Helianthus occidentalis

Labdanes.—The cis- and trans-isomers of (-)-ozic acid (9) have been isolated from the wild sunflower, Helianthus occidentalis (Compositae). Their presence in this plant may be associated with resistance to insect attack. The diene... 

Homeosoma electellum) contain high concentrations of tra-chyloban-19-oic acid (70) and ( —)-16-kauren-19-oic acid (71) in their florets. As sunflower florets that contain only small amounts of these compounds are a major portion of the diet of first instar larvae of this insect, it is likely that these acids serve as feeding inhibitors. At the 1% level, both kaurenoic and trachylobanoic acids decreased the growth of sunflower moth larvae and tobacco budworm (Heliothis virescens) by about 50%. At the 0.5% level, both reduced larval growth of the cotton bollworm and the pink bollworm to less than 5% (Fig. 22.23) (Mabry and Gill, 1979). The Z-and -isomers of (- )-ozic acid (72) have been isolated from Helianthus occidentalis and may be associated with resistance to insect attack (Stipanovic et al., 1979). 

Stipanovic, R. D., D. H. O Brien, C. E. Rogers, and T. E. Thompson, Diterpenoid acids, — )-cis- and (-)-trans-ozic acid, in wild sunflower, Helianthus occidentalis, J. Agric. Food Chem., 27, 458-459 (1979). 

Aspilia floribunda Aspilia foliacea Campovassouria bupleurifolia Goyazianthus tetrastichus Helianthus occidentalis Oyedaea boliviana... 

Helianthus debilis subsp. cucumerifolius Helianthus occidentalis Helianthus occidentalis var. dowellianus... 

Helianthus occidentalis Helianthus petiolaris Helianthus radula Helianthus simulans Helichrysum diosmifolium Sigesbeckia pubescens Steiractinia mollis Viguiera excelsa Viguiera latibracteata Wedelia calycina... 

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