Decodon verticillatus

Two hundred and thirty samples tested included several known from earlier literature to be positive Decodon verticillatus (17/17), Heimia myrlifolta (18/18), H. saltctfolia (10/13), Legerstroemla indica (1/3), L. speciosa (1/3), Lawsonia lanceolatum (2/3). 

Lythraceae Alkaloids.—Results showing that lysine (15) is a precursor for decodine (22) and decinine (23) in Decodon verticillatus, which were published in preliminary form (cf. Vol. 1, p. 6), are now available in a full paper.8 Label from either C-2 or C-6 of the amino-acid was found to be spread equally over C-5 and C-9 of the alkaloids, indicating that ring A derived from this amino-acid and that incorporation was via a symmetrical intermediate. Cadaverine (16),... 

The first isolation of the Lythraceae alkaloids from Decodon verticillatus (L) Ell was reported by Ferris in 1962 (2). Those were lactonic biphenyl alkaloids (type A) decinine, decodine, verticillatine, decamine, vertine, lactonic ether alcaloids, decaline, and vertaline. 

Verticillatine (20) was isolated by Ferris from Decodon verticillatus (2). Dihydroverticillatine (21) and lagerstroemine (23) were isolated by Ferris et al. from Lagerstroemia indica (25) and sinicuichine (22) by Blomster et al. from H. salicifolia (1). Lagerstroemine was also detected in Plantago psylium... 

Six alkaloids belong to this group decaline (49), demethyldecaline (50), vertaline (51), demethylvertaline (52), lagerine (53), and methyllagerine (54). In the first two alkaloids the quinolizidine ring is trans-fused and in the latter four it is cis-fused. These compounds are listed in Table III (7, 2, 77, 25, 36, 41, 42). Decaline and vertaline were isolated by Ferris from Decodon verticillatus (2). 

Over 40 alkaloids have been isolated from Lythraceous plants since Ferris isolated 7 alkaloids from Decodon verticillatus in 1962 (/). Before the last review in this treatise (2), the structures and stereochemistries of all Lythraceous alkaloids had been established. No reports on the isolation of new alkaloids from this family have been published since 1981. On the other hand, development of new synthetic technologies has opened new avenues to the total synthesis of Lythraceous alkaloids. The earlier classification (types A-E) of Lythraceous alkaloids introduced by Fuji et al. (J) and adopted in the last review (2) is not used in this chapter because it does not indicate the structural features. This chapter covers the literature from 1979 to 1987, except for two papers (4, 5) already included in the last review (2) in Volume 18 of this treatise. 

The possible origins of rings a, b, and c are illustrated for the alkaloids decodine (19) and decinine (20) (Scheme 4). Both [2- C]-DL-lysine and [6- C]-DL-lysine were incorporated into these alkaloids in Decodon verticillatus Degradation indicated that lysine was utilized as an intact C5N unit and, further, a symmetrical intermediate was involved. [l- C]Lysine gave totally inactive alkaloid. 

Partial degradation of the lythraceae alkaloids decodine (22) and decimine (23), isolated from Decodon verticillatus after being fed either 2-14c or 6 4c-lysine, indicated that the amino acid enters the alkaloid in a non-random fashion through a symmetrical intermediate. It was also demonstrated that two fragments derived from phenylalanine are incorporated into decodine. 

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