Tuesday, May 22, 2007

The Quassinoids, a review.

Quassinoids, (termed quassin after a man by the name of Quassi who treated fever with the bark of these plants) are bitter principles most occurring in Simaroubaceae family.

They are degraded triterpenes.

Because of the wide spectrum of their biological properties there is interest in figuring out new trends about them. One of the most important effects of them are antiviral & cytotoxic.

General structural features of the quassinoids are: 1. Most of them are C20 (tetra or pentacyclic) 2. Highly oxygenated lactones 3. Except for C4, C5, C9 & C10, there are oxygenated groups on all the other carbons.

•Main requirements for antileukaemic activity: (SAR) (as in glaucarubolone 2) are

–an a,b unsaturated ketol group at position 1 & 2 or at 2 & 3 in ring A
–an epoxymethano bridge between C8
& C11 or between C8 & C13 in ring C
–presence of a free OH group in ring A
& at C12 in addition to an ester group
at C15 &/or C6

For structural features, SAR (structure activity relationship), pharmacological effects, mechanism of action, examples of quassinoid bearing plants, biosynthesis, synthesis, extraction and ... see more

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