Piper trichostachyon

The structure (83) of the new alkaloid piperstachine has been established on the basis of spectral data and the synthesis of its hexahydro-derivative.  

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Piper trichostachyon C.DC. from India contains a variety of pyrrolidine alkaloids in its stem and leaves. Among these one finds trichostachyne (135) (210), its C2 homolog 1-piperettylpyrrolidine (141) (211), tricholein (142) (212), and a long-chain dienamide trichonine or l-pyrrolidinyl-(E, )-eicosa-2,4-di-enamide (143) (213). 

Several new alkaloids have been isolated from pepper species. Tricholeine, for example, occurring in the stems of Piper trichostachyon, is the pyrrolidine amide (2) of fra s-9-(3,4-methylenedioxyphenyl)-A8-nonenoic acid, the structure being established by spectroscopic and degradative studies.4 Piper guineense seeds contain okolasine (6-methoxytrichostachine) (3),5 which is probably identical to the earlier known wisanidine. 4,5-Dihydro-wisanidine (4) is also found in the same... 

This section summarises recent work on alkaloids containing the pyrrolidine nucleus. A short review concerning the synthesis of this group has appeared. A variety of Labiatae plants have been screened and some of them have been shown to contain pyrrolidine alkaloids. Cuskhygrine has been found in the roots of three Datura species and stachydrine has been obtained from Capparis spinosa3 The structure of trichostachine (1) Piper trichostachyon) has been elucidated by spectral means and confirmed by synthesis. Ficine (5), an interesting flavonoid alkaloid, has been synthesised. Friedel-Crafts reaction between... 

The dienamides (5) [13] and (7) [14] have been isolated from Leucocyclus formosus and the tetradecadienoylpyrrolidine (8) and piperidine (9) have been found in Achillea arten [14] and Otanthus maritimus [15] respectively. The isobutylamides (10-12) have been extracted from the fruits of Piper guineense collected in the western parts of Nigeria [16]. Trichonine (13) and compounds (12) and (16) have the longest dienamide chains isolated so far and they are found in Piper trichostachyon leaves [17]. 

A review of recent chemistry of Indian Piper spp. has appeared it includes some pyrrolidine alkaloids.8 The synthesis of tricholeine (6), an alkaloid of P. trichostachyon, has been reported the pathway is summarized in Scheme 2.9... 

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