Hexahydroxydiphenoyl Metabolites — Group

Earlier in this review good reasons were advanced for using the patterns of phenolic metabolism in the leaves of higher plants as the basis for a comparison of this activity in different plants and plant 

The metabolites produced in this manner are referred to here as class B metabolites. Plants whose phenolic metabolism places them within this category furnish, along with P-penta-o-galloyl-D-glucose (11), one or more of the hexahydroxydiphenoyl esters (40, 41, 42) and (43) as key phenolic metabolites 26). The ratio of these four metabolites varies quite markedly 

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Table 8. Hexahydroxydiphenoyl Metabolites — Group C. Occurrence in Plant Families 26,61)...

Biogenetically one important and perhaps unexpected variation of the hexahydroxydiphenoyl ester group found in a limited number of metabolites is the dehydro hexahydroxydiphenoyl ester (45) first identified by Schmidt °> and later noted in other metabolites of the families Gerania-ceae, Euphorbiaceae and Aceraceae. Isomerization occurs in solution and leads to an equilibrium mixture of internal hemi-acetal forms (45a, 45b) he attainment of... 

Table 7.2.8. Hexahydroxydiphenoyl ester metabolites Group 2B, occurrence in plant families...

Geraniin has been isolated and identified from the leaves of various Acer and Fuchsia species (26). Its occurrence in Fuchsia is interesting since it remains the sole example of a plant species to produce both group B and C hexahydroxydiphenoyl metabolites. 

The presence of a hexahydroxydiphenoyl group in a polyphenolic metabolite is readily defined by spectroscopic means (41, 43, 103, 104). The chirality (and hence their probable position of attachment to the D-glucose core) may be determined by cd spectra (43, 103, 104). 

Table 7.2.6. Hexahydroxydiphenoyl ester derivatives, Group 2B The structure of some dimeric and trimeric C-O oxidatively coupled metabolites...

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