Iridoids valeriana-type

The hemiacetalic C-2 fimction can be blocked by a sugar residue, affording the methylcyclopentanoid monoterpenes known as glycosidic iridoids. Otherwise the same function can be esterified giving rise to the non-glycosidic iridoids of plumeria or valeriana-type ( fig.6 ). 

This skeleton is typical of iridoid glycosides, but several non-glycosidic iridoids, e.g. plumeria-type and valeriana-type compounds, are also characterised by the same skeleton. 

Valeriana-Type Iridoid Glucosides Having Cjo -Aglucone Skeleton ... 

Viburnum prunifolium contains coumarins (scopoletin, scopolin, aesculetin), alkaloids, P-sitosterin, arbutin, triterpenes (a- and P-amyrin, ursolic acid, oleanolic acid), amento-flavone, and iridoid glucosides Valeriana type)." Other constituents include malic, citric, oxalic, and valeric acids) tannin bitter resin and others (merck). 1 -Methyl-2,3-dibutyl hemi-mellitate was isolated from the stem bark. ... 

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