Pleiocarpa mutica

According to a recent report on some unpublished work by Joshi and Taylor (92a), the acid hydrolysis of villalstonine affords pleiocarpamine (LXXIIa) (92b), one of the constituent bases of Pleiocarpa mutica Benth. (92c) and Hunteria ebumea Pichon (92d). 

A continuing examination of Pleiocarpa mutica Benth. and P. tubicina Stapf has revealed the alkaloids summarized in Table II. Although extracts of these plants have shown prolonged blood pressure-lowering properties (41), the active component(s) has not yet been identified. 

These two bases, pleiomutine from Pleiocarpa mutica Benth. and umbellamine from Hunteria umbellata (K. Schum.) Hall. F. Carpodinus umbellatus K. Schum., Polyodoa umbellata Stapf., Picralima umbellata Stapf.), possess a common building block, namely 14,15-dihydroeburnamenine (229). This is bonded through C(14) to the aromatic ring of the second monomeric component, an indoline. Umbellamine is probably identical with the alkaloid hunterine, of unknown constitution, from Hunteria eburnea Pichon. ... 

C21H27N2O2 4849-01-8 45 jVa-Methy sarpagine metho salt Pleiocarpa mutica 135... 

VIII) may be briefly summarized as follows. Villalstonine is a dimeric, diacidic base, which contains one methoxycarbonyl group, two methyl-imino groups, and an ethylidene group. Its UV spectrum is consistent with the presence of indole and dihydroindole chromophores containing no substituents in the benzene rings. Alkali fusion yields 2-methylindole, indole 2-carboxylic acid, and a /3-carboline derivative selenium dehydrogenation also affords a j8-carboline derivative, so far unidentified. Acid hydrolysis of villalstonine yields pleiocarpamine (XV), one of the alkaloids of Pleiocarpa mutica Benth. 

The new alkaloids of this group, all from Pleiocarpa species, are tubo-flavine (I) from Pleiocarpa tubicina Stapf [P. pycnantha. (K. Schum.) Stapf var. tubicina (Stapf) Pichon], the same alkaloid, isotuboflavine (II) (mp 263°-265°) and norisotuboflavine (III) (mp 282°-284°) from Pleiocarpa mutica Benth. l-Methoxycarbonyl-(8-carboline was also isolated along with the latter alkaloids (3). 

The structure of pleiomutine, IX (mp 225°) (9), a constituent of Pleiocarpa mutica 10), has been established largely on the basis of a detailed analysis of the mass spectra of derivatives, deuterium exchange,... 

Hunterburnine a- and j8-methochlorides and huntrabrine metho-chloride have been isolated from the closely related plant, Pleiocarpa mutica Benth. (3d). The mass spectra of hunterburnine a- and /3-metho-chlorides have been studied along with other quaternary salts (31). Both... 

The tertiary alkaloid pleiocarpamine, C20H22N2O2 (mp 159°), was first isolated 2) from the roots of Pleiocarpa mutica Benth. and subsequently (3) from the bark of Hunteria eburnea Pichon (both Apocynaceae). It possesses (2) an A-substituted indole chromophore and its IR-spectrum indicated the presence of a carbonyl group (1727 cm i in Nujol or KBr) OH and NH absorptions were absent. Analysis revealed the presence of one methoxyl and one C-methyl group and the absence of A-methyl groups. 

Another oxidized form of pleiocarpine, which occurs in Pleiocarpa mutica, was shown by high-resolution mass spectrometry to be C23H24N2O6 31). Losses of CO, CO-1-C2H4, and CO-1-C4H6O2 were indicative of the presence of a cyclic carbonyl, —CH2—CH2— and... 

Achenbach and Biemann [1 c] quote the hi /-values of 10 compounds which they obtained during isolation of the isotuboflavine and noriso-tuboflavine from Pleiocarpa mutica, using chloroform-methanol (90 +10) or chloroform-ethyl acetate-methanol (75 + 20 + 5) on silica gel G. 

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