Lophocereus

Schottenol (sterol) Lophocereus schottii (Senita cactus) [Precursor for fruit fly... 

In agreement with the results obtained in Lophocereus schottii on the origin of the C5 unit (C-1,T,2, 3, 4 ) in lophocerine (62), a specific incorporation of [3, 4- C]mevalonic acid and [2- " C]leucine was obtained into this alkaloid in Pachycereus marginatus. Degradation revealed a labelling pattern consistent with an equal distribution between C-T and C-4 plus C-3 from the experiment... 

The cactus alkaloid pilocerine (67) had earlier been shown to incorporate activity from [N-methyl-14C]lophocerine (66). This result has been confirmed40 by feeding [l-14C,lV-met/ry7-3H]Iophocerine to Lophocereus schlottii the precursor was incorporated intact without change in isotopic ratio. 

Lophocereine (5), a related compound with a five-carbon unit inserted into the nitrogen-containing ring, is found in another cactus species, Lophocereus schottii. The usual carbonyl precursor probably is 4-methyl-2-oxopentanoic acid (6), an entity that probably arises by transamination of leucine (Geissman and Grout, 1969) (Fig. 32.2). However, feed-... 

In addition to simple monomeric units with isoquinoline structures, a number of dimeric and oligomeric alkaloids of this series are known. An example of this type, pilocereine (8) (Fig. 32.3), known from Pachycereus, Pilocereus, and Lophocereus (all Cactaceae), is derived by coupling of isoquinoline alkaloid units (probably by a free-radical mechanism, although proof for this is lacking), much in the same manner as the dimerization process leading to bisbenzyliso-quinoline alkaloids, a topic discussed below. 

Schottenol Sa-stigma-7-ene-3p-ol, a widely distributed phytosterol (see Sterols), M, 414.72, m.p. 151 °C, isolated, e.g. from the cactus Lophocereus schottU. S. is an essential dietary constituent for the insect Drosophila pachea, which lives on this plant. 

In a separate series of experiments, working with intact Lophocereus schottii (Engelm.) Britt. Rose plants, it was demonstrated again by means of [ C]-labeling that the five-carbon unit in lophocerine probably arises independently from both leucine and mevalonic acid by the pathways indicated below. In this instance, no a-keto acid is involved in the Mannich cyclization. ... 

The alkaloids of the sinita cactus Lophocereus schottii and other Lophocereus species are unique in having an isobutyl substituent at carbon-1. These plants mainly contain the trimeric pilocereine, but the monomeric lophocerine has also been isolated (Djerassi et al. 1954). 

There are no reports on phenethylamine derivatives from Lophocereus species however, these cacti are rich in dopamine, a possible progenitor of the various isoquinolines found (Lundstrom unpublished). 

O Donovan DG, Barry E (1974) Biosynthesis of lophocerine in Lophocereus schottii, part II. J Chem Soc Perkin Trans 1. 2528-2529... 

The order Caryophyllales is composed of 12 families (Fig. 1) and was selected for a chemosystematic analysis of sterols based on early reports of 24-alkyl-A7-sterols in three families i.e. Spinacia (Chenopodiaceae), Lophocereus (Cactaceae) and Phytolacca (Phytolaccaceae) . Phytosterol structure and composition was analyzed with respect to each plant s taxonomic assignment. Isolation, identification methods, taxonomic classification, nomenclature systems and tribal arrangements are presented elsewhere only mature photosynthetic tissue was analyzed to avoid... 

Villotti, "The Neutral Constituents of the Cactus Lophocereus schottii," J. Amer. Chem. Soc. 80 6284 (1958). 

Nason, J.D., Haimick, J.L., and Fleming, T.H. (2002) Historical vicariance and postglacial colonization effects on the evolution of genetic structure in Lophocereus, a Sonoran Desert columnar cactus. Evolution, 56 2214-2226. 

---