Helichrysum bracteatum

The seed oil of Helichrysum bracteatum contains an acetylenic acid of a different kind in that the double bond at AlO appears before the triple bond at A12. 

Coronaric acid (9,10-epoxyoctadec-12-enoic), a positional isomer of vernolic acid, is the second most common epoxy acid and sometimes the two acids cooccur. It is present, for example, in the seed oils of Chrysanthemum coronarium (14%), Helichrysum bracteatum (14%, including some 9,10-epoxy-octadec-12-ynoic acid) and Xeranthemum annuum (8%, along with vernolic acid and 9,10-epoxystearic acid). 

Present in Helichrysum bracteatum seed oil probably as the 95, 10/ -form. 

Methanolic extracts of Coreopsis spp.. Dahlia spp., and Helichrysum bracteatum containing chalcones and aurones have been tested on silica gel plates with ethyl acetate-formic acid-water (60 12 16) as the mobile phase. The plates are developed to 8.S cm (ca. 40 min), dried, and sprayed with NP/PEG 4000. The clear yellow zones turn to violet and red, and the red-to-orange fluorescent colors seen under longwave UV light confirm the presence of chalcone and aurone pigments. Ammonia vapor intensifies the colors after spraying. 

Aster Aster Aster Helichrysum bracteatum AstHelbra... 

The acetylenic epoxy-acid (9), c/,s-9,10-epoxyoctadec-12-ynoic acid, discovered along with other epoxy-acids and other acetylenic acids in the seed oil of Helichrysum bracteatum may be an intermediate in the bioconversion of crepenynic acid (8) to helenynolic acid (10), both of which had been identified previously in this source. 

---