The present paper reviews the occurrence of glycosidically bound aroma compounds in the plant kingdom and discusses different hypotheses concerning their role in plants. Emphasis is on biotechnological methods for flavor release and flavor enhancement through enzymatic hydrolysis of glycoconjugated aroma substances.

Glycoconjugated aroma compounds: occurrence, role and biotechnological transformation.

Iridoid and megastigmane glycosides from Phlomis aurea.

This review brings up to date the research that has been undertaken on thirteen carbon (C13) norisoprenoid glycosides in plant tissues. Emphasis is on data concerning their occurrence, chemical composition, and reactivity. In particular, their important role as flavour precursors is discussed.

C13-Norisoprenoid glycosides in plant tissues: An overview on their occurrence, composition and role as flavour precursors

Summary

Decimation of cereal growth and yields by hemiparasitic Striga species cannot be accounted for entirely by the removal of host-plant resources. The production of toxic compounds by the parasite has been suggested. An investigation of three species of the economically important Striga and the related Alectra vogelii has now resulted in the isolation of eight iridoid glucosides (mussaenosidic acid, mussaenoside, gardoside methyl ester, bartsioside, isoaucubin, melittoside, aucubin and eurostoside), two caffeoyl phenylethyl glycosides (calceolarioside  A and verbascoside) as well as shikimic acid and trigonelline, all identified by NMR spectroscopy. The iridoids are potent cytotoxins and probably represent an anti-herbivore defence system common to Scrophulariaceae (sensu lato). This has the potential to explain differences in tolerance apparent for contrasting host taxa and cultivars. The nature of the iridoids present also provides additional validation of the recent transferral of parasitic Scrophulariaceae (s.l.) to Orobanchaceae.

Cytotoxic constituents of Alectra and Striga species

Iridoids as systematic markers in dicotyledon

Three glycosides named hydroxy-β-ionone glucoside (1), aeginetoside (2) and isoaucubin (3) were isolated from the n-butanol extract of Aeginetia indica L. var. gracilis NAKAI. The structures of 1, 2 and 3 were elucidated by chemical and spectral studies.

Thoru Endo

Papers

Studies on the Constituents of Aeginetia indica L. var. gracilis NAKAI. Structures of Three Glycosides isolated from the Whole Plant