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Chemistry and taxonomy of Fouquieria splendens Engelm: A new member of the asperuloside group

1964; Elsevier BV; Volume: 3; Issue: 5 Linguagem: Inglês

10.1016/s0031-9422(00)82938-6

1873-3700

E.C. Bate-Smith,

Botany, Ecology, and Taxonomy Studies

IN HIS book l%e Taxonomy of Vascular Plants,l Lawrence writes: “The phyletic position of the Fouquieriaceae is unsettled. In earlier Englerian works, and by Wettstein, it was included in the Parietales, and was advanced to its present position [following the Polemoniaceae in the Tubiflorae] by Engler and Gilg (1924). Ressey included it in his Ebenales and Hutchinson in his Tamaricales.” It was suggested that an examination of the phenolic constituents of Fouquieriu species might assist in current studies.* The leaves, outer bark and inner bark from F. splendens Engehn. (“Ckotillo”) were therefore examined by the methods routinely employed in this laboratory in surveys of the phenolic constituents of leaves2 From the systematic point of view the most signa and the coumarin, scopoletin, were all present. The occurrence together in one plant of leuco-anthocyanins and ellagic acid is of quite common occurrence in the dicotyledons, especially in woody families, but this combination associated with the absence of leucodelphinidin and myricetin is rare. Families in which this pattern has been found include Rosaceae-Rosoideae, the Tamaricaceae and the Comaceae. Ellagic acid has not been found in any of the families in the Englerian system beyond the Ebenaceae, and leuco-anthocyanins relatively rarely in these families. It seems unlikely, therefore, that the athnities of the Fouquieriaceae lie in this systematic area. This leaves a wide choice, from the chemical evidence so far considered, as to where these aSnit& might be, but relationship with the Tamaricaceae is certainly included among the possibilities. However, there is further evidence which may ultimately help to narrow down the area of possibility. In the course of acid hydrolysis of the leaves and bark it was observed that a blue colour developed in the aqueous extract, soon replaced by a dark precipitate. This behaviour is characteristic of asperuloside (I). The precursor substance, which was not present in my great quantity in any of the tissues examined, was extracted by boiling with water, diluting the extract with an equal volume of n-propanol, salting out the propanol with NaCl, and evaporating the alcoholic solution to dryness in a stream of warm air. The ethanolic extract of the residue was separated on Whatman No. 3 paper in either 6 % aqueous acid or in butanol : acetic acid: water (6: 1: 2), the position of the chromogen being ascertained by boiling test sections in 2 N HCl. The corresponding strips were eluted with 70 % ethanol, and the eluates l 1 em grateful to Professor B. L. Turner, Austin, Texas, for this suggestion.