtained ( -)-reserpiline (II), ( -)-ajmalicine (V), ( + )-vellosimine (VI) and ( + )-yohimbine (VII). The leaves afforded ( -)-reserpiline (II), ( -)-ajmalicine (V) and the new alkaloids (-)-raucubaine (VIII) and (-)-raucubainine (IX).The structure of raucubaine (VIII) was determined already by X-ray analysis 3 ,4.Its IH-NMR spectrum displays signals of four arom atic protons whose mutual interactions indicate an ortho-disubstituted benzene nucleu s, a singlet at (5 2·71 due Part XLVI in the series Plant Substances; Part XLV: This Journal 47, 644 (1982). This work represents part of the Thesis of P. Sierra

Alkaloids from Roots ofStrempeliopsis strempelioides- Structures of Strempeliopine and Strempeliopidine

“…The mass spectrum of vallesamidine differed from that Part XCVII in the series Plant Substances; Part XCVI: see ref. (1). This work represents a part of the Thesis of A.…”

“…Quel. (Tricholomataceae) are used for the treatment of dizziness, headache, neurasthenia, insomnia, numbness in limbs and infantile convulsion (1). For investigation of the effective principles of this drug we have studied its chemical constituents, Recently, Midland (2) and Donnelly (3) reported that two new sesquiterpenoid aromatic esters, which have antibacterial activity, were isolated from A. mellea.…”

Recent progress in the chemistry of indole alkaloids and mould metabolites

“…has revealed the presence of (+)-ajmalidine in the root bark and (+)-vellosimine in the stem bark. 57 The presence of (-)raucubaine (136) in the leaves was confirmed, together with a closely related alkaloid, (-)-raucubainine (1 39), which is converted into raucubaine on reaction with methanol in acid solution. Raucubainine thus has the same gross structure as quaternoxine, but the two bases appear not to be identical, and hence may differ in the configuration of the epoxide function.…”

“…Ajmalicine, reserpiline, and yohimbine were isolated from the tree bark, and ajmalicine and reserpiline from the leaves. 57 Hunteria congofana Pichon contains 23 alkaloids, including pleiocarpamine and its 2,7-dihydro-derivative from this group. 58 The nineteen alkaloids extracted from the stem and root bark of New Caledonian Afstonia pfumosa Labill.…”

Application of the Asymmetric Pictet–Spengler Reaction in the Total Synthesis of Natural Products and Relevant Biologically Active Compounds

“…Also, in Brazilian folk medicine it was described to have curare-like properties [ 87 ]. Moreover, (+)-vellosimine was extracted from different species of Rauwolfia that are widely dispersed thought Asia and Africa [ 88 , 89 , 90 , 91 ]. These plants are broadly used in traditional Chinese medicine for the treatment of hypertension [ 89 , 92 ] neuralgia, and migraine [ 93 ].…”