Sweroside

The full paper of Tietze s biogenetic-type synthesis of secologanin aglucone methyl ether and sweroside aglucone methyl ether has been published (Vol. 5, p. 18), and a second paper independently reports in full the rapid enzymic cleavage of secologanin to the bicyclic hemiacetal previously described by R. T. Brown (Vol. 7, p. 27) longer reaction times result in the formation of (146). ... 

Alstonia macrophylla Wall, ex G. Don / stem EtOH/ Maceration Sweroside, naresuanoside [128]... 

Preparative chromatography was performed with thin layer chromatography (TLC) aluminum sheets and 8 2 chloroform/ methanol as mobile phase of a fraction from the 95% EtOH extract of stems of Alstonia macrophylla. This procedure led to the isolation of the compounds sweroside (2 mg) and naresuanoside (3 mg) [128]... 

Several studies have examined its mode of incorporation and the fate of selected protons. However, the utilization of both secologanin (29) and sweroside (30) ° raises an interesting question as to the mechanism of ring... 

Cyclopentanes, Iridoids.—A very useful review of the biosynthesis of the known sweroside-, morroniside-, and oleuropein-type secoiridoid glucosides, together with the biosynthesis of alkaloidal glucosides which can be regarded as secoiridoid... 

The specific incorporation of [4- " C]sweroside into vindoline (4) seems best understood by interconversion of secologanin (34) and sweroside (36). The biological change (34) -> (36) was shown above and the reverse was proven by feeding [6- H2]sweroside to Vinca rosea and isolating therefrom [6- H2]seco-loganin specific labelling was proven. 

S)-isomer. Related studies with [3R,2R- H]mevalonic acid showed that one tritium atom is probably incorporated but none is incorporated from the (2S)-isomer. This implies that if secologanin (36) is a precursor then the aldehyde proton should be labelled. Other precursors which have been proved effective include loganic acid (35 R = H), loganin (35 R = Me), and sweroside ... 

Although the direct incorporation of secologanin (154) into the Ginchona alkaloids was not studied, an indication for the intermediacy of 154 was indirectly provided by the incorporation of sweroside-ll- C... 

B Treatment with the VS reagents generates two prominent blue and two minor blue zonCvS in the Rf range 0.55-0,8. They represent foliamenthin, menthafolin and dihydro-fbliamenthin (T4,T5). The iridoid loganine (T3). migrates as a violet-blue zone to R, -0.45. Brown zones directly below are due to compounds such as sweroside (R,- 0.35). 

S. nervosa Wall. Ex DC is an annual, erect, branched, glabrous herb, distributed in north temperate Himalaya. Sweroside (7) and swertiamarin (60) and secoiridoid glycoside vegeloside (61) have been reported from this species [91]. 

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