Heimia salicifolia Lythraceae alkaloids

Anti-inflammatory Compounds.—Claims for anti-inflammatory activity of alkaloids appear in the literature from time to time, but in view of the difficulties connected with the testing of such compounds, positive results should be viewed with caution. Recently it has been stated that cryogenine from Heimia salicifolia (Lythraceae) has anti-inflammatory activity. Lythraceae have been investigated broadly during recent years, probably because of an early claim that these alkaloids have hallucinogenic properties. The structure (31) has been proposed for cryogenine. ... 

Lythraceae Alkaloids.— The rate at which quinolizidine alkaloids of the cryogenine (35) type are synthesized and degraded in Heimia salicifolia has been studied as has their sequence of appearance in growing plants. " The results do not yet add to the preliminary data so far obtained on these alkaloids. ... 

Alkaloids of the family Lythraceae were reviewed in Volumes 18 and 35 of this series (595, S). The latter review, published in 1989, was devoted to developments during the period 1979-1987, and overtyped to some extent with the review on simple indolizidine and quinolizidine alkaloids in Volume 28 (1). Also worth noting is a phytochemical and phytopharmacological review on the New World flowering shrub Heimia salicifolia, an important source of these alkaloids (596). 

Lythraceae Alkaloids.—Cryogenine (18) has been shown to incorporate [3- " C]-phenylalanine in Heimia salicifolia. Oxidative degradation established the incorporation of labels at the positions shown in (18) the difference in incorporation of the two units may be a function of the stage at which they normally enter the biosynthetic pathway. Although ring d and the whole of its C3 side chain are probably derived from phenylalanine, it is not yet clear whether this precursor supplies three or only one carbon atom of the quinolizidine system. 

After the recent considerable activity in the synthesis of macrocyclic Lythraceae alkaloids, published work this year has been confined to the isolation of the new aryl-quinolizidine alkaloids desmethoxyabresoline (28) and 10-ep/-desmethoxyabresoline (29) from Heimia salicifolia The structure of alkaloid (28) was established by spectroscopy and by conversion into two known compounds, the alcohol (27) (c/. Vol. 6, p. 97) obtained by basic hydrolysis and... 

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