Title: | Attractive and defensive functions of the ultraviolet pigments of a flower (Hypericum calycinum) |
Author(s): | Gronquist M; Bezzerides A; Attygalle A; Meinwald J; Eisner M; Eisner T; |
Address: | "Department of Chemistry and Chemical Biology, Baker Laboratory, Cornell University, Ithaca, NY 14853, USA" |
ISSN/ISBN: | 0027-8424 (Print) 1091-6490 (Electronic) 0027-8424 (Linking) |
Abstract: | "The flower of Hypericum calycinum, which appears uniformly yellow to humans, bears a UV pattern, presumably visible to insects. Two categories of pigments, flavonoids and dearomatized isoprenylated phloroglucinols (DIPs), are responsible for the UV demarcations of this flower. Flavonoids had been shown previously to function as floral UV pigments, but DIPs had not been demonstrated to serve in that capacity. We found the DIPs to be present in high concentration in the anthers and ovarian wall of the flower, suggesting that the compounds also serve in defense. Indeed, feeding tests done with one of the DIPs (hypercalin A) showed the compound to be deterrent and toxic to a caterpillar (Utetheisa ornatrix). The possibility that floral UV pigments fulfill both a visual and a defensive function had not previously been contemplated. DIPs may also serve for protection of female reproductive structures in other plants, for example in hops (Humulus lupulus). The DIPs of hops are put to human use as bitter flavoring agents and preservatives in beer" |
Keywords: | "Animals Hypericum/chemistry/*physiology *Insect Repellents/chemistry Molecular Structure Moths Pheromones/chemistry/*physiology *Phloroglucinol/chemistry Pigments, Biological/chemistry/*physiology Ultraviolet Rays;" |
Notes: | "MedlineGronquist, M Bezzerides, A Attygalle, A Meinwald, J Eisner, M Eisner, T eng R01 AI002908/AI/NIAID NIH HHS/ R01 GM053830/GM/NIGMS NIH HHS/ AI02908/AI/NIAID NIH HHS/ GM53830/GM/NIGMS NIH HHS/ Research Support, U.S. Gov't, P.H.S. 2001/11/15 Proc Natl Acad Sci U S A. 2001 Nov 20; 98(24):13745-50. doi: 10.1073/pnas.231471698. Epub 2001 Nov 13" |